From 6d3e953cceb62e066ea43c28d9160f018323e1a4 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Mon, 21 Apr 2025 13:45:31 -0300 Subject: math: Optimize float ilogb/llogb By removing the wrapper and setting FE_INVALID and errno inline. --- sysdeps/ieee754/flt-32/e_ilogbf.c | 42 +---------------------- sysdeps/ieee754/flt-32/w_ilogbf.c | 70 +++++++++++++++++++++++++++++++++++++++ sysdeps/ieee754/flt-32/w_llogbf.c | 2 ++ 3 files changed, 73 insertions(+), 41 deletions(-) create mode 100644 sysdeps/ieee754/flt-32/w_ilogbf.c create mode 100644 sysdeps/ieee754/flt-32/w_llogbf.c diff --git a/sysdeps/ieee754/flt-32/e_ilogbf.c b/sysdeps/ieee754/flt-32/e_ilogbf.c index 024b114638..a27fb94732 100644 --- a/sysdeps/ieee754/flt-32/e_ilogbf.c +++ b/sysdeps/ieee754/flt-32/e_ilogbf.c @@ -1,41 +1 @@ -/* Get integer exponent of a floating-point value. - Copyright (C) 1999-2025 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -#include -#include -#include -#include "math_config.h" - -int -__ieee754_ilogbf (float x) -{ - uint32_t ux = asuint (x); - int ex = (ux & ~SIGN_MASK) >> MANTISSA_WIDTH; - if (ex == 0) /* zero or subnormal */ - { - /* Clear sign and exponent. */ - ux <<= 1 + EXPONENT_WIDTH; - if (ux == 0) - return FP_ILOGB0; - /* sbunormal */ - return -127 - stdc_leading_zeros (ux); - } - if (ex == EXPONENT_MASK >> MANTISSA_WIDTH) /* NaN or Inf */ - return ux << (1 + EXPONENT_WIDTH) ? FP_ILOGBNAN : INT_MAX; - return ex - 127; -} +/* ilogbf is implemented at w_ilogbf.c */ diff --git a/sysdeps/ieee754/flt-32/w_ilogbf.c b/sysdeps/ieee754/flt-32/w_ilogbf.c new file mode 100644 index 0000000000..21e40c7721 --- /dev/null +++ b/sysdeps/ieee754/flt-32/w_ilogbf.c @@ -0,0 +1,70 @@ +/* Get integer exponent of a floating-point value. + Copyright (C) 1999-2025 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include +#include +#include +#include "math_config.h" + +#ifdef DEF_AS_LLOGBF +# define IMPL_NAME __llogb +# define FUNC_NAME llogb +# define RET_TYPE long int +# define RET_LOGB0 FP_LLOGB0 +# define RET_LOGBNAN FP_LLOGBNAN +# define RET_LOGMAX LONG_MAX +#else +# define IMPL_NAME __ilogb +# define FUNC_NAME ilogb +# define RET_TYPE int +# define RET_LOGB0 FP_ILOGB0 +# define RET_LOGBNAN FP_ILOGBNAN +# define RET_LOGMAX INT_MAX +#endif + +static inline RET_TYPE +invalid_ret (RET_TYPE r) +{ + __set_errno (EDOM); + __feraiseexcept (FE_INVALID); + return r; +} + +RET_TYPE +M_DECL_FUNC (IMPL_NAME) (float x) +{ + uint32_t ux = asuint (x); + int ex = (ux & ~SIGN_MASK) >> MANTISSA_WIDTH; + if (ex == 0) /* zero or subnormal */ + { + /* Clear sign and exponent. */ + ux <<= 1 + EXPONENT_WIDTH; + if (ux == 0) + return invalid_ret (RET_LOGB0); + /* sbunormal */ + return (RET_TYPE)-127 - stdc_leading_zeros (ux); + } + if (ex == EXPONENT_MASK >> MANTISSA_WIDTH) /* NaN or Inf */ + return invalid_ret (ux << (1 + EXPONENT_WIDTH) ? RET_LOGBNAN : RET_LOGMAX); + return ex - 127; +} +libm_alias_float (IMPL_NAME, FUNC_NAME); diff --git a/sysdeps/ieee754/flt-32/w_llogbf.c b/sysdeps/ieee754/flt-32/w_llogbf.c new file mode 100644 index 0000000000..8676434f6e --- /dev/null +++ b/sysdeps/ieee754/flt-32/w_llogbf.c @@ -0,0 +1,2 @@ +#define DEF_AS_LLOGBF +#include "w_ilogbf.c" -- cgit v1.2.3