| Message ID | alpine.DEB.2.20.1806121657420.18047@digraph.polyomino.org.uk |
|---|---|
| State | New |
| Headers | show |
| Series | Do not use const attribute for nan functions (bug 23277) [committed] | expand |
* Joseph Myers: > +static int > +do_test (void) > +{ > + char buf[2] = { '2', 0 }; > + float a = nanf (buf); > + buf[0] = '3'; > + float b = nanf (buf); > + return memcmp (&a, &b, sizeof (float)) == 0; > +} By the way, there's TEST_COMPARE_BLOB now, which can simplify debugging of test failures because the failure message includes the blobs that differ.
On Tue, 12 Jun 2018, Florian Weimer wrote: > * Joseph Myers: > > > +static int > > +do_test (void) > > +{ > > + char buf[2] = { '2', 0 }; > > + float a = nanf (buf); > > + buf[0] = '3'; > > + float b = nanf (buf); > > + return memcmp (&a, &b, sizeof (float)) == 0; > > +} > > By the way, there's TEST_COMPARE_BLOB now, which can simplify > debugging of test failures because the failure message includes the > blobs that differ. In this case, the requirement is actually that the blobs must differ, with a failure if they are the same (if the compiler optimized out the second nanf call and so produced the same NaN for both calls).
* Joseph Myers: > On Tue, 12 Jun 2018, Florian Weimer wrote: > >> * Joseph Myers: >> >> > +static int >> > +do_test (void) >> > +{ >> > + char buf[2] = { '2', 0 }; >> > + float a = nanf (buf); >> > + buf[0] = '3'; >> > + float b = nanf (buf); >> > + return memcmp (&a, &b, sizeof (float)) == 0; >> > +} >> >> By the way, there's TEST_COMPARE_BLOB now, which can simplify >> debugging of test failures because the failure message includes the >> blobs that differ. > > In this case, the requirement is actually that the blobs must differ, with > a failure if they are the same (if the compiler optimized out the second > nanf call and so produced the same NaN for both calls). Oh, right. I was confused.
diff --git a/math/Makefile b/math/Makefile index ea141cb..335b1fb 100644 --- a/math/Makefile +++ b/math/Makefile @@ -235,7 +235,7 @@ tests = test-matherr-3 test-fenv basic-test \ test-iseqsig-excess-precision test-flt-eval-method \ test-fp-ilogb-constants test-fp-llogb-constants \ test-fe-snans-always-signal test-finite-macros test-narrow-macros \ - $(tests-static) + test-nan-const $(tests-static) tests-static = test-fpucw-static test-fpucw-ieee-static \ test-signgam-uchar-static test-signgam-uchar-init-static \ test-signgam-uint-static test-signgam-uint-init-static \ @@ -442,6 +442,8 @@ CFLAGS-test-fe-snans-always-signal.c += -fsignaling-nans CFLAGS-test-finite-macros.c += -ffinite-math-only +CFLAGS-test-nan-const.c += -fno-builtin + include ../Rules gen-all-calls = $(gen-libm-calls) $(gen-calls) diff --git a/math/bits/mathcalls.h b/math/bits/mathcalls.h index 9200363..cf87313 100644 --- a/math/bits/mathcalls.h +++ b/math/bits/mathcalls.h @@ -198,7 +198,7 @@ __MATHCALLX (copysign,, (_Mdouble_ __x, _Mdouble_ __y), (__const__)); #ifdef __USE_ISOC99 /* Return representation of qNaN for double type. */ -__MATHCALLX (nan,, (const char *__tagb), (__const__)); +__MATHCALL (nan,, (const char *__tagb)); #endif diff --git a/math/test-nan-const.c b/math/test-nan-const.c new file mode 100644 index 0000000..f7bba9e --- /dev/null +++ b/math/test-nan-const.c @@ -0,0 +1,32 @@ +/* Test nan functions do not have const attribute. Bug 23277. + Copyright (C) 2018 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 + <http://www.gnu.org/licenses/>. */ + +#include <math.h> +#include <string.h> + +static int +do_test (void) +{ + char buf[2] = { '2', 0 }; + float a = nanf (buf); + buf[0] = '3'; + float b = nanf (buf); + return memcmp (&a, &b, sizeof (float)) == 0; +} + +#include <support/test-driver.c>