40 lines
1.3 KiB
C
40 lines
1.3 KiB
C
//===-- ashrdi3.c - Implement __ashrdi3 -----------------------------------===//
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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 __ashrdi3 for the compiler_rt library.
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//
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//===----------------------------------------------------------------------===//
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#include "int_lib.h"
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// Returns: arithmetic a >> b
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// Precondition: 0 <= b < bits_in_dword
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COMPILER_RT_ABI di_int __ashrdi3(di_int a, int b) {
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const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT);
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dwords input;
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dwords result;
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input.all = a;
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if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */ {
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// result.s.high = input.s.high < 0 ? -1 : 0
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result.s.high = input.s.high >> (bits_in_word - 1);
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result.s.low = input.s.high >> (b - bits_in_word);
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} else /* 0 <= b < bits_in_word */ {
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if (b == 0)
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return a;
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result.s.high = input.s.high >> b;
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result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b);
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}
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return result.all;
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}
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#if defined(__ARM_EABI__)
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COMPILER_RT_ALIAS(__ashrdi3, __aeabi_lasr)
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#endif
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