divsi3.S revision 222656
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.align 3 25// Ok, APCS and AAPCS agree on 32 bit args, so it's safe to use the same routine. 26DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_idiv, __divsi3) 27DEFINE_COMPILERRT_FUNCTION(__divsi3) 28 ESTABLISH_FRAME 29// Set aside the sign of the quotient. 30 eor r4, r0, r1 31// Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). 32 eor r2, r0, r0, asr #31 33 eor r3, r1, r1, asr #31 34 sub r0, r2, r0, asr #31 35 sub r1, r3, r1, asr #31 36// abs(a) / abs(b) 37 bl SYMBOL_NAME(__udivsi3) 38// Apply sign of quotient to result and return. 39 eor r0, r0, r4, asr #31 40 sub r0, r0, r4, asr #31 41 CLEAR_FRAME_AND_RETURN 42