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//===-- divsi3.S - 32-bit signed integer divide ---------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the __divsi3 (32-bit signed integer divide) 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
DEFINE_CODE_STATE
.p2align 3
// Ok, APCS and AAPCS agree on 32 bit args, so it's safe to use the same routine.
DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_idiv, __divsi3)
@ int __divsi3(int divident, int divisor)
@ Calculate and return the quotient of the (signed) division.
DEFINE_COMPILERRT_FUNCTION(__divsi3)
#if __ARM_ARCH_EXT_IDIV__
tst r1,r1
beq LOCAL_LABEL(divzero)
sdiv r0, r0, r1
bx lr
LOCAL_LABEL(divzero):
mov r0,#0
bx lr
#else
ESTABLISH_FRAME
// Set aside the sign of the quotient.
# if defined(USE_THUMB_1)
movs r4, r0
eors r4, r1
# else
eor r4, r0, r1
# endif
// Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31).
# if defined(USE_THUMB_1)
asrs r2, r0, #31
asrs r3, r1, #31
eors r0, r2
eors r1, r3
subs r0, r0, r2
subs r1, r1, r3
# else
eor r2, r0, r0, asr #31
eor r3, r1, r1, asr #31
sub r0, r2, r0, asr #31
sub r1, r3, r1, asr #31
# endif
// abs(a) / abs(b)
bl SYMBOL_NAME(__udivsi3)
// Apply sign of quotient to result and return.
# if defined(USE_THUMB_1)
asrs r4, #31
eors r0, r4
subs r0, r0, r4
# else
eor r0, r0, r4, asr #31
sub r0, r0, r4, asr #31
# endif
CLEAR_FRAME_AND_RETURN
#endif
END_COMPILERRT_FUNCTION(__divsi3)
NO_EXEC_STACK_DIRECTIVE
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