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authorJoseph Myers <joseph@codesourcery.com>2015-10-28 18:50:20 +0000
committerJoseph Myers <joseph@codesourcery.com>2015-10-28 18:50:20 +0000
commit0b9af583a5c2d68085e88cece13952bf05dc4882 (patch)
treeefc4a66a9b018447c371749d91cf8a5b8508754f /sysdeps
parenteae6c382bdca2e7ac582a69d56c9c228b678ee67 (diff)
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Fix i386/x86_64 fesetenv SSE exception clearing (bug 19181).
The i386 and x86_64 versions of fesetenv, when called with FE_DFL_ENV or FE_NOMASK_ENV as argument, do not clear SSE exceptions raised in MXCSR. These arguments should, like other fenv_t values, represent the whole of the floating-point state, so such exceptions should be cleared; this patch adds the required clearing. (Discovered while working on bug 16068.) Tested for x86_64 and x86. [BZ #19181] * sysdeps/i386/fpu/fesetenv.c (__fesetenv): Clear already-raised SSE exceptions when argument is FE_DFL_ENV or FE_NOMASK_ENV. * sysdeps/x86_64/fpu/fesetenv.c (__fesetenv): Likewise. * math/test-fenv-clear-main.c: New file. * math/test-fenv-clear.c: Likewise. * math/Makefile (tests): Add test-fenv-clear. * sysdeps/x86/fpu/test-fenv-clear-sse.c: New file. * sysdeps/x86/fpu/Makefile [$(subdir) = math] (tests): Add test-fenv-clear-sse. [$(subdir) = math] (CFLAGS-test-fenv-clear-sse.c): New variable.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/i386/fpu/fesetenv.c4
-rw-r--r--sysdeps/x86/fpu/Makefile3
-rw-r--r--sysdeps/x86/fpu/test-fenv-clear-sse.c45
-rw-r--r--sysdeps/x86_64/fpu/fesetenv.c4
4 files changed, 55 insertions, 1 deletions
diff --git a/sysdeps/i386/fpu/fesetenv.c b/sysdeps/i386/fpu/fesetenv.c
index 9566e09..910aa09 100644
--- a/sysdeps/i386/fpu/fesetenv.c
+++ b/sysdeps/i386/fpu/fesetenv.c
@@ -72,6 +72,8 @@ __fesetenv (const fenv_t *envp)
if (envp == FE_DFL_ENV)
{
+ /* Clear SSE exceptions. */
+ mxcsr &= ~FE_ALL_EXCEPT;
/* Set mask for SSE MXCSR. */
mxcsr |= (FE_ALL_EXCEPT << 7);
/* Set rounding to FE_TONEAREST. */
@@ -80,6 +82,8 @@ __fesetenv (const fenv_t *envp)
}
else if (envp == FE_NOMASK_ENV)
{
+ /* Clear SSE exceptions. */
+ mxcsr &= ~FE_ALL_EXCEPT;
/* Do not mask exceptions. */
mxcsr &= ~(FE_ALL_EXCEPT << 7);
/* Set rounding to FE_TONEAREST. */
diff --git a/sysdeps/x86/fpu/Makefile b/sysdeps/x86/fpu/Makefile
index 9cb7bb2..d38497c 100644
--- a/sysdeps/x86/fpu/Makefile
+++ b/sysdeps/x86/fpu/Makefile
@@ -1,5 +1,6 @@
ifeq ($(subdir),math)
libm-support += powl_helper
-tests += test-fenv-sse
+tests += test-fenv-sse test-fenv-clear-sse
CFLAGS-test-fenv-sse.c += -msse2 -mfpmath=sse
+CFLAGS-test-fenv-clear-sse.c += -msse2 -mfpmath=sse
endif
diff --git a/sysdeps/x86/fpu/test-fenv-clear-sse.c b/sysdeps/x86/fpu/test-fenv-clear-sse.c
new file mode 100644
index 0000000..531164c
--- /dev/null
+++ b/sysdeps/x86/fpu/test-fenv-clear-sse.c
@@ -0,0 +1,45 @@
+/* Test fesetenv (FE_DFL_ENV) and fesetenv (FE_NOMASK_ENV) clear
+ exceptions (bug 19181). SSE version.
+ Copyright (C) 2015 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 <cpuid.h>
+#include <stdbool.h>
+
+static bool
+have_sse2 (void)
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ if (!__get_cpuid (1, &eax, &ebx, &ecx, &edx))
+ return false;
+
+ return (edx & bit_SSE2) != 0;
+}
+
+#define CHECK_CAN_TEST \
+ do \
+ { \
+ if (!have_sse2 ()) \
+ { \
+ puts ("CPU does not support SSE2, cannot test"); \
+ return 0; \
+ } \
+ } \
+ while (0)
+
+#include <test-fenv-clear-main.c>
diff --git a/sysdeps/x86_64/fpu/fesetenv.c b/sysdeps/x86_64/fpu/fesetenv.c
index 3e3fd84..9950aa7 100644
--- a/sysdeps/x86_64/fpu/fesetenv.c
+++ b/sysdeps/x86_64/fpu/fesetenv.c
@@ -42,6 +42,8 @@ __fesetenv (const fenv_t *envp)
temp.__opcode = 0;
temp.__data_offset = 0;
temp.__data_selector = 0;
+ /* Clear SSE exceptions. */
+ temp.__mxcsr &= ~FE_ALL_EXCEPT;
/* Set mask for SSE MXCSR. */
temp.__mxcsr |= (FE_ALL_EXCEPT << 7);
/* Set rounding to FE_TONEAREST. */
@@ -57,6 +59,8 @@ __fesetenv (const fenv_t *envp)
temp.__opcode = 0;
temp.__data_offset = 0;
temp.__data_selector = 0;
+ /* Clear SSE exceptions. */
+ temp.__mxcsr &= ~FE_ALL_EXCEPT;
/* Set mask for SSE MXCSR. */
/* Set rounding to FE_TONEAREST. */
temp.__mxcsr &= ~ 0x6000;