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authorRichard Henderson <rth@twiddle.net>2012-03-18 15:51:53 -0700
committerRichard Henderson <rth@twiddle.net>2012-03-19 06:51:06 -0700
commitd0adc9223031b606c3c7781b4ec41462796ab313 (patch)
treedabdb4d73fadc785c77dfb54db347c777c5a1304 /sysdeps/i386
parent0fe0f1f86f82f9e08ca4d4b85111de03f4c2f876 (diff)
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i386/x86_64: Optimize feholdexcept.
Diffstat (limited to 'sysdeps/i386')
-rw-r--r--sysdeps/i386/fpu/feholdexcpt.c19
1 files changed, 4 insertions, 15 deletions
diff --git a/sysdeps/i386/fpu/feholdexcpt.c b/sysdeps/i386/fpu/feholdexcpt.c
index a09d45ebd0..7e1038955f 100644
--- a/sysdeps/i386/fpu/feholdexcpt.c
+++ b/sysdeps/i386/fpu/feholdexcpt.c
@@ -1,6 +1,5 @@
 /* Store current floating-point environment and clear exceptions.
-   Copyright (C) 1997, 1999, 2003, 2004, 2005, 2007
-   Free Software Foundation, Inc.
+   Copyright (C) 1997-2012 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
 
@@ -26,19 +25,9 @@
 int
 feholdexcept (fenv_t *envp)
 {
-  fenv_t temp;
-
-  /* Store the environment.  */
-  __asm__ ("fnstenv %0" : "=m" (temp));
-  *envp = temp;
-
-  /* Now set all exceptions to non-stop.  */
-  temp.__control_word |= 0x3f;
-
-  /* And clear all exceptions.  */
-  temp.__status_word &= ~0x3f;
-
-  __asm__ ("fldenv %0" : : "m" (temp));
+  /* Store the environment.  Recall that fnstenv has a side effect of
+     masking all exceptions.  Then clear all exceptions.  */
+  __asm__ volatile ("fnstenv %0; fnclex" : "=m" (*envp));
 
   /* If the CPU supports SSE we set the MXCSR as well.  */
   if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)