/*===-- divmodsi4.S - 32-bit signed integer divide and modulus ------------===//
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
*===----------------------------------------------------------------------===//
*
* This file implements the __divmodsi4 (32-bit signed integer divide and
* modulus) function for the ARM architecture. A naive digit-by-digit
* computation is employed for simplicity.
*
*===----------------------------------------------------------------------===*/
#include "../assembly.h"
#define ESTABLISH_FRAME \
push {r4-r7, lr} #define CLEAR_FRAME_AND_RETURN \
pop {r4-r7, pc}
.syntax unified
.align 3
DEFINE_COMPILERRT_FUNCTION(__divmodsi4)
ESTABLISH_FRAME
// Set aside the sign of the quotient and modulus, and the address for the
// modulus.
eor r4, r0, r1
mov r5, r0
mov r6, r2
// Take the absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31).
eor ip, r0, r0, asr #31
eor lr, r1, r1, asr #31
sub r0, ip, r0, asr #31
sub r1, lr, r1, asr #31
// Unsigned divmod:
bl SYMBOL_NAME(__udivmodsi4)
// Apply the sign of quotient and modulus
ldr r1, [r6]
eor r0, r0, r4, asr #31
eor r1, r1, r5, asr #31
sub r0, r0, r4, asr #31
sub r1, r1, r5, asr #31
str r1, [r6]
CLEAR_FRAME_AND_RETURN