obtained gcc-4.6.4.tar.bz2 from upstream website;upstream

verified gcc-4.6.4.tar.bz2.sig;
imported gcc-4.6.4 source tree from verified upstream tarball.

downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
to the one extracted from the above tarball.

if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
directory might differ from line-endings of the respective
files in the upstream repository.

1 files changed, 89 insertions, 0 deletions

diff --git a/gcc/config/i386/crtfastmath.c b/gcc/config/i386/crtfastmath.c
new file mode 100644
index 000000000..1c1ce2c78
--- /dev/null
+++ b/gcc/config/i386/crtfastmath.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2005, 2007, 2009 Free Software Foundation, Inc.
+ *
+ * This file is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 3, or (at your option) any
+ * later version.
+ * 
+ * This file 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
+ * General Public License for more details.
+ * 
+ * Under Section 7 of GPL version 3, you are granted additional
+ * permissions described in the GCC Runtime Library Exception, version
+ * 3.1, as published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License and
+ * a copy of the GCC Runtime Library Exception along with this program;
+ * see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#define MXCSR_DAZ (1 << 6)	/* Enable denormals are zero mode */
+#define MXCSR_FTZ (1 << 15)	/* Enable flush to zero mode */
+
+#ifndef __x86_64__
+/* All 64-bit targets have SSE and DAZ;
+   only check them explicitly for 32-bit ones. */
+#include "cpuid.h"
+#endif
+
+static void __attribute__((constructor))
+#ifndef __x86_64__
+/* The i386 ABI only requires 4-byte stack alignment, so this is necessary
+   to make sure the fxsave struct gets correct alignment.
+   See PR27537 and PR28621.  */
+__attribute__ ((force_align_arg_pointer))
+#endif
+set_fast_math (void)
+{
+#ifndef __x86_64__
+  unsigned int eax, ebx, ecx, edx;
+
+  if (!__get_cpuid (1, &eax, &ebx, &ecx, &edx))
+    return;
+
+  if (edx & bit_SSE)
+    {
+      unsigned int mxcsr = __builtin_ia32_stmxcsr ();
+  
+      mxcsr |= MXCSR_FTZ;
+
+      if (edx & bit_FXSAVE)
+	{
+	  /* Check if DAZ is available.  */
+	  struct
+	    {
+	      unsigned short int cwd;
+	      unsigned short int swd;
+	      unsigned short int twd;
+	      unsigned short int fop;
+	      long int fip;
+	      long int fcs;
+	      long int foo;
+	      long int fos;
+	      long int mxcsr;
+	      long int mxcsr_mask;
+	      long int st_space[32];
+	      long int xmm_space[32];
+	      long int padding[56];
+	    } __attribute__ ((aligned (16))) fxsave;
+
+	  __builtin_memset (&fxsave, 0, sizeof (fxsave));
+
+	  asm volatile ("fxsave %0" : "=m" (fxsave) : "m" (fxsave));
+
+	  if (fxsave.mxcsr_mask & MXCSR_DAZ)
+	    mxcsr |= MXCSR_DAZ;
+	}
+
+      __builtin_ia32_ldmxcsr (mxcsr);
+    }
+#else
+  unsigned int mxcsr = __builtin_ia32_stmxcsr ();
+  mxcsr |= MXCSR_DAZ | MXCSR_FTZ;
+  __builtin_ia32_ldmxcsr (mxcsr);
+#endif
+}