| 1 | //===-- lib/fixdfsi.c - Double-precision -> integer conversion ----*- C -*-===// |
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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 float to unsigned integer conversion for the |
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| 10 | // compiler-rt library. |
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| 11 | // |
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| 12 | //===----------------------------------------------------------------------===// |
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| 13 | |
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| 14 | #include "fp_lib.h" |
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| 15 | |
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| 16 | static __inline fixuint_t __fixuint(fp_t a) { |
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| 17 | // Break a into sign, exponent, significand parts. |
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| 18 | const rep_t aRep = toRep(x: a); |
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| 19 | const rep_t aAbs = aRep & absMask; |
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| 20 | const int sign = aRep & signBit ? -1 : 1; |
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| 21 | const int exponent = (aAbs >> significandBits) - exponentBias; |
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| 22 | const rep_t significand = (aAbs & significandMask) | implicitBit; |
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| 23 | |
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| 24 | // If either the value or the exponent is negative, the result is zero. |
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| 25 | if (sign == -1 || exponent < 0) |
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| 26 | return 0; |
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| 27 | |
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| 28 | // If the value is too large for the integer type, saturate. |
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| 29 | if ((unsigned)exponent >= sizeof(fixuint_t) * CHAR_BIT) |
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| 30 | return ~(fixuint_t)0; |
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| 31 | |
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| 32 | // If 0 <= exponent < significandBits, right shift to get the result. |
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| 33 | // Otherwise, shift left. |
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| 34 | if (exponent < significandBits) |
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| 35 | return significand >> (significandBits - exponent); |
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| 36 | else |
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| 37 | return (fixuint_t)significand << (exponent - significandBits); |
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| 38 | } |
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| 39 | |
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