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#if __ARM_ARCH_ISA_THUMB == 2 26 .thumb 27#endif 28 29 .p2align 3 30// Ok, APCS and AAPCS agree on 32 bit args, so it's safe to use the same routine. 31DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_idiv, __divsi3) 32 33@ int __divsi3(int divident, int divisor) 34@ Calculate and return the quotient of the (signed) division. 35 36DEFINE_COMPILERRT_FUNCTION(__divsi3) 37#if __ARM_ARCH_EXT_IDIV__ 38 tst r1,r1 39 beq LOCAL_LABEL(divzero) 40 sdiv r0, r0, r1 41 bx lr 42LOCAL_LABEL(divzero): 43 mov r0,#0 44 bx lr 45#else 46ESTABLISH_FRAME 47// Set aside the sign of the quotient. 48 eor r4, r0, r1 49// Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). 50 eor r2, r0, r0, asr #31 51 eor r3, r1, r1, asr #31 52 sub r0, r2, r0, asr #31 53 sub r1, r3, r1, asr #31 54// abs(a) / abs(b) 55 bl SYMBOL_NAME(__udivsi3) 56// Apply sign of quotient to result and return. 57 eor r0, r0, r4, asr #31 58 sub r0, r0, r4, asr #31 59 CLEAR_FRAME_AND_RETURN 60#endif 61END_COMPILERRT_FUNCTION(__divsi3) 62