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.p2align 3 25DEFINE_COMPILERRT_FUNCTION(__modsi3) 26#if __ARM_ARCH_EXT_IDIV__ 27 tst r1, r1 28 beq LOCAL_LABEL(divzero) 29 sdiv r2, r0, r1 30 mls r0, r2, r1, r0 31 bx lr 32LOCAL_LABEL(divzero): 33 mov r0, #0 34 bx lr 35#else 36 ESTABLISH_FRAME 37 // Set aside the sign of the dividend. 38 mov r4, r0 39 // Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). 40 eor r2, r0, r0, asr #31 41 eor r3, r1, r1, asr #31 42 sub r0, r2, r0, asr #31 43 sub r1, r3, r1, asr #31 44 // abs(a) % abs(b) 45 bl SYMBOL_NAME(__umodsi3) 46 // Apply sign of dividend to result and return. 47 eor r0, r0, r4, asr #31 48 sub r0, r0, r4, asr #31 49 CLEAR_FRAME_AND_RETURN 50#endif 51END_COMPILERRT_FUNCTION(__modsi3) 52