4 files changed, 98 insertions, 2 deletions
diff --git a/sysdeps/i386/fpu/fclrexcpt.c b/sysdeps/i386/fpu/fclrexcpt.c
index c3e7c3ed48..f7ccd3acf6 100644
--- a/sysdeps/i386/fpu/fclrexcpt.c
+++ b/sysdeps/i386/fpu/fclrexcpt.c
@@ -19,6 +19,9 @@
    02111-1307 USA.  */
 
 #include <fenv.h>
+#include <unistd.h>
+#include <ldsodefs.h>
+#include <dl-procinfo.h>
 
 int
 __feclearexcept (int excepts)
@@ -38,6 +41,21 @@ __feclearexcept (int excepts)
   /* Put the new data in effect.  */
   __asm__ ("fldenv %0" : : "m" (*&temp));
 
+  /* If the CPU supports SSE, we clear the MXCSR as well.  */
+  if ((GL(dl_hwcap) & HWCAP_I386_XMM) != 0)
+    {
+      unsigned int xnew_exc;
+
+      /* Get the current MXCSR.  */
+      __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
+      
+      /* Clear the relevant bits.  */
+      xnew_exc &= excepts ^ FE_ALL_EXCEPT;
+      
+      /* Put the new data in effect.  */
+      __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
+    }
+
   /* Success.  */
   return 0;
 }
diff --git a/sysdeps/i386/fpu/fsetexcptflg.c b/sysdeps/i386/fpu/fsetexcptflg.c
index 2bfc736054..d262738b68 100644
--- a/sysdeps/i386/fpu/fsetexcptflg.c
+++ b/sysdeps/i386/fpu/fsetexcptflg.c
@@ -21,6 +21,9 @@
 #include <fenv.h>
 #include <math.h>
 #include <bp-sym.h>
+#include <unistd.h>
+#include <ldsodefs.h>
+#include <dl-procinfo.h>
 
 int
 __fesetexceptflag (const fexcept_t *flagp, int excepts)
@@ -39,6 +42,22 @@ __fesetexceptflag (const fexcept_t *flagp, int excepts)
      the next floating-point instruction.  */
   __asm__ ("fldenv %0" : : "m" (*&temp));
 
+  /* If the CPU supports SSE, we set the MXCSR as well.  */
+  if ((GL(dl_hwcap) & HWCAP_I386_XMM) != 0)
+    {
+      unsigned int xnew_exc;
+
+      /* Get the current MXCSR.  */
+      __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
+
+      /* Set the relevant bits.  */
+      xnew_exc &= ~(excepts & FE_ALL_EXCEPT);
+      xnew_exc |= *flagp & excepts & FE_ALL_EXCEPT;
+
+      /* Put the new data in effect.  */
+      __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
+    }
+  
   /* Success.  */
   return 0;
 }
diff --git a/sysdeps/i386/fpu_control.h b/sysdeps/i386/fpu_control.h
index ed9bf388a8..e2d00467b7 100644
--- a/sysdeps/i386/fpu_control.h
+++ b/sysdeps/i386/fpu_control.h
@@ -1,5 +1,5 @@
 /* FPU control word bits.  i387 version.
-   Copyright (C) 1993,1995,1996,1997,1998,2000,2001 Free Software Foundation, Inc.
+   Copyright (C) 1993,1995-1998,2000,2001,2003 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Olaf Flebbe.
 
@@ -88,7 +88,11 @@
 /* Type of the control word.  */
 typedef unsigned int fpu_control_t __attribute__ ((__mode__ (__HI__)));
 
-/* Macros for accessing the hardware control word.  */
+/* Macros for accessing the hardware control word.
+
+   Note that the use of these macros is no sufficient anymore with
+   recent hardware.  Some floating point operations are executed in
+   the SSE/SSE2 engines which have their own control and status register.  */
 #define _FPU_GETCW(cw) __asm__ ("fnstcw %0" : "=m" (*&cw))
 #define _FPU_SETCW(cw) __asm__ ("fldcw %0" : : "m" (*&cw))
 
diff --git a/sysdeps/i386/setfpucw.c b/sysdeps/i386/setfpucw.c
new file mode 100644
index 0000000000..0a6af25ddf
--- /dev/null
+++ b/sysdeps/i386/setfpucw.c
@@ -0,0 +1,55 @@
+/* Set the FPU control word for x86.
+   Copyright (C) 2003 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <math.h>
+#include <fpu_control.h>
+#include <fenv.h>
+#include <unistd.h>
+#include <ldsodefs.h>
+#include <dl-procinfo.h>
+
+void
+__setfpucw (fpu_control_t set)
+{
+  fpu_control_t cw;
+
+  /* Fetch the current control word.  */
+  __asm__ ("fnstcw %0" : "=m" (*&cw));
+
+  /* Preserve the reserved bits, and set the rest as the user
+     specified (or the default, if the user gave zero).  */
+  cw &= _FPU_RESERVED;
+  cw |= set & ~_FPU_RESERVED;
+
+  __asm__ ("fldcw %0" : : "m" (*&cw));
+
+  /* If the CPU supports SSE, we set the MXCSR as well.  */
+  if ((GL(dl_hwcap) & HWCAP_I386_XMM) != 0)
+    {
+      unsigned int xnew_exc;
+
+      /* Get the current MXCSR.  */
+      __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
+
+      xnew_exc &= ~((0xc00 << 3) | (FE_ALL_EXCEPT << 7));
+      xnew_exc |= ((set & 0xc00) << 3) | ((set & FE_ALL_EXCEPT) << 7);
+
+      __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
+    }
+}