| 1 | //===-- lshrti3.c - Implement __lshrti3 -----------------------------------===// |
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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 __lshrti3 for the compiler_rt library. |
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| 10 | // |
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| 11 | //===----------------------------------------------------------------------===// |
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| 12 | |
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| 13 | #include "int_lib.h" |
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| 14 | |
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| 15 | #ifdef CRT_HAS_128BIT |
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| 16 | |
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| 17 | // Returns: logical a >> b |
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| 18 | |
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| 19 | // Precondition: 0 <= b < bits_in_tword |
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| 20 | |
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| 21 | COMPILER_RT_ABI ti_int __lshrti3(ti_int a, int b) { |
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| 22 | const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT); |
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| 23 | utwords input; |
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| 24 | utwords result; |
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| 25 | input.all = a; |
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| 26 | if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ { |
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| 27 | result.s.high = 0; |
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| 28 | result.s.low = input.s.high >> (b - bits_in_dword); |
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| 29 | } else /* 0 <= b < bits_in_dword */ { |
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| 30 | if (b == 0) |
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| 31 | return a; |
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| 32 | result.s.high = input.s.high >> b; |
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| 33 | result.s.low = (input.s.high << (bits_in_dword - b)) | (input.s.low >> b); |
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| 34 | } |
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| 35 | return result.all; |
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| 36 | } |
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| 37 | |
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| 38 | #endif // CRT_HAS_128BIT |
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| 39 | |
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