// Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).
// All rights reserved.
// This component and the accompanying materials are made available
// under the terms of the License "Eclipse Public License v1.0"
// which accompanies this distribution, and is available
// at the URL "http://www.eclipse.org/legal/epl-v10.html".
//
// Initial Contributors:
// Nokia Corporation - initial contribution.
//
// Contributors:
//
// Description:
// e32\euser\epoc\x86\uc_realx.cia
//
//
#include "u32std.h"
#include <e32math.h>
void TRealXPanic(TInt aErr);
LOCAL_C __NAKED__ void TRealXPanicEax(void)
{
asm("push eax");
asm("call %a0": : "i"(&TRealXPanic));
}
LOCAL_C __NAKED__ void TRealXRealIndefinite(void)
{
// return 'real indefinite' NaN in ecx,edx:ebx
asm("mov ecx, 0xFFFF0001"); // exponent=FFFF, sign negative
asm("mov edx, 0xC0000000"); // mantissa=C0000000 00000000
asm("xor ebx, ebx");
asm("mov eax, -6"); // return KErrArgument
asm("ret");
}
LOCAL_C __NAKED__ void TRealXBinOpNaN(void)
{
// generic routine to process NaN's in binary operations
// destination operand in ecx,edx:eax
// source operand at [esi]
asm("mov eax, [esi+8]"); // source operand into eax,edi:ebp
asm("mov edi, [esi+4]");
asm("mov ebp, [esi]");
asm("cmp ecx, 0xFFFF0000"); // check if dest is a NaN
asm("jb short TRealXBinOpNaN1"); // if not, swap them
asm("cmp edx, 0x80000000");
asm("jne short TRealXBinOpNaN2");
asm("test ebx, ebx");
asm("jne short TRealXBinOpNaN2");
asm("TRealXBinOpNaN1:"); // swap the operands
asm("xchg ecx, eax");
asm("xchg edx, edi");
asm("xchg ebx, ebp");
asm("TRealXBinOpNaN2:");
asm("cmp eax, 0xFFFF0000"); // check if both operands are NaNs
asm("jb short TRealXBinOpNaN4"); // if not, ignore non-NaN operand
asm("cmp edi, 0x80000000");
asm("jne short TRealXBinOpNaN3");
asm("test ebp, ebp");
asm("je short TRealXBinOpNaN4");
asm("TRealXBinOpNaN3:"); // if both operands are NaN's, compare significands
asm("cmp edx, edi");
asm("ja short TRealXBinOpNaN4");
asm("jb short TRealXBinOpNaN5");
asm("cmp ebx, ebp");
asm("jae short TRealXBinOpNaN4");
asm("TRealXBinOpNaN5:"); // come here if dest is smaller - copy source to dest
asm("mov ecx, eax");
asm("mov edx, edi");
asm("mov ebx, ebp");
asm("TRealXBinOpNaN4:"); // NaN with larger significand is in ecx,edx:ebx
asm("or edx, 0x40000000"); // convert an SNaN to a QNaN
asm("mov eax, -6"); // return KErrArgument
asm("ret");
}
// Add TRealX at [esi] + ecx,edx:ebx
// Result in ecx,edx:ebx
// Error code in eax
// Note: +0 + +0 = +0, -0 + -0 = -0, +0 + -0 = -0 + +0 = +0,
// +/-0 + X = X + +/-0 = X, X + -X = -X + X = +0
LOCAL_C __NAKED__ void TRealXAdd()
{
asm("xor ch, ch"); // clear rounding flags
asm("cmp ecx, 0xFFFF0000"); // check if dest=NaN or infinity
asm("jnc addfpsd"); // branch if it is
asm("mov eax, [esi+8]"); // fetch sign/exponent of source
asm("cmp eax, 0xFFFF0000"); // check if source=NaN or infinity
asm("jnc addfpss"); // branch if it is
asm("cmp eax, 0x10000"); // check if source=0
asm("jc addfp0s"); // branch if it is
asm("cmp ecx, 0x10000"); // check if dest=0
asm("jc addfp0d"); // branch if it is
asm("and cl, 1"); // clear bits 1-7 of ecx
asm("and al, 1"); // clear bits 1-7 of eax
asm("mov ch, cl");
asm("xor ch, al"); // xor of signs into ch bit 0
asm("add ch, ch");
asm("or cl, ch"); // and into cl bit 1
asm("or al, ch"); // and al bit 1
asm("xor ch, ch"); // clear rounding flags
asm("mov ebp, [esi]"); // fetch source mantissa 0-31
asm("mov edi, [esi+4]"); // fetch source mantissa 32-63
asm("ror ecx, 16"); // dest exponent into cx
asm("ror eax, 16"); // source exponent into ax
asm("push ecx"); // push dest exponent/sign
asm("sub cx, ax"); // cx = dest exponent - source exponent
asm("je short addfp3b"); // if equal, no shifting required
asm("ja short addfp1"); // branch if dest exponent >= source exponent
asm("xchg ebx, ebp"); // make sure edi:ebp contains the mantissa to be shifted
asm("xchg edx, edi");
asm("xchg eax, [esp]"); // and larger exponent and corresponding sign is on the stack
asm("neg cx"); // make cx positive = number of right shifts needed
asm("addfp1:");
asm("cmp cx, 64"); // if more than 64 shifts needed
asm("ja addfp2"); // branch to output larger number
asm("jb addfp3"); // branch if <64 shifts
asm("mov eax, edi"); // exactly 64 shifts needed - rounding word=mant high
asm("test ebp, ebp"); // check bits lost
asm("jz short addfp3a");
asm("or ch, 1"); // if not all zero, set rounded-down flag
asm("addfp3a:");
asm("xor edi, edi"); // clear edx:ebx
asm("xor ebp, ebp");
asm("jmp short addfp5"); // finished shifting
asm("addfp3b:"); // exponents equal
asm("xor eax, eax"); // set rounding word=0
asm("jmp short addfp5");
asm("addfp3:");
asm("cmp cl, 32"); // 32 or more shifts needed ?
asm("jb short addfp4"); // skip if <32
asm("mov eax, ebp"); // rounding word=mant low
asm("mov ebp, edi"); // mant low=mant high
asm("xor edi, edi"); // mant high=0
asm("sub cl, 32"); // reduce count by 32
asm("jz short addfp5"); // if now zero, finished shifting
asm("shrd edi, eax, cl"); // shift ebp:eax:edi right by cl bits
asm("shrd eax, ebp, cl"); //
asm("shr ebp, cl"); //
asm("test edi, edi"); // check bits lost in shift
asm("jz short addfp5"); // if all zero, finished
asm("or ch, 1"); // else set rounded-down flag
asm("xor edi, edi"); // clear edx again
asm("jmp short addfp5"); // finished shifting
asm("addfp4:"); // <32 shifts needed now
asm("xor eax, eax"); // clear rounding word initially
asm("shrd eax, ebp, cl"); // shift edi:ebp:eax right by cl bits
asm("shrd ebp, edi, cl"); //
asm("shr edi, cl"); //
asm("addfp5:");
asm("mov [esp+3], ch"); // rounding flag into ch image on stack
asm("pop ecx"); // recover sign and exponent into ecx, with rounding flag
asm("ror ecx, 16"); // into normal position
asm("test cl, 2"); // addition or subtraction needed ?
asm("jnz short subfp1"); // branch if subtraction
asm("add ebx,ebp"); // addition required - add mantissas
asm("adc edx,edi"); //
asm("jnc short roundfp"); // branch if no carry
asm("rcr edx,1"); // shift carry right into mantissa
asm("rcr ebx,1"); //
asm("rcr eax,1"); // and into rounding word
asm("jnc short addfp5a");
asm("or ch, 1"); // if 1 shifted out, set rounded-down flag
asm("addfp5a:");
asm("add ecx, 0x10000"); // and increment exponent
// perform rounding based on rounding word in eax and rounding flag in ch
asm("roundfp:");
asm("cmp eax, 0x80000000");
asm("jc roundfp0"); // if rounding word<80000000, round down
asm("ja roundfp1"); // if >80000000, round up
asm("test ch, 1");
asm("jnz short roundfp1"); // if rounded-down flag set, round up
asm("test ch, 2");
asm("jnz short roundfp0"); // if rounded-up flag set, round down
asm("test bl, 1"); // else test mantissa lsb
asm("jz short roundfp0"); // round down if 0, up if 1 [round to even]
asm("roundfp1:"); // Come here to round up
asm("add ebx, 1"); // increment mantissa
asm("adc edx,0"); //
asm("jnc roundfp1a"); // if no carry OK
asm("rcr edx,1"); // else shift carry into mantissa [edx:ebx=0 here]
asm("add ecx, 0x10000"); // and increment exponent
asm("roundfp1a:");
asm("cmp ecx, 0xFFFF0000"); // check for overflow
asm("jae short addfpovfw"); // jump if overflow
asm("mov ch, 2"); // else set rounded-up flag
asm("xor eax, eax"); // return KErrNone
asm("ret");
asm("roundfp0:"); // Come here to round down
asm("cmp ecx, 0xFFFF0000"); // check for overflow
asm("jae short addfpovfw"); // jump if overflow
asm("test eax, eax"); // else check if rounding word zero
asm("jz short roundfp0a"); // if so, leave rounding flags as they are
asm("mov ch, 1"); // else set rounded-down flag
asm("roundfp0a:");
asm("xor eax, eax"); // return KErrNone
asm("ret");
asm("addfpovfw:"); // Come here if overflow occurs
asm("xor ch, ch"); // clear rounding flags, exponent=FFFF
asm("xor ebx, ebx");
asm("mov edx, 0x80000000"); // mantissa=80000000 00000000 for infinity
asm("mov eax, -9"); // return KErrOverflow
asm("ret");
// exponents differ by more than 64 - output larger number
asm("addfp2:");
asm("pop ecx"); // recover exponent and sign
asm("ror ecx, 16"); // into normal position
asm("or ch, 1"); // set rounded-down flag
asm("test cl, 2"); // check if signs the same
asm("jz addfp2a");
asm("xor ch, 3"); // if not, set rounded-up flag
asm("addfp2a:");
asm("xor eax, eax"); // return KErrNone
asm("ret");
// signs differ, so must subtract mantissas
asm("subfp1:");
asm("add ch, ch"); // if rounded-down flag set, change it to rounded-up
asm("neg eax"); // subtract rounding word from 0
asm("sbb ebx, ebp"); // and subtract mantissas with borrow
asm("sbb edx, edi"); //
asm("jnc short subfp2"); // if no borrow, sign is correct
asm("xor cl, 1"); // else change sign of result
asm("shr ch, 1"); // change rounding back to rounded-down
asm("not eax"); // negate rounding word
asm("not ebx"); // and mantissa
asm("not edx"); //
asm("add eax,1"); // two's complement negation
asm("adc ebx,0"); //
asm("adc edx,0"); //
asm("subfp2:");
asm("jnz short subfp3"); // branch if edx non-zero at this point
asm("mov edx, ebx"); // else shift ebx into edx
asm("or edx, edx"); //
asm("jz short subfp4"); // if still zero, branch
asm("mov ebx, eax"); // else shift rounding word into ebx
asm("xor eax, eax"); // and zero rounding word
asm("sub ecx, 0x200000"); // decrease exponent by 32 due to shift
asm("jnc short subfp3"); // if no borrow, carry on
asm("jmp short subfpundflw"); // if borrow here, underflow
asm("subfp4:");
asm("mov edx, eax"); // move rounding word into edx
asm("or edx, edx"); // is edx still zero ?
asm("jz short subfp0"); // if so, result is precisely zero
asm("xor ebx, ebx"); // else zero ebx and rounding word
asm("xor eax, eax"); //
asm("sub ecx, 0x400000"); // and decrease exponent by 64 due to shift
asm("jc short subfpundflw"); // if borrow, underflow
asm("subfp3:");
asm("mov edi, ecx"); // preserve sign and exponent
asm("bsr ecx, edx"); // position of most significant 1 into ecx
asm("neg ecx"); //
asm("add ecx, 31"); // cl = 31-position of MS 1 = number of shifts to normalise
asm("shld edx, ebx, cl"); // shift edx:ebx:eax left by cl bits
asm("shld ebx, eax, cl"); //
asm("shl eax, cl"); //
asm("mov ebp, ecx"); // bit count into ebp for subtraction
asm("shl ebp, 16"); // shift left by 16 to align with exponent
asm("mov ecx, edi"); // exponent, sign, rounding flags back into ecx
asm("sub ecx, ebp"); // subtract shift count from exponent
asm("jc short subfpundflw"); // if borrow, underflow
asm("cmp ecx, 0x10000"); // check if exponent 0
asm("jnc roundfp"); // if not, jump to round result, else underflow
// come here if underflow
asm("subfpundflw:");
asm("and ecx, 1"); // set exponent to zero, leave sign
asm("xor edx, edx");
asm("xor ebx, ebx");
asm("mov eax, -10"); // return KErrUnderflow
asm("ret");
// come here to return zero result
asm("subfp0:");
asm("xor ecx, ecx"); // set exponent to zero, positive sign
asm("xor edx, edx");
asm("xor ebx, ebx");
asm("addfp0snzd:");
asm("xor eax, eax"); // return KErrNone
asm("ret");
// come here if source=0 - eax=source exponent/sign
asm("addfp0s:");
asm("cmp ecx, 0x10000"); // check if dest=0
asm("jnc addfp0snzd"); // if not, return dest unaltered
asm("and ecx, eax"); // else both zero, result negative iff both zeros negative
asm("and ecx, 1");
asm("xor eax, eax"); // return KErrNone
asm("ret");
// come here if dest=0, source nonzero
asm("addfp0d:");
asm("mov ebx, [esi]"); // return source unaltered
asm("mov edx, [esi+4]");
asm("mov ecx, [esi+8]");
asm("xor eax, eax"); // return KErrNone
asm("ret");
// come here if dest=NaN or infinity
asm("addfpsd:");
asm("cmp edx, 0x80000000"); // check for infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebx, ebx");
_ASM_jn(e,TRealXBinOpNaN)
asm("mov eax, [esi+8]"); // eax=second operand exponent
asm("cmp eax, 0xFFFF0000"); // check second operand for NaN or infinity
asm("jae short addfpsd1"); // branch if NaN or infinity
asm("addfpsd2:");
asm("mov eax, -9"); // else return dest unaltered [infinity] and KErrOverflow
asm("ret");
asm("addfpsd1:");
asm("mov ebp, [esi]"); // source mantissa into edi:ebp
asm("mov edi, [esi+4]");
asm("cmp edi, 0x80000000"); // check for infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebp, ebp");
_ASM_jn(e,TRealXBinOpNaN)
asm("xor al, cl"); // both operands are infinity - check signs
asm("test al, 1");
asm("jz short addfpsd2"); // if both the same, return KErrOverflow
asm("jmp %a0": : "i"(&TRealXRealIndefinite)); // else return 'real indefinite'
// come here if source=NaN or infinity, dest finite
asm("addfpss:");
asm("mov ebp, [esi]"); // source mantissa into edi:ebp
asm("mov edi, [esi+4]");
asm("cmp edi, 0x80000000"); // check for infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebp, ebp");
_ASM_jn(e,TRealXBinOpNaN)
asm("mov ecx, eax"); // if source=infinity, return source unaltered
asm("mov edx, edi");
asm("mov ebx, ebp");
asm("mov eax, -9"); // return KErrOverflow
asm("ret");
}
// Subtract TRealX at [esi] - ecx,edx:ebx
// Result in ecx,edx:ebx
// Error code in eax
LOCAL_C __NAKED__ void TRealXSubtract()
{
asm("xor cl, 1"); // negate subtrahend
asm("jmp %a0": :"i"(&TRealXAdd));
}
// Multiply TRealX at [esi] * ecx,edx:ebx
// Result in ecx,edx:ebx
// Error code in eax
LOCAL_C __NAKED__ void TRealXMultiply()
{
asm("xor ch, ch"); // clear rounding flags
asm("mov eax, [esi+8]"); // fetch sign/exponent of source
asm("xor cl, al"); // xor signs
asm("cmp ecx, 0xFFFF0000"); // check if dest=NaN or infinity
asm("jnc mulfpsd"); // branch if it is
asm("cmp eax, 0xFFFF0000"); // check if source=NaN or infinity
asm("jnc mulfpss"); // branch if it is
asm("cmp eax, 0x10000"); // check if source=0
asm("jc mulfp0"); // branch if it is
asm("cmp ecx, 0x10000"); // check if dest=0
asm("jc mulfp0"); // branch if it is
asm("push ecx"); // save result sign
asm("shr ecx, 16"); // dest exponent into cx
asm("shr eax, 16"); // source exponent into ax
asm("add eax, ecx"); // add exponents
asm("sub eax, 0x7FFE"); // eax now contains result exponent
asm("push eax"); // save it
asm("mov edi, edx"); // save dest mantissa high
asm("mov eax, ebx"); // dest mantissa low -> eax
asm("mul dword ptr [esi]"); // dest mantissa low * source mantissa low -> edx:eax
asm("xchg ebx, eax"); // result dword 0 -> ebx, dest mant low -> eax
asm("mov ebp, edx"); // result dword 1 -> ebp
asm("mul dword ptr [esi+4]"); // dest mant low * src mant high -> edx:eax
asm("add ebp, eax"); // add in partial product to dwords 1 and 2
asm("adc edx, 0"); //
asm("mov ecx, edx"); // result dword 2 -> ecx
asm("mov eax, edi"); // dest mant high -> eax
asm("mul dword ptr [esi+4]"); // dest mant high * src mant high -> edx:eax
asm("add ecx, eax"); // add in partial product to dwords 2, 3
asm("adc edx, 0"); //
asm("mov eax, edi"); // dest mant high -> eax
asm("mov edi, edx"); // result dword 3 -> edi
asm("mul dword ptr [esi]"); // dest mant high * src mant low -> edx:eax
asm("add ebp, eax"); // add in partial product to dwords 1, 2
asm("adc ecx, edx"); //
asm("adc edi, 0"); // 128-bit mantissa product is now in edi:ecx:ebp:ebx
asm("mov edx, edi"); // top 64 bits into edx:ebx
asm("mov edi, ebx");
asm("mov ebx, ecx"); // bottom 64 bits now in ebp:edi
asm("pop ecx"); // recover exponent
asm("js short mulfp1"); // skip if mantissa normalised
asm("add edi, edi"); // else shift left [only one shift will be needed]
asm("adc ebp, ebp");
asm("adc ebx, ebx");
asm("adc edx, edx");
asm("dec ecx"); // and decrement exponent
asm("mulfp1:");
asm("cmp ebp, 0x80000000"); // compare bottom 64 bits with 80000000 00000000 for rounding
asm("ja short mulfp2"); // branch to round up
asm("jb short mulfp3"); // branch to round down
asm("test edi, edi");
asm("jnz short mulfp2"); // branch to round up
asm("test bl, 1"); // if exactly half-way, test LSB of result mantissa
asm("jz short mulfp4"); // if LSB=0, round down [round to even]
asm("mulfp2:");
asm("add ebx, 1"); // round up - increment mantissa
asm("adc edx, 0");
asm("jnc short mulfp2a");
asm("rcr edx, 1");
asm("inc ecx");
asm("mulfp2a:");
asm("mov al, 2"); // set rounded-up flag
asm("jmp short mulfp5");
asm("mulfp3:"); // round down
asm("xor al, al"); // clear rounding flags
asm("or ebp, edi"); // check for exact result
asm("jz short mulfp5"); // skip if exact
asm("mulfp4:"); // come here to round down when we know result inexact
asm("mov al, 1"); // else set rounded-down flag
asm("mulfp5:"); // final mantissa now in edx:ebx, exponent in ecx
asm("cmp ecx, 0xFFFF"); // check for overflow
asm("jge short mulfp6"); // branch if overflow
asm("cmp ecx, 0"); // check for underflow
asm("jle short mulfp7"); // branch if underflow
asm("shl ecx, 16"); // else exponent up to top end of ecx
asm("mov ch, al"); // rounding flags into ch
asm("pop eax"); // recover result sign
asm("mov cl, al"); // into cl
asm("xor eax, eax"); // return KErrNone
asm("ret");
// come here if overflow
asm("mulfp6:");
asm("pop eax"); // recover result sign
asm("mov ecx, 0xFFFF0000"); // exponent=FFFF
asm("mov cl, al"); // sign into cl
asm("mov edx, 0x80000000"); // set mantissa to 80000000 00000000 for infinity
asm("xor ebx, ebx");
asm("mov eax, -9"); // return KErrOverflow
asm("ret");
// come here if underflow
asm("mulfp7:");
asm("pop eax"); // recover result sign
asm("xor ecx, ecx"); // exponent=0
asm("mov cl, al"); // sign into cl
asm("xor edx, edx");
asm("xor ebx, ebx");
asm("mov eax, -10"); // return KErrUnderflow
asm("ret");
// come here if either operand zero
asm("mulfp0:");
asm("and ecx, 1"); // set exponent=0, keep sign
asm("xor edx, edx");
asm("xor ebx, ebx");
asm("xor eax, eax"); // return KErrNone
asm("ret");
// come here if destination operand NaN or infinity
asm("mulfpsd:");
asm("cmp edx, 0x80000000"); // check for infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebx, ebx");
_ASM_jn(e,TRealXBinOpNaN)
asm("cmp eax, 0xFFFF0000"); // check second operand for NaN or infinity
asm("jae short mulfpsd1"); // branch if NaN or infinity
asm("cmp eax, 0x10000"); // check if second operand zero
_ASM_j(c,TRealXRealIndefinite) // if so, return 'real indefinite'
asm("mov eax, -9"); // else return dest [infinity] with xor sign and KErrOverflow
asm("ret");
asm("mulfpsd1:");
asm("mov ebp, [esi]"); // source mantissa into edi:ebp
asm("mov edi, [esi+4]");
asm("cmp edi, 0x80000000"); // check for infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebp, ebp");
_ASM_jn(e,TRealXBinOpNaN)
asm("mov eax, -9"); // both operands infinity - return infinity with xor sign
asm("ret"); // and KErrOverflow
// come here if source operand NaN or infinity, destination finite
asm("mulfpss:");
asm("mov ebp, [esi]"); // source mantissa into edi:ebp
asm("mov edi, [esi+4]");
asm("cmp edi, 0x80000000"); // check for infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebp, ebp");
_ASM_jn(e,TRealXBinOpNaN)
asm("cmp ecx, 0x10000"); // source=infinity, check if dest=0
_ASM_j(c,TRealXRealIndefinite) // if so, return 'real indefinite'
asm("or ecx, 0xFFFF0000"); // set exp=FFFF, leave xor sign in cl
asm("mov edx, edi"); // set mantissa for infinity
asm("mov ebx, ebp");
asm("mov eax, -9"); // return KErrOverflow
asm("ret");
}
// Divide 96-bit unsigned dividend EDX:EAX:0 by 64-bit unsigned divisor ECX:EBX
// Assume ECX bit 31 = 1, ie 2^63 <= divisor < 2^64
// Assume the quotient fits in 32 bits
// Return 32 bit quotient in EDI
// Return 64 bit remainder in EBP:ESI
LOCAL_C __NAKED__ void LongDivide(void)
{
asm("push edx"); // save dividend
asm("push eax"); //
asm("cmp edx, ecx"); // check if truncation of divisor will overflow DIV instruction
asm("jb short longdiv1"); // skip if not
asm("xor eax, eax"); // else return quotient of 0xFFFFFFFF
asm("dec eax"); //
asm("jmp short longdiv2"); //
asm("longdiv1:");
asm("div ecx"); // divide EDX:EAX by ECX to give approximate quotient in EAX
asm("longdiv2:");
asm("mov edi, eax"); // save approx quotient
asm("mul ebx"); // multiply approx quotient by full divisor ECX:EBX
asm("mov esi, eax"); // first partial product into EBP:ESI
asm("mov ebp, edx"); //
asm("mov eax, edi"); // approx quotient back into eax
asm("mul ecx"); // upper partial product now in EDX:EAX
asm("add eax, ebp"); // add to form 96-bit product in EDX:EAX:ESI
asm("adc edx, 0"); //
asm("neg esi"); // remainder = dividend - approx quotient * divisor
asm("mov ebp, [esp]"); // fetch dividend bits 32-63
asm("sbb ebp, eax"); //
asm("mov eax, [esp+4]"); // fetch dividend bits 64-95
asm("sbb eax, edx"); // remainder is now in EAX:EBP:ESI
asm("jns short longdiv4"); // if remainder positive, quotient is correct, so exit
asm("longdiv3:");
asm("dec edi"); // else quotient is too big, so decrement it
asm("add esi, ebx"); // and add divisor to remainder
asm("adc ebp, ecx"); //
asm("adc eax, 0"); //
asm("js short longdiv3"); // if still negative, repeat [requires <4 iterations]
asm("longdiv4:");
asm("add esp, 8"); // remove dividend from stack
asm("ret"); // return with quotient in EDI, remainder in EBP:ESI
}
// Divide TRealX at [esi] / ecx,edx:ebx
// Result in ecx,edx:ebx
// Error code in eax
LOCAL_C __NAKED__ void TRealXDivide(void)
{
asm("xor ch, ch"); // clear rounding flags
asm("mov eax, [esi+8]"); // fetch sign/exponent of dividend
asm("xor cl, al"); // xor signs
asm("cmp eax, 0xFFFF0000"); // check if dividend=NaN or infinity
asm("jnc divfpss"); // branch if it is
asm("cmp ecx, 0xFFFF0000"); // check if divisor=NaN or infinity
asm("jnc divfpsd"); // branch if it is
asm("cmp ecx, 0x10000"); // check if divisor=0
asm("jc divfpdv0"); // branch if it is
asm("cmp eax, 0x10000"); // check if dividend=0
asm("jc divfpdd0"); // branch if it is
asm("push esi"); // save pointer to dividend
asm("push ecx"); // save result sign
asm("shr ecx, 16"); // divisor exponent into cx
asm("shr eax, 16"); // dividend exponent into ax
asm("sub eax, ecx"); // subtract exponents
asm("add eax, 0x7FFE"); // eax now contains result exponent
asm("push eax"); // save it
asm("mov ecx, edx"); // divisor mantissa into ecx:ebx
asm("mov edx, [esi+4]"); // dividend mantissa into edx:eax
asm("mov eax, [esi]");
asm("xor edi, edi"); // clear edi initially
asm("cmp edx, ecx"); // compare EDX:EAX with ECX:EBX
asm("jb short divfp1"); // if EDX:EAX < ECX:EBX, leave everything as is
asm("ja short divfp2"); //
asm("cmp eax, ebx"); // if EDX=ECX, then compare ls dwords
asm("jb short divfp1"); // if dividend mant < divisor mant, leave everything as is
asm("divfp2:");
asm("sub eax, ebx"); // else dividend mant -= divisor mant
asm("sbb edx, ecx"); //
asm("inc edi"); // and EDI=1 [bit 0 of EDI is the integer part of the result]
asm("inc dword ptr [esp]"); // also increment result exponent
asm("divfp1:");
asm("push edi"); // save top bit of result
asm("call %a0": : "i"(&LongDivide)); // divide EDX:EAX:0 by ECX:EBX to give next 32 bits of result in EDI
asm("push edi"); // save next 32 bits of result
asm("mov edx, ebp"); // remainder from EBP:ESI into EDX:EAX
asm("mov eax, esi"); //
asm("call %a0": : "i"(&LongDivide)); // divide EDX:EAX:0 by ECX:EBX to give next 32 bits of result in EDI
asm("test byte ptr [esp+4], 1"); // test integer bit of result
asm("jnz short divfp4"); // if set, no need to calculate another bit
asm("xor eax, eax"); //
asm("add esi, esi"); // 2*remainder into EAX:EBP:ESI
asm("adc ebp, ebp"); //
asm("adc eax, eax"); //
asm("sub esi, ebx"); // subtract divisor to generate final quotient bit
asm("sbb ebp, ecx"); //
asm("sbb eax, 0"); //
asm("jnc short divfp3"); // skip if no borrow - in this case eax=0
asm("add esi, ebx"); // if borrow add back - final remainder now in EBP:ESI
asm("adc ebp, ecx"); //
asm("adc eax, 0"); // eax will be zero after this and carry will be set
asm("divfp3:");
asm("cmc"); // final bit = 1-C
asm("rcr eax, 1"); // shift it into eax bit 31
asm("mov ebx, edi"); // result into EDX:EBX:EAX, remainder in EBP:ESI
asm("pop edx");
asm("add esp, 4"); // discard integer bit [zero]
asm("jmp short divfp5"); // branch to round
asm("divfp4:"); // integer bit was set
asm("mov ebx, edi"); // result into EDX:EBX:EAX
asm("pop edx"); //
asm("pop eax"); // integer part of result into eax [=1]
asm("stc"); // shift a 1 into top end of mantissa
asm("rcr edx,1"); //
asm("rcr ebx,1"); //
asm("rcr eax,1"); // bottom bit into eax bit 31
// when we get to here we have 65 bits of quotient mantissa in
// EDX:EBX:EAX (bottom bit in eax bit 31)
// and the remainder is in EBP:ESI
asm("divfp5:");
asm("pop ecx"); // recover result exponent
asm("add eax, eax"); // test rounding bit
asm("jnc short divfp6"); // branch to round down
asm("or ebp, esi"); // test remainder to see if we are exactly half-way
asm("jnz short divfp7"); // if not, round up
asm("test bl, 1"); // exactly halfway - test LSB of mantissa
asm("jz short divfp8"); // round down if LSB=0 [round to even]
asm("divfp7:");
asm("add ebx, 1"); // round up - increment mantissa
asm("adc edx, 0");
asm("jnc short divfp7a");
asm("rcr edx, 1"); // if carry, shift 1 into mantissa MSB
asm("inc ecx"); // and increment exponent
asm("divfp7a:");
asm("mov al, 2"); // set rounded-up flag
asm("jmp short divfp9");
asm("divfp6:");
asm("xor al, al"); // round down - first clear rounding flags
asm("or ebp, esi"); // test if result exact
asm("jz short divfp9"); // skip if exact
asm("divfp8:"); // come here to round down when we know result is inexact
asm("mov al, 1"); // set rounded-down flag
asm("divfp9:"); // final mantissa now in edx:ebx, exponent in ecx
asm("cmp ecx, 0xFFFF"); // check for overflow
asm("jge short divfp10"); // branch if overflow
asm("cmp ecx, 0"); // check for underflow
asm("jle short divfp11"); // branch if underflow
asm("shl ecx, 16"); // else exponent up to top end of ecx
asm("mov ch, al"); // rounding flags into ch
asm("pop eax"); // recover result sign
asm("mov cl, al"); // into cl
asm("pop esi"); // recover dividend pointer
asm("xor eax, eax"); // return KErrNone
asm("ret");
// come here if overflow
asm("divfp10:");
asm("pop eax"); // recover result sign
asm("mov ecx, 0xFFFF0000"); // exponent=FFFF
asm("mov cl, al"); // sign into cl
asm("mov edx, 0x80000000"); // set mantissa to 80000000 00000000 for infinity
asm("xor ebx, ebx");
asm("mov eax, -9"); // return KErrOverflow
asm("pop esi"); // recover dividend pointer
asm("ret");
// come here if underflow
asm("divfp11:");
asm("pop eax"); // recover result sign
asm("xor ecx, ecx"); // exponent=0
asm("mov cl, al"); // sign into cl
asm("xor edx, edx");
asm("xor ebx, ebx");
asm("mov eax, -10"); // return KErrUnderflow
asm("pop esi"); // recover dividend pointer
asm("ret");
// come here if divisor=0, dividend finite
asm("divfpdv0:");
asm("cmp eax, 0x10000"); // check if dividend also zero
_ASM_j(c,TRealXRealIndefinite) // if so, return 'real indefinite'
asm("or ecx, 0xFFFF0000"); // else set exponent=FFFF, leave xor sign in cl
asm("mov edx, 0x80000000"); // set mantissa for infinity
asm("xor ebx, ebx");
asm("mov eax, -41"); // return KErrDivideByZero
asm("ret");
// come here if dividend=0, divisor finite and nonzero
asm("divfpdd0:");
asm("and ecx, 1"); // exponent=0, leave xor sign in cl
asm("xor eax, eax"); // return KErrNone
asm("ret");
// come here if dividend is a NaN or infinity
asm("divfpss:");
asm("mov ebp, [esi]"); // dividend mantissa into edi:ebp
asm("mov edi, [esi+4]");
asm("cmp edi, 0x80000000"); // check for infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebp, ebp");
_ASM_jn(e,TRealXBinOpNaN)
asm("cmp ecx, 0xFFFF0000"); // check divisor for NaN or infinity
asm("jae short divfpss1"); // branch if NaN or infinity
asm("or ecx, 0xFFFF0000"); // infinity/finite - return infinity with xor sign
asm("mov edx, 0x80000000");
asm("xor ebx, ebx");
asm("mov eax, -9"); // return KErrOverflow
asm("ret");
asm("divfpss1:");
asm("cmp edx, 0x80000000"); // check for infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebx, ebx");
_ASM_jn(e,TRealXBinOpNaN)
asm("jmp %a0": : "i"(&TRealXRealIndefinite)); // if both operands infinite, return 'real indefinite'
// come here if divisor is a NaN or infinity, dividend finite
asm("divfpsd:");
asm("cmp edx, 0x80000000"); // check for infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebx, ebx");
_ASM_jn(e,TRealXBinOpNaN)
asm("and ecx, 1"); // dividend is finite, divisor=infinity, so return 0 with xor sign
asm("xor edx, edx");
asm("xor ebx, ebx");
asm("xor eax, eax"); // return KErrNone
asm("ret");
}
// TRealX modulo - dividend at [esi], divisor in ecx,edx:ebx
// Result in ecx,edx:ebx
// Error code in eax
LOCAL_C __NAKED__ void TRealXModulo(void)
{
asm("mov eax, [esi+8]"); // fetch sign/exponent of dividend
asm("mov cl, al"); // result sign=dividend sign
asm("xor ch, ch"); // clear rounding flags
asm("cmp eax, 0xFFFF0000"); // check if dividend=NaN or infinity
asm("jnc short modfpss"); // branch if it is
asm("cmp ecx, 0xFFFF0000"); // check if divisor=NaN or infinity
asm("jnc short modfpsd"); // branch if it is
asm("cmp ecx, 0x10000"); // check if divisor=0
_ASM_j(c,TRealXRealIndefinite) // if so, return 'real indefinite'
asm("shr eax, 16"); // ax=dividend exponent
asm("ror ecx, 16"); // cx=divisor exponent
asm("sub ax, cx"); // ax=dividend exponent-divisor exponent
asm("jc short modfpdd0"); // if dividend exponent is smaller, return dividend
asm("cmp ax, 64"); // check if exponents differ by >= 64 bits
asm("jnc short modfplp"); // if so, underflow
asm("mov ah, 0"); // ah bit 0 acts as 65th accumulator bit
asm("mov ebp, [esi]"); // edi:ebp=dividend mantissa
asm("mov edi, [esi+4]"); //
asm("jmp short modfp2"); // skip left shift on first iteration
asm("modfp1:");
asm("add ebp, ebp"); // shift accumulator left [65 bits]
asm("adc edi, edi");
asm("adc ah, ah");
asm("modfp2:");
asm("sub ebp, ebx"); // subtract divisor from dividend
asm("sbb edi, edx");
asm("sbb ah, 0");
asm("jnc short modfp3"); // skip if no borrow
asm("add ebp, ebx"); // else add back
asm("adc edi, edx");
asm("adc ah, 0");
asm("modfp3:");
asm("dec al"); // any more bits to do?
asm("jns short modfp1"); // loop if there are
asm("mov edx, edi"); // result mantissa [not yet normalised] into edx:ebx
asm("mov ebx, ebp");
asm("or edi, ebx"); // check for zero
asm("jz short modfp0"); // jump if result zero
asm("or edx, edx"); // check if ms dword zero
asm("jnz short modfp4");
asm("mov edx, ebx"); // if so, shift left by 32
asm("xor ebx, ebx");
asm("sub cx, 32"); // and decrement exponent by 32
asm("jbe short modfpund"); // if borrow or exponent zero, underflow
asm("modfp4:");
asm("mov edi, ecx"); // preserve sign and exponent
asm("bsr ecx, edx"); // position of most significant 1 into ecx
asm("neg ecx"); //
asm("add ecx, 31"); // cl = 31-position of MS 1 = number of shifts to normalise
asm("shld edx, ebx, cl"); // shift edx:ebx left by cl bits
asm("shl ebx, cl"); //
asm("mov ebp, ecx"); // bit count into ebp for subtraction
asm("mov ecx, edi"); // exponent & sign back into ecx
asm("sub cx, bp"); // subtract shift count from exponent
asm("jbe short modfpund"); // if borrow or exponent 0, underflow
asm("rol ecx, 16"); // else ecx=exponent:sign
asm("xor eax, eax"); // normal exit, result in ecx,edx:ebx
asm("ret");
// dividend=NaN or infinity
asm("modfpss:");
asm("mov ebp, [esi]"); // dividend mantissa into edi:ebp
asm("mov edi, [esi+4]");
asm("cmp edi, 0x80000000"); // check for infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebp, ebp");
_ASM_jn(e,TRealXBinOpNaN)
asm("cmp ecx, 0xFFFF0000"); // check divisor for NaN or infinity
_ASM_j(b,TRealXRealIndefinite) // infinity%finite - return 'real indefinite'
asm("cmp edx, 0x80000000"); // check for divisor=infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebx, ebx");
_ASM_jn(e,TRealXBinOpNaN)
asm("jmp %a0": : "i"(&TRealXRealIndefinite)); // if both operands infinite, return 'real indefinite'
// divisor=NaN or infinity, dividend finite
asm("modfpsd:");
asm("cmp edx, 0x80000000"); // check for infinity
_ASM_jn(e,TRealXBinOpNaN) // branch if NaN
asm("test ebx, ebx");
_ASM_jn(e,TRealXBinOpNaN)
// finite%infinity - return dividend unaltered
asm("modfpdd0:");
asm("mov ebx, [esi]"); // normal exit, return dividend unaltered
asm("mov edx, [esi+4]");
asm("mov ecx, [esi+8]");
asm("xor eax, eax");
asm("ret");
asm("modfp0:");
asm("shr ecx, 16"); // normal exit, result 0
asm("xor eax, eax");
asm("ret");
asm("modfpund:");
asm("shr ecx, 16"); // underflow, result 0
asm("mov eax, -10"); // return KErrUnderflow
asm("ret");
asm("modfplp:");
asm("shr ecx, 16"); // loss of precision, result 0
asm("mov eax, -7"); // return KErrTotalLossOfPrecision
asm("ret");
}
__NAKED__ EXPORT_C TRealX::TRealX()
/**
Constructs a default extended precision object.
This sets the value to zero.
*/
{
THISCALL_PROLOG0()
asm("xor eax, eax");
asm("mov [ecx], eax"); // set value to zero
asm("mov [ecx+4], eax");
asm("mov [ecx+8], eax");
asm("mov eax, ecx"); // must return this
THISCALL_EPILOG0()
}
__NAKED__ EXPORT_C TRealX::TRealX(TUint /*aExp*/, TUint /*aMantHi*/, TUint /*aMantLo*/)
/**
Constructs an extended precision object from an explicit exponent and
a 64 bit mantissa.
@param aExp The exponent
@param aMantHi The high order 32 bits of the 64 bit mantissa
@param aMantLo The low order 32 bits of the 64 bit mantissa
*/
{
THISCALL_PROLOG3()
asm("mov eax, [esp+4]"); // eax=aExp
asm("mov [ecx+8], eax");
asm("mov eax, [esp+8]"); // eax=aMantHi
asm("mov [ecx+4], eax");
asm("mov eax, [esp+12]"); // eax=aMantLo
asm("mov [ecx], eax");
asm("mov eax, ecx"); // must return this
THISCALL_EPILOG3()
}
__NAKED__ EXPORT_C TInt TRealX::Set(TInt /*aInt*/)
/**
Gives this extended precision object a new value taken
from a signed integer.
@param aInt The signed integer value.
@return KErrNone, always.
*/
{
THISCALL_PROLOG1()
// on entry ecx=this, [esp+4]=aInt, return code in eax
asm("mov edx, [esp+4]"); // edx=aInt
asm("or edx, edx"); // test sign/zero
asm("mov eax, 0x7FFF");
asm("jz short trealxfromint0_2"); // branch if 0
asm("jns short trealxfromint1_2");// skip if positive
asm("neg edx"); // take absolute value
asm("add eax, 0x10000"); // sign bit in eax bit 16
asm("trealxfromint1_2:");
asm("push ecx"); // save this
asm("bsr ecx, edx"); // bit number of edx MSB into ecx
asm("add eax, ecx"); // add to eax to form result exponent
asm("neg cl");
asm("add cl, 31"); // 31-bit number = number of shifts to normalise edx
asm("shl edx, cl"); // normalise edx
asm("pop ecx"); // this back into ecx
asm("ror eax, 16"); // sign/exponent into normal positions
asm("mov [ecx+4], edx"); // store mantissa high word
asm("mov [ecx+8], eax"); // store sign/exponent
asm("xor eax, eax");
asm("mov [ecx], eax"); // zero mantissa low word
THISCALL_EPILOG1() // return KErrNone
asm("trealxfromint0_2:");
asm("mov [ecx], edx");
asm("mov [ecx+4], edx"); // store mantissa high word=0
asm("mov [ecx+8], edx"); // store sign/exponent=0
asm("xor eax, eax"); // return KErrNone
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C TInt TRealX::Set(TUint /*aInt*/)
/**
Gives this extended precision object a new value taken from
an unsigned integer.
@param aInt The unsigned integer value.
@return KErrNone, always.
*/
{
THISCALL_PROLOG1()
asm("mov edx, [esp+4]"); // edx=aInt
asm("mov eax, 0x7FFF");
asm("or edx, edx"); // test for 0
asm("jz short trealxfromuint0_");// branch if 0
asm("push ecx"); // save this
asm("bsr ecx, edx"); // bit number of edx MSB into ecx
asm("add eax, ecx"); // add to eax to form result exponent
asm("neg cl");
asm("add cl, 31"); // 31-bit number = number of shifts to normalise edx
asm("shl edx, cl"); // normalise edx
asm("pop ecx"); // this back into ecx
asm("shl eax, 16"); // exponent into normal position
asm("mov [ecx+4], edx"); // store mantissa high word
asm("mov [ecx+8], eax"); // store exponent
asm("xor eax, eax");
asm("mov [ecx], eax"); // zero mantissa low word
THISCALL_EPILOG1() // return KErrNone
asm("trealxfromuint0_:");
asm("mov [ecx], edx");
asm("mov [ecx+4], edx"); // store mantissa high word=0
asm("mov [ecx+8], edx"); // store sign/exponent=0
asm("xor eax, eax"); // return KErrNone
THISCALL_EPILOG1()
}
LOCAL_C __NAKED__ void TRealXFromTInt64(void)
{
// Convert TInt64 in edx:ebx to TRealX in ecx,edx:ebx
asm("mov eax, 0x7FFF");
asm("or edx, edx"); // test sign/zero
asm("jz short trealxfromtint64a"); // branch if top word zero
asm("jns short trealxfromtint64b");
asm("add eax, 0x10000"); // sign bit into eax bit 16
asm("neg edx"); // take absolute value
asm("neg ebx");
asm("sbb edx, 0");
asm("jz short trealxfromtint64d"); // branch if top word zero
asm("trealxfromtint64b:");
asm("bsr ecx, edx"); // ecx=bit number of edx MSB
asm("add eax, ecx"); // add to exponent in eax
asm("add eax, 32");
asm("neg cl");
asm("add cl, 31"); // 31-bit number = number of left shifts to normalise
asm("shld edx, ebx, cl"); // shift left to normalise edx:ebx
asm("shl ebx, cl");
asm("mov ecx, eax"); // sign/exponent into ecx
asm("ror ecx, 16"); // and into normal positions
asm("ret");
asm("trealxfromtint64a:"); // come here if top word zero
asm("or ebx, ebx"); // test for bottom word also zero
asm("jz short trealxfromtint64c"); // branch if it is
asm("trealxfromtint64d:"); // come here if top word zero, bottom word not
asm("mov edx, ebx"); // shift edx:ebx left 32
asm("xor ebx, ebx");
asm("bsr ecx, edx"); // ecx=bit number of edx MSB
asm("add eax, ecx"); // add to exponent in eax
asm("neg cl");
asm("add cl, 31"); // 31-bit number = number of left shifts to normalise
asm("shl edx, cl"); // normalise
asm("mov ecx, eax"); // sign/exponent into ecx
asm("ror ecx, 16"); // and into normal positions
asm("ret");
asm("trealxfromtint64c:"); // entire number is zero
asm("xor ecx, ecx");
asm("ret");
}
__NAKED__ EXPORT_C TInt TRealX::Set(const TInt64& /*aInt*/)
/**
Gives this extended precision object a new value taken from
a 64 bit integer.
@param aInt The 64 bit integer value.
@return KErrNone, always.
*/
{
// on entry ecx=this, [esp+4]=address of aInt, return code in eax
THISCALL_PROLOG1()
asm("push ebx");
asm("push ecx");
asm("mov edx, [esp+12]"); // edx=address of aInt
asm("mov ebx, [edx]");
asm("mov edx, [edx+4]"); // edx:ebx=aInt
asm("call %a0": : "i"(&TRealXFromTInt64)); // convert to TRealX in ecx,edx:ebx
asm("pop eax"); // eax=this
asm("mov [eax], ebx"); // store result
asm("mov [eax+4], edx");
asm("mov [eax+8], ecx");
asm("xor eax, eax"); // return KErrNone
asm("pop ebx");
THISCALL_EPILOG1()
}
LOCAL_C __NAKED__ void __6TRealXi()
{
// common function for int to TRealX
THISCALL_PROLOG1()
asm("mov edx, [esp+4]"); // edx=aInt
asm("or edx, edx"); // test sign/zero
asm("mov eax, 0x7FFF");
asm("jz short trealxfromint0"); // branch if 0
asm("jns short trealxfromint1"); // skip if positive
asm("neg edx"); // take absolute value
asm("add eax, 0x10000"); // sign bit in eax bit 16
asm("trealxfromint1:");
asm("push ecx"); // save this
asm("bsr ecx, edx"); // bit number of edx MSB into ecx
asm("add eax, ecx"); // add to eax to form result exponent
asm("neg cl");
asm("add cl, 31"); // 31-bit number = number of shifts to normalise edx
asm("shl edx, cl"); // normalise edx
asm("pop ecx"); // this back into ecx
asm("ror eax, 16"); // sign/exponent into normal positions
asm("mov [ecx+4], edx"); // store mantissa high word
asm("mov [ecx+8], eax"); // store sign/exponent
asm("xor eax, eax");
asm("mov [ecx], eax"); // zero mantissa low word
asm("mov eax, ecx"); // return eax=this
THISCALL_EPILOG1()
asm("trealxfromint0:");
asm("mov [ecx], edx");
asm("mov [ecx+4], edx"); // store mantissa high word=0
asm("mov [ecx+8], edx"); // store sign/exponent=0
asm("mov eax, ecx"); // return eax=this
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C TRealX::TRealX(TInt /*aInt*/)
/**
Constructs an extended precision object from a signed integer value.
@param aInt The signed integer value.
*/
{
// on entry ecx=this, [esp+4]=aInt, return eax=this
asm("jmp %a0": : "i"(&__6TRealXi));
}
__NAKED__ EXPORT_C TRealX& TRealX::operator=(TInt /*aInt*/)
/**
Assigns the specified signed integer value to this extended precision object.
@param aInt The signed integer value.
@return A reference to this extended precision object.
*/
{
// on entry ecx=this, [esp+4]=aInt, return eax=this
asm("jmp %a0": : "i"(&__6TRealXi));
}
LOCAL_C __NAKED__ void __6TRealXui()
{
// common function for unsigned int to TRealX
THISCALL_PROLOG1()
asm("mov edx, [esp+4]"); // edx=aInt
asm("mov eax, 0x7FFF");
asm("or edx, edx"); // test for zero
asm("jz short trealxfromuint0"); // branch if 0
asm("push ecx"); // save this
asm("bsr ecx, edx"); // bit number of edx MSB into ecx
asm("add eax, ecx"); // add to eax to form result exponent
asm("neg cl");
asm("add cl, 31"); // 31-bit number = number of shifts to normalise edx
asm("shl edx, cl"); // normalise edx
asm("pop ecx"); // this back into ecx
asm("shl eax, 16"); // exponent into normal position
asm("mov [ecx+4], edx"); // store mantissa high word
asm("mov [ecx+8], eax"); // store exponent
asm("xor eax, eax");
asm("mov [ecx], eax"); // zero mantissa low word
asm("mov eax, ecx"); // return eax=this
THISCALL_EPILOG1()
asm("trealxfromuint0:");
asm("mov [ecx], edx");
asm("mov [ecx+4], edx"); // store mantissa high word=0
asm("mov [ecx+8], edx"); // store sign/exponent=0
asm("mov eax, ecx"); // return eax=this
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C TRealX::TRealX(TUint /*aInt*/)
/**
Constructs an extended precision object from an unsigned integer value.
@param aInt The unsigned integer value.
*/
{
// on entry ecx=this, [esp+4]=aInt, return eax=this
asm("jmp %a0": : "i"(&__6TRealXui));
}
__NAKED__ EXPORT_C TRealX& TRealX::operator=(TUint /*aInt*/)
/**
Assigns the specified unsigned integer value to this extended precision object.
@param aInt The unsigned integer value.
@return A reference to this extended precision object.
*/
{
// on entry ecx=this, [esp+4]=aInt, return eax=this
asm("jmp %a0": : "i"(&__6TRealXui));
}
LOCAL_C __NAKED__ void __6TRealXRC6TInt64()
{
// common function for TInt64 to TRealX
THISCALL_PROLOG1()
asm("push ebx"); // preserve ebx
asm("push ecx"); // save this
asm("mov edx, [esp+12]"); // edx=address of aInt
asm("mov ebx, [edx]");
asm("mov edx, [edx+4]"); // edx:ebx=aInt
asm("call %a0": : "i"(&TRealXFromTInt64)); // convert to TRealX in ecx,edx:ebx
asm("pop eax"); // eax=this
asm("mov [eax], ebx"); // store result
asm("mov [eax+4], edx");
asm("mov [eax+8], ecx");
asm("mov ecx, eax"); // restore this ptr
asm("pop ebx"); // restore ebx
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C TRealX::TRealX(const TInt64& /*aInt*/)
/**
Constructs an extended precision object from a 64 bit integer.
@param aInt A reference to a 64 bit integer.
*/
{
// on entry ecx=this, [esp+4]=address of aInt, return eax=this
asm("jmp %a0": : "i"(&__6TRealXRC6TInt64));
}
__NAKED__ EXPORT_C TRealX& TRealX::operator=(const TInt64& /*aInt*/)
/**
Assigns the specified 64 bit integer value to this extended precision object.
@param aInt A reference to a 64 bit integer.
@return A reference to this extended precision object.
*/
{
// on entry ecx=this, [esp+4]=address of aInt, return eax=this
asm("jmp %a0": : "i"(&__6TRealXRC6TInt64));
}
LOCAL_C __NAKED__ void ConvertTReal32ToTRealX(void)
{
// Convert TReal32 in edx to TRealX in ecx:edx,ebx
asm("xor ebx, ebx"); // mant low always zero
asm("mov eax, edx");
asm("shr eax, 23"); // exponent now in al, sign in ah bit 0
asm("test al, al"); // check for denormal/zero
asm("jz short treal32totrealx2"); // branch if denormal/zero
asm("xor ecx, ecx");
asm("mov cl, al");
asm("add ecx, 0x7F80"); // bias exponent correctly for TRealX
asm("cmp al, 0xFF"); // check for infinity/NaN
asm("jnz short treal32totrealx1"); // skip if neither
asm("mov cl, al"); // else set TRealX exponent to FFFF
asm("mov ch, al");
asm("treal32totrealx1:");
asm("shl edx, 8"); // left-justify mantissa in edx
asm("or edx, 0x80000000"); // put in implied integer bit
asm("shl ecx, 16"); // exponent into ecx bits 16-31
asm("mov cl, ah"); // sign into ecx bit 0
asm("ret");
asm("treal32totrealx2:"); // come here if exponent 0
asm("shl edx, 9"); // left-justify mantissa in edx [shift out integer bit as well]
asm("jnz short treal32totrealx3"); // jump if denormal
asm("xor ecx, ecx"); // else return 0
asm("mov cl, ah"); // with same sign as input value
asm("ret");
asm("treal32totrealx3:"); // come here if denormal
asm("bsr ecx, edx"); // ecx=bit number of MSB of edx
asm("neg ecx");
asm("add ecx, 31"); // ecx=number of left shifts to normalise edx
asm("shl edx, cl"); // normalise
asm("neg ecx");
asm("add ecx, 0x7F80"); // exponent=7F80-number of shifts
asm("shl ecx, 16"); // exponent into ecx bits 16-31
asm("mov cl, ah"); // sign into ecx bit 0
asm("ret");
}
LOCAL_C __NAKED__ void ConvertTReal64ToTRealX(void)
{
// Convert TReal64 in edx:ebx to TRealX in ecx:edx,ebx
asm("mov eax, edx");
asm("shr eax, 20");
asm("mov ecx, 0x7FF");
asm("and ecx, eax"); // ecx=exponent
asm("jz short treal64totrealx1"); // branch if zero/denormal
asm("add ecx, 0x7C00"); // else bias exponent correctly for TRealX
asm("cmp ecx, 0x83FF"); // check for infinity/NaN
asm("jnz short treal64totrealx2");
asm("mov ch, cl"); // if so, set exponent to FFFF
asm("treal64totrealx2:");
asm("shl ecx, 16"); // exponent into ecx bits 16-31
asm("mov cl, 11"); // number of shifts needed to justify mantissa correctly
asm("shld edx, ebx, cl"); // shift mantissa left
asm("shl ebx, cl");
asm("or edx, 0x80000000"); // put in implied integer bit
asm("shr eax, 11"); // sign bit into al bit 0
asm("mov cl, al"); // into ecx bit 0
asm("ret");
asm("treal64totrealx1:"); // come here if zero/denormal
asm("mov cl, 12"); // number of shifts needed to justify mantissa correctly
asm("shld edx, ebx, cl"); // shift mantissa left
asm("shl ebx, cl");
asm("test edx, edx"); // check for zero
asm("jnz short treal64totrealx3");
asm("test ebx, ebx");
asm("jnz short treal64totrealx4");
asm("shr eax, 11"); // sign bit into eax bit 0, rest of eax=0
asm("mov ecx, eax"); // return 0 result with correct sign
asm("ret");
asm("treal64totrealx4:"); // come here if denormal, edx=0
asm("mov edx, ebx"); // shift mantissa left 32
asm("xor ebx, ebx");
asm("bsr ecx, edx"); // ecx=bit number of MSB of edx
asm("neg ecx");
asm("add ecx, 31"); // ecx=number of left shifts to normalise edx
asm("shl edx, cl"); // normalise
asm("neg ecx");
asm("add ecx, 0x7BE0"); // exponent=7BE0-number of shifts
asm("shl ecx, 16"); // exponent into bits 16-31 of ecx
asm("shr eax, 11");
asm("mov cl, al"); // sign into bit 0 of ecx
asm("ret");
asm("treal64totrealx3:"); // come here if denormal, edx nonzero
asm("bsr ecx, edx"); // ecx=bit number of MSB of edx
asm("neg ecx");
asm("add ecx, 31"); // ecx=number of left shifts to normalise edx:ebx
asm("shld edx, ebx, cl"); // normalise
asm("shl ebx, cl");
asm("neg ecx");
asm("add ecx, 0x7C00"); // exponent=7C00-number of shifts
asm("shl ecx, 16"); // exponent into bits 16-31 of ecx
asm("shr eax, 11");
asm("mov cl, al"); // sign into bit 0 of ecx
asm("ret");
}
__NAKED__ EXPORT_C TInt TRealX::Set(TReal32 /*aReal*/)
/**
Gives this extended precision object a new value taken from
a single precision floating point number.
@param aReal The single precision floating point value.
@return KErrNone, if a valid number;
KErrOverflow, if the number is infinite;
KErrArgument, if not a number.
*/
{
// on entry, ecx=this and aReal is in [esp+4]
// on exit, error code in eax
THISCALL_PROLOG1()
asm("push ecx");
asm("push ebx"); // save ebx
asm("push ecx"); // save this
asm("mov edx, [esp+16]"); // aReal into edx
asm("call %a0": : "i"(&ConvertTReal32ToTRealX));
asm("pop eax"); // eax=this
asm("mov [eax], ebx"); // store result
asm("mov [eax+4], edx");
asm("mov [eax+8], ecx");
asm("xor eax, eax"); // error code=KErrNone initially
asm("cmp ecx, 0xFFFF0000"); // check for infinity/NaN
asm("jb short trealxsettreal32a"); // if neither, return KErrNone
asm("mov eax, -9"); // eax=KErrOverflow
asm("cmp edx, 0x80000000"); // check for infinity
asm("je short trealxsettreal32a"); // if infinity, return KErrOverflow
asm("mov eax, -6"); // if NaN, return KErrArgument
asm("trealxsettreal32a:");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C TInt TRealX::Set(TReal64 /*aReal*/)
/**
Gives this extended precision object a new value taken from
a double precision floating point number.
@param aReal The double precision floating point value.
@return KErrNone, if a valid number;
KErrOverflow, if the number is infinite;
KErrArgument, if not a number.
*/
{
// on entry, ecx=this and aReal is in [esp+4] (mant low) and [esp+8] (sign/exp/mant high)
// on exit, error code in eax
THISCALL_PROLOG2()
asm("push ecx");
asm("push ebx"); // save ebx
asm("push ecx"); // save this
asm("mov ebx, [esp+16]"); // aReal into edx:ebx
asm("mov edx, [esp+20]");
asm("call %a0": : "i"(&ConvertTReal64ToTRealX));
asm("pop eax"); // eax=this
asm("mov [eax], ebx"); // store result
asm("mov [eax+4], edx");
asm("mov [eax+8], ecx");
asm("xor eax, eax"); // error code=KErrNone initially
asm("cmp ecx, 0xFFFF0000"); // check for infinity/NaN
asm("jb short trealxsettreal64a"); // if neither, return KErrNone
asm("mov eax, -9"); // eax=KErrOverflow
asm("cmp edx, 0x80000000"); // check for infinity
asm("jne short trealxsettreal64b"); // branch if NaN
asm("test ebx, ebx");
asm("je short trealxsettreal64a"); // if infinity, return KErrOverflow
asm("trealxsettreal64b:");
asm("mov eax, -6"); // if NaN, return KErrArgument
asm("trealxsettreal64a:");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG2()
}
LOCAL_C __NAKED__ void __6TRealXf()
{
// common function for float to TRealX
THISCALL_PROLOG1()
asm("push ebx"); // save ebx
asm("push ecx"); // save this
asm("mov edx, [esp+12]"); // aReal into edx
asm("call %a0": : "i"(&ConvertTReal32ToTRealX));
asm("pop eax"); // eax=this
asm("mov [eax], ebx"); // store result
asm("mov [eax+4], edx");
asm("mov [eax+8], ecx");
asm("pop ebx");
asm("mov ecx,eax");
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C TRealX::TRealX(TReal32 /*aReal*/)
/**
Constructs an extended precision object from
a single precision floating point number.
@param aReal The single precision floating point value.
*/
{
// on entry, ecx=this and aReal is in [esp+4]
// on exit, eax=this
asm("jmp %a0": : "i"(&__6TRealXf));
}
__NAKED__ EXPORT_C TRealX& TRealX::operator=(TReal32 /*aReal*/)
/**
Assigns the specified single precision floating point number to
this extended precision object.
@param aReal The single precision floating point value.
@return A reference to this extended precision object.
*/
{
// on entry, ecx=this and aReal is in [esp+4]
// on exit, eax=this
asm("jmp %a0": : "i"(&__6TRealXf));
}
LOCAL_C __NAKED__ void __6TRealXd()
{
// common function for double to TRealX
THISCALL_PROLOG2()
asm("push ebx"); // save ebx
asm("push ecx"); // save this
asm("mov ebx, [esp+12]"); // aReal into edx:ebx
asm("mov edx, [esp+16]");
asm("call %a0": : "i"(&ConvertTReal64ToTRealX));
asm("pop eax"); // eax=this
asm("mov [eax], ebx"); // store result
asm("mov [eax+4], edx");
asm("mov [eax+8], ecx");
asm("pop ebx");
asm("mov ecx,eax");
THISCALL_EPILOG2()
}
__NAKED__ EXPORT_C TRealX::TRealX(TReal64 /*aReal*/)
/**
Constructs an extended precision object from
a double precision floating point number.
@param aReal The double precision floating point value.
*/
{
// on entry, ecx=this and aReal is in [esp+4] (mant low) and [esp+8] (sign/exp/mant high)
// on exit, eax=this
asm("jmp %a0": : "i"(&__6TRealXd));
}
__NAKED__ EXPORT_C TRealX& TRealX::operator=(TReal64 /*aReal*/)
/**
Assigns the specified double precision floating point number to
this extended precision object.
@param aReal The double precision floating point value.
@return A reference to this extended precision object.
*/
{
// on entry, ecx=this and aReal is in [esp+4] (mant low) and [esp+8] (sign/exp/mant high)
// on exit, eax=this
asm("jmp %a0": : "i"(&__6TRealXd));
}
__NAKED__ EXPORT_C TRealX::operator TInt() const
/**
Gets the extended precision value as a signed integer value.
The operator asm("returns:");
1. zero , if the extended precision value is not a number
2. 0x7FFFFFFF, if the value is positive and too big to fit into a TInt.
3. 0x80000000, if the value is negative and too big to fit into a TInt.
*/
{
// on entry ecx=this, return value in eax
THISCALL_PROLOG0()
asm("push ecx");
asm("mov edx, [ecx]"); // edx=mantissa low
asm("mov eax, [ecx+4]"); // eax=mantissa high
asm("mov ecx, [ecx+8]"); // ecx=exponent/sign
asm("ror ecx, 16"); // exponent into cx
asm("cmp cx, 0xFFFF");
asm("jz short trealxtoint1"); // branch if exp=FFFF
asm("mov dx, cx");
asm("mov cx, 0x801E");
asm("sub cx, dx"); // cx=number of right shifts needed to convert mantissa to int
asm("jbe short trealxtoint2"); // if exp>=801E, saturate result
asm("cmp cx, 31"); // more than 31 shifts needed?
asm("ja short trealxtoint0"); // if so, underflow to zero
asm("shr eax, cl"); // else ABS[result]=eax>>cl
asm("test ecx, 0x10000"); // test sign
asm("jz short trealxtoint3"); // skip if +
asm("neg eax");
asm("trealxtoint3:");
asm("pop ecx");
THISCALL_EPILOG0()
asm("trealxtoint1:"); // come here if exponent=FFFF
asm("cmp eax, 0x80000000"); // check for infinity
asm("jnz short trealxtoint0"); // if NaN, return 0
asm("test edx, edx");
asm("jnz short trealxtoint0"); // if NaN, return 0
asm("trealxtoint2:"); // come here if argument too big for 32-bit integer
asm("mov eax, 0x7FFFFFFF");
asm("shr ecx, 17"); // sign bit into carry flag
asm("adc eax, 0"); // eax=7FFFFFFF if +, 80000000 if -
asm("pop ecx");
THISCALL_EPILOG0() // return saturated value
asm("trealxtoint0:"); // come here if INT{argument}=0 or NaN
asm("xor eax, eax"); // return 0
asm("pop ecx");
THISCALL_EPILOG0()
}
__NAKED__ EXPORT_C TRealX::operator TUint() const
/**
Returns the extended precision value as an unsigned signed integer value.
The operator asm("returns:");
1. zero, if the extended precision value is not a number
2. 0xFFFFFFFF, if the value is positive and too big to fit into a TUint.
3. zero, if the value is negative and too big to fit into a TUint.
*/
{
// on entry ecx=this, return value in eax
THISCALL_PROLOG0()
asm("push ecx");
asm("mov edx, [ecx]"); // edx=mantissa low
asm("mov eax, [ecx+4]"); // eax=mantissa high
asm("mov ecx, [ecx+8]"); // ecx=exponent/sign
asm("ror ecx, 16"); // exponent into cx
asm("cmp cx, 0xFFFF");
asm("jz short trealxtouint1"); // branch if exp=FFFF
asm("mov dx, cx");
asm("mov cx, 0x801E");
asm("sub cx, dx"); // cx=number of right shifts needed to convert mantissa to int
asm("jb short trealxtouint2"); // if exp>801E, saturate result
asm("cmp cx, 31"); // more than 31 shifts needed?
asm("ja short trealxtouint0"); // if so, underflow to zero
asm("test ecx, 0x10000"); // test sign
asm("jnz short trealxtouint0"); // if -, return 0
asm("shr eax, cl"); // else result=eax>>cl
asm("pop ecx");
THISCALL_EPILOG0()
asm("trealxtouint1:"); // come here if exponent=FFFF
asm("cmp eax, 0x80000000"); // check for infinity
asm("jnz short trealxtouint0"); // if NaN, return 0
asm("test edx, edx");
asm("jnz short trealxtouint0"); // if NaN, return 0
asm("trealxtouint2:"); // come here if argument too big for 32-bit integer
asm("mov eax, 0xFFFFFFFF");
asm("shr ecx, 17"); // sign bit into carry flag
asm("adc eax, 0"); // eax=FFFFFFFF if +, 0 if -
asm("pop ecx");
THISCALL_EPILOG0() // return saturated value
asm("trealxtouint0:"); // come here if INT{argument}=0 or NaN
asm("xor eax, eax"); // return 0
asm("pop ecx");
THISCALL_EPILOG0()
}
LOCAL_C __NAKED__ void ConvertTRealXToTInt64(void)
{
// Convert TRealX in ecx,edx:ebx to TInt64 in edx:ebx
asm("ror ecx, 16"); // exponent into cx
asm("cmp cx, 0xFFFF");
asm("jz short trealxtoint64a"); // branch if exp=FFFF
asm("mov ax, cx");
asm("mov cx, 0x803E");
asm("sub cx, ax"); // cx=number of right shifts needed to convert mantissa to int
asm("jbe short trealxtoint64b"); // if exp>=803E, saturate result
asm("cmp cx, 63"); // more than 63 shifts needed?
asm("ja short trealxtoint64z"); // if so, underflow to zero
asm("cmp cl, 31"); // more than 31 shifts needed?
asm("jbe short trealxtoint64d"); // branch if not
asm("sub cl, 32"); // cl=shift count - 32
asm("mov ebx, edx"); // shift right by 32
asm("xor edx, edx");
asm("trealxtoint64d:");
asm("shrd ebx, edx, cl"); // shift edx:ebx right by cl to give ABS{result}
asm("shr edx, cl");
asm("test ecx, 0x10000"); // test sign
asm("jz short trealxtoint64c"); // skip if +
asm("neg edx"); // if -, negate
asm("neg ebx");
asm("sbb edx, 0");
asm("trealxtoint64c:");
asm("ret");
asm("trealxtoint64a:"); // come here if exponent=FFFF
asm("cmp edx, 0x80000000"); // check for infinity
asm("jnz short trealxtoint64z"); // if NaN, return 0
asm("test ebx, ebx");
asm("jnz short trealxtoint64z"); // if NaN, return 0
asm("trealxtoint64b:"); // come here if argument too big for 32-bit integer
asm("mov edx, 0x7FFFFFFF");
asm("mov ebx, 0xFFFFFFFF");
asm("shr ecx, 17"); // sign bit into carry flag
asm("adc ebx, 0"); // edx:ebx=7FFFFFFF FFFFFFFF if +,
asm("adc edx, 0"); // or 80000000 00000000 if -
asm("ret"); // return saturated value
asm("trealxtoint64z:"); // come here if INT{argument}=0 or NaN
asm("xor edx, edx"); // return 0
asm("xor ebx, ebx");
asm("ret");
}
/**
Returns the extended precision value as a 64 bit integer value.
The operator asm("returns:");
1. zero, if the extended precision value is not a number
2. 0x7FFFFFFF FFFFFFFF, if the value is positive and too big to fit
into a TInt64
3. 0x80000000 00000000, if the value is negative and too big to fit
into a TInt.
*/
__NAKED__ EXPORT_C TRealX::operator TInt64() const
{
// on entry, ecx=this, return value in edx:eax
THISCALL_PROLOG0()
asm("push ecx");
asm("push ebx");
asm("mov ebx, [ecx]"); // get TRealX value into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&ConvertTRealXToTInt64));
asm("mov eax, ebx"); // result low into eax
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG0()
}
LOCAL_C __NAKED__ void TRealXGetTReal32(void)
{
// Convert TRealX in ecx,edx:ebx to TReal32 in edx
// Return error code in eax
asm("cmp ecx, 0xFFFF0000"); // check for infinity/NaN
asm("jnc short trealxgettreal32a");
asm("xor eax, eax");
asm("ror ecx, 16"); // exponent into cx
asm("sub cx, 0x7F80"); // cx=result exponent if normalised
asm("jbe short trealxgettreal32b"); // jump if denormal, zero or underflow
asm("cmp cx, 0xFF"); // check if overflow
asm("jb short trealxgettreal32c"); // jump if not
asm("trealxgettreal32d:"); // come here if overflow
asm("xor edx, edx"); // set mantissa=0 to generate infinity
asm("ror ecx, 16"); // ecx back to normal format
asm("trealxgettreal32a:"); // come here if infinity or NaN
asm("shr edx, 7");
asm("or edx, 0xFF000000"); // set exponent to FF
asm("shr ecx, 1"); // sign bit -> carry
asm("rcr edx, 1"); // sign bit -> MSB of result
asm("mov eax, edx");
asm("shl eax, 9"); // test for infinity or NaN
asm("mov eax, -9"); // eax=KErrOverflow
asm("jz short trealxgettreal32e");
asm("mov eax, -6"); // if NaN, eax=KErrArgument
asm("trealxgettreal32e:");
asm("ret");
asm("trealxgettreal32b:"); // come here if exponent<=7F80
asm("cmp cx, -24"); // check for zero or total underflow
asm("jle short trealxgettreal32z");
asm("neg cl");
asm("inc cl"); // cl=number of right shifts to form denormal mantissa
asm("shrd eax, ebx, cl"); // shift mantissa right into eax
asm("shrd ebx, edx, cl");
asm("shr edx, cl");
asm("or edx, 0x80000000"); // set top bit to ensure correct rounding up
asm("xor cl, cl"); // cl=result exponent=0
asm("trealxgettreal32c:"); // come here if result normalised
asm("cmp dl, 0x80"); // check rounding bits
asm("ja short trealxgettreal32f"); // branch to round up
asm("jb short trealxgettreal32g"); // branch to round down
asm("test ebx, ebx");
asm("jnz short trealxgettreal32f"); // branch to round up
asm("test eax, eax");
asm("jnz short trealxgettreal32f"); // branch to round up
asm("test ecx, 0x01000000"); // check rounded-down flag
asm("jnz short trealxgettreal32f"); // branch to round up
asm("test ecx, 0x02000000"); // check rounded-up flag
asm("jnz short trealxgettreal32g"); // branch to round down
asm("test dh, 1"); // else round to even
asm("jz short trealxgettreal32g"); // branch to round down if LSB=0
asm("trealxgettreal32f:"); // come here to round up
asm("add edx, 0x100"); // increment mantissa
asm("jnc short trealxgettreal32g");
asm("rcr edx, 1");
asm("inc cl"); // if carry, increment exponent
asm("cmp cl, 0xFF"); // and check for overflow
asm("jz short trealxgettreal32d"); // branch out if overflow
asm("trealxgettreal32g:"); // come here to round down
asm("xor dl, dl");
asm("add edx, edx"); // shift out integer bit
asm("mov dl, cl");
asm("ror edx, 8"); // exponent->edx bits 24-31, mantissa in 23-1
asm("test edx, edx"); // check if underflow
asm("jz short trealxgettreal32h"); // branch out if underflow
asm("shr ecx, 17"); // sign bit->carry
asm("rcr edx, 1"); // ->edx bit 31, exp->edx bits 23-30, mant->edx bits 22-0
asm("xor eax, eax"); // return KErrNone
asm("ret");
asm("trealxgettreal32z:"); // come here if zero or underflow
asm("xor eax, eax");
asm("cmp cx, 0x8080"); // check for zero
asm("jz short trealxgettreal32y"); // if zero, return KErrNone
asm("trealxgettreal32h:"); // come here if underflow after rounding
asm("mov eax, -10"); // eax=KErrUnderflow
asm("trealxgettreal32y:");
asm("xor edx, edx");
asm("shr ecx, 17");
asm("rcr edx, 1"); // sign bit into edx bit 31, rest of edx=0
asm("ret");
}
LOCAL_C __NAKED__ void TRealXGetTReal64(void)
{
// Convert TRealX in ecx,edx:ebx to TReal64 in edx:ebx
// Return error code in eax
// edi, esi also modified
asm("ror ecx, 16"); // exponent into cx
asm("cmp cx, 0xFFFF"); // check for infinity/NaN
asm("jnc short trealxgettreal64a");
asm("xor eax, eax");
asm("xor edi, edi");
asm("sub cx, 0x7C00"); // cx=result exponent if normalised
asm("jbe short trealxgettreal64b"); // jump if denormal, zero or underflow
asm("cmp cx, 0x07FF"); // check if overflow
asm("jb short trealxgettreal64c"); // jump if not
asm("trealxgettreal64d:"); // come here if overflow
asm("xor edx, edx"); // set mantissa=0 to generate infinity
asm("xor ebx, ebx");
asm("trealxgettreal64a:"); // come here if infinity or NaN
asm("mov cl, 10");
asm("shrd ebx, edx, cl");
asm("shr edx, cl");
asm("or edx, 0xFFE00000"); // set exponent to 7FF
asm("shr ecx, 17"); // sign bit -> carry
asm("rcr edx, 1"); // sign bit -> MSB of result
asm("rcr ebx, 1");
asm("mov eax, edx");
asm("shl eax, 12"); // test for infinity or NaN
asm("mov eax, -9"); // eax=KErrOverflow
asm("jnz short trealxgettreal64n");
asm("test ebx, ebx");
asm("jz short trealxgettreal64e");
asm("trealxgettreal64n:");
asm("mov eax, -6"); // if NaN, eax=KErrArgument
asm("trealxgettreal64e:");
asm("ret");
asm("trealxgettreal64b:"); // come here if exponent<=7C00
asm("cmp cx, -53"); // check for zero or total underflow
asm("jle short trealxgettreal64z");
asm("neg cl");
asm("inc cl"); // cl=number of right shifts to form denormal mantissa
asm("cmp cl, 32");
asm("jb trealxgettreal64x");
asm("mov eax, ebx"); // if >=32 shifts, do 32 shifts and decrement count by 32
asm("mov ebx, edx");
asm("xor edx, edx");
asm("trealxgettreal64x:");
asm("shrd edi, eax, cl");
asm("shrd eax, ebx, cl"); // shift mantissa right into eax
asm("shrd ebx, edx, cl");
asm("shr edx, cl");
asm("or edx, 0x80000000"); // set top bit to ensure correct rounding up
asm("xor cx, cx"); // cx=result exponent=0
asm("trealxgettreal64c:"); // come here if result normalised
asm("mov esi, ebx");
asm("and esi, 0x7FF"); // esi=rounding bits
asm("cmp esi, 0x400"); // check rounding bits
asm("ja short trealxgettreal64f"); // branch to round up
asm("jb short trealxgettreal64g"); // branch to round down
asm("test eax, eax");
asm("jnz short trealxgettreal64f"); // branch to round up
asm("test edi, edi");
asm("jnz short trealxgettreal64f"); // branch to round up
asm("test ecx, 0x01000000"); // check rounded-down flag
asm("jnz short trealxgettreal64f"); // branch to round up
asm("test ecx, 0x02000000"); // check rounded-up flag
asm("jnz short trealxgettreal64g"); // branch to round down
asm("test ebx, 0x800"); // else round to even
asm("jz short trealxgettreal64g"); // branch to round down if LSB=0
asm("trealxgettreal64f:"); // come here to round up
asm("add ebx, 0x800"); // increment mantissa
asm("adc edx, 0");
asm("jnc short trealxgettreal64g");
asm("rcr edx, 1");
asm("inc cx"); // if carry, increment exponent
asm("cmp cx, 0x7FF"); // and check for overflow
asm("jz short trealxgettreal64d"); // branch out if overflow
asm("trealxgettreal64g:"); // come here to round down
asm("xor bl, bl"); // clear rounding bits
asm("and bh, 0xF8");
asm("mov di, cx"); // save exponent
asm("mov cl, 10");
asm("and edx, 0x7FFFFFFF"); // clear integer bit
asm("shrd ebx, edx, cl"); // shift mantissa right by 10
asm("shr edx, cl");
asm("shl edi, 21"); // exponent into edi bits 21-31
asm("or edx, edi"); // into edx bits 21-31
asm("test edx, edx"); // check if underflow
asm("jnz short trealxgettreal64i");
asm("test ebx, ebx");
asm("jz short trealxgettreal64h"); // branch out if underflow
asm("trealxgettreal64i:");
asm("shr ecx, 17"); // sign bit->carry
asm("rcr edx, 1"); // ->edx bit 31, exp->edx bits 20-30, mant->edx bits 20-0
asm("rcr ebx, 1");
asm("xor eax, eax"); // return KErrNone
asm("ret");
asm("trealxgettreal64z:"); // come here if zero or underflow
asm("xor eax, eax");
asm("cmp cx, 0x8400"); // check for zero
asm("jz short trealxgettreal64y"); // if zero, return KErrNone
asm("trealxgettreal64h:"); // come here if underflow after rounding
asm("mov eax, -10"); // eax=KErrUnderflow
asm("trealxgettreal64y:");
asm("xor edx, edx");
asm("xor ebx, ebx");
asm("shr ecx, 17");
asm("rcr edx, 1"); // sign bit into edx bit 31, rest of edx=0, ebx=0
asm("ret");
}
__NAKED__ EXPORT_C TRealX::operator TReal32() const
/**
Returns the extended precision value as
a single precision floating point value.
*/
{
// On entry, ecx=this
// On exit, TReal32 value on top of FPU stack
THISCALL_PROLOG0()
asm("push ecx");
asm("push ebx");
asm("mov ebx, [ecx]"); // *this into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXGetTReal32)); // Convert to TReal32 in edx
asm("push edx"); // push TReal32 onto stack
asm("fld dword ptr [esp]"); // push TReal32 onto FPU stack
asm("pop edx");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG0()
}
__NAKED__ EXPORT_C TRealX::operator TReal64() const
/**
Returns the extended precision value as
a double precision floating point value.
*/
{
// On entry, ecx=this
// On exit, TReal64 value on top of FPU stack
THISCALL_PROLOG0()
asm("push ecx");
asm("push ebx");
asm("push esi");
asm("push edi");
asm("mov ebx, [ecx]"); // *this into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXGetTReal64)); // Convert to TReal32 in edx:ebx
asm("push edx"); // push TReal64 onto stack
asm("push ebx");
asm("fld qword ptr [esp]"); // push TReal64 onto FPU stack
asm("add esp, 8");
asm("pop edi");
asm("pop esi");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG0()
}
__NAKED__ EXPORT_C TInt TRealX::GetTReal(TReal32& /*aVal*/) const
/**
Extracts the extended precision value as
a single precision floating point value.
@param aVal A reference to a single precision object which contains
the result of the operation.
@return KErrNone, if the operation is successful;
KErrOverflow, if the operation results in overflow;
KErrUnderflow, if the operation results in underflow.
*/
{
// On entry, ecx=this, [esp+4]=address of aVal
// On exit, eax=return code
THISCALL_PROLOG1()
asm("push ecx");
asm("push ebx");
asm("mov ebx, [ecx]"); // *this into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXGetTReal32));
asm("mov ecx, [esp+12]"); // ecx=address of aVal
asm("mov [ecx], edx"); // store result
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG1() // return with error code in eax
}
__NAKED__ EXPORT_C TInt TRealX::GetTReal(TReal64& /*aVal*/) const
/**
Extracts the extended precision value as
a double precision floating point value.
@param aVal A reference to a double precision object which
contains the result of the operation.
@return KErrNone, if the operation is successful;
KErrOverflow, if the operation results in overflow;
KErrUnderflow, if the operation results in underflow.
*/
{
// On entry, ecx=this, [esp+4]=address of aVal
// On exit, eax=return code
THISCALL_PROLOG1()
asm("push ecx");
asm("push ebx");
asm("push esi");
asm("push edi");
asm("mov ebx, [ecx]"); // *this into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXGetTReal64));
asm("mov ecx, [esp+20]"); // ecx=address of aVal
asm("mov [ecx], ebx"); // store result
asm("mov [ecx+4], edx");
asm("pop edi");
asm("pop esi");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG1() // return with error code in eax
}
__NAKED__ EXPORT_C void TRealX::SetZero(TBool /*aNegative*/)
/**
Sets the value of this extended precision object to zero.
@param aNegative ETrue, the value is a negative zero;
EFalse, the value is a positive zero, this is the default.
*/
{
THISCALL_PROLOG1()
asm("mov edx, [esp+4]"); // aNegative into edx
asm("xor eax, eax"); // eax=0
asm("mov [ecx], eax");
asm("mov [ecx+4], eax");
asm("test edx, edx");
asm("jz short setzero1");
asm("inc eax"); // eax=1 if aNegative!=0
asm("setzero1:");
asm("mov [ecx+8], eax"); // generate positive or negative zero
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C void TRealX::SetNaN()
/**
Sets the value of this extended precision object to 'not a number'.
*/
{
THISCALL_PROLOG0()
asm("xor eax, eax"); // set *this to 'real indefinite'
asm("mov [ecx], eax");
asm("mov eax, 0xC0000000");
asm("mov [ecx+4], eax");
asm("mov eax, 0xFFFF0001");
asm("mov [ecx+8], eax");
THISCALL_EPILOG0()
}
__NAKED__ EXPORT_C void TRealX::SetInfinite(TBool /*aNegative*/)
/**
Sets the value of this extended precision object to infinity.
@param aNegative ETrue, the value is a negative zero;
EFalse, the value is a positive zero.
*/
{
THISCALL_PROLOG1()
asm("mov edx, [esp+4]"); // aNegative into edx
asm("mov eax, 0xFFFF0000"); // exponent=FFFF, sign=0 initially
asm("test edx, edx");
asm("jz short setinf1");
asm("inc eax"); // sign=1 if aNegative!=0
asm("setinf1:");
asm("mov [ecx+8], eax");
asm("mov eax, 0x80000000"); // generate positive or negative infinity
asm("mov [ecx+4], eax");
asm("xor eax, eax");
asm("mov [ecx], eax");
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C TBool TRealX::IsZero() const
/**
Determines whether the extended precision value is zero.
@return True, if the extended precision value is zero, false, otherwise.
*/
{
THISCALL_PROLOG0()
asm("mov eax, [ecx+8]"); // check exponent
asm("shr eax, 16"); // move exponent into ax
asm("jz short iszero1"); // branch if zero
asm("xor eax, eax"); // else return 0
THISCALL_EPILOG0()
asm("iszero1:");
asm("inc eax"); // if zero, return 1
THISCALL_EPILOG0()
}
__NAKED__ EXPORT_C TBool TRealX::IsNaN() const
/**
Determines whether the extended precision value is 'not a number'.
@return True, if the extended precision value is 'not a number',
false, otherwise.
*/
{
THISCALL_PROLOG0()
asm("mov eax, [ecx+8]"); // check exponent
asm("cmp eax, 0xFFFF0000");
asm("jc short isnan0"); // branch if not FFFF
asm("mov eax, [ecx+4]");
asm("cmp eax, 0x80000000"); // check for infinity
asm("jne short isnan1");
asm("mov eax, [ecx]");
asm("test eax, eax");
asm("jne short isnan1");
asm("isnan0:");
asm("xor eax, eax"); // return 0 if not NaN
THISCALL_EPILOG0()
asm("isnan1:");
asm("mov eax, 1"); // return 1 if NaN
THISCALL_EPILOG0()
}
__NAKED__ EXPORT_C TBool TRealX::IsInfinite() const
/**
Determines whether the extended precision value has a finite value.
@return True, if the extended precision value is finite,
false, if the value is 'not a number' or is infinite,
*/
{
THISCALL_PROLOG0()
asm("mov eax, [ecx+8]"); // check exponent
asm("cmp eax, 0xFFFF0000");
asm("jc short isinf0"); // branch if not FFFF
asm("mov eax, [ecx+4]");
asm("cmp eax, 0x80000000"); // check for infinity
asm("jne short isinf0");
asm("mov eax, [ecx]");
asm("test eax, eax");
asm("jne short isinf0");
asm("inc eax"); // return 1 if infinity
THISCALL_EPILOG0()
asm("isinf0:");
asm("xor eax, eax"); // return 0 if not infinity
THISCALL_EPILOG0()
}
__NAKED__ EXPORT_C TBool TRealX::IsFinite() const
/**
Determines whether the extended precision value has a finite value.
@return True, if the extended precision value is finite,
false, if the value is 'not a number' or is infinite,
*/
{
THISCALL_PROLOG0()
asm("mov eax, [ecx+8]"); // check exponent
asm("cmp eax, 0xFFFF0000"); // check for NaN or infinity
asm("jnc short isfinite0"); // branch if NaN or infinity
asm("mov eax, 1"); // return 1 if finite
THISCALL_EPILOG0()
asm("isfinite0:");
asm("xor eax, eax"); // return 0 if NaN or infinity
THISCALL_EPILOG0()
}
__NAKED__ EXPORT_C const TRealX& TRealX::operator+=(const TRealX& /*aVal*/)
/**
Adds an extended precision value to this extended precision number.
@param aVal The extended precision value to be added.
@return A reference to this object.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of aVal
THISCALL_PROLOG1()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+20]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": :"i"(&TRealXAdd)); // do addition, result in ecx,edx:ebx, error code in eax
asm("mov [esi], ebx"); // store result in *this
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax");
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // return this in eax
asm("mov ecx, esi"); // restore registers
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C const TRealX& TRealX::operator-=(const TRealX& /*aVal*/)
/**
Subtracts an extended precision value from this extended precision number.
@param aVal The extended precision value to be subtracted.
@return A reference to this object.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of aVal
THISCALL_PROLOG1()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+20]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXSubtract)); // do subtraction, result in ecx,edx:ebx, error code in eax
asm("mov [esi], ebx"); // store result in *this
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax");
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // return this in eax
asm("mov ecx, esi"); // restore registers
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C const TRealX& TRealX::operator*=(const TRealX& /*aVal*/)
/**
Multiplies this extended precision number by an extended precision value.
@param aVal The extended precision value to be subtracted.
@return A reference to this object.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of aVal
THISCALL_PROLOG1()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // esi = this
asm("mov ecx, [esp+20]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXMultiply)); // do multiplication, result in ecx,edx:ebx, error code in eax
asm("mov [esi], ebx"); // store result in *this
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax");
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // return this in eax
asm("mov ecx, esi"); // restore registers
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C const TRealX& TRealX::operator/=(const TRealX& /*aVal*/)
/**
Divides this extended precision number by an extended precision value.
@param aVal The extended precision value to be used as the divisor.
@return A reference to this object.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
@panic MATHX KErrDivideByZero if the divisor is zero.
*/
{
// on entry ecx=this, [esp+4]=address of aVal
THISCALL_PROLOG1()
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+20]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXDivide)); // do division, result in ecx,edx:ebx, error code in eax
asm("mov [esi], ebx"); // store result in *this
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax");
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // return this in eax
asm("mov ecx, esi"); // restore registers
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C const TRealX& TRealX::operator%=(const TRealX& /*aVal*/)
/**
Modulo-divides this extended precision number by an extended precision value.
@param aVal The extended precision value to be used as the divisor.
@return A reference to this object.
@panic MATHX KErrTotalLossOfPrecision panic if precision is lost.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of aVal
THISCALL_PROLOG1()
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+20]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXModulo)); // do modulo, result in ecx,edx:ebx, error code in eax
asm("mov [esi], ebx"); // store result in *this
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax");
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // return this in eax
asm("mov ecx, esi"); // restore registers
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1()
}
__NAKED__ EXPORT_C TInt TRealX::AddEq(const TRealX& /*aVal*/)
/**
Adds an extended precision value to this extended precision number.
@param aVal The extended precision value to be added.
@return KErrNone, if the operation is successful;
KErrOverflow,if the operation results in overflow;
KErrUnderflow, if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of aVal
THISCALL_PROLOG1()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+20]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": :"i"(&TRealXAdd)); // do addition, result in ecx,edx:ebx, error code in eax
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("mov ecx, esi"); // restore registers
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1() // return with error code in eax
}
__NAKED__ EXPORT_C TInt TRealX::SubEq(const TRealX& /*aVal*/)
/**
Subtracts an extended precision value from this extended precision number.
@param aVal The extended precision value to be subtracted.
@return KErrNone, if the operation is successful;
KErrOverflow, if the operation results in overflow;
KErrUnderflow, if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of aVal
THISCALL_PROLOG1()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+20]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXSubtract)); // do subtraction, result in ecx,edx:ebx, error code in eax
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("mov ecx, esi"); // restore registers
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1() // return with error code in eax
}
__NAKED__ EXPORT_C TInt TRealX::MultEq(const TRealX& /*aVal*/)
/**
Multiplies this extended precision number by an extended precision value.
@param aVal The extended precision value to be used as the multiplier.
@return KErrNone, if the operation is successful;
KErrOverflow, if the operation results in overflow;
KErrUnderflow, if the operation results in underflow
*/
{
// on entry ecx=this, [esp+4]=address of aVal
THISCALL_PROLOG1()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+20]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXMultiply)); // do multiplication, result in ecx,edx:ebx, error code in eax
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("mov ecx, esi"); // restore registers
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1() // return with error code in eax
}
__NAKED__ EXPORT_C TInt TRealX::DivEq(const TRealX& /*aVal*/)
/**
Divides this extended precision number by an extended precision value.
@param aVal The extended precision value to be used as the divisor.
@return KErrNone, if the operation is successful;
KErrOverflow, if the operation results in overflow;
KErrUnderflow, if the operation results in underflow;
KErrDivideByZero, if the divisor is zero.
*/
{
// on entry ecx=this, [esp+4]=address of aVal
THISCALL_PROLOG1()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+20]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXDivide)); // do division, result in ecx,edx:ebx, error code in eax
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("mov ecx, esi"); // restore registers
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1() // return with error code in eax
}
__NAKED__ EXPORT_C TInt TRealX::ModEq(const TRealX& /*aVal*/)
/**
Modulo-divides this extended precision number by an extended precision value.
@param aVal The extended precision value to be used as the divisor.
@return KErrNone, if the operation is successful;
KErrTotalLossOfPrecision, if precision is lost;
KErrUnderflow, if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of aVal
THISCALL_PROLOG1()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+20]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXModulo)); // do modulo, result in ecx,edx:ebx, error code in eax
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("mov ecx, esi"); // restore registers
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1() // return with error code in eax
}
__NAKED__ EXPORT_C TRealX TRealX::operator+() const
/**
Returns this extended precision number unchanged.
Note that this may also be referred to as a unary plus operator.
@return The extended precision number.
*/
{
THISCALL_PROLOG0_BIGRETVAL()
asm("mov eax, [esp+4]"); // eax=address to write return value
asm("mov edx, [ecx]");
asm("mov [eax], edx");
asm("mov edx, [ecx+4]");
asm("mov [eax+4], edx");
asm("mov edx, [ecx+8]");
asm("mov [eax+8], edx"); // return address of return value in eax
THISCALL_EPILOG0_BIGRETVAL()
}
__NAKED__ EXPORT_C TRealX TRealX::operator-() const
/**
Negates this extended precision number.
This may also be referred to as a unary minus operator.
@return The negative of the extended precision number.
*/
{
THISCALL_PROLOG0_BIGRETVAL()
asm("mov eax, [esp+4]"); // eax=address to write return value
asm("mov edx, [ecx]");
asm("mov [eax], edx");
asm("mov edx, [ecx+4]");
asm("mov [eax+4], edx");
asm("mov edx, [ecx+8]");
asm("xor dl, 1"); // change sign bit
asm("mov [eax+8], edx");
THISCALL_EPILOG0_BIGRETVAL() // return address of return value in eax
}
__NAKED__ EXPORT_C TRealX& TRealX::operator++()
/**
Increments this extended precision number by one,
and then returns a reference to it.
This is also referred to as a prefix operator.
@return A reference to this object.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// pre-increment
// on entry ecx=this, return this in eax
THISCALL_PROLOG0()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, 0x7FFF0000"); // set ecx,edx:ebx to 1.0
asm("mov edx, 0x80000000");
asm("xor ebx, ebx");
asm("call %a0": :"i"(&TRealXAdd)); // add 1 to *this
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax"); // check error code
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // else return this in eax
asm("mov ecx, esi");
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG0()
}
__NAKED__ EXPORT_C TRealX TRealX::operator++(TInt)
/**
Returns this extended precision number before incrementing it by one.
This is also referred to as a postfix operator.
@return A reference to this object.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// post-increment
// on entry ecx=this, [esp+4]=address of return value, [esp+8]=dummy int
THISCALL_PROLOG1_BIGRETVAL()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov edi, [esp+20]"); // address of return value into edi
asm("mov eax, [ecx]"); // copy initial value of *this into [edi]
asm("mov [edi], eax");
asm("mov eax, [ecx+4]");
asm("mov [edi+4], eax");
asm("mov eax, [ecx+8]");
asm("mov [edi+8], eax");
asm("mov ecx, 0x7FFF0000"); // set ecx,edx:ebx to 1.0
asm("mov edx, 0x80000000");
asm("xor ebx, ebx");
asm("call %a0": :"i"(&TRealXAdd)); // add 1 to *this
asm("mov [esi], ebx"); // store result in *this
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax"); // check error code
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, [esp+20]"); // address of return value into eax
asm("mov ecx, esi");
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1_BIGRETVAL()
}
__NAKED__ EXPORT_C TRealX& TRealX::operator--()
/**
Decrements this extended precision number by one,
and then returns a reference to it.
This is also referred to as a prefix operator.
@return A reference to this object.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// pre-decrement
// on entry ecx=this, return this in eax
THISCALL_PROLOG0()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, 0x7FFF0001"); // set ecx,edx:ebx to -1.0
asm("mov edx, 0x80000000");
asm("xor ebx, ebx");
asm("call %a0": :"i"(&TRealXAdd)); // add -1 to *this
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax"); // check error code
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // else return this in eax
asm("mov ecx, esi");
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG0()
}
__NAKED__ EXPORT_C TRealX TRealX::operator--(TInt)
/**
Returns this extended precision number before decrementing it by one.
This is also referred to as a postfix operator.
@return A reference to this object.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// post-decrement
// on entry ecx=this, [esp+4]=address of return value, [esp+8]=dummy int
THISCALL_PROLOG1_BIGRETVAL()
asm("push ebx"); // save registers
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov edi, [esp+20]"); // address of return value into edi
asm("mov eax, [ecx]"); // copy initial value of *this into [edi]
asm("mov [edi], eax");
asm("mov eax, [ecx+4]");
asm("mov [edi+4], eax");
asm("mov eax, [ecx+8]");
asm("mov [edi+8], eax");
asm("mov ecx, 0x7FFF0001"); // set ecx,edx:ebx to -1.0
asm("mov edx, 0x80000000");
asm("xor ebx, ebx");
asm("call %a0": :"i"(&TRealXAdd)); // add -1 to *this
asm("mov [esi], ebx"); // store result in *this
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax"); // check error code
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, [esp+20]"); // address of return value into eax
asm("mov ecx, esi");
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
THISCALL_EPILOG1_BIGRETVAL()
}
__NAKED__ EXPORT_C TRealX TRealX::operator+(const TRealX& /*aVal*/) const
/**
Adds an extended precision value to this extended precision number.
@param aVal The extended precision value to be added.
@return An extended precision object containing the result.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of return value, [esp+8]=address of aVal
THISCALL_PROLOG1_BIGRETVAL()
asm("push ecx"); // save registers
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+28]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": :"i"(&TRealXAdd)); // do addition, result in ecx,edx:ebx, error code in eax
asm("mov esi, [esp+24]"); // esi=address of return value
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax");
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // return address of return value in eax
asm("pop edi"); // restore registers
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG1_BIGRETVAL()
}
__NAKED__ EXPORT_C TRealX TRealX::operator-(const TRealX& /*aVal*/) const
/**
Subtracts an extended precision value from this extended precision number.
@param aVal The extended precision value to be subtracted.
@return An extended precision object containing the result.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of return value, [esp+8]=address of aVal
THISCALL_PROLOG1_BIGRETVAL()
asm("push ecx"); // save registers
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+28]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXSubtract)); // do subtraction, result in ecx,edx:ebx, error code in eax
asm("mov esi, [esp+24]"); // esi=address of return value
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax");
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // return address of return value in eax
asm("pop edi"); // restore registers
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG1_BIGRETVAL()
}
__NAKED__ EXPORT_C TRealX TRealX::operator*(const TRealX& /*aVal*/) const
/**
Multiplies this extended precision number by an extended precision value.
@param aVal The extended precision value to be used as the multiplier.
@return An extended precision object containing the result.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of return value, [esp+8]=address of aVal
THISCALL_PROLOG1_BIGRETVAL()
asm("push ecx"); // save registers
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+28]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXMultiply)); // do multiplication, result in ecx,edx:ebx, error code in eax
asm("mov esi, [esp+24]"); // esi=address of return value
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax");
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // return address of return value in eax
asm("pop edi"); // restore registers
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG1_BIGRETVAL()
}
__NAKED__ EXPORT_C TRealX TRealX::operator/(const TRealX& /*aVal*/) const
/**
Divides this extended precision number by an extended precision value.
@param aVal The extended precision value to be used as the divisor.
@return An extended precision object containing the result.
@panic MATHX KErrOverflow if the operation results in overflow.
@panic MATHX KErrUnderflow if the operation results in underflow.
@panic MATHX KErrDivideByZero if the divisor is zero.
*/
{
// on entry ecx=this, [esp+4]=address of return value, [esp+8]=address of aVal
THISCALL_PROLOG1_BIGRETVAL()
asm("push ecx"); // save registers
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+28]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXDivide)); // do division, result in ecx,edx:ebx, error code in eax
asm("mov esi, [esp+24]"); // esi=address of return value
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax");
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // return address of return value in eax
asm("pop edi"); // restore registers
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG1_BIGRETVAL()
}
__NAKED__ EXPORT_C TRealX TRealX::operator%(const TRealX& /*aVal*/) const
/**
Modulo-divides this extended precision number by an extended precision value.
@param aVal The extended precision value to be used as the divisor.
@return An extended precision object containing the result.
@panic MATHX KErrTotalLossOfPrecision if precision is lost.
@panic MATHX KErrUnderflow if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of return value, [esp+8]=address of aVal
THISCALL_PROLOG1_BIGRETVAL()
asm("push ecx"); // save registers
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+28]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXModulo)); // do modulo, result in ecx,edx:ebx, error code in eax
asm("mov esi, [esp+24]"); // esi=address of return value
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("test eax, eax");
_ASM_jn(z,TRealXPanicEax) // panic if error
asm("mov eax, esi"); // return address of return value in eax
asm("pop edi"); // restore registers
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG1_BIGRETVAL()
}
__NAKED__ EXPORT_C TInt TRealX::Add(TRealX& /*aResult*/, const TRealX& /*aVal*/) const
/**
Adds an extended precision value to this extended precision number.
@param aResult On return, a reference to an extended precision object
containing the result of the operation.
@param aVal The extended precision value to be added.
@return KErrNone, if the operation is successful;
KErrOverflow, if the operation results in overflow;
KErrUnderflow, if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of aResult, [esp+8]=address of aVal
THISCALL_PROLOG2()
asm("push ecx"); // save registers
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+28]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": :"i"(&TRealXAdd)); // do addition, result in ecx,edx:ebx, error code in eax
asm("mov esi, [esp+24]"); // esi=address of aResult
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("pop edi"); // restore registers
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG2() // return with error code in eax
}
__NAKED__ EXPORT_C TInt TRealX::Sub(TRealX& /*aResult*/, const TRealX& /*aVal*/) const
/**
Subtracts an extended precision value from this extended precision number.
@param aResult On return, a reference to an extended precision object
containing the result of the operation.
@param aVal The extended precision value to be subtracted.
@return KErrNone, if the operation is successful;
KErrOverflow, if the operation results in overflow;
KErrUnderflow, if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of aResult, [esp+8]=address of aVal
THISCALL_PROLOG2()
asm("push ecx"); // save registers
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+28]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXSubtract)); // do subtraction, result in ecx,edx:ebx, error code in eax
asm("mov esi, [esp+24]"); // esi=address of aResult
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("pop edi"); // restore registers
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG2() // return with error code in eax
}
__NAKED__ EXPORT_C TInt TRealX::Mult(TRealX& /*aResult*/, const TRealX& /*aVal*/) const
/**
Multiplies this extended precision number by an extended precision value.
@param aResult On return, a reference to an extended precision object
containing the result of the operation.
@param aVal The extended precision value to be used as the multiplier.
@return KErrNone, if the operation is successful;
KErrOverflow, if the operation results in overflow;
KErrUnderflow, if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of aResult, [esp+8]=address of aVal
THISCALL_PROLOG2()
asm("push ecx"); // save registers
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+28]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXMultiply)); // do multiplication, result in ecx,edx:ebx, error code in eax
asm("mov esi, [esp+24]"); // esi=address of aResult
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("pop edi"); // restore registers
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG2() // return with error code in eax
}
__NAKED__ EXPORT_C TInt TRealX::Div(TRealX& /*aResult*/, const TRealX& /*aVal*/) const
/**
Divides this extended precision number by an extended precision value.
@param aResult On return, a reference to an extended precision object
containing the result of the operation.
@param aVal The extended precision value to be used as the divisor.
@return KErrNone, if the operation is successful;
KErrOverflow, if the operation results in overflow;
KErrUnderflow, if the operation results in underflow;
KErrDivideByZero, if the divisor is zero.
*/
{
// on entry ecx=this, [esp+4]=address of aResult, [esp+8]=address of aVal
THISCALL_PROLOG2()
asm("push ecx"); // save registers
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+28]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXDivide)); // do division, result in ecx,edx:ebx, error code in eax
asm("mov esi, [esp+24]"); // esi=address of aResult
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("pop edi"); // restore registers
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG2() // return with error code in eax
}
__NAKED__ EXPORT_C TInt TRealX::Mod(TRealX& /*aResult*/, const TRealX& /*aVal*/) const
/**
Modulo-divides this extended precision number by an extended precision value.
@param aResult On return, a reference to an extended precision object
containing the result of the operation.
@param aVal The extended precision value to be used as the divisor.
@return KErrNone, if the operation is successful;
KErrTotalLossOfPrecision, if precision is lost;
KErrUnderflow, if the operation results in underflow.
*/
{
// on entry ecx=this, [esp+4]=address of aResult, [esp+8]=address of aVal
THISCALL_PROLOG2()
asm("push ecx"); // save registers
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, ecx"); // this into esi
asm("mov ecx, [esp+28]"); // address of aVal into ecx
asm("mov ebx, [ecx]"); // aVal into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXModulo)); // do modulo, result in ecx,edx:ebx, error code in eax
asm("mov esi, [esp+24]"); // esi=address of aResult
asm("mov [esi], ebx"); // store result
asm("mov [esi+4], edx");
asm("mov [esi+8], ecx");
asm("pop edi"); // restore registers
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG2() // return with error code in eax
}
// Compare TRealX in ecx,edx:ebx (op1) to TRealX at [esi] (op2)
// Return 1 if op1<op2
// Return 2 if op1=op2
// Return 4 if op1>op2
// Return 8 if unordered
// Return value in eax
LOCAL_C __NAKED__ void TRealXCompare(void)
{
asm("cmp ecx, 0xFFFF0000"); // check if op1=NaN or infinity
asm("jc short fpcmp1"); // branch if not
asm("cmp edx, 0x80000000"); // check for infinity
asm("jnz short fpcmpunord"); // branch if NaN
asm("test ebx, ebx");
asm("jz short fpcmp1"); // if infinity, process normally
asm("fpcmpunord:"); // come here if unordered
asm("mov eax, 8"); // return 8
asm("ret");
asm("fpcmp1:"); // op1 is not a NaN
asm("mov eax, [esi+8]"); // get op2 into eax,edi:ebp
asm("mov edi, [esi+4]");
asm("mov ebp, [esi]");
asm("cmp eax, 0xFFFF0000"); // check for NaN or infinity
asm("jc short fpcmp2"); // branch if neither
asm("cmp edi, 0x80000000"); // check for infinity
asm("jnz short fpcmpunord"); // branch if NaN
asm("test ebp, ebp");
asm("jnz short fpcmpunord");
asm("fpcmp2:"); // neither operand is a NaN
asm("cmp ecx, 0x10000"); // check if op1=0
asm("jc short fpcmpop1z"); // branch if it is
asm("cmp eax, 0x10000"); // check if op2=0
asm("jc short fpcmp4"); // branch if it is
asm("xor al, cl"); // check if signs the same
asm("test al, 1");
asm("jnz short fpcmp4"); // branch if different
asm("push ecx");
asm("shr ecx, 16"); // op1 exponent into cx
asm("shr eax, 16"); // op2 exponent into ax
asm("cmp ecx, eax"); // compare exponents
asm("pop ecx");
asm("ja short fpcmp4"); // if op1 exp > op2 exp op1>op2 if +ve
asm("jb short fpcmp5"); // if op1 exp < op2 exp op1<op2 if +ve
asm("cmp edx, edi"); // else compare mantissa high words
asm("ja short fpcmp4");
asm("jb short fpcmp5");
asm("cmp ebx, ebp"); // if equal compare mantissa low words
asm("ja short fpcmp4");
asm("jb short fpcmp5");
asm("fpcmp0:");
asm("mov eax, 2"); // numbers exactly equal
asm("ret");
asm("fpcmp4:"); // come here if ABS{op1}>ABS{op2} or if signs different
// or if op2 zero, op1 nonzero
asm("mov eax, 4"); // return 4 if +ve
asm("test cl, 1"); // check sign
asm("jz short fpcmp4a"); // skip if +
asm("mov al, 1"); // return 1 if -ve
asm("fpcmp4a:");
asm("ret");
asm("fpcmp5:"); // come here if ABS{op1}<ABS{op2}
asm("mov eax, 1"); // return 1 if +ve
asm("test cl, 1"); // check sign
asm("jz short fpcmp5a"); // skip if +
asm("mov al, 4"); // return 4 if -ve
asm("fpcmp5a:");
asm("ret");
asm("fpcmpop1z:"); // come here if op1=0
asm("cmp eax, 0x10000"); // check if op2 also zero
asm("jc short fpcmp0"); // if so, they are equal
asm("test al, 1"); // test sign of op 2
asm("mov eax, 4"); // if -, return 4
asm("jnz short fpcmpop1z2n"); // skip if -
asm("mov al, 1"); // else return 1
asm("fpcmpop1z2n:");
asm("ret");
}
__NAKED__ EXPORT_C TRealX::TRealXOrder TRealX::Compare(const TRealX& /*aVal*/) const
/**
*/
{
// On entry ecx=this, [esp+4]=address of aVal
THISCALL_PROLOG1()
asm("push ecx"); // save registers
asm("push ebx");
asm("push ebp");
asm("push esi");
asm("push edi");
asm("mov esi, [esp+24]"); // address of aVal into esi
asm("mov ebx, [ecx]"); // *this into ecx,edx:ebx
asm("mov edx, [ecx+4]");
asm("mov ecx, [ecx+8]");
asm("call %a0": : "i"(&TRealXCompare)); // result in eax
asm("pop edi");
asm("pop esi");
asm("pop ebp");
asm("pop ebx");
asm("pop ecx");
THISCALL_EPILOG1()
}