From 93eb85ceb25ee7aff432ddea0abf559f53d7a5fc Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 24 Nov 2016 18:44:50 +0000 Subject: Refactor float_t, double_t information into bits/flt-eval-method.h. At present, definitions of float_t and double_t are split among many bits/mathdef.h headers. For all but three architectures, these types are float and double. Furthermore, if you assume __FLT_EVAL_METHOD__ to be defined, that provides a more generic way of determining the correct values of these typedefs. Defining these typedefs more generally based on __FLT_EVAL_METHOD__ was previously proposed by Paul Eggert in . This patch refactors things in the way I proposed in . A new header bits/flt-eval-method.h defines a single macro, __GLIBC_FLT_EVAL_METHOD, which is then used by math.h to define float_t and double_t. The default is based on __FLT_EVAL_METHOD__ (although actually a default to 0 would have the same effect for current ports, because ports where values other than 0 or 16 are possible all have their own headers). To avoid changing the existing semantics in any case, including for compilers not defining __FLT_EVAL_METHOD__, architecture-specific files are then added for m68k, s390, x86 which replicate the existing semantics. At least with __FLT_EVAL_METHOD__ values possible with GCC, there should be no change to the choices of float_t and double_t for any supported configuration. Architecture maintainer notes: * m68k: sysdeps/m68k/m680x0/bits/flt-eval-method.h always defines __GLIBC_FLT_EVAL_METHOD to 2 to replicate the existing logic. But actually GCC defines __FLT_EVAL_METHOD__ to 0 if TARGET_68040. It might make sense to make the header prefer to base things on __FLT_EVAL_METHOD__ if defined, like the x86 version, and so make the choices of these types more accurate (with a NEWS entry as for the other changes to these types on particular architectures). * s390: sysdeps/s390/bits/flt-eval-method.h always defines __GLIBC_FLT_EVAL_METHOD to 1 to replicate the existing logic. As previously discussed, it might make sense in coordination with GCC to eliminate the historic mistake, avoid excess precision in the -fexcess-precision=standard case and make the typedefs match (with a NEWS entry, again). Tested for x86-64 and x86. Also did compilation-only testing with build-many-glibcs.py. * bits/flt-eval-method.h: New file. * sysdeps/m68k/m680x0/bits/flt-eval-method.h: Likewise. * sysdeps/s390/bits/flt-eval-method.h: Likewise. * sysdeps/x86/bits/flt-eval-method.h: Likewise. * math/Makefile (headers): Add bits/flt-eval-method.h. * math/math.h: Include . [__USE_ISOC99] (float_t): Define based on __GLIBC_FLT_EVAL_METHOD. [__USE_ISOC99] (double_t): Likewise. * bits/mathdef.h (float_t): Remove. (double_t): Likewise. * sysdeps/aarch64/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/alpha/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/arm/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/hppa/fpu/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/ia64/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/m68k/m680x0/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/mips/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/powerpc/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/s390/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/sh/sh4/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/sparc/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/tile/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. * sysdeps/x86/bits/mathdef.h (float_t): Likewise. (double_t): Likewise. --- sysdeps/s390/bits/flt-eval-method.h | 24 ++++++++++++++++++++++++ sysdeps/s390/bits/mathdef.h | 7 ------- 2 files changed, 24 insertions(+), 7 deletions(-) create mode 100644 sysdeps/s390/bits/flt-eval-method.h (limited to 'sysdeps/s390/bits') diff --git a/sysdeps/s390/bits/flt-eval-method.h b/sysdeps/s390/bits/flt-eval-method.h new file mode 100644 index 0000000000..5793175fc5 --- /dev/null +++ b/sysdeps/s390/bits/flt-eval-method.h @@ -0,0 +1,24 @@ +/* Define __GLIBC_FLT_EVAL_METHOD. S/390 version. + Copyright (C) 2016 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 + . */ + +#ifndef _MATH_H +# error "Never use directly; include instead." +#endif + +/* This value is used because of a historical mistake. */ +#define __GLIBC_FLT_EVAL_METHOD 1 diff --git a/sysdeps/s390/bits/mathdef.h b/sysdeps/s390/bits/mathdef.h index 8c47ade208..5ad04aecef 100644 --- a/sysdeps/s390/bits/mathdef.h +++ b/sysdeps/s390/bits/mathdef.h @@ -22,13 +22,6 @@ #if defined __USE_ISOC99 && defined _MATH_H && !defined _MATH_H_MATHDEF # define _MATH_H_MATHDEF 1 -/* Normally, there is no long double type and the `float' and `double' - expressions are evaluated as `double'. */ -typedef double float_t; /* `float' expressions are evaluated as - `double'. */ -typedef double double_t; /* `double' expressions are evaluated as - `double'. */ - /* The values returned by `ilogb' for 0 and NaN respectively. */ # define FP_ILOGB0 (-2147483647) # define FP_ILOGBNAN 2147483647 -- cgit v1.2.3