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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/i386
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/i386')
-rw-r--r--sysdeps/i386/fpu/fesetenv.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/sysdeps/i386/fpu/fesetenv.c b/sysdeps/i386/fpu/fesetenv.c
index 9566e092ca..910aa0991c 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.  */