1/*===-- modsi3.S - 32-bit signed integer modulus --------------------------===//
2 *
3 *                     The LLVM Compiler Infrastructure
4 *
5 * This file is dual licensed under the MIT and the University of Illinois Open
6 * Source Licenses. See LICENSE.TXT for details.
7 *
8 *===----------------------------------------------------------------------===//
9 *
10 * This file implements the __modsi3 (32-bit signed integer modulus) function
11 * for the ARM architecture as a wrapper around the unsigned routine.
12 *
13 *===----------------------------------------------------------------------===*/
14
15#include "../assembly.h"
16
17#define ESTABLISH_FRAME \
18    push   {r4, r7, lr}    ;\
19    add     r7,     sp, #4
20#define CLEAR_FRAME_AND_RETURN \
21    pop    {r4, r7, pc}
22
23	.syntax unified
24	.text
25#if __ARM_ARCH_ISA_THUMB == 2
26	.thumb
27#endif
28
29@ int __modsi3(int divident, int divisor)
30@   Calculate and return the remainder of the (signed) division.
31
32	.p2align 3
33#if __ARM_ARCH_ISA_THUMB == 2
34DEFINE_COMPILERRT_THUMB_FUNCTION(__modsi3)
35#else
36DEFINE_COMPILERRT_FUNCTION(__modsi3)
37#endif
38#if __ARM_ARCH_EXT_IDIV__
39	tst     r1, r1
40	beq     LOCAL_LABEL(divzero)
41	sdiv	r2, r0, r1
42	mls 	r0, r2, r1, r0
43	bx      lr
44LOCAL_LABEL(divzero):
45	mov     r0, #0
46	bx      lr
47#else
48    ESTABLISH_FRAME
49    //  Set aside the sign of the dividend.
50    mov     r4,     r0
51    //  Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31).
52    eor     r2,     r0, r0, asr #31
53    eor     r3,     r1, r1, asr #31
54    sub     r0,     r2, r0, asr #31
55    sub     r1,     r3, r1, asr #31
56    //  abs(a) % abs(b)
57    bl     SYMBOL_NAME(__umodsi3)
58    //  Apply sign of dividend to result and return.
59    eor     r0,     r0, r4, asr #31
60    sub     r0,     r0, r4, asr #31
61    CLEAR_FRAME_AND_RETURN
62#endif
63END_COMPILERRT_FUNCTION(__modsi3)
64