1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
//===-- modsi3.S - 32-bit signed integer modulus --------------------------===//
//
// 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 __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
DEFINE_CODE_STATE
@ int __modsi3(int divident, int divisor)
@ Calculate and return the remainder of the (signed) division.
.p2align 3
DEFINE_COMPILERRT_FUNCTION(__modsi3)
#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)
NO_EXEC_STACK_DIRECTIVE
|
