| 1 | //===-- clzti2.c - Implement __clzti2 -------------------------------------===// |
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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 __clzti2 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: the number of leading 0-bits |
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| 18 | |
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| 19 | // Precondition: a != 0 |
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| 20 | |
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| 21 | COMPILER_RT_ABI int __clzti2(ti_int a) { |
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| 22 | twords x; |
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| 23 | x.all = a; |
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| 24 | const di_int f = -(x.s.high == 0); |
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| 25 | return __builtin_clzll((x.s.high & ~f) | (x.s.low & f)) + |
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| 26 | ((si_int)f & ((si_int)(sizeof(di_int) * CHAR_BIT))); |
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| 27 | } |
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| 28 | |
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| 29 | #endif // CRT_HAS_128BIT |
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| 30 | |
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