// Copyright (c) 1995-2009 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\common\arm\cgcchelp.cia
//
//
#include "../common.h"
#ifdef __KERNEL_MODE__
#include "nkern.h"
#endif
extern "C" {
#ifdef __GCC32__
EXPORT_C __NAKED__ TInt __divsi3(TInt /*dividend*/,TInt /*divisor*/)
//
// Signed divide of r0 by r1: returns quotient in r0
// Quotient is truncated (rounded towards zero).
// Destroys r2, r3 and ip
// Negates dividend and divisor, then does an unsigned divide; signs
// get sorted out again at the end.
//
// Have to calculate the sign of the result for the end of the calculation.
// Store this in the LSB of ip which also saves the old lr.
//
{
asm("STMFD sp!, {lr} ");
asm("ANDS r3, r1, #0x80000000 "); // r3 bit 31=sign of divisor, rest of r3=0
asm("RSBMI r1, r1, #0 "); // r1=ABS(divisor)
asm("EORS ip, r3, r0, ASR #32 "); // ip bit 31=sign of quotient, all other bits=carry=sign of dividend
asm("RSBCS r0, r0, #0 "); // r0=ABS(dividend)
asm(".EXTERN ");
asm("BL __umodsi3_start ");
asm("MOV r0, r3 ");
asm("CMP ip, #0 "); // test sign of quotient
asm("RSBMI r0, r0, #0 "); // negate if necessary
__POPRET("");
}
EXPORT_C __NAKED__ TInt __modsi3(TInt /*dividend*/,TInt /*divisor*/)
//
// Signed divide of r0 by r1: returns remainder in r0
// Sign of remainder = sign of dividend.
// Destroys r2, r3 and ip
// Negates dividend and divisor, then does an unsigned divide; signs
// get sorted out again at the end.
//
// Have to save sign of dividend in order to apply sign to remainder
// at the end of the calculation. Store this in the LSB of ip which also
// saves the old lr.
//
{
asm("STMFD sp!, {lr} ");
asm("MOVS r1, r1 ");
asm("RSBMI r1, r1, #0 ");
asm("MOVS ip, r0 ");
asm("RSBMI r0, r0, #0 ");
asm(".EXTERN ");
asm("BL __umodsi3_start ");
asm("MOVS ip, ip ");
asm("RSBMI r0, r0, #0 ");
__POPRET("");
}
EXPORT_C __NAKED__ TUint __udivsi3(TUint /*dividend*/,TUint /*divisor*/)
//
// Unsigned divide of r0 by r1: returns quotient in r0
// Quotient is truncated (rounded towards zero).
// Destroys r2, r3 and ip
//
{
asm("MOV ip, lr ");
asm(".EXTERN ");
asm("BL __umodsi3_start ");
asm("MOV r0, r3 ");
__JUMP(,ip);
}
EXPORT_C __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,");
}
EXPORT_C __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,");
}
EXPORT_C __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,");
}
EXPORT_C __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);
}
EXPORT_C __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);
}
EXPORT_C __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);
}
EXPORT_C __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);
}
EXPORT_C __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);
}
EXPORT_C __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,");
}
EXPORT_C __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);
}
EXPORT_C __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
EXPORT_C __NAKED__ TUint __umodsi3(TUint /*dividend*/,TUint /*divisor*/)
//
// Unsigned divide of r0 by r1: returns remainder in r0, quotient in r3
// Sign of remainder = sign of dividend.
// Destroys r2, r3
//
{
asm("__umodsi3_start:");
//
// Use lookup table for divisors less than 17, and jump to
// an optimised routine if available
//
asm("MOV r3, #0 ");
asm("CMP r1, #16 ");
asm("LDRLS r3, [pc, #modtable - . - 8]");
asm("LDRLS r3, [r3, r1, asl #2] ");
asm("CMP r3, #0 ");
__JUMP(NE,r3);
//
// r3 must be zero when entering this point
//
asm("MOV r2, r1 ");
asm("__umodsi3_loop: ");
asm("CMP r2, r0, LSR #8 ");
asm("MOVLS r2, r2, LSL #8 ");
asm("BLO __umodsi3_loop ");
asm("CMP r2, r0, LSR #1 ");
asm("BHI __umodsi3_jump7 ");
asm("CMP r2, r0, LSR #2 ");
asm("BHI __umodsi3_jump6 ");
asm("CMP r2, r0, LSR #3 ");
asm("BHI __umodsi3_jump5 ");
asm("CMP r2, r0, LSR #4 ");
asm("BHI __umodsi3_jump4 ");
asm("CMP r2, r0, LSR #5 ");
asm("BHI __umodsi3_jump3 ");
asm("CMP r2, r0, LSR #6 ");
asm("BHI __umodsi3_jump2 ");
asm("CMP r2, r0, LSR #7 ");
asm("BHI __umodsi3_jump1 ");
asm("__umodsi3_loop2: ");
asm("MOVHI r2, r2, LSR #8 ");
asm("CMP r0, r2, LSL #7 ");
asm("ADC r3, r3, r3 ");
asm("SUBCS r0, r0, r2, LSL #7 ");
asm("CMP r0, r2, LSL #6 ");
asm("__umodsi3_jump1: ");
asm("ADC r3, r3, r3 ");
asm("SUBCS r0, r0, r2, LSL #6 ");
asm("CMP r0, r2, LSL #5 ");
asm("__umodsi3_jump2: ");
asm("ADC r3, r3, r3 ");
asm("SUBCS r0, r0, r2, LSL #5 ");
asm("CMP r0, r2, LSL #4 ");
asm("__umodsi3_jump3: ");
asm("ADC r3, r3, r3 ");
asm("SUBCS r0, r0, r2, LSL #4 ");
asm("CMP r0, r2, LSL #3 ");
asm("__umodsi3_jump4: ");
asm("ADC r3, r3, r3 ");
asm("SUBCS r0, r0, r2, LSL #3 ");
asm("CMP r0, r2, LSL #2 ");
asm("__umodsi3_jump5: ");
asm("ADC r3, r3, r3 ");
asm("SUBCS r0, r0, r2, LSL #2 ");
asm("CMP r0, r2, LSL #1 ");
asm("__umodsi3_jump6: ");
asm("ADC r3, r3, r3 ");
asm("SUBCS r0, r0, r2, LSL #1 ");
asm("__umodsi3_jump7: ");
asm("CMP r0, r2 ");
asm("ADC r3, r3, r3 ");
asm("SUBCS r0, r0, r2 ");
asm("CMP r2, r1 ");
asm("BNE __umodsi3_loop2 ");
__JUMP(,lr);
asm("modtable: ");
asm(".word mod_jump_table ");
//
// Lookup for optimised divide routines
//
asm("mod_jump_table: ");
asm(".word " DIV_BY_ZERO); // 0
asm(".word __mod1 "); // 1
asm(".word __mod2 "); // 2
asm(".word 0 "); // 3
asm(".word __mod4 "); // 4
asm(".word __mod5 "); // 5
asm(".word 0 "); // 6
asm(".word __mod7 "); // 7
asm(".word __mod8 "); // 8
asm(".word 0 "); // 9
asm(".word __mod10 "); // 10
asm(".word 0 "); // 11
asm(".word 0 "); // 12
asm(".word 0 "); // 13
asm(".word 0 "); // 14
asm(".word 0 "); // 15
asm(".word __mod16 "); // 16
asm("__mod16: ");
asm("MOV r3,r0,LSR #4 ");
asm("AND r0,r0,#15 ");
__JUMP(,lr);
asm("__mod1: ");
asm("MOV r3,r0 ");
asm("MOV r0,#0 ");
__JUMP(,lr);
asm("__mod2: ");
asm("MOV r3,r0,LSR #1 ");
asm("AND r0,r0,#1 ");
__JUMP(,lr);
asm("__mod4: ");
asm("MOV r3,r0,LSR #2 ");
asm("AND r0,r0,#3 ");
__JUMP(,lr);
asm("__mod8: ");
asm("MOV r3,r0,LSR #3 ");
asm("AND r0,r0,#7 ");
__JUMP(,lr);
asm("__mod10: ");
asm("MOV r3, r0 ");
asm("SUB r0, r3, #10 ");
asm("SUB r3, r3, r3, LSR #2 ");
asm("ADD r3, r3, r3, LSR #4 ");
asm("ADD r3, r3, r3, LSR #8 ");
asm("ADD r3, r3, r3, LSR #16 ");
asm("MOV r3, r3, LSR #3 ");
asm("ADD r2, r3, r3, ASL #2 ");
asm("SUBS r0, r0, r2, ASL #1 ");
asm("ADDPL r3, r3, #1 ");
asm("ADDMI r0, r0, #10 ");
__JUMP(,lr);
asm("__mod7: ");
asm("MOV r3, r0 ");
asm("SUB r0, r3, #7 ");
asm("MOV r3, r3, lsr #1 ");
asm("ADD r3, r3, r3, lsr #3 ");
asm("ADD r3, r3, r3, lsr #6 ");
asm("ADD r3, r3, r3, lsr #12 ");
asm("ADD r3, r3, r3, lsr #24 ");
asm("MOV r3, r3, lsr #2 ");
asm("RSB r2, r3, r3, asl #3 ");
asm("SUBS r0, r0, r2, asl #0 ");
asm("ADDPL r3, r3, #1 ");
asm("ADDMI r0, r0, #7 ");
__JUMP(,lr);
asm("__mod5: ");
asm("MOV r3, r0 ");
asm("SUB r0, r3, #5 ");
asm("SUB r3, r3, r3, lsr #2 ");
asm("ADD r3, r3, r3, lsr #4 ");
asm("ADD r3, r3, r3, lsr #8 ");
asm("ADD r3, r3, r3, lsr #16 ");
asm("MOV r3, r3, lsr #2 ");
asm("ADD r2, r3, r3, asl #2 ");
asm("SUBS r0, r0, r2, asl #0 ");
asm("ADDPL r3, r3, #1 ");
asm("ADDMI r0, r0, #5 ");
__JUMP(,lr);
}
EXPORT_C __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("stmfd sp!, {r11,lr} ");
__EH_FRAME_PUSH2(r11,lr)
asm("mov r11, sp ");
asm("bic sp, sp, #4 ");
asm("bl " DIV_BY_ZERO);
asm("mov sp, r11 ");
__POPRET("r11,");
}
}