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/*===-- modsi3.S - 32-bit signed integer 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 __modsi3 (32-bit signed integer modulus) function
* for the ARM architecture as a wrapper around the unsigned routine.
*
*===----------------------------------------------------------------------===*/
#include "../assembly.h"
#define ESTABLISH_FRAME \
push {r4, r7, lr} ;\
add r7, sp, #4
#define CLEAR_FRAME_AND_RETURN \
pop {r4, r7, pc}
.syntax unified
.text
#if __ARM_ARCH_ISA_THUMB == 2
.thumb
#endif
@ int __modsi3(int divident, int divisor)
@ Calculate and return the remainder of the (signed) division.
.p2align 3
#if __ARM_ARCH_ISA_THUMB == 2
DEFINE_COMPILERRT_THUMB_FUNCTION(__modsi3)
#else
DEFINE_COMPILERRT_FUNCTION(__modsi3)
#endif
#if __ARM_ARCH_EXT_IDIV__
tst r1, r1
beq LOCAL_LABEL(divzero)
sdiv r2, r0, r1
mls r0, r2, r1, r0
bx lr
LOCAL_LABEL(divzero):
mov r0, #0
bx lr
#else
ESTABLISH_FRAME
// Set aside the sign of the dividend.
mov r4, r0
// Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31).
eor r2, r0, r0, asr #31
eor r3, r1, r1, asr #31
sub r0, r2, r0, asr #31
sub r1, r3, r1, asr #31
// abs(a) % abs(b)
bl SYMBOL_NAME(__umodsi3)
// Apply sign of dividend to result and return.
eor r0, r0, r4, asr #31
sub r0, r0, r4, asr #31
CLEAR_FRAME_AND_RETURN
#endif
END_COMPILERRT_FUNCTION(__modsi3)
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