From b0216d3e4d98a3528bad428c22ff96fcbcc102a4 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Wed, 23 Nov 2016 00:28:30 +0000 Subject: Fix default float_t definition (bug 20855). The default (top-level) version of bits/mathdef.h defines float_t to double. It is used on ColdFire, MicroBlaze, Nios II and SH3, all of which define FLT_EVAL_METHOD to 0, so float_t should be float (and C11 requires a certain correspondence between these typedefs and FLT_EVAL_METHOD values). I proposed fixing this default in , with no objections from architecture maintainers, and this patch makes that fix. As noted in the NEWS entry added, this might affect the ABIs of non-glibc libraries (ImageMagick has been mentioned in gcc-patches discussion of the S/390 case - which is unaffected by this patch), but as noted in my previous message, affected libraries would have problems with -mfpmath=sse anyway on 32-bit x86. A (compilation) testcase is added to verify the required correspondence of typedefs to FLT_EVAL_METHOD values. This test is built with -fexcess-precision=standard to avoid any issues with GCC 7 on S/390 providing a more accurate FLT_EVAL_METHOD definition in the default (no excess precision) mode. (This will also be usable to test a fix for the recently reported bug about these typedefs on x86_64 -mfpmath=387, as architecture-specific tests can be added that It is entirely possible that the fixed default makes some architecture-specific versions of bits/mathdef.h semantically equivalent to the default version and so no longer required. I don't intend to investigate that separately from the refactoring I proposed in , which will create as few header variants as possible for each group of definitions. Tested (compilation only) with build-many-glibcs.py. [BZ #20855] * bits/mathdef.h (float_t): Define to float. * math/test-flt-eval-method.c: New file. * math/Makefile (tests): Add test-flt-eval-method. (CFLAGS-test-flt-eval-method.c): New variable. --- math/test-flt-eval-method.c | 65 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 math/test-flt-eval-method.c (limited to 'math/test-flt-eval-method.c') diff --git a/math/test-flt-eval-method.c b/math/test-flt-eval-method.c new file mode 100644 index 0000000..84706a5 --- /dev/null +++ b/math/test-flt-eval-method.c @@ -0,0 +1,65 @@ +/* Test evaluation method typedefs match FLT_EVAL_METHOD. + 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 + . */ + +#include +#include + +#if FLT_EVAL_METHOD == -1 +/* Cannot test. */ +typedef float_t my_float_t; +typedef double_t my_double_t; +#elif FLT_EVAL_METHOD == 0 || FLT_EVAL_METHOD == 16 +typedef float my_float_t; +typedef double my_double_t; +#elif FLT_EVAL_METHOD == 1 +typedef double my_float_t; +typedef double my_double_t; +#elif FLT_EVAL_METHOD == 2 +typedef long double my_float_t; +typedef long double my_double_t; +#elif FLT_EVAL_METHOD == 32 +typedef _Float32 my_float_t; +typedef double my_double_t; +#elif FLT_EVAL_METHOD == 33 +typedef _Float32x my_float_t; +typedef _Float32x my_double_t; +#elif FLT_EVAL_METHOD == 64 +typedef _Float64 my_float_t; +typedef _Float64 my_double_t; +#elif FLT_EVAL_METHOD == 65 +typedef _Float64x my_float_t; +typedef _Float64x my_double_t; +#elif FLT_EVAL_METHOD == 128 +typedef _Float128 my_float_t; +typedef _Float128 my_double_t; +#elif FLT_EVAL_METHOD == 129 +typedef _Float128x my_float_t; +typedef _Float128x my_double_t; +#else +# error "Unknown FLT_EVAL_METHOD" +#endif + +extern float_t test_float_t; +extern my_float_t test_float_t; + +extern double_t test_double_t; +extern my_double_t test_double_t; + +/* This is a compilation test. */ +#define TEST_FUNCTION 0 +#include "../test-skeleton.c" -- cgit v1.1