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, 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 .p2align 3 29// Ok, APCS and AAPCS agree on 32 bit args, so it's safe to use the same routine. 30DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_idiv, __divsi3) 31 32@ int __divsi3(int divident, int divisor) 33@ Calculate and return the quotient of the (signed) division. 34 35#if __ARM_ARCH_ISA_THUMB == 2 36DEFINE_COMPILERRT_THUMB_FUNCTION(__divsi3) 37#else 38DEFINE_COMPILERRT_FUNCTION(__divsi3) 39#endif 40#if __ARM_ARCH_EXT_IDIV__ 41 tst r1,r1 42 beq LOCAL_LABEL(divzero) 43 sdiv r0, r0, r1 44 bx lr 45LOCAL_LABEL(divzero): 46 mov r0,#0 47 bx lr 48#else 49ESTABLISH_FRAME 50// Set aside the sign of the quotient. 51 eor r4, r0, r1 52// Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). 53 eor r2, r0, r0, asr #31 54 eor r3, r1, r1, asr #31 55 sub r0, r2, r0, asr #31 56 sub r1, r3, r1, asr #31 57// abs(a) / abs(b) 58 bl SYMBOL_NAME(__udivsi3) 59// Apply sign of quotient to result and return. 60 eor r0, r0, r4, asr #31 61 sub r0, r0, r4, asr #31 62 CLEAR_FRAME_AND_RETURN 63#endif 64END_COMPILERRT_FUNCTION(__divsi3) 65