forked from OSchip/llvm-project
39 lines
1.4 KiB
C
39 lines
1.4 KiB
C
//===-- lib/fixdfsi.c - Double-precision -> integer conversion ----*- C -*-===//
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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 float to unsigned integer conversion for the
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// compiler-rt library.
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//
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//===----------------------------------------------------------------------===//
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#include "fp_lib.h"
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static __inline fixuint_t __fixuint(fp_t a) {
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// Break a into sign, exponent, significand parts.
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const rep_t aRep = toRep(a);
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const rep_t aAbs = aRep & absMask;
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const int sign = aRep & signBit ? -1 : 1;
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const int exponent = (aAbs >> significandBits) - exponentBias;
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const rep_t significand = (aAbs & significandMask) | implicitBit;
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// If either the value or the exponent is negative, the result is zero.
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if (sign == -1 || exponent < 0)
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return 0;
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// If the value is too large for the integer type, saturate.
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if ((unsigned)exponent >= sizeof(fixuint_t) * CHAR_BIT)
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return ~(fixuint_t)0;
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// If 0 <= exponent < significandBits, right shift to get the result.
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// Otherwise, shift left.
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if (exponent < significandBits)
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return significand >> (significandBits - exponent);
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else
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return (fixuint_t)significand << (exponent - significandBits);
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}
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