| //===-- divsi3.S - 32-bit signed integer divide ---------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the __divsi3 (32-bit signed integer divide) function |
| // for the ARM architecture as a wrapper around the unsigned routine. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "../assembly.h" |
| |
| #define ESTABLISH_FRAME \ |
| push {r4, r7, lr} ;\ |
| add r7, sp, #4 |
| #define CLEAR_FRAME_AND_RETURN \ |
| pop {r4, r7, pc} |
| |
| .syntax unified |
| .text |
| DEFINE_CODE_STATE |
| |
| .p2align 3 |
| // Ok, APCS and AAPCS agree on 32 bit args, so it's safe to use the same routine. |
| DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_idiv, __divsi3) |
| |
| @ int __divsi3(int divident, int divisor) |
| @ Calculate and return the quotient of the (signed) division. |
| |
| DEFINE_COMPILERRT_FUNCTION(__divsi3) |
| #if __ARM_ARCH_EXT_IDIV__ |
| tst r1,r1 |
| beq LOCAL_LABEL(divzero) |
| sdiv r0, r0, r1 |
| bx lr |
| LOCAL_LABEL(divzero): |
| // Use movs for compatibility with v8-m.base. |
| movs r0,#0 |
| bx lr |
| #else |
| ESTABLISH_FRAME |
| // Set aside the sign of the quotient. |
| # if defined(USE_THUMB_1) |
| movs r4, r0 |
| eors r4, r1 |
| # else |
| eor r4, r0, r1 |
| # endif |
| // Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). |
| # if defined(USE_THUMB_1) |
| asrs r2, r0, #31 |
| asrs r3, r1, #31 |
| eors r0, r2 |
| eors r1, r3 |
| subs r0, r0, r2 |
| subs r1, r1, r3 |
| # else |
| eor r2, r0, r0, asr #31 |
| eor r3, r1, r1, asr #31 |
| sub r0, r2, r0, asr #31 |
| sub r1, r3, r1, asr #31 |
| # endif |
| // abs(a) / abs(b) |
| bl SYMBOL_NAME(__udivsi3) |
| // Apply sign of quotient to result and return. |
| # if defined(USE_THUMB_1) |
| asrs r4, #31 |
| eors r0, r4 |
| subs r0, r0, r4 |
| # else |
| eor r0, r0, r4, asr #31 |
| sub r0, r0, r4, asr #31 |
| # endif |
| CLEAR_FRAME_AND_RETURN |
| #endif |
| END_COMPILERRT_FUNCTION(__divsi3) |
| |
| NO_EXEC_STACK_DIRECTIVE |
| |
