symbian-qemu-0.9.1-12/python-2.6.1/Lib/test/decimaltestdata/add.decTest
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Lib/test/decimaltestdata/add.decTest	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,2716 @@
+------/cancell----------------------------------------------------------
+-- add.decTest -- decimal addition                                    --
+-- Copyright (c) IBM Corporation, 1981, 2008.  All rights reserved.   --
+------------------------------------------------------------------------
+-- Please see the document "General Decimal Arithmetic Testcases"     --
+-- at http://www2.hursley.ibm.com/decimal for the description of      --
+-- these testcases.                                                   --
+--                                                                    --
+-- These testcases are experimental ('beta' versions), and they       --
+-- may contain errors.  They are offered on an as-is basis.  In       --
+-- particular, achieving the same results as the tests here is not    --
+-- a guarantee that an implementation complies with any Standard      --
+-- or specification.  The tests are not exhaustive.                   --
+--                                                                    --
+-- Please send comments, suggestions, and corrections to the author:  --
+--   Mike Cowlishaw, IBM Fellow                                       --
+--   IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK         --
+--   mfc@uk.ibm.com                                                   --
+------------------------------------------------------------------------
+version: 2.58
+
+precision:   9
+rounding:    half_up
+maxExponent: 384
+minexponent: -383
+extended:    1
+
+-- [first group are 'quick confidence check']
+addx001 add 1       1       ->  2
+addx002 add 2       3       ->  5
+addx003 add '5.75'  '3.3'   ->  9.05
+addx004 add '5'     '-3'    ->  2
+addx005 add '-5'    '-3'    ->  -8
+addx006 add '-7'    '2.5'   ->  -4.5
+addx007 add '0.7'   '0.3'   ->  1.0
+addx008 add '1.25'  '1.25'  ->  2.50
+addx009 add '1.23456789'  '1.00000000' -> '2.23456789'
+addx010 add '1.23456789'  '1.00000011' -> '2.23456800'
+
+addx011 add '0.4444444444'  '0.5555555555' -> '1.00000000' Inexact Rounded
+addx012 add '0.4444444440'  '0.5555555555' -> '1.00000000' Inexact Rounded
+addx013 add '0.4444444444'  '0.5555555550' -> '0.999999999' Inexact Rounded
+addx014 add '0.44444444449'    '0' -> '0.444444444' Inexact Rounded
+addx015 add '0.444444444499'   '0' -> '0.444444444' Inexact Rounded
+addx016 add '0.4444444444999'  '0' -> '0.444444444' Inexact Rounded
+addx017 add '0.4444444445000'  '0' -> '0.444444445' Inexact Rounded
+addx018 add '0.4444444445001'  '0' -> '0.444444445' Inexact Rounded
+addx019 add '0.444444444501'   '0' -> '0.444444445' Inexact Rounded
+addx020 add '0.44444444451'    '0' -> '0.444444445' Inexact Rounded
+
+addx021 add 0 1 -> 1
+addx022 add 1 1 -> 2
+addx023 add 2 1 -> 3
+addx024 add 3 1 -> 4
+addx025 add 4 1 -> 5
+addx026 add 5 1 -> 6
+addx027 add 6 1 -> 7
+addx028 add 7 1 -> 8
+addx029 add 8 1 -> 9
+addx030 add 9 1 -> 10
+
+-- some carrying effects
+addx031 add '0.9998'  '0.0000' -> '0.9998'
+addx032 add '0.9998'  '0.0001' -> '0.9999'
+addx033 add '0.9998'  '0.0002' -> '1.0000'
+addx034 add '0.9998'  '0.0003' -> '1.0001'
+
+addx035 add '70'  '10000e+9' -> '1.00000000E+13' Inexact Rounded
+addx036 add '700'  '10000e+9' -> '1.00000000E+13' Inexact Rounded
+addx037 add '7000'  '10000e+9' -> '1.00000000E+13' Inexact Rounded
+addx038 add '70000'  '10000e+9' -> '1.00000001E+13' Inexact Rounded
+addx039 add '700000'  '10000e+9' -> '1.00000007E+13' Rounded
+
+-- symmetry:
+addx040 add '10000e+9'  '70' -> '1.00000000E+13' Inexact Rounded
+addx041 add '10000e+9'  '700' -> '1.00000000E+13' Inexact Rounded
+addx042 add '10000e+9'  '7000' -> '1.00000000E+13' Inexact Rounded
+addx044 add '10000e+9'  '70000' -> '1.00000001E+13' Inexact Rounded
+addx045 add '10000e+9'  '700000' -> '1.00000007E+13' Rounded
+
+-- same, higher precision
+precision: 15
+addx046 add '10000e+9'  '7' -> '10000000000007'
+addx047 add '10000e+9'  '70' -> '10000000000070'
+addx048 add '10000e+9'  '700' -> '10000000000700'
+addx049 add '10000e+9'  '7000' -> '10000000007000'
+addx050 add '10000e+9'  '70000' -> '10000000070000'
+addx051 add '10000e+9'  '700000' -> '10000000700000'
+addx052 add '10000e+9'  '7000000' -> '10000007000000'
+
+-- examples from decarith
+addx053 add '12' '7.00' -> '19.00'
+addx054 add '1.3' '-1.07' -> '0.23'
+addx055 add '1.3' '-1.30' -> '0.00'
+addx056 add '1.3' '-2.07' -> '-0.77'
+addx057 add '1E+2' '1E+4' -> '1.01E+4'
+
+-- zero preservation
+precision: 6
+addx060 add '10000e+9'  '70000' -> '1.00000E+13' Inexact Rounded
+addx061 add 1 '0.0001' -> '1.0001'
+addx062 add 1 '0.00001' -> '1.00001'
+addx063 add 1 '0.000001' -> '1.00000' Inexact Rounded
+addx064 add 1 '0.0000001' -> '1.00000' Inexact Rounded
+addx065 add 1 '0.00000001' -> '1.00000' Inexact Rounded
+
+-- some funny zeros [in case of bad signum]
+addx070 add 1  0    -> 1
+addx071 add 1 0.    -> 1
+addx072 add 1  .0   -> 1.0
+addx073 add 1 0.0   -> 1.0
+addx074 add 1 0.00  -> 1.00
+addx075 add  0  1   -> 1
+addx076 add 0.  1   -> 1
+addx077 add  .0 1   -> 1.0
+addx078 add 0.0 1   -> 1.0
+addx079 add 0.00 1  -> 1.00
+
+precision: 9
+
+-- some carries
+addx080 add 999999998 1  -> 999999999
+addx081 add 999999999 1  -> 1.00000000E+9 Rounded
+addx082 add  99999999 1  -> 100000000
+addx083 add   9999999 1  -> 10000000
+addx084 add    999999 1  -> 1000000
+addx085 add     99999 1  -> 100000
+addx086 add      9999 1  -> 10000
+addx087 add       999 1  -> 1000
+addx088 add        99 1  -> 100
+addx089 add         9 1  -> 10
+
+
+-- more LHS swaps
+addx090 add '-56267E-10'   0 ->  '-0.0000056267'
+addx091 add '-56267E-6'    0 ->  '-0.056267'
+addx092 add '-56267E-5'    0 ->  '-0.56267'
+addx093 add '-56267E-4'    0 ->  '-5.6267'
+addx094 add '-56267E-3'    0 ->  '-56.267'
+addx095 add '-56267E-2'    0 ->  '-562.67'
+addx096 add '-56267E-1'    0 ->  '-5626.7'
+addx097 add '-56267E-0'    0 ->  '-56267'
+addx098 add '-5E-10'       0 ->  '-5E-10'
+addx099 add '-5E-7'        0 ->  '-5E-7'
+addx100 add '-5E-6'        0 ->  '-0.000005'
+addx101 add '-5E-5'        0 ->  '-0.00005'
+addx102 add '-5E-4'        0 ->  '-0.0005'
+addx103 add '-5E-1'        0 ->  '-0.5'
+addx104 add '-5E0'         0 ->  '-5'
+addx105 add '-5E1'         0 ->  '-50'
+addx106 add '-5E5'         0 ->  '-500000'
+addx107 add '-5E8'         0 ->  '-500000000'
+addx108 add '-5E9'         0 ->  '-5.00000000E+9'   Rounded
+addx109 add '-5E10'        0 ->  '-5.00000000E+10'  Rounded
+addx110 add '-5E11'        0 ->  '-5.00000000E+11'  Rounded
+addx111 add '-5E100'       0 ->  '-5.00000000E+100' Rounded
+
+-- more RHS swaps
+addx113 add 0  '-56267E-10' ->  '-0.0000056267'
+addx114 add 0  '-56267E-6'  ->  '-0.056267'
+addx116 add 0  '-56267E-5'  ->  '-0.56267'
+addx117 add 0  '-56267E-4'  ->  '-5.6267'
+addx119 add 0  '-56267E-3'  ->  '-56.267'
+addx120 add 0  '-56267E-2'  ->  '-562.67'
+addx121 add 0  '-56267E-1'  ->  '-5626.7'
+addx122 add 0  '-56267E-0'  ->  '-56267'
+addx123 add 0  '-5E-10'     ->  '-5E-10'
+addx124 add 0  '-5E-7'      ->  '-5E-7'
+addx125 add 0  '-5E-6'      ->  '-0.000005'
+addx126 add 0  '-5E-5'      ->  '-0.00005'
+addx127 add 0  '-5E-4'      ->  '-0.0005'
+addx128 add 0  '-5E-1'      ->  '-0.5'
+addx129 add 0  '-5E0'       ->  '-5'
+addx130 add 0  '-5E1'       ->  '-50'
+addx131 add 0  '-5E5'       ->  '-500000'
+addx132 add 0  '-5E8'       ->  '-500000000'
+addx133 add 0  '-5E9'       ->  '-5.00000000E+9'    Rounded
+addx134 add 0  '-5E10'      ->  '-5.00000000E+10'   Rounded
+addx135 add 0  '-5E11'      ->  '-5.00000000E+11'   Rounded
+addx136 add 0  '-5E100'     ->  '-5.00000000E+100'  Rounded
+
+-- related
+addx137 add  1  '0E-12'      ->  '1.00000000'  Rounded
+addx138 add -1  '0E-12'      ->  '-1.00000000' Rounded
+addx139 add '0E-12' 1        ->  '1.00000000'  Rounded
+addx140 add '0E-12' -1       ->  '-1.00000000' Rounded
+addx141 add 1E+4    0.0000   ->  '10000.0000'
+addx142 add 1E+4    0.00000  ->  '10000.0000'  Rounded
+addx143 add 0.000   1E+5     ->  '100000.000'
+addx144 add 0.0000  1E+5     ->  '100000.000'  Rounded
+
+-- [some of the next group are really constructor tests]
+addx146 add '00.0'  0       ->  '0.0'
+addx147 add '0.00'  0       ->  '0.00'
+addx148 add  0      '0.00'  ->  '0.00'
+addx149 add  0      '00.0'  ->  '0.0'
+addx150 add '00.0'  '0.00'  ->  '0.00'
+addx151 add '0.00'  '00.0'  ->  '0.00'
+addx152 add '3'     '.3'    ->  '3.3'
+addx153 add '3.'    '.3'    ->  '3.3'
+addx154 add '3.0'   '.3'    ->  '3.3'
+addx155 add '3.00'  '.3'    ->  '3.30'
+addx156 add '3'     '3'     ->  '6'
+addx157 add '3'     '+3'    ->  '6'
+addx158 add '3'     '-3'    ->  '0'
+addx159 add '0.3'   '-0.3'  ->  '0.0'
+addx160 add '0.03'  '-0.03' ->  '0.00'
+
+-- try borderline precision, with carries, etc.
+precision: 15
+addx161 add '1E+12' '-1'    -> '999999999999'
+addx162 add '1E+12'  '1.11' -> '1000000000001.11'
+addx163 add '1.11'  '1E+12' -> '1000000000001.11'
+addx164 add '-1'    '1E+12' -> '999999999999'
+addx165 add '7E+12' '-1'    -> '6999999999999'
+addx166 add '7E+12'  '1.11' -> '7000000000001.11'
+addx167 add '1.11'  '7E+12' -> '7000000000001.11'
+addx168 add '-1'    '7E+12' -> '6999999999999'
+
+--             123456789012345      123456789012345      1 23456789012345
+addx170 add '0.444444444444444'  '0.555555555555563' -> '1.00000000000001' Inexact Rounded
+addx171 add '0.444444444444444'  '0.555555555555562' -> '1.00000000000001' Inexact Rounded
+addx172 add '0.444444444444444'  '0.555555555555561' -> '1.00000000000001' Inexact Rounded
+addx173 add '0.444444444444444'  '0.555555555555560' -> '1.00000000000000' Inexact Rounded
+addx174 add '0.444444444444444'  '0.555555555555559' -> '1.00000000000000' Inexact Rounded
+addx175 add '0.444444444444444'  '0.555555555555558' -> '1.00000000000000' Inexact Rounded
+addx176 add '0.444444444444444'  '0.555555555555557' -> '1.00000000000000' Inexact Rounded
+addx177 add '0.444444444444444'  '0.555555555555556' -> '1.00000000000000' Rounded
+addx178 add '0.444444444444444'  '0.555555555555555' -> '0.999999999999999'
+addx179 add '0.444444444444444'  '0.555555555555554' -> '0.999999999999998'
+addx180 add '0.444444444444444'  '0.555555555555553' -> '0.999999999999997'
+addx181 add '0.444444444444444'  '0.555555555555552' -> '0.999999999999996'
+addx182 add '0.444444444444444'  '0.555555555555551' -> '0.999999999999995'
+addx183 add '0.444444444444444'  '0.555555555555550' -> '0.999999999999994'
+
+-- and some more, including residue effects and different roundings
+precision: 9
+rounding: half_up
+addx200 add '123456789' 0             -> '123456789'
+addx201 add '123456789' 0.000000001   -> '123456789' Inexact Rounded
+addx202 add '123456789' 0.000001      -> '123456789' Inexact Rounded
+addx203 add '123456789' 0.1           -> '123456789' Inexact Rounded
+addx204 add '123456789' 0.4           -> '123456789' Inexact Rounded
+addx205 add '123456789' 0.49          -> '123456789' Inexact Rounded
+addx206 add '123456789' 0.499999      -> '123456789' Inexact Rounded
+addx207 add '123456789' 0.499999999   -> '123456789' Inexact Rounded
+addx208 add '123456789' 0.5           -> '123456790' Inexact Rounded
+addx209 add '123456789' 0.500000001   -> '123456790' Inexact Rounded
+addx210 add '123456789' 0.500001      -> '123456790' Inexact Rounded
+addx211 add '123456789' 0.51          -> '123456790' Inexact Rounded
+addx212 add '123456789' 0.6           -> '123456790' Inexact Rounded
+addx213 add '123456789' 0.9           -> '123456790' Inexact Rounded
+addx214 add '123456789' 0.99999       -> '123456790' Inexact Rounded
+addx215 add '123456789' 0.999999999   -> '123456790' Inexact Rounded
+addx216 add '123456789' 1             -> '123456790'
+addx217 add '123456789' 1.000000001   -> '123456790' Inexact Rounded
+addx218 add '123456789' 1.00001       -> '123456790' Inexact Rounded
+addx219 add '123456789' 1.1           -> '123456790' Inexact Rounded
+
+rounding: half_even
+addx220 add '123456789' 0             -> '123456789'
+addx221 add '123456789' 0.000000001   -> '123456789' Inexact Rounded
+addx222 add '123456789' 0.000001      -> '123456789' Inexact Rounded
+addx223 add '123456789' 0.1           -> '123456789' Inexact Rounded
+addx224 add '123456789' 0.4           -> '123456789' Inexact Rounded
+addx225 add '123456789' 0.49          -> '123456789' Inexact Rounded
+addx226 add '123456789' 0.499999      -> '123456789' Inexact Rounded
+addx227 add '123456789' 0.499999999   -> '123456789' Inexact Rounded
+addx228 add '123456789' 0.5           -> '123456790' Inexact Rounded
+addx229 add '123456789' 0.500000001   -> '123456790' Inexact Rounded
+addx230 add '123456789' 0.500001      -> '123456790' Inexact Rounded
+addx231 add '123456789' 0.51          -> '123456790' Inexact Rounded
+addx232 add '123456789' 0.6           -> '123456790' Inexact Rounded
+addx233 add '123456789' 0.9           -> '123456790' Inexact Rounded
+addx234 add '123456789' 0.99999       -> '123456790' Inexact Rounded
+addx235 add '123456789' 0.999999999   -> '123456790' Inexact Rounded
+addx236 add '123456789' 1             -> '123456790'
+addx237 add '123456789' 1.00000001    -> '123456790' Inexact Rounded
+addx238 add '123456789' 1.00001       -> '123456790' Inexact Rounded
+addx239 add '123456789' 1.1           -> '123456790' Inexact Rounded
+-- critical few with even bottom digit...
+addx240 add '123456788' 0.499999999   -> '123456788' Inexact Rounded
+addx241 add '123456788' 0.5           -> '123456788' Inexact Rounded
+addx242 add '123456788' 0.500000001   -> '123456789' Inexact Rounded
+
+rounding: down
+addx250 add '123456789' 0             -> '123456789'
+addx251 add '123456789' 0.000000001   -> '123456789' Inexact Rounded
+addx252 add '123456789' 0.000001      -> '123456789' Inexact Rounded
+addx253 add '123456789' 0.1           -> '123456789' Inexact Rounded
+addx254 add '123456789' 0.4           -> '123456789' Inexact Rounded
+addx255 add '123456789' 0.49          -> '123456789' Inexact Rounded
+addx256 add '123456789' 0.499999      -> '123456789' Inexact Rounded
+addx257 add '123456789' 0.499999999   -> '123456789' Inexact Rounded
+addx258 add '123456789' 0.5           -> '123456789' Inexact Rounded
+addx259 add '123456789' 0.500000001   -> '123456789' Inexact Rounded
+addx260 add '123456789' 0.500001      -> '123456789' Inexact Rounded
+addx261 add '123456789' 0.51          -> '123456789' Inexact Rounded
+addx262 add '123456789' 0.6           -> '123456789' Inexact Rounded
+addx263 add '123456789' 0.9           -> '123456789' Inexact Rounded
+addx264 add '123456789' 0.99999       -> '123456789' Inexact Rounded
+addx265 add '123456789' 0.999999999   -> '123456789' Inexact Rounded
+addx266 add '123456789' 1             -> '123456790'
+addx267 add '123456789' 1.00000001    -> '123456790' Inexact Rounded
+addx268 add '123456789' 1.00001       -> '123456790' Inexact Rounded
+addx269 add '123456789' 1.1           -> '123456790' Inexact Rounded
+
+-- input preparation tests (operands should not be rounded)
+precision: 3
+rounding: half_up
+
+addx270 add '12345678900000'  9999999999999 ->  '2.23E+13' Inexact Rounded
+addx271 add  '9999999999999' 12345678900000 ->  '2.23E+13' Inexact Rounded
+
+addx272 add '12E+3'  '3444'   ->  '1.54E+4' Inexact Rounded
+addx273 add '12E+3'  '3446'   ->  '1.54E+4' Inexact Rounded
+addx274 add '12E+3'  '3449.9' ->  '1.54E+4' Inexact Rounded
+addx275 add '12E+3'  '3450.0' ->  '1.55E+4' Inexact Rounded
+addx276 add '12E+3'  '3450.1' ->  '1.55E+4' Inexact Rounded
+addx277 add '12E+3'  '3454'   ->  '1.55E+4' Inexact Rounded
+addx278 add '12E+3'  '3456'   ->  '1.55E+4' Inexact Rounded
+
+addx281 add '3444'   '12E+3'  ->  '1.54E+4' Inexact Rounded
+addx282 add '3446'   '12E+3'  ->  '1.54E+4' Inexact Rounded
+addx283 add '3449.9' '12E+3'  ->  '1.54E+4' Inexact Rounded
+addx284 add '3450.0' '12E+3'  ->  '1.55E+4' Inexact Rounded
+addx285 add '3450.1' '12E+3'  ->  '1.55E+4' Inexact Rounded
+addx286 add '3454'   '12E+3'  ->  '1.55E+4' Inexact Rounded
+addx287 add '3456'   '12E+3'  ->  '1.55E+4' Inexact Rounded
+
+rounding: half_down
+addx291 add '3444'   '12E+3'  ->  '1.54E+4' Inexact Rounded
+addx292 add '3446'   '12E+3'  ->  '1.54E+4' Inexact Rounded
+addx293 add '3449.9' '12E+3'  ->  '1.54E+4' Inexact Rounded
+addx294 add '3450.0' '12E+3'  ->  '1.54E+4' Inexact Rounded
+addx295 add '3450.1' '12E+3'  ->  '1.55E+4' Inexact Rounded
+addx296 add '3454'   '12E+3'  ->  '1.55E+4' Inexact Rounded
+addx297 add '3456'   '12E+3'  ->  '1.55E+4' Inexact Rounded
+
+-- 1 in last place tests
+rounding: half_up
+addx301 add  -1   1      ->   0
+addx302 add   0   1      ->   1
+addx303 add   1   1      ->   2
+addx304 add  12   1      ->  13
+addx305 add  98   1      ->  99
+addx306 add  99   1      -> 100
+addx307 add 100   1      -> 101
+addx308 add 101   1      -> 102
+addx309 add  -1  -1      ->  -2
+addx310 add   0  -1      ->  -1
+addx311 add   1  -1      ->   0
+addx312 add  12  -1      ->  11
+addx313 add  98  -1      ->  97
+addx314 add  99  -1      ->  98
+addx315 add 100  -1      ->  99
+addx316 add 101  -1      -> 100
+
+addx321 add -0.01  0.01    ->  0.00
+addx322 add  0.00  0.01    ->  0.01
+addx323 add  0.01  0.01    ->  0.02
+addx324 add  0.12  0.01    ->  0.13
+addx325 add  0.98  0.01    ->  0.99
+addx326 add  0.99  0.01    ->  1.00
+addx327 add  1.00  0.01    ->  1.01
+addx328 add  1.01  0.01    ->  1.02
+addx329 add -0.01 -0.01    -> -0.02
+addx330 add  0.00 -0.01    -> -0.01
+addx331 add  0.01 -0.01    ->  0.00
+addx332 add  0.12 -0.01    ->  0.11
+addx333 add  0.98 -0.01    ->  0.97
+addx334 add  0.99 -0.01    ->  0.98
+addx335 add  1.00 -0.01    ->  0.99
+addx336 add  1.01 -0.01    ->  1.00
+
+-- some more cases where adding 0 affects the coefficient
+precision: 9
+addx340 add 1E+3    0    ->         1000
+addx341 add 1E+8    0    ->    100000000
+addx342 add 1E+9    0    ->   1.00000000E+9   Rounded
+addx343 add 1E+10   0    ->   1.00000000E+10  Rounded
+-- which simply follow from these cases ...
+addx344 add 1E+3    1    ->         1001
+addx345 add 1E+8    1    ->    100000001
+addx346 add 1E+9    1    ->   1.00000000E+9   Inexact Rounded
+addx347 add 1E+10   1    ->   1.00000000E+10  Inexact Rounded
+addx348 add 1E+3    7    ->         1007
+addx349 add 1E+8    7    ->    100000007
+addx350 add 1E+9    7    ->   1.00000001E+9   Inexact Rounded
+addx351 add 1E+10   7    ->   1.00000000E+10  Inexact Rounded
+
+-- tryzeros cases
+precision:   7
+rounding:    half_up
+maxExponent: 92
+minexponent: -92
+addx361  add 0E+50 10000E+1  -> 1.0000E+5
+addx362  add 10000E+1 0E-50  -> 100000.0  Rounded
+addx363  add 10000E+1 10000E-50  -> 100000.0  Rounded Inexact
+addx364  add 9.999999E+92 -9.999999E+92 -> 0E+86
+
+-- a curiosity from JSR 13 testing
+rounding:    half_down
+precision:   10
+addx370 add 99999999 81512 -> 100081511
+precision:      6
+addx371 add 99999999 81512 -> 1.00082E+8 Rounded Inexact
+rounding:    half_up
+precision:   10
+addx372 add 99999999 81512 -> 100081511
+precision:      6
+addx373 add 99999999 81512 -> 1.00082E+8 Rounded Inexact
+rounding:    half_even
+precision:   10
+addx374 add 99999999 81512 -> 100081511
+precision:      6
+addx375 add 99999999 81512 -> 1.00082E+8 Rounded Inexact
+
+-- ulp replacement tests
+precision: 9
+maxexponent: 999999999
+minexponent: -999999999
+addx400 add   1   77e-7       ->  1.0000077
+addx401 add   1   77e-8       ->  1.00000077
+addx402 add   1   77e-9       ->  1.00000008 Inexact Rounded
+addx403 add   1   77e-10      ->  1.00000001 Inexact Rounded
+addx404 add   1   77e-11      ->  1.00000000 Inexact Rounded
+addx405 add   1   77e-12      ->  1.00000000 Inexact Rounded
+addx406 add   1   77e-999     ->  1.00000000 Inexact Rounded
+addx407 add   1   77e-9999999 ->  1.00000000 Inexact Rounded
+
+addx410 add  10   77e-7       ->  10.0000077
+addx411 add  10   77e-8       ->  10.0000008 Inexact Rounded
+addx412 add  10   77e-9       ->  10.0000001 Inexact Rounded
+addx413 add  10   77e-10      ->  10.0000000 Inexact Rounded
+addx414 add  10   77e-11      ->  10.0000000 Inexact Rounded
+addx415 add  10   77e-12      ->  10.0000000 Inexact Rounded
+addx416 add  10   77e-999     ->  10.0000000 Inexact Rounded
+addx417 add  10   77e-9999999 ->  10.0000000 Inexact Rounded
+
+addx420 add  77e-7        1   ->  1.0000077
+addx421 add  77e-8        1   ->  1.00000077
+addx422 add  77e-9        1   ->  1.00000008 Inexact Rounded
+addx423 add  77e-10       1   ->  1.00000001 Inexact Rounded
+addx424 add  77e-11       1   ->  1.00000000 Inexact Rounded
+addx425 add  77e-12       1   ->  1.00000000 Inexact Rounded
+addx426 add  77e-999      1   ->  1.00000000 Inexact Rounded
+addx427 add  77e-9999999  1   ->  1.00000000 Inexact Rounded
+
+addx430 add  77e-7       10   ->  10.0000077
+addx431 add  77e-8       10   ->  10.0000008 Inexact Rounded
+addx432 add  77e-9       10   ->  10.0000001 Inexact Rounded
+addx433 add  77e-10      10   ->  10.0000000 Inexact Rounded
+addx434 add  77e-11      10   ->  10.0000000 Inexact Rounded
+addx435 add  77e-12      10   ->  10.0000000 Inexact Rounded
+addx436 add  77e-999     10   ->  10.0000000 Inexact Rounded
+addx437 add  77e-9999999 10   ->  10.0000000 Inexact Rounded
+
+-- negative ulps
+addx440 add   1   -77e-7       ->  0.9999923
+addx441 add   1   -77e-8       ->  0.99999923
+addx442 add   1   -77e-9       ->  0.999999923
+addx443 add   1   -77e-10      ->  0.999999992 Inexact Rounded
+addx444 add   1   -77e-11      ->  0.999999999 Inexact Rounded
+addx445 add   1   -77e-12      ->  1.00000000 Inexact Rounded
+addx446 add   1   -77e-999     ->  1.00000000 Inexact Rounded
+addx447 add   1   -77e-9999999 ->  1.00000000 Inexact Rounded
+
+addx450 add  10   -77e-7       ->   9.9999923
+addx451 add  10   -77e-8       ->   9.99999923
+addx452 add  10   -77e-9       ->   9.99999992 Inexact Rounded
+addx453 add  10   -77e-10      ->   9.99999999 Inexact Rounded
+addx454 add  10   -77e-11      ->  10.0000000 Inexact Rounded
+addx455 add  10   -77e-12      ->  10.0000000 Inexact Rounded
+addx456 add  10   -77e-999     ->  10.0000000 Inexact Rounded
+addx457 add  10   -77e-9999999 ->  10.0000000 Inexact Rounded
+
+addx460 add  -77e-7        1   ->  0.9999923
+addx461 add  -77e-8        1   ->  0.99999923
+addx462 add  -77e-9        1   ->  0.999999923
+addx463 add  -77e-10       1   ->  0.999999992 Inexact Rounded
+addx464 add  -77e-11       1   ->  0.999999999 Inexact Rounded
+addx465 add  -77e-12       1   ->  1.00000000 Inexact Rounded
+addx466 add  -77e-999      1   ->  1.00000000 Inexact Rounded
+addx467 add  -77e-9999999  1   ->  1.00000000 Inexact Rounded
+
+addx470 add  -77e-7       10   ->   9.9999923
+addx471 add  -77e-8       10   ->   9.99999923
+addx472 add  -77e-9       10   ->   9.99999992 Inexact Rounded
+addx473 add  -77e-10      10   ->   9.99999999 Inexact Rounded
+addx474 add  -77e-11      10   ->  10.0000000 Inexact Rounded
+addx475 add  -77e-12      10   ->  10.0000000 Inexact Rounded
+addx476 add  -77e-999     10   ->  10.0000000 Inexact Rounded
+addx477 add  -77e-9999999 10   ->  10.0000000 Inexact Rounded
+
+-- negative ulps
+addx480 add  -1    77e-7       ->  -0.9999923
+addx481 add  -1    77e-8       ->  -0.99999923
+addx482 add  -1    77e-9       ->  -0.999999923
+addx483 add  -1    77e-10      ->  -0.999999992 Inexact Rounded
+addx484 add  -1    77e-11      ->  -0.999999999 Inexact Rounded
+addx485 add  -1    77e-12      ->  -1.00000000 Inexact Rounded
+addx486 add  -1    77e-999     ->  -1.00000000 Inexact Rounded
+addx487 add  -1    77e-9999999 ->  -1.00000000 Inexact Rounded
+
+addx490 add -10    77e-7       ->   -9.9999923
+addx491 add -10    77e-8       ->   -9.99999923
+addx492 add -10    77e-9       ->   -9.99999992 Inexact Rounded
+addx493 add -10    77e-10      ->   -9.99999999 Inexact Rounded
+addx494 add -10    77e-11      ->  -10.0000000 Inexact Rounded
+addx495 add -10    77e-12      ->  -10.0000000 Inexact Rounded
+addx496 add -10    77e-999     ->  -10.0000000 Inexact Rounded
+addx497 add -10    77e-9999999 ->  -10.0000000 Inexact Rounded
+
+addx500 add   77e-7       -1   ->  -0.9999923
+addx501 add   77e-8       -1   ->  -0.99999923
+addx502 add   77e-9       -1   ->  -0.999999923
+addx503 add   77e-10      -1   ->  -0.999999992 Inexact Rounded
+addx504 add   77e-11      -1   ->  -0.999999999 Inexact Rounded
+addx505 add   77e-12      -1   ->  -1.00000000 Inexact Rounded
+addx506 add   77e-999     -1   ->  -1.00000000 Inexact Rounded
+addx507 add   77e-9999999 -1   ->  -1.00000000 Inexact Rounded
+
+addx510 add   77e-7       -10  ->   -9.9999923
+addx511 add   77e-8       -10  ->   -9.99999923
+addx512 add   77e-9       -10  ->   -9.99999992 Inexact Rounded
+addx513 add   77e-10      -10  ->   -9.99999999 Inexact Rounded
+addx514 add   77e-11      -10  ->  -10.0000000 Inexact Rounded
+addx515 add   77e-12      -10  ->  -10.0000000 Inexact Rounded
+addx516 add   77e-999     -10  ->  -10.0000000 Inexact Rounded
+addx517 add   77e-9999999 -10  ->  -10.0000000 Inexact Rounded
+
+
+-- long operands
+maxexponent: 999
+minexponent: -999
+precision: 9
+addx521 add 12345678000 0 -> 1.23456780E+10 Rounded
+addx522 add 0 12345678000 -> 1.23456780E+10 Rounded
+addx523 add 1234567800  0 -> 1.23456780E+9 Rounded
+addx524 add 0 1234567800  -> 1.23456780E+9 Rounded
+addx525 add 1234567890  0 -> 1.23456789E+9 Rounded
+addx526 add 0 1234567890  -> 1.23456789E+9 Rounded
+addx527 add 1234567891  0 -> 1.23456789E+9 Inexact Rounded
+addx528 add 0 1234567891  -> 1.23456789E+9 Inexact Rounded
+addx529 add 12345678901 0 -> 1.23456789E+10 Inexact Rounded
+addx530 add 0 12345678901 -> 1.23456789E+10 Inexact Rounded
+addx531 add 1234567896  0 -> 1.23456790E+9 Inexact Rounded
+addx532 add 0 1234567896  -> 1.23456790E+9 Inexact Rounded
+
+precision: 15
+-- still checking
+addx541 add 12345678000 0 -> 12345678000
+addx542 add 0 12345678000 -> 12345678000
+addx543 add 1234567800  0 -> 1234567800
+addx544 add 0 1234567800  -> 1234567800
+addx545 add 1234567890  0 -> 1234567890
+addx546 add 0 1234567890  -> 1234567890
+addx547 add 1234567891  0 -> 1234567891
+addx548 add 0 1234567891  -> 1234567891
+addx549 add 12345678901 0 -> 12345678901
+addx550 add 0 12345678901 -> 12345678901
+addx551 add 1234567896  0 -> 1234567896
+addx552 add 0 1234567896  -> 1234567896
+
+-- verify a query
+precision:    16
+maxExponent: +394
+minExponent: -393
+rounding:     down
+addx561 add 1e-398 9.000000000000000E+384 -> 9.000000000000000E+384 Inexact Rounded
+addx562 add      0 9.000000000000000E+384 -> 9.000000000000000E+384 Rounded
+-- and using decimal64 bounds (see also ddadd.decTest)
+precision:    16
+maxExponent: +384
+minExponent: -383
+rounding:     down
+addx563 add 1e-388 9.000000000000000E+374 -> 9.000000000000000E+374 Inexact Rounded
+addx564 add      0 9.000000000000000E+374 -> 9.000000000000000E+374 Rounded
+
+
+-- some more residue effects with extreme rounding
+precision:   9
+rounding: half_up
+addx601 add 123456789  0.000001 -> 123456789 Inexact Rounded
+rounding: half_even
+addx602 add 123456789  0.000001 -> 123456789 Inexact Rounded
+rounding: half_down
+addx603 add 123456789  0.000001 -> 123456789 Inexact Rounded
+rounding: floor
+addx604 add 123456789  0.000001 -> 123456789 Inexact Rounded
+rounding: ceiling
+addx605 add 123456789  0.000001 -> 123456790 Inexact Rounded
+rounding: up
+addx606 add 123456789  0.000001 -> 123456790 Inexact Rounded
+rounding: down
+addx607 add 123456789  0.000001 -> 123456789 Inexact Rounded
+
+rounding: half_up
+addx611 add 123456789 -0.000001 -> 123456789 Inexact Rounded
+rounding: half_even
+addx612 add 123456789 -0.000001 -> 123456789 Inexact Rounded
+rounding: half_down
+addx613 add 123456789 -0.000001 -> 123456789 Inexact Rounded
+rounding: floor
+addx614 add 123456789 -0.000001 -> 123456788 Inexact Rounded
+rounding: ceiling
+addx615 add 123456789 -0.000001 -> 123456789 Inexact Rounded
+rounding: up
+addx616 add 123456789 -0.000001 -> 123456789 Inexact Rounded
+rounding: down
+addx617 add 123456789 -0.000001 -> 123456788 Inexact Rounded
+
+rounding: half_up
+addx621 add 123456789  0.499999 -> 123456789 Inexact Rounded
+rounding: half_even
+addx622 add 123456789  0.499999 -> 123456789 Inexact Rounded
+rounding: half_down
+addx623 add 123456789  0.499999 -> 123456789 Inexact Rounded
+rounding: floor
+addx624 add 123456789  0.499999 -> 123456789 Inexact Rounded
+rounding: ceiling
+addx625 add 123456789  0.499999 -> 123456790 Inexact Rounded
+rounding: up
+addx626 add 123456789  0.499999 -> 123456790 Inexact Rounded
+rounding: down
+addx627 add 123456789  0.499999 -> 123456789 Inexact Rounded
+
+rounding: half_up
+addx631 add 123456789 -0.499999 -> 123456789 Inexact Rounded
+rounding: half_even
+addx632 add 123456789 -0.499999 -> 123456789 Inexact Rounded
+rounding: half_down
+addx633 add 123456789 -0.499999 -> 123456789 Inexact Rounded
+rounding: floor
+addx634 add 123456789 -0.499999 -> 123456788 Inexact Rounded
+rounding: ceiling
+addx635 add 123456789 -0.499999 -> 123456789 Inexact Rounded
+rounding: up
+addx636 add 123456789 -0.499999 -> 123456789 Inexact Rounded
+rounding: down
+addx637 add 123456789 -0.499999 -> 123456788 Inexact Rounded
+
+rounding: half_up
+addx641 add 123456789  0.500001 -> 123456790 Inexact Rounded
+rounding: half_even
+addx642 add 123456789  0.500001 -> 123456790 Inexact Rounded
+rounding: half_down
+addx643 add 123456789  0.500001 -> 123456790 Inexact Rounded
+rounding: floor
+addx644 add 123456789  0.500001 -> 123456789 Inexact Rounded
+rounding: ceiling
+addx645 add 123456789  0.500001 -> 123456790 Inexact Rounded
+rounding: up
+addx646 add 123456789  0.500001 -> 123456790 Inexact Rounded
+rounding: down
+addx647 add 123456789  0.500001 -> 123456789 Inexact Rounded
+
+rounding: half_up
+addx651 add 123456789 -0.500001 -> 123456788 Inexact Rounded
+rounding: half_even
+addx652 add 123456789 -0.500001 -> 123456788 Inexact Rounded
+rounding: half_down
+addx653 add 123456789 -0.500001 -> 123456788 Inexact Rounded
+rounding: floor
+addx654 add 123456789 -0.500001 -> 123456788 Inexact Rounded
+rounding: ceiling
+addx655 add 123456789 -0.500001 -> 123456789 Inexact Rounded
+rounding: up
+addx656 add 123456789 -0.500001 -> 123456789 Inexact Rounded
+rounding: down
+addx657 add 123456789 -0.500001 -> 123456788 Inexact Rounded
+
+-- long operand triangle
+rounding: half_up
+precision:  37
+addx660 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.42211023638922337114834538
+precision:  36
+addx661 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.4221102363892233711483454  Inexact Rounded
+precision:  35
+addx662 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.422110236389223371148345   Inexact Rounded
+precision:  34
+addx663 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.42211023638922337114835    Inexact Rounded
+precision:  33
+addx664 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.4221102363892233711483     Inexact Rounded
+precision:  32
+addx665 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.422110236389223371148      Inexact Rounded
+precision:  31
+addx666 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.42211023638922337115       Inexact Rounded
+precision:  30
+addx667 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.4221102363892233711        Inexact Rounded
+precision:  29
+addx668 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.422110236389223371         Inexact Rounded
+precision:  28
+addx669 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.42211023638922337          Inexact Rounded
+precision:  27
+addx670 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.4221102363892234           Inexact Rounded
+precision:  26
+addx671 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.422110236389223            Inexact Rounded
+precision:  25
+addx672 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.42211023638922             Inexact Rounded
+precision:  24
+addx673 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.4221102363892              Inexact Rounded
+precision:  23
+addx674 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.422110236389               Inexact Rounded
+precision:  22
+addx675 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.42211023639                Inexact Rounded
+precision:  21
+addx676 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.4221102364                 Inexact Rounded
+precision:  20
+addx677 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.422110236                  Inexact Rounded
+precision:  19
+addx678 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.42211024                   Inexact Rounded
+precision:  18
+addx679 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.4221102                    Inexact Rounded
+precision:  17
+addx680 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.422110                     Inexact Rounded
+precision:  16
+addx681 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.42211                      Inexact Rounded
+precision:  15
+addx682 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.4221                       Inexact Rounded
+precision:  14
+addx683 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.422                        Inexact Rounded
+precision:  13
+addx684 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.42                         Inexact Rounded
+precision:  12
+addx685 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166.4                          Inexact Rounded
+precision:  11
+addx686 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 98471174166                            Inexact Rounded
+precision:  10
+addx687 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 9.847117417E+10                        Inexact Rounded
+precision:   9
+addx688 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 9.84711742E+10                         Inexact Rounded
+precision:   8
+addx689 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 9.8471174E+10                          Inexact Rounded
+precision:   7
+addx690 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 9.847117E+10                          Inexact Rounded
+precision:   6
+addx691 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 9.84712E+10                          Inexact Rounded
+precision:   5
+addx692 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 9.8471E+10                          Inexact Rounded
+precision:   4
+addx693 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 9.847E+10                          Inexact Rounded
+precision:   3
+addx694 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 9.85E+10                          Inexact Rounded
+precision:   2
+addx695 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 9.8E+10                          Inexact Rounded
+precision:   1
+addx696 add 98471198160.56524417578665886060 -23994.14313393939743548945165462 -> 1E+11                          Inexact Rounded
+
+-- more zeros, etc.
+rounding: half_up
+precision:   9
+
+addx701 add 5.00 1.00E-3 -> 5.00100
+addx702 add 00.00 0.000  -> 0.000
+addx703 add 00.00 0E-3   -> 0.000
+addx704 add 0E-3  00.00  -> 0.000
+
+addx710 add 0E+3  00.00  -> 0.00
+addx711 add 0E+3  00.0   -> 0.0
+addx712 add 0E+3  00.    -> 0
+addx713 add 0E+3  00.E+1 -> 0E+1
+addx714 add 0E+3  00.E+2 -> 0E+2
+addx715 add 0E+3  00.E+3 -> 0E+3
+addx716 add 0E+3  00.E+4 -> 0E+3
+addx717 add 0E+3  00.E+5 -> 0E+3
+addx718 add 0E+3  -00.0   -> 0.0
+addx719 add 0E+3  -00.    -> 0
+addx731 add 0E+3  -00.E+1 -> 0E+1
+
+addx720 add 00.00  0E+3  -> 0.00
+addx721 add 00.0   0E+3  -> 0.0
+addx722 add 00.    0E+3  -> 0
+addx723 add 00.E+1 0E+3  -> 0E+1
+addx724 add 00.E+2 0E+3  -> 0E+2
+addx725 add 00.E+3 0E+3  -> 0E+3
+addx726 add 00.E+4 0E+3  -> 0E+3
+addx727 add 00.E+5 0E+3  -> 0E+3
+addx728 add -00.00 0E+3  -> 0.00
+addx729 add -00.0  0E+3  -> 0.0
+addx730 add -00.   0E+3  -> 0
+
+addx732 add  0     0     ->  0
+addx733 add  0    -0     ->  0
+addx734 add -0     0     ->  0
+addx735 add -0    -0     -> -0     -- IEEE 854 special case
+
+addx736 add  1    -1     ->  0
+addx737 add -1    -1     -> -2
+addx738 add  1     1     ->  2
+addx739 add -1     1     ->  0
+
+addx741 add  0    -1     -> -1
+addx742 add -0    -1     -> -1
+addx743 add  0     1     ->  1
+addx744 add -0     1     ->  1
+addx745 add -1     0     -> -1
+addx746 add -1    -0     -> -1
+addx747 add  1     0     ->  1
+addx748 add  1    -0     ->  1
+
+addx751 add  0.0  -1     -> -1.0
+addx752 add -0.0  -1     -> -1.0
+addx753 add  0.0   1     ->  1.0
+addx754 add -0.0   1     ->  1.0
+addx755 add -1.0   0     -> -1.0
+addx756 add -1.0  -0     -> -1.0
+addx757 add  1.0   0     ->  1.0
+addx758 add  1.0  -0     ->  1.0
+
+addx761 add  0    -1.0   -> -1.0
+addx762 add -0    -1.0   -> -1.0
+addx763 add  0     1.0   ->  1.0
+addx764 add -0     1.0   ->  1.0
+addx765 add -1     0.0   -> -1.0
+addx766 add -1    -0.0   -> -1.0
+addx767 add  1     0.0   ->  1.0
+addx768 add  1    -0.0   ->  1.0
+
+addx771 add  0.0  -1.0   -> -1.0
+addx772 add -0.0  -1.0   -> -1.0
+addx773 add  0.0   1.0   ->  1.0
+addx774 add -0.0   1.0   ->  1.0
+addx775 add -1.0   0.0   -> -1.0
+addx776 add -1.0  -0.0   -> -1.0
+addx777 add  1.0   0.0   ->  1.0
+addx778 add  1.0  -0.0   ->  1.0
+
+-- Specials
+addx780 add -Inf  -Inf   -> -Infinity
+addx781 add -Inf  -1000  -> -Infinity
+addx782 add -Inf  -1     -> -Infinity
+addx783 add -Inf  -0     -> -Infinity
+addx784 add -Inf   0     -> -Infinity
+addx785 add -Inf   1     -> -Infinity
+addx786 add -Inf   1000  -> -Infinity
+addx787 add -1000 -Inf   -> -Infinity
+addx788 add -Inf  -Inf   -> -Infinity
+addx789 add -1    -Inf   -> -Infinity
+addx790 add -0    -Inf   -> -Infinity
+addx791 add  0    -Inf   -> -Infinity
+addx792 add  1    -Inf   -> -Infinity
+addx793 add  1000 -Inf   -> -Infinity
+addx794 add  Inf  -Inf   ->  NaN  Invalid_operation
+
+addx800 add  Inf  -Inf   ->  NaN  Invalid_operation
+addx801 add  Inf  -1000  ->  Infinity
+addx802 add  Inf  -1     ->  Infinity
+addx803 add  Inf  -0     ->  Infinity
+addx804 add  Inf   0     ->  Infinity
+addx805 add  Inf   1     ->  Infinity
+addx806 add  Inf   1000  ->  Infinity
+addx807 add  Inf   Inf   ->  Infinity
+addx808 add -1000  Inf   ->  Infinity
+addx809 add -Inf   Inf   ->  NaN  Invalid_operation
+addx810 add -1     Inf   ->  Infinity
+addx811 add -0     Inf   ->  Infinity
+addx812 add  0     Inf   ->  Infinity
+addx813 add  1     Inf   ->  Infinity
+addx814 add  1000  Inf   ->  Infinity
+addx815 add  Inf   Inf   ->  Infinity
+
+addx821 add  NaN -Inf    ->  NaN
+addx822 add  NaN -1000   ->  NaN
+addx823 add  NaN -1      ->  NaN
+addx824 add  NaN -0      ->  NaN
+addx825 add  NaN  0      ->  NaN
+addx826 add  NaN  1      ->  NaN
+addx827 add  NaN  1000   ->  NaN
+addx828 add  NaN  Inf    ->  NaN
+addx829 add  NaN  NaN    ->  NaN
+addx830 add -Inf  NaN    ->  NaN
+addx831 add -1000 NaN    ->  NaN
+addx832 add -1    NaN    ->  NaN
+addx833 add -0    NaN    ->  NaN
+addx834 add  0    NaN    ->  NaN
+addx835 add  1    NaN    ->  NaN
+addx836 add  1000 NaN    ->  NaN
+addx837 add  Inf  NaN    ->  NaN
+
+addx841 add  sNaN -Inf   ->  NaN  Invalid_operation
+addx842 add  sNaN -1000  ->  NaN  Invalid_operation
+addx843 add  sNaN -1     ->  NaN  Invalid_operation
+addx844 add  sNaN -0     ->  NaN  Invalid_operation
+addx845 add  sNaN  0     ->  NaN  Invalid_operation
+addx846 add  sNaN  1     ->  NaN  Invalid_operation
+addx847 add  sNaN  1000  ->  NaN  Invalid_operation
+addx848 add  sNaN  NaN   ->  NaN  Invalid_operation
+addx849 add  sNaN sNaN   ->  NaN  Invalid_operation
+addx850 add  NaN  sNaN   ->  NaN  Invalid_operation
+addx851 add -Inf  sNaN   ->  NaN  Invalid_operation
+addx852 add -1000 sNaN   ->  NaN  Invalid_operation
+addx853 add -1    sNaN   ->  NaN  Invalid_operation
+addx854 add -0    sNaN   ->  NaN  Invalid_operation
+addx855 add  0    sNaN   ->  NaN  Invalid_operation
+addx856 add  1    sNaN   ->  NaN  Invalid_operation
+addx857 add  1000 sNaN   ->  NaN  Invalid_operation
+addx858 add  Inf  sNaN   ->  NaN  Invalid_operation
+addx859 add  NaN  sNaN   ->  NaN  Invalid_operation
+
+-- propagating NaNs
+addx861 add  NaN1   -Inf    ->  NaN1
+addx862 add +NaN2   -1000   ->  NaN2
+addx863 add  NaN3    1000   ->  NaN3
+addx864 add  NaN4    Inf    ->  NaN4
+addx865 add  NaN5   +NaN6   ->  NaN5
+addx866 add -Inf     NaN7   ->  NaN7
+addx867 add -1000    NaN8   ->  NaN8
+addx868 add  1000    NaN9   ->  NaN9
+addx869 add  Inf    +NaN10  ->  NaN10
+addx871 add  sNaN11  -Inf   ->  NaN11  Invalid_operation
+addx872 add  sNaN12  -1000  ->  NaN12  Invalid_operation
+addx873 add  sNaN13   1000  ->  NaN13  Invalid_operation
+addx874 add  sNaN14   NaN17 ->  NaN14  Invalid_operation
+addx875 add  sNaN15  sNaN18 ->  NaN15  Invalid_operation
+addx876 add  NaN16   sNaN19 ->  NaN19  Invalid_operation
+addx877 add -Inf    +sNaN20 ->  NaN20  Invalid_operation
+addx878 add -1000    sNaN21 ->  NaN21  Invalid_operation
+addx879 add  1000    sNaN22 ->  NaN22  Invalid_operation
+addx880 add  Inf     sNaN23 ->  NaN23  Invalid_operation
+addx881 add +NaN25  +sNaN24 ->  NaN24  Invalid_operation
+addx882 add -NaN26    NaN28 -> -NaN26
+addx883 add -sNaN27  sNaN29 -> -NaN27  Invalid_operation
+addx884 add  1000    -NaN30 -> -NaN30
+addx885 add  1000   -sNaN31 -> -NaN31  Invalid_operation
+
+-- overflow, underflow and subnormal tests
+maxexponent: 999999999
+minexponent: -999999999
+precision: 9
+addx890 add 1E+999999999     9E+999999999   -> Infinity Overflow Inexact Rounded
+addx891 add 9E+999999999     1E+999999999   -> Infinity Overflow Inexact Rounded
+addx892 add -1.1E-999999999  1E-999999999   -> -1E-1000000000    Subnormal
+addx893 add 1E-999999999    -1.1e-999999999 -> -1E-1000000000    Subnormal
+addx894 add -1.0001E-999999999  1E-999999999   -> -1E-1000000003 Subnormal
+addx895 add 1E-999999999    -1.0001e-999999999 -> -1E-1000000003 Subnormal
+addx896 add -1E+999999999   -9E+999999999   -> -Infinity Overflow Inexact Rounded
+addx897 add -9E+999999999   -1E+999999999   -> -Infinity Overflow Inexact Rounded
+addx898 add +1.1E-999999999 -1E-999999999   -> 1E-1000000000    Subnormal
+addx899 add -1E-999999999   +1.1e-999999999 -> 1E-1000000000    Subnormal
+addx900 add +1.0001E-999999999 -1E-999999999   -> 1E-1000000003 Subnormal
+addx901 add -1E-999999999   +1.0001e-999999999 -> 1E-1000000003 Subnormal
+addx902 add -1E+999999999   +9E+999999999   ->  8E+999999999
+addx903 add -9E+999999999   +1E+999999999   -> -8E+999999999
+
+precision: 3
+addx904 add      0 -9.999E+999999999   -> -Infinity Inexact Overflow Rounded
+addx905 add        -9.999E+999999999 0 -> -Infinity Inexact Overflow Rounded
+addx906 add      0  9.999E+999999999   ->  Infinity Inexact Overflow Rounded
+addx907 add         9.999E+999999999 0 ->  Infinity Inexact Overflow Rounded
+
+precision: 3
+maxexponent: 999
+minexponent: -999
+addx910 add  1.00E-999   0    ->   1.00E-999
+addx911 add  0.1E-999    0    ->   1E-1000   Subnormal
+addx912 add  0.10E-999   0    ->   1.0E-1000 Subnormal
+addx913 add  0.100E-999  0    ->   1.0E-1000 Subnormal Rounded
+addx914 add  0.01E-999   0    ->   1E-1001   Subnormal
+-- next is rounded to Nmin
+addx915 add  0.999E-999  0    ->   1.00E-999 Inexact Rounded Subnormal Underflow
+addx916 add  0.099E-999  0    ->   1.0E-1000 Inexact Rounded Subnormal Underflow
+addx917 add  0.009E-999  0    ->   1E-1001   Inexact Rounded Subnormal Underflow
+addx918 add  0.001E-999  0    ->   0E-1001   Inexact Rounded Subnormal Underflow Clamped
+addx919 add  0.0009E-999 0    ->   0E-1001   Inexact Rounded Subnormal Underflow Clamped
+addx920 add  0.0001E-999 0    ->   0E-1001   Inexact Rounded Subnormal Underflow Clamped
+
+addx930 add -1.00E-999   0    ->  -1.00E-999
+addx931 add -0.1E-999    0    ->  -1E-1000   Subnormal
+addx932 add -0.10E-999   0    ->  -1.0E-1000 Subnormal
+addx933 add -0.100E-999  0    ->  -1.0E-1000 Subnormal Rounded
+addx934 add -0.01E-999   0    ->  -1E-1001   Subnormal
+-- next is rounded to Nmin
+addx935 add -0.999E-999  0    ->  -1.00E-999 Inexact Rounded Subnormal Underflow
+addx936 add -0.099E-999  0    ->  -1.0E-1000 Inexact Rounded Subnormal Underflow
+addx937 add -0.009E-999  0    ->  -1E-1001   Inexact Rounded Subnormal Underflow
+addx938 add -0.001E-999  0    ->  -0E-1001   Inexact Rounded Subnormal Underflow Clamped
+addx939 add -0.0009E-999 0    ->  -0E-1001   Inexact Rounded Subnormal Underflow Clamped
+addx940 add -0.0001E-999 0    ->  -0E-1001   Inexact Rounded Subnormal Underflow Clamped
+
+-- some non-zero subnormal adds
+addx950 add  1.00E-999    0.1E-999  ->   1.10E-999
+addx951 add  0.1E-999     0.1E-999  ->   2E-1000    Subnormal
+addx952 add  0.10E-999    0.1E-999  ->   2.0E-1000  Subnormal
+addx953 add  0.100E-999   0.1E-999  ->   2.0E-1000  Subnormal Rounded
+addx954 add  0.01E-999    0.1E-999  ->   1.1E-1000  Subnormal
+addx955 add  0.999E-999   0.1E-999  ->   1.10E-999  Inexact Rounded
+addx956 add  0.099E-999   0.1E-999  ->   2.0E-1000  Inexact Rounded Subnormal Underflow
+addx957 add  0.009E-999   0.1E-999  ->   1.1E-1000  Inexact Rounded Subnormal Underflow
+addx958 add  0.001E-999   0.1E-999  ->   1.0E-1000  Inexact Rounded Subnormal Underflow
+addx959 add  0.0009E-999  0.1E-999  ->   1.0E-1000  Inexact Rounded Subnormal Underflow
+addx960 add  0.0001E-999  0.1E-999  ->   1.0E-1000  Inexact Rounded Subnormal Underflow
+-- negatives...
+addx961 add  1.00E-999   -0.1E-999  ->   9.0E-1000  Subnormal
+addx962 add  0.1E-999    -0.1E-999  ->   0E-1000
+addx963 add  0.10E-999   -0.1E-999  ->   0E-1001
+addx964 add  0.100E-999  -0.1E-999  ->   0E-1001    Clamped
+addx965 add  0.01E-999   -0.1E-999  ->   -9E-1001   Subnormal
+addx966 add  0.999E-999  -0.1E-999  ->   9.0E-1000  Inexact Rounded Subnormal Underflow
+addx967 add  0.099E-999  -0.1E-999  ->   -0E-1001   Inexact Rounded Subnormal Underflow Clamped
+addx968 add  0.009E-999  -0.1E-999  ->   -9E-1001   Inexact Rounded Subnormal Underflow
+addx969 add  0.001E-999  -0.1E-999  ->   -1.0E-1000 Inexact Rounded Subnormal Underflow
+addx970 add  0.0009E-999 -0.1E-999  ->   -1.0E-1000 Inexact Rounded Subnormal Underflow
+addx971 add  0.0001E-999 -0.1E-999  ->   -1.0E-1000 Inexact Rounded Subnormal Underflow
+
+-- some 'real' numbers
+maxExponent: 384
+minExponent: -383
+precision: 8
+addx566 add 99999061735E-394  0E-394 -> 9.999906E-384 Inexact Rounded Underflow Subnormal
+precision: 7
+addx567 add 99999061735E-394  0E-394 -> 9.99991E-384 Inexact Rounded Underflow Subnormal
+precision: 6
+addx568 add 99999061735E-394  0E-394 -> 9.9999E-384 Inexact Rounded Underflow Subnormal
+
+-- now the case where we can get underflow but the result is normal
+-- [note this can't happen if the operands are also bounded, as we
+-- cannot represent 1E-399, for example]
+precision:   16
+rounding:    half_up
+maxExponent: 384
+minExponent: -383
+
+addx571 add       1E-383       0  -> 1E-383
+addx572 add       1E-384       0  -> 1E-384   Subnormal
+addx573 add       1E-383  1E-384  -> 1.1E-383
+addx574 subtract  1E-383  1E-384  ->   9E-384 Subnormal
+
+-- Here we explore the boundary of rounding a subnormal to Nmin
+addx575 subtract  1E-383  1E-398  ->   9.99999999999999E-384  Subnormal
+addx576 subtract  1E-383  1E-398  ->   9.99999999999999E-384  Subnormal
+addx577 subtract  1E-383  1E-399  ->   1.000000000000000E-383 Underflow Inexact Subnormal Rounded
+addx578 subtract  1E-383  1E-400  ->   1.000000000000000E-383 Underflow Inexact Subnormal Rounded
+addx579 subtract  1E-383  1E-401  ->   1.000000000000000E-383 Underflow Inexact Subnormal Rounded
+addx580 subtract  1E-383  1E-402  ->   1.000000000000000E-383 Underflow Inexact Subnormal Rounded
+
+-- check overflow edge case
+precision:   7
+rounding:    half_up
+maxExponent: 96
+minExponent: -95
+addx972 apply   9.999999E+96         -> 9.999999E+96
+addx973 add     9.999999E+96  1      -> 9.999999E+96 Inexact Rounded
+addx974 add      9999999E+90  1      -> 9.999999E+96 Inexact Rounded
+addx975 add      9999999E+90  1E+90  -> Infinity Overflow Inexact Rounded
+addx976 add      9999999E+90  9E+89  -> Infinity Overflow Inexact Rounded
+addx977 add      9999999E+90  8E+89  -> Infinity Overflow Inexact Rounded
+addx978 add      9999999E+90  7E+89  -> Infinity Overflow Inexact Rounded
+addx979 add      9999999E+90  6E+89  -> Infinity Overflow Inexact Rounded
+addx980 add      9999999E+90  5E+89  -> Infinity Overflow Inexact Rounded
+addx981 add      9999999E+90  4E+89  -> 9.999999E+96 Inexact Rounded
+addx982 add      9999999E+90  3E+89  -> 9.999999E+96 Inexact Rounded
+addx983 add      9999999E+90  2E+89  -> 9.999999E+96 Inexact Rounded
+addx984 add      9999999E+90  1E+89  -> 9.999999E+96 Inexact Rounded
+
+addx985 apply  -9.999999E+96         -> -9.999999E+96
+addx986 add    -9.999999E+96 -1      -> -9.999999E+96 Inexact Rounded
+addx987 add     -9999999E+90 -1      -> -9.999999E+96 Inexact Rounded
+addx988 add     -9999999E+90 -1E+90  -> -Infinity Overflow Inexact Rounded
+addx989 add     -9999999E+90 -9E+89  -> -Infinity Overflow Inexact Rounded
+addx990 add     -9999999E+90 -8E+89  -> -Infinity Overflow Inexact Rounded
+addx991 add     -9999999E+90 -7E+89  -> -Infinity Overflow Inexact Rounded
+addx992 add     -9999999E+90 -6E+89  -> -Infinity Overflow Inexact Rounded
+addx993 add     -9999999E+90 -5E+89  -> -Infinity Overflow Inexact Rounded
+addx994 add     -9999999E+90 -4E+89  -> -9.999999E+96 Inexact Rounded
+addx995 add     -9999999E+90 -3E+89  -> -9.999999E+96 Inexact Rounded
+addx996 add     -9999999E+90 -2E+89  -> -9.999999E+96 Inexact Rounded
+addx997 add     -9999999E+90 -1E+89  -> -9.999999E+96 Inexact Rounded
+
+-- check for double-rounded subnormals
+precision:   5
+maxexponent: 79
+minexponent: -79
+-- Add: lhs and rhs 0
+addx1001 add       1.52444E-80 0 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+addx1002 add       1.52445E-80 0 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+addx1003 add       1.52446E-80 0 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+addx1004 add       0 1.52444E-80 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+addx1005 add       0 1.52445E-80 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+addx1006 add       0 1.52446E-80 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+
+-- Add: lhs >> rhs and vice versa
+addx1011 add       1.52444E-80 1E-100 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+addx1012 add       1.52445E-80 1E-100 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+addx1013 add       1.52446E-80 1E-100 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+addx1014 add       1E-100 1.52444E-80 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+addx1015 add       1E-100 1.52445E-80 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+addx1016 add       1E-100 1.52446E-80 -> 1.524E-80 Inexact Rounded Subnormal Underflow
+
+-- Add: lhs + rhs addition carried out
+addx1021 add       1.52443E-80 1.00001E-80  -> 2.524E-80 Inexact Rounded Subnormal Underflow
+addx1022 add       1.52444E-80 1.00001E-80  -> 2.524E-80 Inexact Rounded Subnormal Underflow
+addx1023 add       1.52445E-80 1.00001E-80  -> 2.524E-80 Inexact Rounded Subnormal Underflow
+addx1024 add       1.00001E-80  1.52443E-80 -> 2.524E-80 Inexact Rounded Subnormal Underflow
+addx1025 add       1.00001E-80  1.52444E-80 -> 2.524E-80 Inexact Rounded Subnormal Underflow
+addx1026 add       1.00001E-80  1.52445E-80 -> 2.524E-80 Inexact Rounded Subnormal Underflow
+
+-- And for round down full and subnormal results
+precision:    16
+maxExponent: +384
+minExponent: -383
+rounding:     down
+
+addx1100 add 1e+2 -1e-383    -> 99.99999999999999 Rounded Inexact
+addx1101 add 1e+1 -1e-383    -> 9.999999999999999  Rounded Inexact
+addx1103 add   +1 -1e-383    -> 0.9999999999999999  Rounded Inexact
+addx1104 add 1e-1 -1e-383    -> 0.09999999999999999  Rounded Inexact
+addx1105 add 1e-2 -1e-383    -> 0.009999999999999999  Rounded Inexact
+addx1106 add 1e-3 -1e-383    -> 0.0009999999999999999  Rounded Inexact
+addx1107 add 1e-4 -1e-383    -> 0.00009999999999999999  Rounded Inexact
+addx1108 add 1e-5 -1e-383    -> 0.000009999999999999999  Rounded Inexact
+addx1109 add 1e-6 -1e-383    -> 9.999999999999999E-7  Rounded Inexact
+
+rounding:     ceiling
+addx1110 add -1e+2 +1e-383   -> -99.99999999999999 Rounded Inexact
+addx1111 add -1e+1 +1e-383   -> -9.999999999999999  Rounded Inexact
+addx1113 add    -1 +1e-383   -> -0.9999999999999999  Rounded Inexact
+addx1114 add -1e-1 +1e-383   -> -0.09999999999999999  Rounded Inexact
+addx1115 add -1e-2 +1e-383   -> -0.009999999999999999  Rounded Inexact
+addx1116 add -1e-3 +1e-383   -> -0.0009999999999999999  Rounded Inexact
+addx1117 add -1e-4 +1e-383   -> -0.00009999999999999999  Rounded Inexact
+addx1118 add -1e-5 +1e-383   -> -0.000009999999999999999  Rounded Inexact
+addx1119 add -1e-6 +1e-383   -> -9.999999999999999E-7  Rounded Inexact
+addx1120 add +1e-383 -1e+2   -> -99.99999999999999 Rounded Inexact
+addx1121 add +1e-383 -1e+1   -> -9.999999999999999  Rounded Inexact
+addx1123 add +1e-383    -1   -> -0.9999999999999999  Rounded Inexact
+addx1124 add +1e-383 -1e-1   -> -0.09999999999999999  Rounded Inexact
+addx1125 add +1e-383 -1e-2   -> -0.009999999999999999  Rounded Inexact
+addx1126 add +1e-383 -1e-3   -> -0.0009999999999999999  Rounded Inexact
+addx1127 add +1e-383 -1e-4   -> -0.00009999999999999999  Rounded Inexact
+addx1128 add +1e-383 -1e-5   -> -0.000009999999999999999  Rounded Inexact
+addx1129 add +1e-383 -1e-6   -> -9.999999999999999E-7  Rounded Inexact
+
+rounding:     down
+precision:    7
+maxExponent: +96
+minExponent: -95
+addx1130 add   1            -1e-200  -> 0.9999999  Rounded Inexact
+-- subnormal boundary
+addx1131 add   1.000000E-94  -1e-200  ->  9.999999E-95  Rounded Inexact
+addx1132 add   1.000001E-95  -1e-200  ->  1.000000E-95  Rounded Inexact
+addx1133 add   1.000000E-95  -1e-200  ->  9.99999E-96  Rounded Inexact Subnormal Underflow
+addx1134 add   0.999999E-95  -1e-200  ->  9.99998E-96  Rounded Inexact Subnormal Underflow
+addx1135 add   0.001000E-95  -1e-200  ->  9.99E-99  Rounded Inexact Subnormal Underflow
+addx1136 add   0.000999E-95  -1e-200  ->  9.98E-99  Rounded Inexact Subnormal Underflow
+addx1137 add   1.000000E-95  -1e-101  ->  9.99999E-96  Subnormal
+addx1138 add      10000E-101 -1e-200  ->  9.999E-98  Subnormal Inexact Rounded Underflow
+addx1139 add       1000E-101 -1e-200  ->  9.99E-99   Subnormal Inexact Rounded Underflow
+addx1140 add        100E-101 -1e-200  ->  9.9E-100   Subnormal Inexact Rounded Underflow
+addx1141 add         10E-101 -1e-200  ->  9E-101     Subnormal Inexact Rounded Underflow
+addx1142 add          1E-101 -1e-200  ->  0E-101     Subnormal Inexact Rounded Underflow Clamped
+addx1143 add          0E-101 -1e-200  -> -0E-101     Subnormal Inexact Rounded Underflow Clamped
+addx1144 add          1E-102 -1e-200  ->  0E-101     Subnormal Inexact Rounded Underflow Clamped
+
+addx1151 add      10000E-102 -1e-200  ->  9.99E-99  Subnormal Inexact Rounded Underflow
+addx1152 add       1000E-102 -1e-200  ->  9.9E-100  Subnormal Inexact Rounded Underflow
+addx1153 add        100E-102 -1e-200  ->  9E-101   Subnormal Inexact Rounded Underflow
+addx1154 add         10E-102 -1e-200  ->  0E-101     Subnormal Inexact Rounded Underflow Clamped
+addx1155 add          1E-102 -1e-200  ->  0E-101     Subnormal Inexact Rounded Underflow Clamped
+addx1156 add          0E-102 -1e-200  -> -0E-101     Subnormal Inexact Rounded Underflow Clamped
+addx1157 add          1E-103 -1e-200  ->  0E-101     Subnormal Inexact Rounded Underflow Clamped
+
+addx1160 add        100E-105 -1e-101  -> -0E-101 Subnormal Inexact Rounded Underflow Clamped
+addx1161 add        100E-105 -1e-201  ->  0E-101 Subnormal Inexact Rounded Underflow Clamped
+
+-- tests based on Gunnar Degnbol's edge case
+precision:   15
+rounding:    half_up
+maxExponent: 384
+minexponent: -383
+
+addx1200 add 1E15  -0.5                 ->  1.00000000000000E+15 Inexact Rounded
+addx1201 add 1E15  -0.50                ->  1.00000000000000E+15 Inexact Rounded
+addx1210 add 1E15  -0.51                ->  999999999999999      Inexact Rounded
+addx1211 add 1E15  -0.501               ->  999999999999999      Inexact Rounded
+addx1212 add 1E15  -0.5001              ->  999999999999999      Inexact Rounded
+addx1213 add 1E15  -0.50001             ->  999999999999999      Inexact Rounded
+addx1214 add 1E15  -0.500001            ->  999999999999999      Inexact Rounded
+addx1215 add 1E15  -0.5000001           ->  999999999999999      Inexact Rounded
+addx1216 add 1E15  -0.50000001          ->  999999999999999      Inexact Rounded
+addx1217 add 1E15  -0.500000001         ->  999999999999999      Inexact Rounded
+addx1218 add 1E15  -0.5000000001        ->  999999999999999      Inexact Rounded
+addx1219 add 1E15  -0.50000000001       ->  999999999999999      Inexact Rounded
+addx1220 add 1E15  -0.500000000001      ->  999999999999999      Inexact Rounded
+addx1221 add 1E15  -0.5000000000001     ->  999999999999999      Inexact Rounded
+addx1222 add 1E15  -0.50000000000001    ->  999999999999999      Inexact Rounded
+addx1223 add 1E15  -0.500000000000001   ->  999999999999999      Inexact Rounded
+addx1224 add 1E15  -0.5000000000000001  ->  999999999999999      Inexact Rounded
+addx1225 add 1E15  -0.5000000000000000  ->  1.00000000000000E+15 Inexact Rounded
+addx1230 add 1E15  -5000000.000000001   ->  999999995000000      Inexact Rounded
+
+precision:   16
+
+addx1300 add 1E16  -0.5                 ->  1.000000000000000E+16 Inexact Rounded
+addx1310 add 1E16  -0.51                ->  9999999999999999      Inexact Rounded
+addx1311 add 1E16  -0.501               ->  9999999999999999      Inexact Rounded
+addx1312 add 1E16  -0.5001              ->  9999999999999999      Inexact Rounded
+addx1313 add 1E16  -0.50001             ->  9999999999999999      Inexact Rounded
+addx1314 add 1E16  -0.500001            ->  9999999999999999      Inexact Rounded
+addx1315 add 1E16  -0.5000001           ->  9999999999999999      Inexact Rounded
+addx1316 add 1E16  -0.50000001          ->  9999999999999999      Inexact Rounded
+addx1317 add 1E16  -0.500000001         ->  9999999999999999      Inexact Rounded
+addx1318 add 1E16  -0.5000000001        ->  9999999999999999      Inexact Rounded
+addx1319 add 1E16  -0.50000000001       ->  9999999999999999      Inexact Rounded
+addx1320 add 1E16  -0.500000000001      ->  9999999999999999      Inexact Rounded
+addx1321 add 1E16  -0.5000000000001     ->  9999999999999999      Inexact Rounded
+addx1322 add 1E16  -0.50000000000001    ->  9999999999999999      Inexact Rounded
+addx1323 add 1E16  -0.500000000000001   ->  9999999999999999      Inexact Rounded
+addx1324 add 1E16  -0.5000000000000001  ->  9999999999999999      Inexact Rounded
+addx1325 add 1E16  -0.5000000000000000  ->  1.000000000000000E+16 Inexact Rounded
+addx1326 add 1E16  -0.500000000000000   ->  1.000000000000000E+16 Inexact Rounded
+addx1327 add 1E16  -0.50000000000000    ->  1.000000000000000E+16 Inexact Rounded
+addx1328 add 1E16  -0.5000000000000     ->  1.000000000000000E+16 Inexact Rounded
+addx1329 add 1E16  -0.500000000000      ->  1.000000000000000E+16 Inexact Rounded
+addx1330 add 1E16  -0.50000000000       ->  1.000000000000000E+16 Inexact Rounded
+addx1331 add 1E16  -0.5000000000        ->  1.000000000000000E+16 Inexact Rounded
+addx1332 add 1E16  -0.500000000         ->  1.000000000000000E+16 Inexact Rounded
+addx1333 add 1E16  -0.50000000          ->  1.000000000000000E+16 Inexact Rounded
+addx1334 add 1E16  -0.5000000           ->  1.000000000000000E+16 Inexact Rounded
+addx1335 add 1E16  -0.500000            ->  1.000000000000000E+16 Inexact Rounded
+addx1336 add 1E16  -0.50000             ->  1.000000000000000E+16 Inexact Rounded
+addx1337 add 1E16  -0.5000              ->  1.000000000000000E+16 Inexact Rounded
+addx1338 add 1E16  -0.500               ->  1.000000000000000E+16 Inexact Rounded
+addx1339 add 1E16  -0.50                ->  1.000000000000000E+16 Inexact Rounded
+
+addx1340 add 1E16  -5000000.000010001   ->  9999999995000000      Inexact Rounded
+addx1341 add 1E16  -5000000.000000001   ->  9999999995000000      Inexact Rounded
+
+addx1349 add 9999999999999999 0.4                 ->  9999999999999999      Inexact Rounded
+addx1350 add 9999999999999999 0.49                ->  9999999999999999      Inexact Rounded
+addx1351 add 9999999999999999 0.499               ->  9999999999999999      Inexact Rounded
+addx1352 add 9999999999999999 0.4999              ->  9999999999999999      Inexact Rounded
+addx1353 add 9999999999999999 0.49999             ->  9999999999999999      Inexact Rounded
+addx1354 add 9999999999999999 0.499999            ->  9999999999999999      Inexact Rounded
+addx1355 add 9999999999999999 0.4999999           ->  9999999999999999      Inexact Rounded
+addx1356 add 9999999999999999 0.49999999          ->  9999999999999999      Inexact Rounded
+addx1357 add 9999999999999999 0.499999999         ->  9999999999999999      Inexact Rounded
+addx1358 add 9999999999999999 0.4999999999        ->  9999999999999999      Inexact Rounded
+addx1359 add 9999999999999999 0.49999999999       ->  9999999999999999      Inexact Rounded
+addx1360 add 9999999999999999 0.499999999999      ->  9999999999999999      Inexact Rounded
+addx1361 add 9999999999999999 0.4999999999999     ->  9999999999999999      Inexact Rounded
+addx1362 add 9999999999999999 0.49999999999999    ->  9999999999999999      Inexact Rounded
+addx1363 add 9999999999999999 0.499999999999999   ->  9999999999999999      Inexact Rounded
+addx1364 add 9999999999999999 0.4999999999999999  ->  9999999999999999      Inexact Rounded
+addx1365 add 9999999999999999 0.5000000000000000  ->  1.000000000000000E+16 Inexact Rounded
+addx1367 add 9999999999999999 0.500000000000000   ->  1.000000000000000E+16 Inexact Rounded
+addx1368 add 9999999999999999 0.50000000000000    ->  1.000000000000000E+16 Inexact Rounded
+addx1369 add 9999999999999999 0.5000000000000     ->  1.000000000000000E+16 Inexact Rounded
+addx1370 add 9999999999999999 0.500000000000      ->  1.000000000000000E+16 Inexact Rounded
+addx1371 add 9999999999999999 0.50000000000       ->  1.000000000000000E+16 Inexact Rounded
+addx1372 add 9999999999999999 0.5000000000        ->  1.000000000000000E+16 Inexact Rounded
+addx1373 add 9999999999999999 0.500000000         ->  1.000000000000000E+16 Inexact Rounded
+addx1374 add 9999999999999999 0.50000000          ->  1.000000000000000E+16 Inexact Rounded
+addx1375 add 9999999999999999 0.5000000           ->  1.000000000000000E+16 Inexact Rounded
+addx1376 add 9999999999999999 0.500000            ->  1.000000000000000E+16 Inexact Rounded
+addx1377 add 9999999999999999 0.50000             ->  1.000000000000000E+16 Inexact Rounded
+addx1378 add 9999999999999999 0.5000              ->  1.000000000000000E+16 Inexact Rounded
+addx1379 add 9999999999999999 0.500               ->  1.000000000000000E+16 Inexact Rounded
+addx1380 add 9999999999999999 0.50                ->  1.000000000000000E+16 Inexact Rounded
+addx1381 add 9999999999999999 0.5                 ->  1.000000000000000E+16 Inexact Rounded
+addx1382 add 9999999999999999 0.5000000000000001  ->  1.000000000000000E+16 Inexact Rounded
+addx1383 add 9999999999999999 0.500000000000001   ->  1.000000000000000E+16 Inexact Rounded
+addx1384 add 9999999999999999 0.50000000000001    ->  1.000000000000000E+16 Inexact Rounded
+addx1385 add 9999999999999999 0.5000000000001     ->  1.000000000000000E+16 Inexact Rounded
+addx1386 add 9999999999999999 0.500000000001      ->  1.000000000000000E+16 Inexact Rounded
+addx1387 add 9999999999999999 0.50000000001       ->  1.000000000000000E+16 Inexact Rounded
+addx1388 add 9999999999999999 0.5000000001        ->  1.000000000000000E+16 Inexact Rounded
+addx1389 add 9999999999999999 0.500000001         ->  1.000000000000000E+16 Inexact Rounded
+addx1390 add 9999999999999999 0.50000001          ->  1.000000000000000E+16 Inexact Rounded
+addx1391 add 9999999999999999 0.5000001           ->  1.000000000000000E+16 Inexact Rounded
+addx1392 add 9999999999999999 0.500001            ->  1.000000000000000E+16 Inexact Rounded
+addx1393 add 9999999999999999 0.50001             ->  1.000000000000000E+16 Inexact Rounded
+addx1394 add 9999999999999999 0.5001              ->  1.000000000000000E+16 Inexact Rounded
+addx1395 add 9999999999999999 0.501               ->  1.000000000000000E+16 Inexact Rounded
+addx1396 add 9999999999999999 0.51                ->  1.000000000000000E+16 Inexact Rounded
+
+-- More GD edge cases, where difference between the unadjusted
+-- exponents is larger than the maximum precision and one side is 0
+precision:   15
+rounding:    half_up
+maxExponent: 384
+minexponent: -383
+
+addx1400 add  0 1.23456789012345     -> 1.23456789012345
+addx1401 add  0 1.23456789012345E-1  -> 0.123456789012345
+addx1402 add  0 1.23456789012345E-2  -> 0.0123456789012345
+addx1403 add  0 1.23456789012345E-3  -> 0.00123456789012345
+addx1404 add  0 1.23456789012345E-4  -> 0.000123456789012345
+addx1405 add  0 1.23456789012345E-5  -> 0.0000123456789012345
+addx1406 add  0 1.23456789012345E-6  -> 0.00000123456789012345
+addx1407 add  0 1.23456789012345E-7  -> 1.23456789012345E-7
+addx1408 add  0 1.23456789012345E-8  -> 1.23456789012345E-8
+addx1409 add  0 1.23456789012345E-9  -> 1.23456789012345E-9
+addx1410 add  0 1.23456789012345E-10 -> 1.23456789012345E-10
+addx1411 add  0 1.23456789012345E-11 -> 1.23456789012345E-11
+addx1412 add  0 1.23456789012345E-12 -> 1.23456789012345E-12
+addx1413 add  0 1.23456789012345E-13 -> 1.23456789012345E-13
+addx1414 add  0 1.23456789012345E-14 -> 1.23456789012345E-14
+addx1415 add  0 1.23456789012345E-15 -> 1.23456789012345E-15
+addx1416 add  0 1.23456789012345E-16 -> 1.23456789012345E-16
+addx1417 add  0 1.23456789012345E-17 -> 1.23456789012345E-17
+addx1418 add  0 1.23456789012345E-18 -> 1.23456789012345E-18
+addx1419 add  0 1.23456789012345E-19 -> 1.23456789012345E-19
+
+-- same, precision 16..
+precision:   16
+addx1420 add  0 1.123456789012345     -> 1.123456789012345
+addx1421 add  0 1.123456789012345E-1  -> 0.1123456789012345
+addx1422 add  0 1.123456789012345E-2  -> 0.01123456789012345
+addx1423 add  0 1.123456789012345E-3  -> 0.001123456789012345
+addx1424 add  0 1.123456789012345E-4  -> 0.0001123456789012345
+addx1425 add  0 1.123456789012345E-5  -> 0.00001123456789012345
+addx1426 add  0 1.123456789012345E-6  -> 0.000001123456789012345
+addx1427 add  0 1.123456789012345E-7  -> 1.123456789012345E-7
+addx1428 add  0 1.123456789012345E-8  -> 1.123456789012345E-8
+addx1429 add  0 1.123456789012345E-9  -> 1.123456789012345E-9
+addx1430 add  0 1.123456789012345E-10 -> 1.123456789012345E-10
+addx1431 add  0 1.123456789012345E-11 -> 1.123456789012345E-11
+addx1432 add  0 1.123456789012345E-12 -> 1.123456789012345E-12
+addx1433 add  0 1.123456789012345E-13 -> 1.123456789012345E-13
+addx1434 add  0 1.123456789012345E-14 -> 1.123456789012345E-14
+addx1435 add  0 1.123456789012345E-15 -> 1.123456789012345E-15
+addx1436 add  0 1.123456789012345E-16 -> 1.123456789012345E-16
+addx1437 add  0 1.123456789012345E-17 -> 1.123456789012345E-17
+addx1438 add  0 1.123456789012345E-18 -> 1.123456789012345E-18
+addx1439 add  0 1.123456789012345E-19 -> 1.123456789012345E-19
+
+-- same, reversed 0
+addx1440 add 1.123456789012345     0 -> 1.123456789012345
+addx1441 add 1.123456789012345E-1  0 -> 0.1123456789012345
+addx1442 add 1.123456789012345E-2  0 -> 0.01123456789012345
+addx1443 add 1.123456789012345E-3  0 -> 0.001123456789012345
+addx1444 add 1.123456789012345E-4  0 -> 0.0001123456789012345
+addx1445 add 1.123456789012345E-5  0 -> 0.00001123456789012345
+addx1446 add 1.123456789012345E-6  0 -> 0.000001123456789012345
+addx1447 add 1.123456789012345E-7  0 -> 1.123456789012345E-7
+addx1448 add 1.123456789012345E-8  0 -> 1.123456789012345E-8
+addx1449 add 1.123456789012345E-9  0 -> 1.123456789012345E-9
+addx1450 add 1.123456789012345E-10 0 -> 1.123456789012345E-10
+addx1451 add 1.123456789012345E-11 0 -> 1.123456789012345E-11
+addx1452 add 1.123456789012345E-12 0 -> 1.123456789012345E-12
+addx1453 add 1.123456789012345E-13 0 -> 1.123456789012345E-13
+addx1454 add 1.123456789012345E-14 0 -> 1.123456789012345E-14
+addx1455 add 1.123456789012345E-15 0 -> 1.123456789012345E-15
+addx1456 add 1.123456789012345E-16 0 -> 1.123456789012345E-16
+addx1457 add 1.123456789012345E-17 0 -> 1.123456789012345E-17
+addx1458 add 1.123456789012345E-18 0 -> 1.123456789012345E-18
+addx1459 add 1.123456789012345E-19 0 -> 1.123456789012345E-19
+
+-- same, Es on the 0
+addx1460 add 1.123456789012345  0E-0   -> 1.123456789012345
+addx1461 add 1.123456789012345  0E-1   -> 1.123456789012345
+addx1462 add 1.123456789012345  0E-2   -> 1.123456789012345
+addx1463 add 1.123456789012345  0E-3   -> 1.123456789012345
+addx1464 add 1.123456789012345  0E-4   -> 1.123456789012345
+addx1465 add 1.123456789012345  0E-5   -> 1.123456789012345
+addx1466 add 1.123456789012345  0E-6   -> 1.123456789012345
+addx1467 add 1.123456789012345  0E-7   -> 1.123456789012345
+addx1468 add 1.123456789012345  0E-8   -> 1.123456789012345
+addx1469 add 1.123456789012345  0E-9   -> 1.123456789012345
+addx1470 add 1.123456789012345  0E-10  -> 1.123456789012345
+addx1471 add 1.123456789012345  0E-11  -> 1.123456789012345
+addx1472 add 1.123456789012345  0E-12  -> 1.123456789012345
+addx1473 add 1.123456789012345  0E-13  -> 1.123456789012345
+addx1474 add 1.123456789012345  0E-14  -> 1.123456789012345
+addx1475 add 1.123456789012345  0E-15  -> 1.123456789012345
+-- next four flag Rounded because the 0 extends the result
+addx1476 add 1.123456789012345  0E-16  -> 1.123456789012345 Rounded
+addx1477 add 1.123456789012345  0E-17  -> 1.123456789012345 Rounded
+addx1478 add 1.123456789012345  0E-18  -> 1.123456789012345 Rounded
+addx1479 add 1.123456789012345  0E-19  -> 1.123456789012345 Rounded
+
+-- sum of two opposite-sign operands is exactly 0 and floor => -0
+precision:   16
+maxExponent: 384
+minexponent: -383
+
+rounding:    half_up
+-- exact zeros from zeros
+addx1500 add  0        0E-19  ->  0E-19
+addx1501 add -0        0E-19  ->  0E-19
+addx1502 add  0       -0E-19  ->  0E-19
+addx1503 add -0       -0E-19  -> -0E-19
+addx1504 add  0E-400   0E-19  ->  0E-398 Clamped
+addx1505 add -0E-400   0E-19  ->  0E-398 Clamped
+addx1506 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx1507 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx1511 add  1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1512 add -1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1513 add  1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1514 add -1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+-- some exact zeros from non-zeros
+addx1515 add  1E-401   1E-401 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1516 add -1E-401   1E-401 ->  0E-398 Clamped
+addx1517 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx1518 add -1E-401  -1E-401 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+
+rounding:    half_down
+-- exact zeros from zeros
+addx1520 add  0        0E-19  ->  0E-19
+addx1521 add -0        0E-19  ->  0E-19
+addx1522 add  0       -0E-19  ->  0E-19
+addx1523 add -0       -0E-19  -> -0E-19
+addx1524 add  0E-400   0E-19  ->  0E-398 Clamped
+addx1525 add -0E-400   0E-19  ->  0E-398 Clamped
+addx1526 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx1527 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx1531 add  1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1532 add -1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1533 add  1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1534 add -1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+-- some exact zeros from non-zeros
+addx1535 add  1E-401   1E-401 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1536 add -1E-401   1E-401 ->  0E-398 Clamped
+addx1537 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx1538 add -1E-401  -1E-401 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+
+rounding:    half_even
+-- exact zeros from zeros
+addx1540 add  0        0E-19  ->  0E-19
+addx1541 add -0        0E-19  ->  0E-19
+addx1542 add  0       -0E-19  ->  0E-19
+addx1543 add -0       -0E-19  -> -0E-19
+addx1544 add  0E-400   0E-19  ->  0E-398 Clamped
+addx1545 add -0E-400   0E-19  ->  0E-398 Clamped
+addx1546 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx1547 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx1551 add  1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1552 add -1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1553 add  1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1554 add -1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+-- some exact zeros from non-zeros
+addx1555 add  1E-401   1E-401 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1556 add -1E-401   1E-401 ->  0E-398 Clamped
+addx1557 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx1558 add -1E-401  -1E-401 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+
+rounding:    up
+-- exact zeros from zeros
+addx1560 add  0        0E-19  ->  0E-19
+addx1561 add -0        0E-19  ->  0E-19
+addx1562 add  0       -0E-19  ->  0E-19
+addx1563 add -0       -0E-19  -> -0E-19
+addx1564 add  0E-400   0E-19  ->  0E-398 Clamped
+addx1565 add -0E-400   0E-19  ->  0E-398 Clamped
+addx1566 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx1567 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx1571 add  1E-401   1E-400 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx1572 add -1E-401   1E-400 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx1573 add  1E-401  -1E-400 -> -1E-398 Subnormal Inexact Rounded Underflow
+addx1574 add -1E-401  -1E-400 -> -1E-398 Subnormal Inexact Rounded Underflow
+-- some exact zeros from non-zeros
+addx1575 add  1E-401   1E-401 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx1576 add -1E-401   1E-401 ->  0E-398 Clamped
+addx1577 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx1578 add -1E-401  -1E-401 -> -1E-398 Subnormal Inexact Rounded Underflow
+
+rounding:    down
+-- exact zeros from zeros
+addx1580 add  0        0E-19  ->  0E-19
+addx1581 add -0        0E-19  ->  0E-19
+addx1582 add  0       -0E-19  ->  0E-19
+addx1583 add -0       -0E-19  -> -0E-19
+addx1584 add  0E-400   0E-19  ->  0E-398 Clamped
+addx1585 add -0E-400   0E-19  ->  0E-398 Clamped
+addx1586 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx1587 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx1591 add  1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1592 add -1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1593 add  1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1594 add -1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+-- some exact zeros from non-zeros
+addx1595 add  1E-401   1E-401 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1596 add -1E-401   1E-401 ->  0E-398 Clamped
+addx1597 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx1598 add -1E-401  -1E-401 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+
+rounding:    ceiling
+-- exact zeros from zeros
+addx1600 add  0        0E-19  ->  0E-19
+addx1601 add -0        0E-19  ->  0E-19
+addx1602 add  0       -0E-19  ->  0E-19
+addx1603 add -0       -0E-19  -> -0E-19
+addx1604 add  0E-400   0E-19  ->  0E-398 Clamped
+addx1605 add -0E-400   0E-19  ->  0E-398 Clamped
+addx1606 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx1607 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx1611 add  1E-401   1E-400 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx1612 add -1E-401   1E-400 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx1613 add  1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1614 add -1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+-- some exact zeros from non-zeros
+addx1615 add  1E-401   1E-401 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx1616 add -1E-401   1E-401 ->  0E-398 Clamped
+addx1617 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx1618 add -1E-401  -1E-401 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+
+-- and the extra-special ugly case; unusual minuses marked by -- *
+rounding:    floor
+-- exact zeros from zeros
+addx1620 add  0        0E-19  ->  0E-19
+addx1621 add -0        0E-19  -> -0E-19           -- *
+addx1622 add  0       -0E-19  -> -0E-19           -- *
+addx1623 add -0       -0E-19  -> -0E-19
+addx1624 add  0E-400   0E-19  ->  0E-398 Clamped
+addx1625 add -0E-400   0E-19  -> -0E-398 Clamped  -- *
+addx1626 add  0E-400  -0E-19  -> -0E-398 Clamped  -- *
+addx1627 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx1631 add  1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1632 add -1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1633 add  1E-401  -1E-400 -> -1E-398 Subnormal Inexact Rounded Underflow
+addx1634 add -1E-401  -1E-400 -> -1E-398 Subnormal Inexact Rounded Underflow
+-- some exact zeros from non-zeros
+addx1635 add  1E-401   1E-401 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx1636 add -1E-401   1E-401 -> -0E-398 Clamped  -- *
+addx1637 add  1E-401  -1E-401 -> -0E-398 Clamped  -- *
+addx1638 add -1E-401  -1E-401 -> -1E-398 Subnormal Inexact Rounded Underflow
+
+-- BigDecimal problem testcases 2006.01.23
+precision:   16
+maxExponent: 384
+minexponent: -383
+
+rounding:  down
+precision: 7
+addx1651 add  10001E+2  -2E+1 -> 1.00008E+6
+precision: 6
+addx1652 add  10001E+2  -2E+1 -> 1.00008E+6
+precision: 5
+addx1653 add  10001E+2  -2E+1 -> 1.0000E+6   Inexact Rounded
+precision: 4
+addx1654 add  10001E+2  -2E+1 -> 1.000E+6    Inexact Rounded
+precision: 3
+addx1655 add  10001E+2  -2E+1 -> 1.00E+6     Inexact Rounded
+precision: 2
+addx1656 add  10001E+2  -2E+1 -> 1.0E+6      Inexact Rounded
+precision: 1
+addx1657 add  10001E+2  -2E+1 -> 1E+6        Inexact Rounded
+
+rounding:  half_even
+precision: 7
+addx1661 add  10001E+2  -2E+1 -> 1.00008E+6
+precision: 6
+addx1662 add  10001E+2  -2E+1 -> 1.00008E+6
+precision: 5
+addx1663 add  10001E+2  -2E+1 -> 1.0001E+6   Inexact Rounded
+precision: 4
+addx1664 add  10001E+2  -2E+1 -> 1.000E+6    Inexact Rounded
+precision: 3
+addx1665 add  10001E+2  -2E+1 -> 1.00E+6     Inexact Rounded
+precision: 2
+addx1666 add  10001E+2  -2E+1 -> 1.0E+6      Inexact Rounded
+precision: 1
+addx1667 add  10001E+2  -2E+1 -> 1E+6        Inexact Rounded
+
+rounding:  up
+precision: 7
+addx1671 add  10001E+2  -2E+1 -> 1.00008E+6
+precision: 6
+addx1672 add  10001E+2  -2E+1 -> 1.00008E+6
+precision: 5
+addx1673 add  10001E+2  -2E+1 -> 1.0001E+6   Inexact Rounded
+precision: 4
+addx1674 add  10001E+2  -2E+1 -> 1.001E+6    Inexact Rounded
+precision: 3
+addx1675 add  10001E+2  -2E+1 -> 1.01E+6     Inexact Rounded
+precision: 2
+addx1676 add  10001E+2  -2E+1 -> 1.1E+6      Inexact Rounded
+precision: 1
+addx1677 add  10001E+2  -2E+1 -> 2E+6        Inexact Rounded
+
+precision:   34
+rounding:    half_up
+maxExponent: 6144
+minExponent: -6143
+-- Examples from SQL proposal (Krishna Kulkarni)
+addx1701  add 130E-2    120E-2    -> 2.50
+addx1702  add 130E-2    12E-1     -> 2.50
+addx1703  add 130E-2    1E0       -> 2.30
+addx1704  add 1E2       1E4       -> 1.01E+4
+addx1705  subtract 130E-2  120E-2 -> 0.10
+addx1706  subtract 130E-2  12E-1  -> 0.10
+addx1707  subtract 130E-2  1E0    -> 0.30
+addx1708  subtract 1E2     1E4    -> -9.9E+3
+
+------------------------------------------------------------------------
+-- Same as above, using decimal64 default parameters                  --
+------------------------------------------------------------------------
+precision:   16
+rounding:    half_even
+maxExponent: 384
+minexponent: -383
+
+-- [first group are 'quick confidence check']
+addx6001 add 1       1       ->  2
+addx6002 add 2       3       ->  5
+addx6003 add '5.75'  '3.3'   ->  9.05
+addx6004 add '5'     '-3'    ->  2
+addx6005 add '-5'    '-3'    ->  -8
+addx6006 add '-7'    '2.5'   ->  -4.5
+addx6007 add '0.7'   '0.3'   ->  1.0
+addx6008 add '1.25'  '1.25'  ->  2.50
+addx6009 add '1.23456789'  '1.00000000' -> '2.23456789'
+addx6010 add '1.23456789'  '1.00000011' -> '2.23456800'
+
+addx6011 add '0.44444444444444444'  '0.55555555555555555' -> '1.000000000000000' Inexact Rounded
+addx6012 add '0.44444444444444440'  '0.55555555555555555' -> '1.000000000000000' Inexact Rounded
+addx6013 add '0.44444444444444444'  '0.55555555555555550' -> '0.9999999999999999' Inexact Rounded
+addx6014 add '0.444444444444444449'    '0' -> '0.4444444444444444' Inexact Rounded
+addx6015 add '0.4444444444444444499'   '0' -> '0.4444444444444444' Inexact Rounded
+addx6016 add '0.44444444444444444999'  '0' -> '0.4444444444444444' Inexact Rounded
+addx6017 add '0.44444444444444445000'  '0' -> '0.4444444444444444' Inexact Rounded
+addx6018 add '0.44444444444444445001'  '0' -> '0.4444444444444445' Inexact Rounded
+addx6019 add '0.4444444444444444501'   '0' -> '0.4444444444444445' Inexact Rounded
+addx6020 add '0.444444444444444451'    '0' -> '0.4444444444444445' Inexact Rounded
+
+addx6021 add 0 1 -> 1
+addx6022 add 1 1 -> 2
+addx6023 add 2 1 -> 3
+addx6024 add 3 1 -> 4
+addx6025 add 4 1 -> 5
+addx6026 add 5 1 -> 6
+addx6027 add 6 1 -> 7
+addx6028 add 7 1 -> 8
+addx6029 add 8 1 -> 9
+addx6030 add 9 1 -> 10
+
+-- some carrying effects
+addx6031 add '0.9998'  '0.0000' -> '0.9998'
+addx6032 add '0.9998'  '0.0001' -> '0.9999'
+addx6033 add '0.9998'  '0.0002' -> '1.0000'
+addx6034 add '0.9998'  '0.0003' -> '1.0001'
+
+addx6035 add '70'      '10000e+16' -> '1.000000000000000E+20' Inexact Rounded
+addx6036 add '700'     '10000e+16' -> '1.000000000000000E+20' Inexact Rounded
+addx6037 add '7000'    '10000e+16' -> '1.000000000000000E+20' Inexact Rounded
+addx6038 add '70000'   '10000e+16' -> '1.000000000000001E+20' Inexact Rounded
+addx6039 add '700000'  '10000e+16' -> '1.000000000000007E+20' Rounded
+
+-- symmetry:
+addx6040 add '10000e+16'  '70' -> '1.000000000000000E+20' Inexact Rounded
+addx6041 add '10000e+16'  '700' -> '1.000000000000000E+20' Inexact Rounded
+addx6042 add '10000e+16'  '7000' -> '1.000000000000000E+20' Inexact Rounded
+addx6044 add '10000e+16'  '70000' -> '1.000000000000001E+20' Inexact Rounded
+addx6045 add '10000e+16'  '700000' -> '1.000000000000007E+20' Rounded
+
+addx6046 add '10000e+9'  '7' -> '10000000000007'
+addx6047 add '10000e+9'  '70' -> '10000000000070'
+addx6048 add '10000e+9'  '700' -> '10000000000700'
+addx6049 add '10000e+9'  '7000' -> '10000000007000'
+addx6050 add '10000e+9'  '70000' -> '10000000070000'
+addx6051 add '10000e+9'  '700000' -> '10000000700000'
+
+-- examples from decarith
+addx6053 add '12' '7.00' -> '19.00'
+addx6054 add '1.3' '-1.07' -> '0.23'
+addx6055 add '1.3' '-1.30' -> '0.00'
+addx6056 add '1.3' '-2.07' -> '-0.77'
+addx6057 add '1E+2' '1E+4' -> '1.01E+4'
+
+-- from above
+addx6060 add 1 '0.1' -> '1.1'
+addx6061 add 1 '0.01' -> '1.01'
+addx6062 add 1 '0.001' -> '1.001'
+addx6063 add 1 '0.0001' -> '1.0001'
+addx6064 add 1 '0.00001' -> '1.00001'
+addx6065 add 1 '0.000001' -> '1.000001'
+addx6066 add 1 '0.0000001' -> '1.0000001'
+addx6067 add 1 '0.00000001' -> '1.00000001'
+
+-- cancellation to integer
+addx6068 add 99999999999999123456789 -99999999999999E+9 -> 123456789
+-- similar from FMA fun
+addx6069 add "-1234567890123455.234567890123454" "1234567890123456" -> 0.765432109876546
+
+-- some funny zeros [in case of bad signum]
+addx6070 add 1  0    -> 1
+addx6071 add 1 0.    -> 1
+addx6072 add 1  .0   -> 1.0
+addx6073 add 1 0.0   -> 1.0
+addx6074 add 1 0.00  -> 1.00
+addx6075 add  0  1   -> 1
+addx6076 add 0.  1   -> 1
+addx6077 add  .0 1   -> 1.0
+addx6078 add 0.0 1   -> 1.0
+addx6079 add 0.00 1  -> 1.00
+
+-- some carries
+addx6080 add 9999999999999998 1  -> 9999999999999999
+addx6081 add 9999999999999999 1  -> 1.000000000000000E+16 Rounded
+addx6082 add  999999999999999 1  -> 1000000000000000
+addx6083 add    9999999999999 1  -> 10000000000000
+addx6084 add      99999999999 1  -> 100000000000
+addx6085 add        999999999 1  -> 1000000000
+addx6086 add          9999999 1  -> 10000000
+addx6087 add            99999 1  -> 100000
+addx6088 add              999 1  -> 1000
+addx6089 add                9 1  -> 10
+
+
+-- more LHS swaps
+addx6090 add '-56267E-10'   0 ->  '-0.0000056267'
+addx6091 add '-56267E-6'    0 ->  '-0.056267'
+addx6092 add '-56267E-5'    0 ->  '-0.56267'
+addx6093 add '-56267E-4'    0 ->  '-5.6267'
+addx6094 add '-56267E-3'    0 ->  '-56.267'
+addx6095 add '-56267E-2'    0 ->  '-562.67'
+addx6096 add '-56267E-1'    0 ->  '-5626.7'
+addx6097 add '-56267E-0'    0 ->  '-56267'
+addx6098 add '-5E-10'       0 ->  '-5E-10'
+addx6099 add '-5E-7'        0 ->  '-5E-7'
+addx6100 add '-5E-6'        0 ->  '-0.000005'
+addx6101 add '-5E-5'        0 ->  '-0.00005'
+addx6102 add '-5E-4'        0 ->  '-0.0005'
+addx6103 add '-5E-1'        0 ->  '-0.5'
+addx6104 add '-5E0'         0 ->  '-5'
+addx6105 add '-5E1'         0 ->  '-50'
+addx6106 add '-5E5'         0 ->  '-500000'
+addx6107 add '-5E15'        0 ->  '-5000000000000000'
+addx6108 add '-5E16'        0 ->  '-5.000000000000000E+16'   Rounded
+addx6109 add '-5E17'        0 ->  '-5.000000000000000E+17'  Rounded
+addx6110 add '-5E18'        0 ->  '-5.000000000000000E+18'  Rounded
+addx6111 add '-5E100'       0 ->  '-5.000000000000000E+100' Rounded
+
+-- more RHS swaps
+addx6113 add 0  '-56267E-10' ->  '-0.0000056267'
+addx6114 add 0  '-56267E-6'  ->  '-0.056267'
+addx6116 add 0  '-56267E-5'  ->  '-0.56267'
+addx6117 add 0  '-56267E-4'  ->  '-5.6267'
+addx6119 add 0  '-56267E-3'  ->  '-56.267'
+addx6120 add 0  '-56267E-2'  ->  '-562.67'
+addx6121 add 0  '-56267E-1'  ->  '-5626.7'
+addx6122 add 0  '-56267E-0'  ->  '-56267'
+addx6123 add 0  '-5E-10'     ->  '-5E-10'
+addx6124 add 0  '-5E-7'      ->  '-5E-7'
+addx6125 add 0  '-5E-6'      ->  '-0.000005'
+addx6126 add 0  '-5E-5'      ->  '-0.00005'
+addx6127 add 0  '-5E-4'      ->  '-0.0005'
+addx6128 add 0  '-5E-1'      ->  '-0.5'
+addx6129 add 0  '-5E0'       ->  '-5'
+addx6130 add 0  '-5E1'       ->  '-50'
+addx6131 add 0  '-5E5'       ->  '-500000'
+addx6132 add 0  '-5E15'      ->  '-5000000000000000'
+addx6133 add 0  '-5E16'      ->  '-5.000000000000000E+16'   Rounded
+addx6134 add 0  '-5E17'      ->  '-5.000000000000000E+17'   Rounded
+addx6135 add 0  '-5E18'      ->  '-5.000000000000000E+18'   Rounded
+addx6136 add 0  '-5E100'     ->  '-5.000000000000000E+100'  Rounded
+
+-- related
+addx6137 add  1  '0E-19'      ->  '1.000000000000000'  Rounded
+addx6138 add -1  '0E-19'      ->  '-1.000000000000000' Rounded
+addx6139 add '0E-19' 1        ->  '1.000000000000000'  Rounded
+addx6140 add '0E-19' -1       ->  '-1.000000000000000' Rounded
+addx6141 add 1E+11   0.0000   ->  '100000000000.0000'
+addx6142 add 1E+11   0.00000  ->  '100000000000.0000'  Rounded
+addx6143 add 0.000   1E+12    ->  '1000000000000.000'
+addx6144 add 0.0000  1E+12    ->  '1000000000000.000'  Rounded
+
+-- [some of the next group are really constructor tests]
+addx6146 add '00.0'  0       ->  '0.0'
+addx6147 add '0.00'  0       ->  '0.00'
+addx6148 add  0      '0.00'  ->  '0.00'
+addx6149 add  0      '00.0'  ->  '0.0'
+addx6150 add '00.0'  '0.00'  ->  '0.00'
+addx6151 add '0.00'  '00.0'  ->  '0.00'
+addx6152 add '3'     '.3'    ->  '3.3'
+addx6153 add '3.'    '.3'    ->  '3.3'
+addx6154 add '3.0'   '.3'    ->  '3.3'
+addx6155 add '3.00'  '.3'    ->  '3.30'
+addx6156 add '3'     '3'     ->  '6'
+addx6157 add '3'     '+3'    ->  '6'
+addx6158 add '3'     '-3'    ->  '0'
+addx6159 add '0.3'   '-0.3'  ->  '0.0'
+addx6160 add '0.03'  '-0.03' ->  '0.00'
+
+-- try borderline precision, with carries, etc.
+addx6161 add '1E+13' '-1'    -> '9999999999999'
+addx6162 add '1E+13'  '1.11' -> '10000000000001.11'
+addx6163 add '1.11'  '1E+13' -> '10000000000001.11'
+addx6164 add '-1'    '1E+13' -> '9999999999999'
+addx6165 add '7E+13' '-1'    -> '69999999999999'
+addx6166 add '7E+13'  '1.11' -> '70000000000001.11'
+addx6167 add '1.11'  '7E+13' -> '70000000000001.11'
+addx6168 add '-1'    '7E+13' -> '69999999999999'
+
+--             1234567890123456      1234567890123456      1 234567890123456
+addx6170 add '0.4444444444444444'  '0.5555555555555563' -> '1.000000000000001' Inexact Rounded
+addx6171 add '0.4444444444444444'  '0.5555555555555562' -> '1.000000000000001' Inexact Rounded
+addx6172 add '0.4444444444444444'  '0.5555555555555561' -> '1.000000000000000' Inexact Rounded
+addx6173 add '0.4444444444444444'  '0.5555555555555560' -> '1.000000000000000' Inexact Rounded
+addx6174 add '0.4444444444444444'  '0.5555555555555559' -> '1.000000000000000' Inexact Rounded
+addx6175 add '0.4444444444444444'  '0.5555555555555558' -> '1.000000000000000' Inexact Rounded
+addx6176 add '0.4444444444444444'  '0.5555555555555557' -> '1.000000000000000' Inexact Rounded
+addx6177 add '0.4444444444444444'  '0.5555555555555556' -> '1.000000000000000' Rounded
+addx6178 add '0.4444444444444444'  '0.5555555555555555' -> '0.9999999999999999'
+addx6179 add '0.4444444444444444'  '0.5555555555555554' -> '0.9999999999999998'
+addx6180 add '0.4444444444444444'  '0.5555555555555553' -> '0.9999999999999997'
+addx6181 add '0.4444444444444444'  '0.5555555555555552' -> '0.9999999999999996'
+addx6182 add '0.4444444444444444'  '0.5555555555555551' -> '0.9999999999999995'
+addx6183 add '0.4444444444444444'  '0.5555555555555550' -> '0.9999999999999994'
+
+-- and some more, including residue effects and different roundings
+rounding: half_up
+addx6200 add '6543210123456789' 0             -> '6543210123456789'
+addx6201 add '6543210123456789' 0.000000001   -> '6543210123456789' Inexact Rounded
+addx6202 add '6543210123456789' 0.000001      -> '6543210123456789' Inexact Rounded
+addx6203 add '6543210123456789' 0.1           -> '6543210123456789' Inexact Rounded
+addx6204 add '6543210123456789' 0.4           -> '6543210123456789' Inexact Rounded
+addx6205 add '6543210123456789' 0.49          -> '6543210123456789' Inexact Rounded
+addx6206 add '6543210123456789' 0.499999      -> '6543210123456789' Inexact Rounded
+addx6207 add '6543210123456789' 0.499999999   -> '6543210123456789' Inexact Rounded
+addx6208 add '6543210123456789' 0.5           -> '6543210123456790' Inexact Rounded
+addx6209 add '6543210123456789' 0.500000001   -> '6543210123456790' Inexact Rounded
+addx6210 add '6543210123456789' 0.500001      -> '6543210123456790' Inexact Rounded
+addx6211 add '6543210123456789' 0.51          -> '6543210123456790' Inexact Rounded
+addx6212 add '6543210123456789' 0.6           -> '6543210123456790' Inexact Rounded
+addx6213 add '6543210123456789' 0.9           -> '6543210123456790' Inexact Rounded
+addx6214 add '6543210123456789' 0.99999       -> '6543210123456790' Inexact Rounded
+addx6215 add '6543210123456789' 0.999999999   -> '6543210123456790' Inexact Rounded
+addx6216 add '6543210123456789' 1             -> '6543210123456790'
+addx6217 add '6543210123456789' 1.000000001   -> '6543210123456790' Inexact Rounded
+addx6218 add '6543210123456789' 1.00001       -> '6543210123456790' Inexact Rounded
+addx6219 add '6543210123456789' 1.1           -> '6543210123456790' Inexact Rounded
+
+rounding: half_even
+addx6220 add '6543210123456789' 0             -> '6543210123456789'
+addx6221 add '6543210123456789' 0.000000001   -> '6543210123456789' Inexact Rounded
+addx6222 add '6543210123456789' 0.000001      -> '6543210123456789' Inexact Rounded
+addx6223 add '6543210123456789' 0.1           -> '6543210123456789' Inexact Rounded
+addx6224 add '6543210123456789' 0.4           -> '6543210123456789' Inexact Rounded
+addx6225 add '6543210123456789' 0.49          -> '6543210123456789' Inexact Rounded
+addx6226 add '6543210123456789' 0.499999      -> '6543210123456789' Inexact Rounded
+addx6227 add '6543210123456789' 0.499999999   -> '6543210123456789' Inexact Rounded
+addx6228 add '6543210123456789' 0.5           -> '6543210123456790' Inexact Rounded
+addx6229 add '6543210123456789' 0.500000001   -> '6543210123456790' Inexact Rounded
+addx6230 add '6543210123456789' 0.500001      -> '6543210123456790' Inexact Rounded
+addx6231 add '6543210123456789' 0.51          -> '6543210123456790' Inexact Rounded
+addx6232 add '6543210123456789' 0.6           -> '6543210123456790' Inexact Rounded
+addx6233 add '6543210123456789' 0.9           -> '6543210123456790' Inexact Rounded
+addx6234 add '6543210123456789' 0.99999       -> '6543210123456790' Inexact Rounded
+addx6235 add '6543210123456789' 0.999999999   -> '6543210123456790' Inexact Rounded
+addx6236 add '6543210123456789' 1             -> '6543210123456790'
+addx6237 add '6543210123456789' 1.00000001    -> '6543210123456790' Inexact Rounded
+addx6238 add '6543210123456789' 1.00001       -> '6543210123456790' Inexact Rounded
+addx6239 add '6543210123456789' 1.1           -> '6543210123456790' Inexact Rounded
+-- critical few with even bottom digit...
+addx6240 add '6543210123456788' 0.499999999   -> '6543210123456788' Inexact Rounded
+addx6241 add '6543210123456788' 0.5           -> '6543210123456788' Inexact Rounded
+addx6242 add '6543210123456788' 0.500000001   -> '6543210123456789' Inexact Rounded
+
+rounding: down
+addx6250 add '6543210123456789' 0             -> '6543210123456789'
+addx6251 add '6543210123456789' 0.000000001   -> '6543210123456789' Inexact Rounded
+addx6252 add '6543210123456789' 0.000001      -> '6543210123456789' Inexact Rounded
+addx6253 add '6543210123456789' 0.1           -> '6543210123456789' Inexact Rounded
+addx6254 add '6543210123456789' 0.4           -> '6543210123456789' Inexact Rounded
+addx6255 add '6543210123456789' 0.49          -> '6543210123456789' Inexact Rounded
+addx6256 add '6543210123456789' 0.499999      -> '6543210123456789' Inexact Rounded
+addx6257 add '6543210123456789' 0.499999999   -> '6543210123456789' Inexact Rounded
+addx6258 add '6543210123456789' 0.5           -> '6543210123456789' Inexact Rounded
+addx6259 add '6543210123456789' 0.500000001   -> '6543210123456789' Inexact Rounded
+addx6260 add '6543210123456789' 0.500001      -> '6543210123456789' Inexact Rounded
+addx6261 add '6543210123456789' 0.51          -> '6543210123456789' Inexact Rounded
+addx6262 add '6543210123456789' 0.6           -> '6543210123456789' Inexact Rounded
+addx6263 add '6543210123456789' 0.9           -> '6543210123456789' Inexact Rounded
+addx6264 add '6543210123456789' 0.99999       -> '6543210123456789' Inexact Rounded
+addx6265 add '6543210123456789' 0.999999999   -> '6543210123456789' Inexact Rounded
+addx6266 add '6543210123456789' 1             -> '6543210123456790'
+addx6267 add '6543210123456789' 1.00000001    -> '6543210123456790' Inexact Rounded
+addx6268 add '6543210123456789' 1.00001       -> '6543210123456790' Inexact Rounded
+addx6269 add '6543210123456789' 1.1           -> '6543210123456790' Inexact Rounded
+
+-- 1 in last place tests
+rounding: half_even
+addx6301 add  -1   1      ->   0
+addx6302 add   0   1      ->   1
+addx6303 add   1   1      ->   2
+addx6304 add  12   1      ->  13
+addx6305 add  98   1      ->  99
+addx6306 add  99   1      -> 100
+addx6307 add 100   1      -> 101
+addx6308 add 101   1      -> 102
+addx6309 add  -1  -1      ->  -2
+addx6310 add   0  -1      ->  -1
+addx6311 add   1  -1      ->   0
+addx6312 add  12  -1      ->  11
+addx6313 add  98  -1      ->  97
+addx6314 add  99  -1      ->  98
+addx6315 add 100  -1      ->  99
+addx6316 add 101  -1      -> 100
+
+addx6321 add -0.01  0.01    ->  0.00
+addx6322 add  0.00  0.01    ->  0.01
+addx6323 add  0.01  0.01    ->  0.02
+addx6324 add  0.12  0.01    ->  0.13
+addx6325 add  0.98  0.01    ->  0.99
+addx6326 add  0.99  0.01    ->  1.00
+addx6327 add  1.00  0.01    ->  1.01
+addx6328 add  1.01  0.01    ->  1.02
+addx6329 add -0.01 -0.01    -> -0.02
+addx6330 add  0.00 -0.01    -> -0.01
+addx6331 add  0.01 -0.01    ->  0.00
+addx6332 add  0.12 -0.01    ->  0.11
+addx6333 add  0.98 -0.01    ->  0.97
+addx6334 add  0.99 -0.01    ->  0.98
+addx6335 add  1.00 -0.01    ->  0.99
+addx6336 add  1.01 -0.01    ->  1.00
+
+-- some more cases where adding 0 affects the coefficient
+addx6340 add 1E+3    0    ->         1000
+addx6341 add 1E+15   0    ->    1000000000000000
+addx6342 add 1E+16   0    ->   1.000000000000000E+16  Rounded
+addx6343 add 1E+17   0    ->   1.000000000000000E+17  Rounded
+-- which simply follow from these cases ...
+addx6344 add 1E+3    1    ->         1001
+addx6345 add 1E+15   1    ->    1000000000000001
+addx6346 add 1E+16   1    ->   1.000000000000000E+16  Inexact Rounded
+addx6347 add 1E+17   1    ->   1.000000000000000E+17  Inexact Rounded
+addx6348 add 1E+3    7    ->         1007
+addx6349 add 1E+15   7    ->    1000000000000007
+addx6350 add 1E+16   7    ->   1.000000000000001E+16  Inexact Rounded
+addx6351 add 1E+17   7    ->   1.000000000000000E+17  Inexact Rounded
+
+-- tryzeros cases
+addx6361  add 0E+50 10000E+1  -> 1.0000E+5
+addx6362  add 10000E+1 0E-50  -> 100000.0000000000  Rounded
+addx6363  add 10000E+1 10000E-50  -> 100000.0000000000  Rounded Inexact
+addx6364  add 12.34    0e-398  -> 12.34000000000000  Rounded
+
+-- ulp replacement tests
+addx6400 add   1   77e-14      ->  1.00000000000077
+addx6401 add   1   77e-15      ->  1.000000000000077
+addx6402 add   1   77e-16      ->  1.000000000000008 Inexact Rounded
+addx6403 add   1   77e-17      ->  1.000000000000001 Inexact Rounded
+addx6404 add   1   77e-18      ->  1.000000000000000 Inexact Rounded
+addx6405 add   1   77e-19      ->  1.000000000000000 Inexact Rounded
+addx6406 add   1   77e-99      ->  1.000000000000000 Inexact Rounded
+
+addx6410 add  10   77e-14      ->  10.00000000000077
+addx6411 add  10   77e-15      ->  10.00000000000008 Inexact Rounded
+addx6412 add  10   77e-16      ->  10.00000000000001 Inexact Rounded
+addx6413 add  10   77e-17      ->  10.00000000000000 Inexact Rounded
+addx6414 add  10   77e-18      ->  10.00000000000000 Inexact Rounded
+addx6415 add  10   77e-19      ->  10.00000000000000 Inexact Rounded
+addx6416 add  10   77e-99      ->  10.00000000000000 Inexact Rounded
+
+addx6420 add  77e-14       1   ->  1.00000000000077
+addx6421 add  77e-15       1   ->  1.000000000000077
+addx6422 add  77e-16       1   ->  1.000000000000008 Inexact Rounded
+addx6423 add  77e-17       1   ->  1.000000000000001 Inexact Rounded
+addx6424 add  77e-18       1   ->  1.000000000000000 Inexact Rounded
+addx6425 add  77e-19       1   ->  1.000000000000000 Inexact Rounded
+addx6426 add  77e-99       1   ->  1.000000000000000 Inexact Rounded
+
+addx6430 add  77e-14      10   ->  10.00000000000077
+addx6431 add  77e-15      10   ->  10.00000000000008 Inexact Rounded
+addx6432 add  77e-16      10   ->  10.00000000000001 Inexact Rounded
+addx6433 add  77e-17      10   ->  10.00000000000000 Inexact Rounded
+addx6434 add  77e-18      10   ->  10.00000000000000 Inexact Rounded
+addx6435 add  77e-19      10   ->  10.00000000000000 Inexact Rounded
+addx6436 add  77e-99      10   ->  10.00000000000000 Inexact Rounded
+
+-- negative ulps
+addx6440 add   1   -77e-14      ->  0.99999999999923
+addx6441 add   1   -77e-15      ->  0.999999999999923
+addx6442 add   1   -77e-16      ->  0.9999999999999923
+addx6443 add   1   -77e-17      ->  0.9999999999999992 Inexact Rounded
+addx6444 add   1   -77e-18      ->  0.9999999999999999 Inexact Rounded
+addx6445 add   1   -77e-19      ->  1.000000000000000 Inexact Rounded
+addx6446 add   1   -77e-99      ->  1.000000000000000 Inexact Rounded
+
+addx6450 add  10   -77e-14      ->   9.99999999999923
+addx6451 add  10   -77e-15      ->   9.999999999999923
+addx6452 add  10   -77e-16      ->   9.999999999999992 Inexact Rounded
+addx6453 add  10   -77e-17      ->   9.999999999999999 Inexact Rounded
+addx6454 add  10   -77e-18      ->  10.00000000000000 Inexact Rounded
+addx6455 add  10   -77e-19      ->  10.00000000000000 Inexact Rounded
+addx6456 add  10   -77e-99      ->  10.00000000000000 Inexact Rounded
+
+addx6460 add  -77e-14       1   ->  0.99999999999923
+addx6461 add  -77e-15       1   ->  0.999999999999923
+addx6462 add  -77e-16       1   ->  0.9999999999999923
+addx6463 add  -77e-17       1   ->  0.9999999999999992 Inexact Rounded
+addx6464 add  -77e-18       1   ->  0.9999999999999999 Inexact Rounded
+addx6465 add  -77e-19       1   ->  1.000000000000000 Inexact Rounded
+addx6466 add  -77e-99       1   ->  1.000000000000000 Inexact Rounded
+
+addx6470 add  -77e-14      10   ->   9.99999999999923
+addx6471 add  -77e-15      10   ->   9.999999999999923
+addx6472 add  -77e-16      10   ->   9.999999999999992 Inexact Rounded
+addx6473 add  -77e-17      10   ->   9.999999999999999 Inexact Rounded
+addx6474 add  -77e-18      10   ->  10.00000000000000 Inexact Rounded
+addx6475 add  -77e-19      10   ->  10.00000000000000 Inexact Rounded
+addx6476 add  -77e-99      10   ->  10.00000000000000 Inexact Rounded
+
+-- negative ulps
+addx6480 add  -1    77e-14      ->  -0.99999999999923
+addx6481 add  -1    77e-15      ->  -0.999999999999923
+addx6482 add  -1    77e-16      ->  -0.9999999999999923
+addx6483 add  -1    77e-17      ->  -0.9999999999999992 Inexact Rounded
+addx6484 add  -1    77e-18      ->  -0.9999999999999999 Inexact Rounded
+addx6485 add  -1    77e-19      ->  -1.000000000000000 Inexact Rounded
+addx6486 add  -1    77e-99      ->  -1.000000000000000 Inexact Rounded
+
+addx6490 add -10    77e-14      ->   -9.99999999999923
+addx6491 add -10    77e-15      ->   -9.999999999999923
+addx6492 add -10    77e-16      ->   -9.999999999999992 Inexact Rounded
+addx6493 add -10    77e-17      ->   -9.999999999999999 Inexact Rounded
+addx6494 add -10    77e-18      ->  -10.00000000000000 Inexact Rounded
+addx6495 add -10    77e-19      ->  -10.00000000000000 Inexact Rounded
+addx6496 add -10    77e-99      ->  -10.00000000000000 Inexact Rounded
+
+addx6500 add   77e-14      -1   ->  -0.99999999999923
+addx6501 add   77e-15      -1   ->  -0.999999999999923
+addx6502 add   77e-16      -1   ->  -0.9999999999999923
+addx6503 add   77e-17      -1   ->  -0.9999999999999992 Inexact Rounded
+addx6504 add   77e-18      -1   ->  -0.9999999999999999 Inexact Rounded
+addx6505 add   77e-19      -1   ->  -1.000000000000000 Inexact Rounded
+addx6506 add   77e-99      -1   ->  -1.000000000000000 Inexact Rounded
+
+addx6510 add   77e-14      -10  ->   -9.99999999999923
+addx6511 add   77e-15      -10  ->   -9.999999999999923
+addx6512 add   77e-16      -10  ->   -9.999999999999992 Inexact Rounded
+addx6513 add   77e-17      -10  ->   -9.999999999999999 Inexact Rounded
+addx6514 add   77e-18      -10  ->  -10.00000000000000 Inexact Rounded
+addx6515 add   77e-19      -10  ->  -10.00000000000000 Inexact Rounded
+addx6516 add   77e-99      -10  ->  -10.00000000000000 Inexact Rounded
+
+
+-- long operands
+addx6521 add 101234562345678000 0 -> 1.012345623456780E+17 Rounded
+addx6522 add 0 101234562345678000 -> 1.012345623456780E+17 Rounded
+addx6523 add 10123456234567800  0 -> 1.012345623456780E+16 Rounded
+addx6524 add 0 10123456234567800  -> 1.012345623456780E+16 Rounded
+addx6525 add 10123456234567890  0 -> 1.012345623456789E+16 Rounded
+addx6526 add 0 10123456234567890  -> 1.012345623456789E+16 Rounded
+addx6527 add 10123456234567891  0 -> 1.012345623456789E+16 Inexact Rounded
+addx6528 add 0 10123456234567891  -> 1.012345623456789E+16 Inexact Rounded
+addx6529 add 101234562345678901 0 -> 1.012345623456789E+17 Inexact Rounded
+addx6530 add 0 101234562345678901 -> 1.012345623456789E+17 Inexact Rounded
+addx6531 add 10123456234567896  0 -> 1.012345623456790E+16 Inexact Rounded
+addx6532 add 0 10123456234567896  -> 1.012345623456790E+16 Inexact Rounded
+
+-- verify a query
+rounding:     down
+addx6561 add 1e-398 9.000000000000000E+384 -> 9.000000000000000E+384 Inexact Rounded
+addx6562 add      0 9.000000000000000E+384 -> 9.000000000000000E+384 Rounded
+-- and using decimal64 bounds...
+rounding:     down
+addx6563 add 1e-388 9.000000000000000E+374 -> 9.000000000000000E+374 Inexact Rounded
+addx6564 add      0 9.000000000000000E+374 -> 9.000000000000000E+374 Rounded
+
+-- more zeros, etc.
+rounding: half_even
+
+addx6701 add 5.00 1.00E-3 -> 5.00100
+addx6702 add 00.00 0.000  -> 0.000
+addx6703 add 00.00 0E-3   -> 0.000
+addx6704 add 0E-3  00.00  -> 0.000
+
+addx6710 add 0E+3  00.00  -> 0.00
+addx6711 add 0E+3  00.0   -> 0.0
+addx6712 add 0E+3  00.    -> 0
+addx6713 add 0E+3  00.E+1 -> 0E+1
+addx6714 add 0E+3  00.E+2 -> 0E+2
+addx6715 add 0E+3  00.E+3 -> 0E+3
+addx6716 add 0E+3  00.E+4 -> 0E+3
+addx6717 add 0E+3  00.E+5 -> 0E+3
+addx6718 add 0E+3  -00.0   -> 0.0
+addx6719 add 0E+3  -00.    -> 0
+addx6731 add 0E+3  -00.E+1 -> 0E+1
+
+addx6720 add 00.00  0E+3  -> 0.00
+addx6721 add 00.0   0E+3  -> 0.0
+addx6722 add 00.    0E+3  -> 0
+addx6723 add 00.E+1 0E+3  -> 0E+1
+addx6724 add 00.E+2 0E+3  -> 0E+2
+addx6725 add 00.E+3 0E+3  -> 0E+3
+addx6726 add 00.E+4 0E+3  -> 0E+3
+addx6727 add 00.E+5 0E+3  -> 0E+3
+addx6728 add -00.00 0E+3  -> 0.00
+addx6729 add -00.0  0E+3  -> 0.0
+addx6730 add -00.   0E+3  -> 0
+
+addx6732 add  0     0     ->  0
+addx6733 add  0    -0     ->  0
+addx6734 add -0     0     ->  0
+addx6735 add -0    -0     -> -0     -- IEEE 854 special case
+
+addx6736 add  1    -1     ->  0
+addx6737 add -1    -1     -> -2
+addx6738 add  1     1     ->  2
+addx6739 add -1     1     ->  0
+
+addx6741 add  0    -1     -> -1
+addx6742 add -0    -1     -> -1
+addx6743 add  0     1     ->  1
+addx6744 add -0     1     ->  1
+addx6745 add -1     0     -> -1
+addx6746 add -1    -0     -> -1
+addx6747 add  1     0     ->  1
+addx6748 add  1    -0     ->  1
+
+addx6751 add  0.0  -1     -> -1.0
+addx6752 add -0.0  -1     -> -1.0
+addx6753 add  0.0   1     ->  1.0
+addx6754 add -0.0   1     ->  1.0
+addx6755 add -1.0   0     -> -1.0
+addx6756 add -1.0  -0     -> -1.0
+addx6757 add  1.0   0     ->  1.0
+addx6758 add  1.0  -0     ->  1.0
+
+addx6761 add  0    -1.0   -> -1.0
+addx6762 add -0    -1.0   -> -1.0
+addx6763 add  0     1.0   ->  1.0
+addx6764 add -0     1.0   ->  1.0
+addx6765 add -1     0.0   -> -1.0
+addx6766 add -1    -0.0   -> -1.0
+addx6767 add  1     0.0   ->  1.0
+addx6768 add  1    -0.0   ->  1.0
+
+addx6771 add  0.0  -1.0   -> -1.0
+addx6772 add -0.0  -1.0   -> -1.0
+addx6773 add  0.0   1.0   ->  1.0
+addx6774 add -0.0   1.0   ->  1.0
+addx6775 add -1.0   0.0   -> -1.0
+addx6776 add -1.0  -0.0   -> -1.0
+addx6777 add  1.0   0.0   ->  1.0
+addx6778 add  1.0  -0.0   ->  1.0
+
+-- Specials
+addx6780 add -Inf  -Inf   -> -Infinity
+addx6781 add -Inf  -1000  -> -Infinity
+addx6782 add -Inf  -1     -> -Infinity
+addx6783 add -Inf  -0     -> -Infinity
+addx6784 add -Inf   0     -> -Infinity
+addx6785 add -Inf   1     -> -Infinity
+addx6786 add -Inf   1000  -> -Infinity
+addx6787 add -1000 -Inf   -> -Infinity
+addx6788 add -Inf  -Inf   -> -Infinity
+addx6789 add -1    -Inf   -> -Infinity
+addx6790 add -0    -Inf   -> -Infinity
+addx6791 add  0    -Inf   -> -Infinity
+addx6792 add  1    -Inf   -> -Infinity
+addx6793 add  1000 -Inf   -> -Infinity
+addx6794 add  Inf  -Inf   ->  NaN  Invalid_operation
+
+addx6800 add  Inf  -Inf   ->  NaN  Invalid_operation
+addx6801 add  Inf  -1000  ->  Infinity
+addx6802 add  Inf  -1     ->  Infinity
+addx6803 add  Inf  -0     ->  Infinity
+addx6804 add  Inf   0     ->  Infinity
+addx6805 add  Inf   1     ->  Infinity
+addx6806 add  Inf   1000  ->  Infinity
+addx6807 add  Inf   Inf   ->  Infinity
+addx6808 add -1000  Inf   ->  Infinity
+addx6809 add -Inf   Inf   ->  NaN  Invalid_operation
+addx6810 add -1     Inf   ->  Infinity
+addx6811 add -0     Inf   ->  Infinity
+addx6812 add  0     Inf   ->  Infinity
+addx6813 add  1     Inf   ->  Infinity
+addx6814 add  1000  Inf   ->  Infinity
+addx6815 add  Inf   Inf   ->  Infinity
+
+addx6821 add  NaN -Inf    ->  NaN
+addx6822 add  NaN -1000   ->  NaN
+addx6823 add  NaN -1      ->  NaN
+addx6824 add  NaN -0      ->  NaN
+addx6825 add  NaN  0      ->  NaN
+addx6826 add  NaN  1      ->  NaN
+addx6827 add  NaN  1000   ->  NaN
+addx6828 add  NaN  Inf    ->  NaN
+addx6829 add  NaN  NaN    ->  NaN
+addx6830 add -Inf  NaN    ->  NaN
+addx6831 add -1000 NaN    ->  NaN
+addx6832 add -1    NaN    ->  NaN
+addx6833 add -0    NaN    ->  NaN
+addx6834 add  0    NaN    ->  NaN
+addx6835 add  1    NaN    ->  NaN
+addx6836 add  1000 NaN    ->  NaN
+addx6837 add  Inf  NaN    ->  NaN
+
+addx6841 add  sNaN -Inf   ->  NaN  Invalid_operation
+addx6842 add  sNaN -1000  ->  NaN  Invalid_operation
+addx6843 add  sNaN -1     ->  NaN  Invalid_operation
+addx6844 add  sNaN -0     ->  NaN  Invalid_operation
+addx6845 add  sNaN  0     ->  NaN  Invalid_operation
+addx6846 add  sNaN  1     ->  NaN  Invalid_operation
+addx6847 add  sNaN  1000  ->  NaN  Invalid_operation
+addx6848 add  sNaN  NaN   ->  NaN  Invalid_operation
+addx6849 add  sNaN sNaN   ->  NaN  Invalid_operation
+addx6850 add  NaN  sNaN   ->  NaN  Invalid_operation
+addx6851 add -Inf  sNaN   ->  NaN  Invalid_operation
+addx6852 add -1000 sNaN   ->  NaN  Invalid_operation
+addx6853 add -1    sNaN   ->  NaN  Invalid_operation
+addx6854 add -0    sNaN   ->  NaN  Invalid_operation
+addx6855 add  0    sNaN   ->  NaN  Invalid_operation
+addx6856 add  1    sNaN   ->  NaN  Invalid_operation
+addx6857 add  1000 sNaN   ->  NaN  Invalid_operation
+addx6858 add  Inf  sNaN   ->  NaN  Invalid_operation
+addx6859 add  NaN  sNaN   ->  NaN  Invalid_operation
+
+-- propagating NaNs
+addx6861 add  NaN1   -Inf    ->  NaN1
+addx6862 add +NaN2   -1000   ->  NaN2
+addx6863 add  NaN3    1000   ->  NaN3
+addx6864 add  NaN4    Inf    ->  NaN4
+addx6865 add  NaN5   +NaN6   ->  NaN5
+addx6866 add -Inf     NaN7   ->  NaN7
+addx6867 add -1000    NaN8   ->  NaN8
+addx6868 add  1000    NaN9   ->  NaN9
+addx6869 add  Inf    +NaN10  ->  NaN10
+addx6871 add  sNaN11  -Inf   ->  NaN11  Invalid_operation
+addx6872 add  sNaN12  -1000  ->  NaN12  Invalid_operation
+addx6873 add  sNaN13   1000  ->  NaN13  Invalid_operation
+addx6874 add  sNaN14   NaN17 ->  NaN14  Invalid_operation
+addx6875 add  sNaN15  sNaN18 ->  NaN15  Invalid_operation
+addx6876 add  NaN16   sNaN19 ->  NaN19  Invalid_operation
+addx6877 add -Inf    +sNaN20 ->  NaN20  Invalid_operation
+addx6878 add -1000    sNaN21 ->  NaN21  Invalid_operation
+addx6879 add  1000    sNaN22 ->  NaN22  Invalid_operation
+addx6880 add  Inf     sNaN23 ->  NaN23  Invalid_operation
+addx6881 add +NaN25  +sNaN24 ->  NaN24  Invalid_operation
+addx6882 add -NaN26    NaN28 -> -NaN26
+addx6883 add -sNaN27  sNaN29 -> -NaN27  Invalid_operation
+addx6884 add  1000    -NaN30 -> -NaN30
+addx6885 add  1000   -sNaN31 -> -NaN31  Invalid_operation
+
+-- now the case where we can get underflow but the result is normal
+-- [note this can't happen if the operands are also bounded, as we
+-- cannot represent 1E-399, for example]
+
+addx6571 add       1E-383       0  -> 1E-383
+addx6572 add       1E-384       0  -> 1E-384   Subnormal
+addx6573 add       1E-383  1E-384  -> 1.1E-383
+addx6574 subtract  1E-383  1E-384  ->   9E-384 Subnormal
+
+-- Here we explore the boundary of rounding a subnormal to Nmin
+addx6575 subtract  1E-383  1E-398  ->   9.99999999999999E-384  Subnormal
+addx6576 subtract  1E-383  1E-398  ->   9.99999999999999E-384  Subnormal
+addx6577 subtract  1E-383  1E-399  ->   1.000000000000000E-383 Underflow Inexact Subnormal Rounded
+addx6578 subtract  1E-383  1E-400  ->   1.000000000000000E-383 Underflow Inexact Subnormal Rounded
+addx6579 subtract  1E-383  1E-401  ->   1.000000000000000E-383 Underflow Inexact Subnormal Rounded
+addx6580 subtract  1E-383  1E-402  ->   1.000000000000000E-383 Underflow Inexact Subnormal Rounded
+
+-- check overflow edge case
+--               1234567890123456
+addx6972 apply   9.999999999999999E+384         -> 9.999999999999999E+384
+addx6973 add     9.999999999999999E+384  1      -> 9.999999999999999E+384 Inexact Rounded
+addx6974 add      9999999999999999E+369  1      -> 9.999999999999999E+384 Inexact Rounded
+addx6975 add      9999999999999999E+369  1E+369  -> Infinity Overflow Inexact Rounded
+addx6976 add      9999999999999999E+369  9E+368  -> Infinity Overflow Inexact Rounded
+addx6977 add      9999999999999999E+369  8E+368  -> Infinity Overflow Inexact Rounded
+addx6978 add      9999999999999999E+369  7E+368  -> Infinity Overflow Inexact Rounded
+addx6979 add      9999999999999999E+369  6E+368  -> Infinity Overflow Inexact Rounded
+addx6980 add      9999999999999999E+369  5E+368  -> Infinity Overflow Inexact Rounded
+addx6981 add      9999999999999999E+369  4E+368  -> 9.999999999999999E+384 Inexact Rounded
+addx6982 add      9999999999999999E+369  3E+368  -> 9.999999999999999E+384 Inexact Rounded
+addx6983 add      9999999999999999E+369  2E+368  -> 9.999999999999999E+384 Inexact Rounded
+addx6984 add      9999999999999999E+369  1E+368  -> 9.999999999999999E+384 Inexact Rounded
+
+addx6985 apply  -9.999999999999999E+384         -> -9.999999999999999E+384
+addx6986 add    -9.999999999999999E+384 -1      -> -9.999999999999999E+384 Inexact Rounded
+addx6987 add     -9999999999999999E+369 -1      -> -9.999999999999999E+384 Inexact Rounded
+addx6988 add     -9999999999999999E+369 -1E+369  -> -Infinity Overflow Inexact Rounded
+addx6989 add     -9999999999999999E+369 -9E+368  -> -Infinity Overflow Inexact Rounded
+addx6990 add     -9999999999999999E+369 -8E+368  -> -Infinity Overflow Inexact Rounded
+addx6991 add     -9999999999999999E+369 -7E+368  -> -Infinity Overflow Inexact Rounded
+addx6992 add     -9999999999999999E+369 -6E+368  -> -Infinity Overflow Inexact Rounded
+addx6993 add     -9999999999999999E+369 -5E+368  -> -Infinity Overflow Inexact Rounded
+addx6994 add     -9999999999999999E+369 -4E+368  -> -9.999999999999999E+384 Inexact Rounded
+addx6995 add     -9999999999999999E+369 -3E+368  -> -9.999999999999999E+384 Inexact Rounded
+addx6996 add     -9999999999999999E+369 -2E+368  -> -9.999999999999999E+384 Inexact Rounded
+addx6997 add     -9999999999999999E+369 -1E+368  -> -9.999999999999999E+384 Inexact Rounded
+
+-- And for round down full and subnormal results
+rounding:     down
+addx61100 add 1e+2 -1e-383    -> 99.99999999999999 Rounded Inexact
+addx61101 add 1e+1 -1e-383    -> 9.999999999999999  Rounded Inexact
+addx61103 add   +1 -1e-383    -> 0.9999999999999999  Rounded Inexact
+addx61104 add 1e-1 -1e-383    -> 0.09999999999999999  Rounded Inexact
+addx61105 add 1e-2 -1e-383    -> 0.009999999999999999  Rounded Inexact
+addx61106 add 1e-3 -1e-383    -> 0.0009999999999999999  Rounded Inexact
+addx61107 add 1e-4 -1e-383    -> 0.00009999999999999999  Rounded Inexact
+addx61108 add 1e-5 -1e-383    -> 0.000009999999999999999  Rounded Inexact
+addx61109 add 1e-6 -1e-383    -> 9.999999999999999E-7  Rounded Inexact
+
+rounding:     ceiling
+addx61110 add -1e+2 +1e-383   -> -99.99999999999999 Rounded Inexact
+addx61111 add -1e+1 +1e-383   -> -9.999999999999999  Rounded Inexact
+addx61113 add    -1 +1e-383   -> -0.9999999999999999  Rounded Inexact
+addx61114 add -1e-1 +1e-383   -> -0.09999999999999999  Rounded Inexact
+addx61115 add -1e-2 +1e-383   -> -0.009999999999999999  Rounded Inexact
+addx61116 add -1e-3 +1e-383   -> -0.0009999999999999999  Rounded Inexact
+addx61117 add -1e-4 +1e-383   -> -0.00009999999999999999  Rounded Inexact
+addx61118 add -1e-5 +1e-383   -> -0.000009999999999999999  Rounded Inexact
+addx61119 add -1e-6 +1e-383   -> -9.999999999999999E-7  Rounded Inexact
+
+-- tests based on Gunnar Degnbol's edge case
+rounding:     half_even
+
+addx61300 add 1E16  -0.5                 ->  1.000000000000000E+16 Inexact Rounded
+addx61310 add 1E16  -0.51                ->  9999999999999999      Inexact Rounded
+addx61311 add 1E16  -0.501               ->  9999999999999999      Inexact Rounded
+addx61312 add 1E16  -0.5001              ->  9999999999999999      Inexact Rounded
+addx61313 add 1E16  -0.50001             ->  9999999999999999      Inexact Rounded
+addx61314 add 1E16  -0.500001            ->  9999999999999999      Inexact Rounded
+addx61315 add 1E16  -0.5000001           ->  9999999999999999      Inexact Rounded
+addx61316 add 1E16  -0.50000001          ->  9999999999999999      Inexact Rounded
+addx61317 add 1E16  -0.500000001         ->  9999999999999999      Inexact Rounded
+addx61318 add 1E16  -0.5000000001        ->  9999999999999999      Inexact Rounded
+addx61319 add 1E16  -0.50000000001       ->  9999999999999999      Inexact Rounded
+addx61320 add 1E16  -0.500000000001      ->  9999999999999999      Inexact Rounded
+addx61321 add 1E16  -0.5000000000001     ->  9999999999999999      Inexact Rounded
+addx61322 add 1E16  -0.50000000000001    ->  9999999999999999      Inexact Rounded
+addx61323 add 1E16  -0.500000000000001   ->  9999999999999999      Inexact Rounded
+addx61324 add 1E16  -0.5000000000000001  ->  9999999999999999      Inexact Rounded
+addx61325 add 1E16  -0.5000000000000000  ->  1.000000000000000E+16 Inexact Rounded
+addx61326 add 1E16  -0.500000000000000   ->  1.000000000000000E+16 Inexact Rounded
+addx61327 add 1E16  -0.50000000000000    ->  1.000000000000000E+16 Inexact Rounded
+addx61328 add 1E16  -0.5000000000000     ->  1.000000000000000E+16 Inexact Rounded
+addx61329 add 1E16  -0.500000000000      ->  1.000000000000000E+16 Inexact Rounded
+addx61330 add 1E16  -0.50000000000       ->  1.000000000000000E+16 Inexact Rounded
+addx61331 add 1E16  -0.5000000000        ->  1.000000000000000E+16 Inexact Rounded
+addx61332 add 1E16  -0.500000000         ->  1.000000000000000E+16 Inexact Rounded
+addx61333 add 1E16  -0.50000000          ->  1.000000000000000E+16 Inexact Rounded
+addx61334 add 1E16  -0.5000000           ->  1.000000000000000E+16 Inexact Rounded
+addx61335 add 1E16  -0.500000            ->  1.000000000000000E+16 Inexact Rounded
+addx61336 add 1E16  -0.50000             ->  1.000000000000000E+16 Inexact Rounded
+addx61337 add 1E16  -0.5000              ->  1.000000000000000E+16 Inexact Rounded
+addx61338 add 1E16  -0.500               ->  1.000000000000000E+16 Inexact Rounded
+addx61339 add 1E16  -0.50                ->  1.000000000000000E+16 Inexact Rounded
+
+addx61340 add 1E16  -5000000.000010001   ->  9999999995000000      Inexact Rounded
+addx61341 add 1E16  -5000000.000000001   ->  9999999995000000      Inexact Rounded
+
+addx61349 add 9999999999999999 0.4                 ->  9999999999999999      Inexact Rounded
+addx61350 add 9999999999999999 0.49                ->  9999999999999999      Inexact Rounded
+addx61351 add 9999999999999999 0.499               ->  9999999999999999      Inexact Rounded
+addx61352 add 9999999999999999 0.4999              ->  9999999999999999      Inexact Rounded
+addx61353 add 9999999999999999 0.49999             ->  9999999999999999      Inexact Rounded
+addx61354 add 9999999999999999 0.499999            ->  9999999999999999      Inexact Rounded
+addx61355 add 9999999999999999 0.4999999           ->  9999999999999999      Inexact Rounded
+addx61356 add 9999999999999999 0.49999999          ->  9999999999999999      Inexact Rounded
+addx61357 add 9999999999999999 0.499999999         ->  9999999999999999      Inexact Rounded
+addx61358 add 9999999999999999 0.4999999999        ->  9999999999999999      Inexact Rounded
+addx61359 add 9999999999999999 0.49999999999       ->  9999999999999999      Inexact Rounded
+addx61360 add 9999999999999999 0.499999999999      ->  9999999999999999      Inexact Rounded
+addx61361 add 9999999999999999 0.4999999999999     ->  9999999999999999      Inexact Rounded
+addx61362 add 9999999999999999 0.49999999999999    ->  9999999999999999      Inexact Rounded
+addx61363 add 9999999999999999 0.499999999999999   ->  9999999999999999      Inexact Rounded
+addx61364 add 9999999999999999 0.4999999999999999  ->  9999999999999999      Inexact Rounded
+addx61365 add 9999999999999999 0.5000000000000000  ->  1.000000000000000E+16 Inexact Rounded
+addx61367 add 9999999999999999 0.500000000000000   ->  1.000000000000000E+16 Inexact Rounded
+addx61368 add 9999999999999999 0.50000000000000    ->  1.000000000000000E+16 Inexact Rounded
+addx61369 add 9999999999999999 0.5000000000000     ->  1.000000000000000E+16 Inexact Rounded
+addx61370 add 9999999999999999 0.500000000000      ->  1.000000000000000E+16 Inexact Rounded
+addx61371 add 9999999999999999 0.50000000000       ->  1.000000000000000E+16 Inexact Rounded
+addx61372 add 9999999999999999 0.5000000000        ->  1.000000000000000E+16 Inexact Rounded
+addx61373 add 9999999999999999 0.500000000         ->  1.000000000000000E+16 Inexact Rounded
+addx61374 add 9999999999999999 0.50000000          ->  1.000000000000000E+16 Inexact Rounded
+addx61375 add 9999999999999999 0.5000000           ->  1.000000000000000E+16 Inexact Rounded
+addx61376 add 9999999999999999 0.500000            ->  1.000000000000000E+16 Inexact Rounded
+addx61377 add 9999999999999999 0.50000             ->  1.000000000000000E+16 Inexact Rounded
+addx61378 add 9999999999999999 0.5000              ->  1.000000000000000E+16 Inexact Rounded
+addx61379 add 9999999999999999 0.500               ->  1.000000000000000E+16 Inexact Rounded
+addx61380 add 9999999999999999 0.50                ->  1.000000000000000E+16 Inexact Rounded
+addx61381 add 9999999999999999 0.5                 ->  1.000000000000000E+16 Inexact Rounded
+addx61382 add 9999999999999999 0.5000000000000001  ->  1.000000000000000E+16 Inexact Rounded
+addx61383 add 9999999999999999 0.500000000000001   ->  1.000000000000000E+16 Inexact Rounded
+addx61384 add 9999999999999999 0.50000000000001    ->  1.000000000000000E+16 Inexact Rounded
+addx61385 add 9999999999999999 0.5000000000001     ->  1.000000000000000E+16 Inexact Rounded
+addx61386 add 9999999999999999 0.500000000001      ->  1.000000000000000E+16 Inexact Rounded
+addx61387 add 9999999999999999 0.50000000001       ->  1.000000000000000E+16 Inexact Rounded
+addx61388 add 9999999999999999 0.5000000001        ->  1.000000000000000E+16 Inexact Rounded
+addx61389 add 9999999999999999 0.500000001         ->  1.000000000000000E+16 Inexact Rounded
+addx61390 add 9999999999999999 0.50000001          ->  1.000000000000000E+16 Inexact Rounded
+addx61391 add 9999999999999999 0.5000001           ->  1.000000000000000E+16 Inexact Rounded
+addx61392 add 9999999999999999 0.500001            ->  1.000000000000000E+16 Inexact Rounded
+addx61393 add 9999999999999999 0.50001             ->  1.000000000000000E+16 Inexact Rounded
+addx61394 add 9999999999999999 0.5001              ->  1.000000000000000E+16 Inexact Rounded
+addx61395 add 9999999999999999 0.501               ->  1.000000000000000E+16 Inexact Rounded
+addx61396 add 9999999999999999 0.51                ->  1.000000000000000E+16 Inexact Rounded
+
+-- More GD edge cases, where difference between the unadjusted
+-- exponents is larger than the maximum precision and one side is 0
+addx61420 add  0 1.123456789012345     -> 1.123456789012345
+addx61421 add  0 1.123456789012345E-1  -> 0.1123456789012345
+addx61422 add  0 1.123456789012345E-2  -> 0.01123456789012345
+addx61423 add  0 1.123456789012345E-3  -> 0.001123456789012345
+addx61424 add  0 1.123456789012345E-4  -> 0.0001123456789012345
+addx61425 add  0 1.123456789012345E-5  -> 0.00001123456789012345
+addx61426 add  0 1.123456789012345E-6  -> 0.000001123456789012345
+addx61427 add  0 1.123456789012345E-7  -> 1.123456789012345E-7
+addx61428 add  0 1.123456789012345E-8  -> 1.123456789012345E-8
+addx61429 add  0 1.123456789012345E-9  -> 1.123456789012345E-9
+addx61430 add  0 1.123456789012345E-10 -> 1.123456789012345E-10
+addx61431 add  0 1.123456789012345E-11 -> 1.123456789012345E-11
+addx61432 add  0 1.123456789012345E-12 -> 1.123456789012345E-12
+addx61433 add  0 1.123456789012345E-13 -> 1.123456789012345E-13
+addx61434 add  0 1.123456789012345E-14 -> 1.123456789012345E-14
+addx61435 add  0 1.123456789012345E-15 -> 1.123456789012345E-15
+addx61436 add  0 1.123456789012345E-16 -> 1.123456789012345E-16
+addx61437 add  0 1.123456789012345E-17 -> 1.123456789012345E-17
+addx61438 add  0 1.123456789012345E-18 -> 1.123456789012345E-18
+addx61439 add  0 1.123456789012345E-19 -> 1.123456789012345E-19
+
+-- same, reversed 0
+addx61440 add 1.123456789012345     0 -> 1.123456789012345
+addx61441 add 1.123456789012345E-1  0 -> 0.1123456789012345
+addx61442 add 1.123456789012345E-2  0 -> 0.01123456789012345
+addx61443 add 1.123456789012345E-3  0 -> 0.001123456789012345
+addx61444 add 1.123456789012345E-4  0 -> 0.0001123456789012345
+addx61445 add 1.123456789012345E-5  0 -> 0.00001123456789012345
+addx61446 add 1.123456789012345E-6  0 -> 0.000001123456789012345
+addx61447 add 1.123456789012345E-7  0 -> 1.123456789012345E-7
+addx61448 add 1.123456789012345E-8  0 -> 1.123456789012345E-8
+addx61449 add 1.123456789012345E-9  0 -> 1.123456789012345E-9
+addx61450 add 1.123456789012345E-10 0 -> 1.123456789012345E-10
+addx61451 add 1.123456789012345E-11 0 -> 1.123456789012345E-11
+addx61452 add 1.123456789012345E-12 0 -> 1.123456789012345E-12
+addx61453 add 1.123456789012345E-13 0 -> 1.123456789012345E-13
+addx61454 add 1.123456789012345E-14 0 -> 1.123456789012345E-14
+addx61455 add 1.123456789012345E-15 0 -> 1.123456789012345E-15
+addx61456 add 1.123456789012345E-16 0 -> 1.123456789012345E-16
+addx61457 add 1.123456789012345E-17 0 -> 1.123456789012345E-17
+addx61458 add 1.123456789012345E-18 0 -> 1.123456789012345E-18
+addx61459 add 1.123456789012345E-19 0 -> 1.123456789012345E-19
+
+-- same, Es on the 0
+addx61460 add 1.123456789012345  0E-0   -> 1.123456789012345
+addx61461 add 1.123456789012345  0E-1   -> 1.123456789012345
+addx61462 add 1.123456789012345  0E-2   -> 1.123456789012345
+addx61463 add 1.123456789012345  0E-3   -> 1.123456789012345
+addx61464 add 1.123456789012345  0E-4   -> 1.123456789012345
+addx61465 add 1.123456789012345  0E-5   -> 1.123456789012345
+addx61466 add 1.123456789012345  0E-6   -> 1.123456789012345
+addx61467 add 1.123456789012345  0E-7   -> 1.123456789012345
+addx61468 add 1.123456789012345  0E-8   -> 1.123456789012345
+addx61469 add 1.123456789012345  0E-9   -> 1.123456789012345
+addx61470 add 1.123456789012345  0E-10  -> 1.123456789012345
+addx61471 add 1.123456789012345  0E-11  -> 1.123456789012345
+addx61472 add 1.123456789012345  0E-12  -> 1.123456789012345
+addx61473 add 1.123456789012345  0E-13  -> 1.123456789012345
+addx61474 add 1.123456789012345  0E-14  -> 1.123456789012345
+addx61475 add 1.123456789012345  0E-15  -> 1.123456789012345
+-- next four flag Rounded because the 0 extends the result
+addx61476 add 1.123456789012345  0E-16  -> 1.123456789012345 Rounded
+addx61477 add 1.123456789012345  0E-17  -> 1.123456789012345 Rounded
+addx61478 add 1.123456789012345  0E-18  -> 1.123456789012345 Rounded
+addx61479 add 1.123456789012345  0E-19  -> 1.123456789012345 Rounded
+
+-- sum of two opposite-sign operands is exactly 0 and floor => -0
+rounding:    half_up
+-- exact zeros from zeros
+addx61500 add  0        0E-19  ->  0E-19
+addx61501 add -0        0E-19  ->  0E-19
+addx61502 add  0       -0E-19  ->  0E-19
+addx61503 add -0       -0E-19  -> -0E-19
+addx61504 add  0E-400   0E-19  ->  0E-398 Clamped
+addx61505 add -0E-400   0E-19  ->  0E-398 Clamped
+addx61506 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx61507 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx61511 add  1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61512 add -1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61513 add  1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61514 add -1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+-- some exact zeros from non-zeros
+addx61515 add  1E-401   1E-401 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61516 add -1E-401   1E-401 ->  0E-398 Clamped
+addx61517 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx61518 add -1E-401  -1E-401 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+
+rounding:    half_down
+-- exact zeros from zeros
+addx61520 add  0        0E-19  ->  0E-19
+addx61521 add -0        0E-19  ->  0E-19
+addx61522 add  0       -0E-19  ->  0E-19
+addx61523 add -0       -0E-19  -> -0E-19
+addx61524 add  0E-400   0E-19  ->  0E-398 Clamped
+addx61525 add -0E-400   0E-19  ->  0E-398 Clamped
+addx61526 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx61527 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx61531 add  1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61532 add -1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61533 add  1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61534 add -1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+-- some exact zeros from non-zeros
+addx61535 add  1E-401   1E-401 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61536 add -1E-401   1E-401 ->  0E-398 Clamped
+addx61537 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx61538 add -1E-401  -1E-401 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+
+rounding:    half_even
+-- exact zeros from zeros
+addx61540 add  0        0E-19  ->  0E-19
+addx61541 add -0        0E-19  ->  0E-19
+addx61542 add  0       -0E-19  ->  0E-19
+addx61543 add -0       -0E-19  -> -0E-19
+addx61544 add  0E-400   0E-19  ->  0E-398 Clamped
+addx61545 add -0E-400   0E-19  ->  0E-398 Clamped
+addx61546 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx61547 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx61551 add  1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61552 add -1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61553 add  1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61554 add -1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+-- some exact zeros from non-zeros
+addx61555 add  1E-401   1E-401 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61556 add -1E-401   1E-401 ->  0E-398 Clamped
+addx61557 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx61558 add -1E-401  -1E-401 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+
+rounding:    up
+-- exact zeros from zeros
+addx61560 add  0        0E-19  ->  0E-19
+addx61561 add -0        0E-19  ->  0E-19
+addx61562 add  0       -0E-19  ->  0E-19
+addx61563 add -0       -0E-19  -> -0E-19
+addx61564 add  0E-400   0E-19  ->  0E-398 Clamped
+addx61565 add -0E-400   0E-19  ->  0E-398 Clamped
+addx61566 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx61567 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx61571 add  1E-401   1E-400 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx61572 add -1E-401   1E-400 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx61573 add  1E-401  -1E-400 -> -1E-398 Subnormal Inexact Rounded Underflow
+addx61574 add -1E-401  -1E-400 -> -1E-398 Subnormal Inexact Rounded Underflow
+-- some exact zeros from non-zeros
+addx61575 add  1E-401   1E-401 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx61576 add -1E-401   1E-401 ->  0E-398 Clamped
+addx61577 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx61578 add -1E-401  -1E-401 -> -1E-398 Subnormal Inexact Rounded Underflow
+
+rounding:    down
+-- exact zeros from zeros
+addx61580 add  0        0E-19  ->  0E-19
+addx61581 add -0        0E-19  ->  0E-19
+addx61582 add  0       -0E-19  ->  0E-19
+addx61583 add -0       -0E-19  -> -0E-19
+addx61584 add  0E-400   0E-19  ->  0E-398 Clamped
+addx61585 add -0E-400   0E-19  ->  0E-398 Clamped
+addx61586 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx61587 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx61591 add  1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61592 add -1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61593 add  1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61594 add -1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+-- some exact zeros from non-zeros
+addx61595 add  1E-401   1E-401 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61596 add -1E-401   1E-401 ->  0E-398 Clamped
+addx61597 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx61598 add -1E-401  -1E-401 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+
+rounding:    ceiling
+-- exact zeros from zeros
+addx61600 add  0        0E-19  ->  0E-19
+addx61601 add -0        0E-19  ->  0E-19
+addx61602 add  0       -0E-19  ->  0E-19
+addx61603 add -0       -0E-19  -> -0E-19
+addx61604 add  0E-400   0E-19  ->  0E-398 Clamped
+addx61605 add -0E-400   0E-19  ->  0E-398 Clamped
+addx61606 add  0E-400  -0E-19  ->  0E-398 Clamped
+addx61607 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx61611 add  1E-401   1E-400 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx61612 add -1E-401   1E-400 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx61613 add  1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61614 add -1E-401  -1E-400 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+-- some exact zeros from non-zeros
+addx61615 add  1E-401   1E-401 ->  1E-398 Subnormal Inexact Rounded Underflow
+addx61616 add -1E-401   1E-401 ->  0E-398 Clamped
+addx61617 add  1E-401  -1E-401 ->  0E-398 Clamped
+addx61618 add -1E-401  -1E-401 -> -0E-398 Subnormal Inexact Rounded Underflow Clamped
+
+-- and the extra-special ugly case; unusual minuses marked by -- *
+rounding:    floor
+-- exact zeros from zeros
+addx61620 add  0        0E-19  ->  0E-19
+addx61621 add -0        0E-19  -> -0E-19           -- *
+addx61622 add  0       -0E-19  -> -0E-19           -- *
+addx61623 add -0       -0E-19  -> -0E-19
+addx61624 add  0E-400   0E-19  ->  0E-398 Clamped
+addx61625 add -0E-400   0E-19  -> -0E-398 Clamped  -- *
+addx61626 add  0E-400  -0E-19  -> -0E-398 Clamped  -- *
+addx61627 add -0E-400  -0E-19  -> -0E-398 Clamped
+-- inexact zeros
+addx61631 add  1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61632 add -1E-401   1E-400 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61633 add  1E-401  -1E-400 -> -1E-398 Subnormal Inexact Rounded Underflow
+addx61634 add -1E-401  -1E-400 -> -1E-398 Subnormal Inexact Rounded Underflow
+-- some exact zeros from non-zeros
+addx61635 add  1E-401   1E-401 ->  0E-398 Subnormal Inexact Rounded Underflow Clamped
+addx61636 add -1E-401   1E-401 -> -0E-398 Clamped  -- *
+addx61637 add  1E-401  -1E-401 -> -0E-398 Clamped  -- *
+addx61638 add -1E-401  -1E-401 -> -1E-398 Subnormal Inexact Rounded Underflow
+
+-- Examples from SQL proposal (Krishna Kulkarni)
+addx61701 add 130E-2    120E-2    -> 2.50
+addx61702 add 130E-2    12E-1     -> 2.50
+addx61703 add 130E-2    1E0       -> 2.30
+addx61704 add 1E2       1E4       -> 1.01E+4
+addx61705 subtract 130E-2  120E-2 -> 0.10
+addx61706 subtract 130E-2  12E-1  -> 0.10
+addx61707 subtract 130E-2  1E0    -> 0.30
+addx61708 subtract 1E2     1E4    -> -9.9E+3
+
+-- Gappy coefficients; check residue handling even with full coefficient gap
+rounding: half_even
+
+addx62001 add 1234567890123456 1      -> 1234567890123457
+addx62002 add 1234567890123456 0.6    -> 1234567890123457  Inexact Rounded
+addx62003 add 1234567890123456 0.06   -> 1234567890123456  Inexact Rounded
+addx62004 add 1234567890123456 6E-3   -> 1234567890123456  Inexact Rounded
+addx62005 add 1234567890123456 6E-4   -> 1234567890123456  Inexact Rounded
+addx62006 add 1234567890123456 6E-5   -> 1234567890123456  Inexact Rounded
+addx62007 add 1234567890123456 6E-6   -> 1234567890123456  Inexact Rounded
+addx62008 add 1234567890123456 6E-7   -> 1234567890123456  Inexact Rounded
+addx62009 add 1234567890123456 6E-8   -> 1234567890123456  Inexact Rounded
+addx62010 add 1234567890123456 6E-9   -> 1234567890123456  Inexact Rounded
+addx62011 add 1234567890123456 6E-10  -> 1234567890123456  Inexact Rounded
+addx62012 add 1234567890123456 6E-11  -> 1234567890123456  Inexact Rounded
+addx62013 add 1234567890123456 6E-12  -> 1234567890123456  Inexact Rounded
+addx62014 add 1234567890123456 6E-13  -> 1234567890123456  Inexact Rounded
+addx62015 add 1234567890123456 6E-14  -> 1234567890123456  Inexact Rounded
+addx62016 add 1234567890123456 6E-15  -> 1234567890123456  Inexact Rounded
+addx62017 add 1234567890123456 6E-16  -> 1234567890123456  Inexact Rounded
+addx62018 add 1234567890123456 6E-17  -> 1234567890123456  Inexact Rounded
+addx62019 add 1234567890123456 6E-18  -> 1234567890123456  Inexact Rounded
+addx62020 add 1234567890123456 6E-19  -> 1234567890123456  Inexact Rounded
+addx62021 add 1234567890123456 6E-20  -> 1234567890123456  Inexact Rounded
+
+-- widening second argument at gap
+addx62030 add 12345678 1                       -> 12345679
+addx62031 add 12345678 0.1                     -> 12345678.1
+addx62032 add 12345678 0.12                    -> 12345678.12
+addx62033 add 12345678 0.123                   -> 12345678.123
+addx62034 add 12345678 0.1234                  -> 12345678.1234
+addx62035 add 12345678 0.12345                 -> 12345678.12345
+addx62036 add 12345678 0.123456                -> 12345678.123456
+addx62037 add 12345678 0.1234567               -> 12345678.1234567
+addx62038 add 12345678 0.12345678              -> 12345678.12345678
+addx62039 add 12345678 0.123456789             -> 12345678.12345679 Inexact Rounded
+addx62040 add 12345678 0.123456785             -> 12345678.12345678 Inexact Rounded
+addx62041 add 12345678 0.1234567850            -> 12345678.12345678 Inexact Rounded
+addx62042 add 12345678 0.1234567851            -> 12345678.12345679 Inexact Rounded
+addx62043 add 12345678 0.12345678501           -> 12345678.12345679 Inexact Rounded
+addx62044 add 12345678 0.123456785001          -> 12345678.12345679 Inexact Rounded
+addx62045 add 12345678 0.1234567850001         -> 12345678.12345679 Inexact Rounded
+addx62046 add 12345678 0.12345678500001        -> 12345678.12345679 Inexact Rounded
+addx62047 add 12345678 0.123456785000001       -> 12345678.12345679 Inexact Rounded
+addx62048 add 12345678 0.1234567850000001      -> 12345678.12345679 Inexact Rounded
+addx62049 add 12345678 0.1234567850000000      -> 12345678.12345678 Inexact Rounded
+--                               90123456
+rounding: half_even
+addx62050 add 12345678 0.0234567750000000      -> 12345678.02345678 Inexact Rounded
+addx62051 add 12345678 0.0034567750000000      -> 12345678.00345678 Inexact Rounded
+addx62052 add 12345678 0.0004567750000000      -> 12345678.00045678 Inexact Rounded
+addx62053 add 12345678 0.0000567750000000      -> 12345678.00005678 Inexact Rounded
+addx62054 add 12345678 0.0000067750000000      -> 12345678.00000678 Inexact Rounded
+addx62055 add 12345678 0.0000007750000000      -> 12345678.00000078 Inexact Rounded
+addx62056 add 12345678 0.0000000750000000      -> 12345678.00000008 Inexact Rounded
+addx62057 add 12345678 0.0000000050000000      -> 12345678.00000000 Inexact Rounded
+addx62060 add 12345678 0.0234567750000001      -> 12345678.02345678 Inexact Rounded
+addx62061 add 12345678 0.0034567750000001      -> 12345678.00345678 Inexact Rounded
+addx62062 add 12345678 0.0004567750000001      -> 12345678.00045678 Inexact Rounded
+addx62063 add 12345678 0.0000567750000001      -> 12345678.00005678 Inexact Rounded
+addx62064 add 12345678 0.0000067750000001      -> 12345678.00000678 Inexact Rounded
+addx62065 add 12345678 0.0000007750000001      -> 12345678.00000078 Inexact Rounded
+addx62066 add 12345678 0.0000000750000001      -> 12345678.00000008 Inexact Rounded
+addx62067 add 12345678 0.0000000050000001      -> 12345678.00000001 Inexact Rounded
+-- far-out residues (full coefficient gap is 16+15 digits)
+rounding: up
+addx62070 add 12345678 1E-8                    -> 12345678.00000001
+addx62071 add 12345678 1E-9                    -> 12345678.00000001 Inexact Rounded
+addx62072 add 12345678 1E-10                   -> 12345678.00000001 Inexact Rounded
+addx62073 add 12345678 1E-11                   -> 12345678.00000001 Inexact Rounded
+addx62074 add 12345678 1E-12                   -> 12345678.00000001 Inexact Rounded
+addx62075 add 12345678 1E-13                   -> 12345678.00000001 Inexact Rounded
+addx62076 add 12345678 1E-14                   -> 12345678.00000001 Inexact Rounded
+addx62077 add 12345678 1E-15                   -> 12345678.00000001 Inexact Rounded
+addx62078 add 12345678 1E-16                   -> 12345678.00000001 Inexact Rounded
+addx62079 add 12345678 1E-17                   -> 12345678.00000001 Inexact Rounded
+addx62080 add 12345678 1E-18                   -> 12345678.00000001 Inexact Rounded
+addx62081 add 12345678 1E-19                   -> 12345678.00000001 Inexact Rounded
+addx62082 add 12345678 1E-20                   -> 12345678.00000001 Inexact Rounded
+addx62083 add 12345678 1E-25                   -> 12345678.00000001 Inexact Rounded
+addx62084 add 12345678 1E-30                   -> 12345678.00000001 Inexact Rounded
+addx62085 add 12345678 1E-31                   -> 12345678.00000001 Inexact Rounded
+addx62086 add 12345678 1E-32                   -> 12345678.00000001 Inexact Rounded
+addx62087 add 12345678 1E-33                   -> 12345678.00000001 Inexact Rounded
+addx62088 add 12345678 1E-34                   -> 12345678.00000001 Inexact Rounded
+addx62089 add 12345678 1E-35                   -> 12345678.00000001 Inexact Rounded
+
+-- payload decapitate
+precision: 5
+addx62100 add      11  sNaN123456789 ->  NaN56789  Invalid_operation
+addx62101 add     -11 -sNaN123456789 -> -NaN56789  Invalid_operation
+addx62102 add      11   NaN123456789 ->  NaN56789
+addx62103 add     -11  -NaN123456789 -> -NaN56789
+
+-- Null tests
+addx9990 add 10  # -> NaN Invalid_operation
+addx9991 add  # 10 -> NaN Invalid_operation