mirror of git://sourceware.org/git/glibc.git
39 lines
1.4 KiB
C
39 lines
1.4 KiB
C
/* Get integer exponent of a floating-point value.
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Copyright (C) 1999-2025 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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static inline RET_TYPE
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IMPL_NAME (float x)
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{
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uint32_t ux = asuint (x);
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int ex = (ux & ~SIGN_MASK) >> MANTISSA_WIDTH;
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if (__glibc_unlikely (ex == 0))
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{
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/* Zero or subnormal.
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Clear sign and exponent. */
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ux <<= 1 + EXPONENT_WIDTH;
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if (ux == 0)
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return RET_INVALID (RET_LOGB0);
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/* subnormal */
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return (RET_TYPE)-127 - stdc_leading_zeros (ux);
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}
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if (__glibc_unlikely (ex == EXPONENT_MASK >> MANTISSA_WIDTH))
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/* NaN or Inf */
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return RET_INVALID (ux << (1 + EXPONENT_WIDTH) ? RET_LOGBNAN : RET_LOGMAX);
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return ex - 127;
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}
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