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 26 .p2align 3 27// Ok, APCS and AAPCS agree on 32 bit args, so it's safe to use the same routine. 28DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_idiv, __divsi3) 29 30@ int __divsi3(int divident, int divisor) 31@ Calculate and return the quotient of the (signed) division. 32 33DEFINE_COMPILERRT_FUNCTION(__divsi3) 34#if __ARM_ARCH_EXT_IDIV__ 35 tst r1,r1 36 beq LOCAL_LABEL(divzero) 37 sdiv r0, r0, r1 38 bx lr 39LOCAL_LABEL(divzero): 40 mov r0,#0 41 bx lr 42#else 43ESTABLISH_FRAME 44// Set aside the sign of the quotient. 45 eor r4, r0, r1 46// Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). 47 eor r2, r0, r0, asr #31 48 eor r3, r1, r1, asr #31 49 sub r0, r2, r0, asr #31 50 sub r1, r3, r1, asr #31 51// abs(a) / abs(b) 52 bl SYMBOL_NAME(__udivsi3) 53// Apply sign of quotient to result and return. 54 eor r0, r0, r4, asr #31 55 sub r0, r0, r4, asr #31 56 CLEAR_FRAME_AND_RETURN 57#endif 58END_COMPILERRT_FUNCTION(__divsi3) 59