| 1 | //===-- divsi3.S - 32-bit signed integer divide ---------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This file implements the __divsi3 (32-bit signed integer divide) function |
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| 10 | // for the ARM architecture as a wrapper around the unsigned routine. |
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| 11 | // |
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| 12 | //===----------------------------------------------------------------------===// |
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| 13 | |
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| 14 | #include "../assembly.h" |
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| 15 | |
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| 16 | #define ESTABLISH_FRAME \ |
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| 17 | push {r4, r7, lr} ;\ |
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| 18 | add r7, sp, #4 |
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| 19 | #define CLEAR_FRAME_AND_RETURN \ |
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| 20 | pop {r4, r7, pc} |
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| 21 | |
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| 22 | .syntax unified |
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| 23 | .text |
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| 24 | DEFINE_CODE_STATE |
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| 25 | |
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| 26 | .p2align 3 |
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| 27 | // Ok, APCS and AAPCS agree on 32 bit args, so it's safe to use the same routine. |
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| 28 | DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_idiv, __divsi3) |
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| 29 | |
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| 30 | @ int __divsi3(int divident, int divisor) |
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| 31 | @ Calculate and return the quotient of the (signed) division. |
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| 32 | |
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| 33 | DEFINE_COMPILERRT_FUNCTION(__divsi3) |
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| 34 | #if __ARM_ARCH_EXT_IDIV__ |
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| 35 | tst r1,r1 |
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| 36 | beq LOCAL_LABEL(divzero) |
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| 37 | sdiv r0, r0, r1 |
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| 38 | bx lr |
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| 39 | LOCAL_LABEL(divzero): |
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| 40 | // Use movs for compatibility with v8-m.base. |
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| 41 | movs r0,#0 |
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| 42 | bx lr |
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| 43 | #else |
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| 44 | ESTABLISH_FRAME |
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| 45 | // Set aside the sign of the quotient. |
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| 46 | # if defined(USE_THUMB_1) |
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| 47 | movs r4, r0 |
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| 48 | eors r4, r1 |
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| 49 | # else |
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| 50 | eor r4, r0, r1 |
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| 51 | # endif |
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| 52 | // Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). |
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| 53 | # if defined(USE_THUMB_1) |
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| 54 | asrs r2, r0, #31 |
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| 55 | asrs r3, r1, #31 |
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| 56 | eors r0, r2 |
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| 57 | eors r1, r3 |
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| 58 | subs r0, r0, r2 |
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| 59 | subs r1, r1, r3 |
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| 60 | # else |
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| 61 | eor r2, r0, r0, asr #31 |
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| 62 | eor r3, r1, r1, asr #31 |
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| 63 | sub r0, r2, r0, asr #31 |
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| 64 | sub r1, r3, r1, asr #31 |
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| 65 | # endif |
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| 66 | // abs(a) / abs(b) |
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| 67 | bl SYMBOL_NAME(__udivsi3) |
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| 68 | // Apply sign of quotient to result and return. |
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| 69 | # if defined(USE_THUMB_1) |
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| 70 | asrs r4, #31 |
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| 71 | eors r0, r4 |
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| 72 | subs r0, r0, r4 |
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| 73 | # else |
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| 74 | eor r0, r0, r4, asr #31 |
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| 75 | sub r0, r0, r4, asr #31 |
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| 76 | # endif |
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| 77 | CLEAR_FRAME_AND_RETURN |
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| 78 | #endif |
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| 79 | END_COMPILERRT_FUNCTION(__divsi3) |
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| 80 | |
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| 81 | NO_EXEC_STACK_DIRECTIVE |
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| 82 | |
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| 83 | |
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