forked from OSchip/llvm-project
60 lines
1.7 KiB
ArmAsm
60 lines
1.7 KiB
ArmAsm
//===-- modsi3.S - 32-bit signed integer modulus --------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the __modsi3 (32-bit signed integer modulus) function
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// for the ARM architecture as a wrapper around the unsigned routine.
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//
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//===----------------------------------------------------------------------===//
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#include "../assembly.h"
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#define ESTABLISH_FRAME \
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push {r4, r7, lr} ;\
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add r7, sp, #4
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#define CLEAR_FRAME_AND_RETURN \
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pop {r4, r7, pc}
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.syntax unified
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.text
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DEFINE_CODE_STATE
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@ int __modsi3(int divident, int divisor)
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@ Calculate and return the remainder of the (signed) division.
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.p2align 3
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DEFINE_COMPILERRT_FUNCTION(__modsi3)
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#if __ARM_ARCH_EXT_IDIV__
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tst r1, r1
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beq LOCAL_LABEL(divzero)
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sdiv r2, r0, r1
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mls r0, r2, r1, r0
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bx lr
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LOCAL_LABEL(divzero):
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mov r0, #0
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bx lr
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#else
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ESTABLISH_FRAME
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// Set aside the sign of the dividend.
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mov r4, r0
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// Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31).
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eor r2, r0, r0, asr #31
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eor r3, r1, r1, asr #31
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sub r0, r2, r0, asr #31
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sub r1, r3, r1, asr #31
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// abs(a) % abs(b)
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bl SYMBOL_NAME(__umodsi3)
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// Apply sign of dividend to result and return.
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eor r0, r0, r4, asr #31
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sub r0, r0, r4, asr #31
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CLEAR_FRAME_AND_RETURN
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#endif
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END_COMPILERRT_FUNCTION(__modsi3)
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NO_EXEC_STACK_DIRECTIVE
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