--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/crypto/weakcryptospi/source/bigint/gcchelp.cpp Fri Nov 06 13:21:00 2009 +0200
@@ -0,0 +1,395 @@
+/*
+* Copyright (c) 2005-2009 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:
+*
+*/
+
+
+/**
+ @file
+*/
+
+
+#include <kernel\u32std.h> // need this for __NAKED__, __JUMP and __POPRET
+
+extern "C" {
+#ifdef __GCC32__
+__NAKED__ long long __divdi3(long long /*dividend*/, long long /*divisor*/)
+//
+// Dividend in r1:r0, divisor in r3:r2, Return quotient in r1:r0
+//
+ {
+ asm("stmfd sp!, {r4-r8,lr} ");
+ asm("eor r8, r1, r3 "); // sign of result into r8
+ asm("movs r1, r1 ");
+ asm("bpl 1f ");
+ asm("rsbs r0, r0, #0 "); // ABS(dividend)
+ asm("rsc r1, r1, #0 ");
+ asm("1: ");
+ asm("movs r3, r3 ");
+ asm("bpl 2f ");
+ asm("rsbs r2, r2, #0 "); // ABS(divisor)
+ asm("rsc r3, r3, #0 ");
+ asm("2: ");
+ asm("bl UDiv01 "); // do the division, result in r4,r5
+ asm("eors r0, r4, r8, asr #32 "); // quotient into r1:r0, inverted if quotient -ve
+ asm("eors r1, r5, r8, asr #32 ");
+ asm("adcs r0, r0, #0 "); // if quotient -ve, add 1
+ asm("adcs r1, r1, #0 ");
+ __POPRET("r4-r8,");
+ }
+
+__NAKED__ long long __moddi3(long long /*dividend*/, long long /*divisor*/) /* signed */
+ {
+ asm("stmfd sp!, {r4-r8,lr} ");
+ asm("movs r8, r1 "); // sign of remainder (=sign of dividend) into r8
+ asm("bpl 1f ");
+ asm("rsbs r0, r0, #0 "); // ABS(dividend)
+ asm("rsc r1, r1, #0 ");
+ asm("1: ");
+ asm("movs r3, r3 ");
+ asm("bpl 2f ");
+ asm("rsbs r2, r2, #0 "); // ABS(divisor)
+ asm("rsc r3, r3, #0 ");
+ asm("2: ");
+ asm("bl UDiv01 "); // do the division, remainder in r3,r6
+ asm("eors r0, r3, r8, asr #32 "); // remainder into r1:r0, inverted if dividend -ve
+ asm("eors r1, r6, r8, asr #32 ");
+ asm("adcs r0, r0, #0 "); // if dividend -ve, add 1
+ asm("adcs r1, r1, #0 ");
+ __POPRET("r4-r8,");
+ }
+
+__NAKED__ long long __umoddi3(unsigned long long /*dividend*/, unsigned long long /*divisor*/) /* unsigned */
+ {
+ asm("stmfd sp!, {r4-r7,lr} ");
+ asm("bl UDiv01 "); // do the division, remainder in r6:r3
+ asm("mov r0, r3 ");
+ asm("mov r1, r6 ");
+ __POPRET("r4-r7,");
+ }
+
+__NAKED__ long long __ashrdi3(long long /*value*/, unsigned int /*count*/)
+ {
+ asm("cmp r2, #63 ");
+ asm("movhi r2, #63 "); // count>63 same as count=63
+ asm("cmp r2, #32 ");
+ asm("bcs Asr01 "); // jump if shift count >=32
+ asm("rsb r12, r2, #32 "); // r12=32-shift count
+ asm("mov r0, r0, lsr r2 "); // shift ls word right
+ asm("orr r0, r0, r1, lsl r12 "); // or in bits shifted out of ms word
+ asm("mov r1, r1, asr r2 "); // shift ms word right
+ __JUMP(,lr);
+ asm("Asr01: ");
+ asm("sub r2, r2, #32 "); // r2=shift count-32
+ asm("mov r0, r1, asr r2 "); // ls word = ms word >> (count-32)
+ asm("mov r1, r1, asr #32 "); // ms word of result=sign extension of r1
+ __JUMP(,lr);
+ }
+
+__NAKED__ long long __ashldi3(long long /*value*/, unsigned int /*count*/)
+ {
+ asm("cmp r2, #63 ");
+ asm("movhi r2, #64 "); // count>63 same as count=64
+ asm("cmp r2, #32 ");
+ asm("bcs Asl01 "); // jump if shift count >=32
+ asm("rsb r12, r2, #32 "); // r12=32-shift count
+ asm("mov r1, r1, asl r2 "); // shift ms word left
+ asm("orr r1, r1, r0, lsr r12 "); // or in bits shifted out of ls word
+ asm("mov r0, r0, asl r2 "); // shift ls word left
+ __JUMP(,lr);
+ asm("Asl01: ");
+ asm("sub r2, r2, #32 "); // r2=shift count-32
+ asm("mov r1, r0, asl r2 "); // result ms word = ls word << (count-32)
+ asm("mov r0, #0 "); // ls word of result is zero
+ __JUMP(,lr);
+ }
+
+__NAKED__ unsigned long long __lshrdi3(unsigned long long /*value*/, unsigned int /*count*/)
+ {
+ asm("cmp r2, #63 ");
+ asm("movhi r2, #64 "); // count>63 same as count=64
+ asm("cmp r2, #32 ");
+ asm("bcs Lsr01 "); // jump if shift count >=32
+ asm("rsb r12, r2, #32 "); // r12=32-shift count
+ asm("mov r0, r0, lsr r2 "); // shift ls word right
+ asm("orr r0, r0, r1, lsl r12 "); // or in bits shifted out of ms word
+ asm("mov r1, r1, lsr r2 "); // shift ms word right
+ __JUMP(,lr);
+ asm("Lsr01: ");
+ asm("sub r2, r2, #32 "); // r2=shift count-32
+ asm("mov r0, r1, lsr r2 "); // ls word = ms word >> (count-32)
+ asm("mov r1, #0 "); // ms word of result = 0
+ __JUMP(,lr);
+ }
+
+__NAKED__ long long __muldi3(long long /*multiplicand*/, long long /*multiplier*/)
+ {
+ asm("mul r1, r2, r1 "); // r1=low2*high1
+ asm("mov ip, r0 "); // ip=low1
+ asm("mla r1, r0, r3, r1 "); // r1+=low1*high2
+ asm("mov r0, #0 ");
+ asm("umlal r0, r1, r2, ip "); // r1:r0 += high1*low1
+ __JUMP(,lr);
+ }
+
+__NAKED__ long long __negdi2(long long /*argument*/)
+ {
+ asm("rsbs r0, r0, #0 "); // r0=0-r0, set carry
+ asm("rscs r1, r1, #0 "); // r1=0-r1-(1-C)
+ __JUMP(,lr);
+ }
+
+__NAKED__ unsigned long long __udivmoddi4 (unsigned long long /*dividend*/,
+ unsigned long long /*divisor*/,
+ unsigned long long* /*p_remainder*/)
+ {
+ asm("stmfd sp!, {r4-r7,lr} ");
+ asm("bl UDiv01 "); // do the division, quotient in r5:r4 remainder in r6:r3
+ asm("ldr r7, [sp, #20] "); // r7=p_remainder
+ asm("mov r0, r4 "); // r0=quotient low
+ asm("stmia r7, {r3,r6} "); // store remainder
+ asm("mov r1, r5 "); // r0=quotient high
+ __POPRET("r4-r7,");
+ }
+
+__NAKED__ int __cmpdi2(long long /*a*/, long long /*b*/)
+ {
+ // return 0 if a<b, 1 if a=b, 2 if a>b
+ asm("subs r0, r2, r0 ");
+ asm("sbcs r1, r3, r1 "); // r1:r0 = b-a, set flags
+ asm("movlt r0, #2 "); // if b<a r0=2
+ __JUMP(lt,lr); // if b<a return
+ asm("cmpeq r0, #0 "); // if top word of difference=0, look at bottom
+ asm("moveq r0, #1 "); // if a=b, r0=1
+ asm("movne r0, #0 "); // else r=0
+ __JUMP(,lr);
+ }
+
+__NAKED__ int __ucmpdi2(unsigned long long /*a*/, unsigned long long /*b*/)
+ {
+ // return 0 if a<b, 1 if a=b, 2 if a>b
+ asm("cmp r1, r3 ");
+ asm("cmpeq r0, r2 "); // compare r1:r0 - r3:r2
+ asm("movhi r0, #2 "); // r0=2 if a>b
+ asm("moveq r0, #1 "); // r0=1 if a=b
+ asm("movlo r0, #0 "); // r0=0 if a<b
+ __JUMP(,lr);
+ }
+#endif
+
+#if defined(__GCC32__)
+void __division_by_zero();
+#define DIV_BY_ZERO " __division_by_zero "
+#elif defined(__ARMCC__)
+void __rt_div0 (void);
+#define DIV_BY_ZERO " __cpp(__rt_div0) "
+#endif
+
+void __division_by_zero()
+ {
+ RThread().RaiseException(EExcIntegerDivideByZero);
+ }
+
+__NAKED__ unsigned long long __udivdi3(unsigned long long /*dividend*/, unsigned long long /*divisor*/)
+//
+// Dividend in r1:r0, divisor in r3:r2, Return quotient in r1:r0
+//
+ {
+ asm("stmfd sp!, {r4-r7,lr} ");
+ asm("bl UDiv01 "); // do the division, result in r4,r5
+ asm("mov r0, r4 ");
+ asm("mov r1, r5 ");
+ __POPRET("r4-r7,");
+
+ // Unsigned 64-bit division. Dividend in r0,r1, divisor in r2,r3
+ // Quotient returned in r4,r5, Remainder in r3,r6
+ // Registers r0-r7,r12 used, r8-r11 unmodified
+ asm(".global UDiv01 ");
+ asm("UDiv01: ");
+ asm("movs r3, r3 "); // check if divisor fits in 32 bits
+ asm("bne udiv64a "); // branch if not
+ asm("movs r2, r2 "); // check if divisor fits in 31 bits
+ asm("bmi udiv64e "); // branch if not
+ asm("beq udiv64_divby0 "); // if divisor=0, branch to error routine
+
+ // Divisor is <0x80000000
+ // This means that a 32-bit accumulator is sufficient
+ asm("mov r4, #0 "); // use r3 as acc, result in r4, r5
+ asm("mov r5, #0 ");
+ asm("mov r6, #8 "); // do 2 set of 32 iterations
+ asm("udiv64b: ");
+ asm("adds r1, r1, r1 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r5, r5, r5 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r1, r1, r1 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r5, r5, r5 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r1, r1, r1 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r5, r5, r5 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r1, r1, r1 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r5, r5, r5 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("subs r6, r6, #1 "); // loop
+ asm("bne udiv64b ");
+ asm("mov r6, #8 "); // 2nd set of 32 iterations
+ asm("udiv64c: ");
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("subs r6, r6, #1 "); // loop
+ asm("bne udiv64c ");
+ __JUMP(,lr);
+
+ // 2^31 <= Divisor < 2^32
+ // Need 33-bit accumulator - use carry flag as 33rd bit
+ asm("udiv64e: ");
+ asm("mov r4, #0 "); // use r3 as acc, result in r4, r5
+ asm("mov r5, #0 ");
+ asm("mov r6, #8 "); // do 2 set of 32 iterations
+ asm("udiv64f: ");
+ asm("adds r1, r1, r1 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subcs r3, r3, r2 ");
+ asm("subccs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r5, r5, r5 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r1, r1, r1 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subcs r3, r3, r2 ");
+ asm("subccs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r5, r5, r5 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r1, r1, r1 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subcs r3, r3, r2 ");
+ asm("subccs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r5, r5, r5 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r1, r1, r1 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subcs r3, r3, r2 ");
+ asm("subccs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r5, r5, r5 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("subs r6, r6, #1 "); // loop
+ asm("bne udiv64f ");
+ asm("mov r6, #8 "); // 2nd set of 32 iterations
+ asm("udiv64g: ");
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subcs r3, r3, r2 ");
+ asm("subccs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subcs r3, r3, r2 ");
+ asm("subccs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subcs r3, r3, r2 ");
+ asm("subccs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r3, r3, r3 ");
+ asm("subcs r3, r3, r2 ");
+ asm("subccs r3, r3, r2 "); // subtract divisor from acc
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("addcc r3, r3, r2 "); // if borrow, add back
+ asm("subs r6, r6, #1 "); // loop
+ asm("bne udiv64g ");
+ __JUMP(,lr);
+
+ // Divisor >= 2^32, so quotient < 2^32
+ // Use 64 bit accumulator, 32 bit quotient
+ asm("udiv64a: ");
+ asm("mov r4, #0 "); // quotient in r4, use r1, r6 as accumulator
+ asm("mov r6, #0 ");
+ asm("mov r5, #8 "); // do 32 iterations
+ asm("udiv64d: ");
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r1, r1, r1 ");
+ asm("adcs r6, r6, r6 ");
+ asm("subs r7, r1, r2 "); // subtract divisor from acc, result into r7,r12
+ asm("sbcs r12, r6, r3 ");
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("movcs r1, r7 "); // if no borrow, update acc
+ asm("movcs r6, r12 ");
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r1, r1, r1 ");
+ asm("adcs r6, r6, r6 ");
+ asm("subs r7, r1, r2 "); // subtract divisor from acc, result into r7,r12
+ asm("sbcs r12, r6, r3 ");
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("movcs r1, r7 "); // if no borrow, update acc
+ asm("movcs r6, r12 ");
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r1, r1, r1 ");
+ asm("adcs r6, r6, r6 ");
+ asm("subs r7, r1, r2 "); // subtract divisor from acc, result into r7,r12
+ asm("sbcs r12, r6, r3 ");
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("movcs r1, r7 "); // if no borrow, update acc
+ asm("movcs r6, r12 ");
+ asm("adds r0, r0, r0 "); // shift dividend left into acc
+ asm("adcs r1, r1, r1 ");
+ asm("adcs r6, r6, r6 ");
+ asm("subs r7, r1, r2 "); // subtract divisor from acc, result into r7,r12
+ asm("sbcs r12, r6, r3 ");
+ asm("adc r4, r4, r4 "); // shift result bit left into quotient
+ asm("movcs r1, r7 "); // if no borrow, update acc
+ asm("movcs r6, r12 ");
+ asm("subs r5, r5, #1 "); // loop
+ asm("bne udiv64d ");
+ asm("mov r3, r1 "); // remainder in r3,r6
+ __JUMP(,lr);
+
+ asm("udiv64_divby0: ");
+ asm("str lr, [sp, #-4]! ");
+ asm("bl " DIV_BY_ZERO);
+ __POPRET("");
+ }
+
+}
+