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, lr} 19#define CLEAR_FRAME_AND_RETURN \ 20 pop {r4, pc} 21 22 .syntax unified 23 .text 24#if __ARM_ARCH_ISA_THUMB == 2 25 .thumb 26#endif 27 28@ int __modsi3(int divident, int divisor) 29@ Calculate and return the remainder of the (signed) division. 30 31 .p2align 3 32#if __ARM_ARCH_ISA_THUMB == 2 33DEFINE_COMPILERRT_THUMB_FUNCTION(__modsi3) 34#else 35DEFINE_COMPILERRT_FUNCTION(__modsi3) 36#endif 37#if __ARM_ARCH_EXT_IDIV__ 38 tst r1, r1 39 beq LOCAL_LABEL(divzero) 40 sdiv r2, r0, r1 41 mls r0, r2, r1, r0 42 bx lr 43LOCAL_LABEL(divzero): 44 mov r0, #0 45 bx lr 46#else 47 ESTABLISH_FRAME 48 // Set aside the sign of the dividend. 49 mov r4, r0 50 // Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). 51 eor r2, r0, r0, asr #31 52 eor r3, r1, r1, asr #31 53 sub r0, r2, r0, asr #31 54 sub r1, r3, r1, asr #31 55 // abs(a) % abs(b) 56 bl SYMBOL_NAME(__umodsi3) 57 // Apply sign of dividend to result and return. 58 eor r0, r0, r4, asr #31 59 sub r0, r0, r4, asr #31 60 CLEAR_FRAME_AND_RETURN 61#endif 62END_COMPILERRT_FUNCTION(__modsi3) 63