43 lines
1.6 KiB
C
43 lines
1.6 KiB
C
/* clang-format off */
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//===-- lib/fixdfsi.c - Double-precision -> integer conversion ----*- C -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is dual licensed under the MIT and the University of Illinois Open
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// Source Licenses. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements float to integer conversion for the
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// compiler-rt library.
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//
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//===----------------------------------------------------------------------===//
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#include "third_party/compiler_rt/fp_lib.inc"
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static __inline fixint_t __fixint(fp_t a) {
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const fixint_t fixint_max = (fixint_t)((~(fixuint_t)0) / 2);
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const fixint_t fixint_min = -fixint_max - 1;
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// Break a into sign, exponent, significand
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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 fixint_t 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 exponent is negative, the result is zero.
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if (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(fixint_t) * CHAR_BIT)
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return sign == 1 ? fixint_max : fixint_min;
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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 sign * (significand >> (significandBits - exponent));
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else
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return sign * ((fixint_t)significand << (exponent - significandBits));
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}
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