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 33DEFINE_COMPILERRT_FUNCTION(__modsi3) 34#if __ARM_ARCH_EXT_IDIV__ 35 tst r1, r1 36 beq LOCAL_LABEL(divzero) 37 sdiv r2, r0, r1 38 mls r0, r2, r1, r0 39 bx lr 40LOCAL_LABEL(divzero): 41 mov r0, #0 42 bx lr 43#else 44 ESTABLISH_FRAME 45 // Set aside the sign of the dividend. 46 mov r4, r0 47 // Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). 48 eor r2, r0, r0, asr #31 49 eor r3, r1, r1, asr #31 50 sub r0, r2, r0, asr #31 51 sub r1, r3, r1, asr #31 52 // abs(a) % abs(b) 53 bl SYMBOL_NAME(__umodsi3) 54 // Apply sign of dividend to result and return. 55 eor r0, r0, r4, asr #31 56 sub r0, r0, r4, asr #31 57 CLEAR_FRAME_AND_RETURN 58#endif 59END_COMPILERRT_FUNCTION(__modsi3) 60