1/*===-- divsi3.S - 32-bit signed integer divide ---------------------------===//
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 __divsi3 (32-bit signed integer divide) 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	.p2align 3
30// Ok, APCS and AAPCS agree on 32 bit args, so it's safe to use the same routine.
31DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_idiv, __divsi3)
32
33@ int __divsi3(int divident, int divisor)
34@   Calculate and return the quotient of the (signed) division.
35
36DEFINE_COMPILERRT_FUNCTION(__divsi3)
37#if __ARM_ARCH_EXT_IDIV__
38   tst     r1,r1
39   beq     LOCAL_LABEL(divzero)
40   sdiv    r0, r0, r1
41   bx      lr
42LOCAL_LABEL(divzero):
43   mov     r0,#0
44   bx      lr
45#else
46ESTABLISH_FRAME
47//  Set aside the sign of the quotient.
48    eor     r4,     r0, r1
49//  Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31).
50    eor     r2,     r0, r0, asr #31
51    eor     r3,     r1, r1, asr #31
52    sub     r0,     r2, r0, asr #31
53    sub     r1,     r3, r1, asr #31
54//  abs(a) / abs(b)
55    bl      SYMBOL_NAME(__udivsi3)
56//  Apply sign of quotient to result and return.
57    eor     r0,     r0, r4, asr #31
58    sub     r0,     r0, r4, asr #31
59    CLEAR_FRAME_AND_RETURN
60#endif
61END_COMPILERRT_FUNCTION(__divsi3)
62