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authorJoseph Myers <joseph@codesourcery.com>2014-03-26 18:59:08 +0000
committerJoseph Myers <joseph@codesourcery.com>2014-03-26 18:59:08 +0000
commit9be36fb8cb5bcdab5bbbc7a36388dc9a3d1cc397 (patch)
tree2cc35309dc7cb65fbe9f8fe46762edf8a50a7f02
parent60a2f3c166cebf56048d00cee47b9ed1969844d6 (diff)
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Make x86_64 fegetenv preserve exception mask (bug 16198).
Bug 16198 is x86_64 fegetenv wrongly masking exceptions for which traps are enabled, because that's a side-effect of the fnstenv instruction. This patch fixes it to use fldenv immediately after fnstenv, like the i386 version. Tested x86_64 and x86. [BZ #16198] * sysdeps/x86_64/fpu/fegetenv.c (fegetenv): Use fldenv after fnstenv. * math/test-fenv-preserve.c: New file. * math/Makefile (tests): Add test-fenv-preserve.
-rw-r--r--ChangeLog8
-rw-r--r--NEWS8
-rw-r--r--math/Makefile2
-rw-r--r--math/test-fenv-preserve.c53
-rw-r--r--sysdeps/x86_64/fpu/fegetenv.c3
5 files changed, 69 insertions, 5 deletions
diff --git a/ChangeLog b/ChangeLog
index c3d2ada..20af1be 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2014-03-26 Joseph Myers <joseph@codesourcery.com>
+
+ [BZ #16198]
+ * sysdeps/x86_64/fpu/fegetenv.c (fegetenv): Use fldenv after
+ fnstenv.
+ * math/test-fenv-preserve.c: New file.
+ * math/Makefile (tests): Add test-fenv-preserve.
+
2014-03-26 Will Newton <will.newton@linaro.org>
* benchtests/bench-strtod.c (TIMEOUT): Define to 10.
diff --git a/NEWS b/NEWS
index 1dbce87..6f16584 100644
--- a/NEWS
+++ b/NEWS
@@ -9,10 +9,10 @@ Version 2.20
* The following bugs are resolved with this release:
- 15347, 15804, 15894, 16002, 16284, 16357, 16447, 16532, 16545, 16574,
- 16599, 16600, 16609, 16610, 16611, 16613, 16623, 16632, 16634, 16639,
- 16642, 16649, 16670, 16674, 16677, 16680, 16683, 16689, 16695, 16701,
- 16706, 16707, 16712, 16713, 16714, 16731, 16743.
+ 15347, 15804, 15894, 16002, 16198, 16284, 16357, 16447, 16532, 16545,
+ 16574, 16599, 16600, 16609, 16610, 16611, 16613, 16623, 16632, 16634,
+ 16639, 16642, 16649, 16670, 16674, 16677, 16680, 16683, 16689, 16695,
+ 16701, 16706, 16707, 16712, 16713, 16714, 16731, 16743.
* Running the testsuite no longer terminates as soon as a test fails.
Instead, a file tests.sum (xtests.sum from "make xcheck") is generated,
diff --git a/math/Makefile b/math/Makefile
index 09d14a0..c13ca80 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -90,7 +90,7 @@ tests = test-matherr test-fenv atest-exp atest-sincos atest-exp2 basic-test \
test-misc test-fpucw test-fpucw-ieee tst-definitions test-tgmath \
test-tgmath-ret bug-nextafter bug-nexttoward bug-tgmath1 \
test-tgmath-int test-tgmath2 test-powl tst-CMPLX tst-CMPLX2 test-snan \
- test-fenv-tls $(tests-static)
+ test-fenv-tls test-fenv-preserve $(tests-static)
tests-static = test-fpucw-static test-fpucw-ieee-static
# We do the `long double' tests only if this data type is available and
# distinct from `double'.
diff --git a/math/test-fenv-preserve.c b/math/test-fenv-preserve.c
new file mode 100644
index 0000000..8288b2c
--- /dev/null
+++ b/math/test-fenv-preserve.c
@@ -0,0 +1,53 @@
+/* Test fegetenv preserves exception mask (bug 16198).
+ Copyright (C) 2014 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 <fenv.h>
+#include <stdio.h>
+
+static int
+do_test (void)
+{
+ fenv_t env;
+
+ if (feenableexcept (FE_INVALID) != 0)
+ {
+ puts ("feenableexcept (FE_INVALID) failed, cannot test");
+ return 0;
+ }
+
+ if (fegetenv (&env) != 0)
+ {
+ puts ("fegetenv failed, cannot test");
+ return 0;
+ }
+
+ int ret = fegetexcept ();
+ if (ret == FE_INVALID)
+ {
+ puts ("fegetenv preserved exception mask, OK");
+ return 0;
+ }
+ else
+ {
+ printf ("fegetexcept returned %d, expected %d\n", ret, FE_INVALID);
+ return 1;
+ }
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff --git a/sysdeps/x86_64/fpu/fegetenv.c b/sysdeps/x86_64/fpu/fegetenv.c
index 364f917..0e0c269 100644
--- a/sysdeps/x86_64/fpu/fegetenv.c
+++ b/sysdeps/x86_64/fpu/fegetenv.c
@@ -22,6 +22,9 @@ int
fegetenv (fenv_t *envp)
{
__asm__ ("fnstenv %0\n"
+ /* fnstenv changes the exception mask, so load back the
+ stored environment. */
+ "fldenv %0\n"
"stmxcsr %1" : "=m" (*envp), "=m" (envp->__mxcsr));
/* Success. */