2005-08-10 H.J. Lu <hongjiu.lu@intel.com>

	* config.gcc (i[34567]86-*-linux*): Add i386/t-crtfm to tm-file.
	(x86_64-*-linux*): Likewise.

	* config/i386/crtfastmath.c: New file.
	* config/i386/t-crtfm: Likewise.

	* config/i386/linux.h (ENDFILE_SPEC): New.
	* config/i386/linux64.h (ENDFILE_SPEC): Likewise.

	* config/i386/t-linux64 (EXTRA_MULTILIB_PARTS): Add
	crtfastmath.o.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@102954 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 72 insertions, 0 deletions

diff --git a/gcc/config/i386/crtfastmath.c b/gcc/config/i386/crtfastmath.c
new file mode 100644
index 00000000000..3412d6ceda6
--- /dev/null
+++ b/gcc/config/i386/crtfastmath.c
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2005 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 2, or (at your option) any
+ * later version.
+ * 
+ * In addition to the permissions in the GNU General Public License, the
+ * Free Software Foundation gives you unlimited permission to link the
+ * compiled version of this file with other programs, and to distribute
+ * those programs without any restriction coming from the use of this
+ * file.  (The General Public License restrictions do apply in other
+ * respects; for example, they cover modification of the file, and
+ * distribution when not linked into another program.)
+ * 
+ * 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.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ * 
+ *    As a special exception, if you link this library with files
+ *    compiled with GCC to produce an executable, this does not cause
+ *    the resulting executable to be covered by the GNU General Public License.
+ *    This exception does not however invalidate any other reasons why
+ *    the executable file might be covered by the GNU General Public License.
+ */
+
+#define MXCSR_DAZ (1 << 6)	/* Enable denormals are zero mode */
+#define MXCSR_FTZ (1 << 15)	/* Enable flush to zero mode */
+
+static void __attribute__((constructor))
+set_fast_math (void)
+{
+#ifndef __x86_64__
+  /* SSE is the part of 64bit. Only need to check it for 32bit.  */
+  unsigned int eax, ebx, ecx, edx;
+
+  /* See if we can use cpuid.  */
+  asm volatile ("pushfl; pushfl; popl %0; movl %0,%1; xorl %2,%0;"
+		"pushl %0; popfl; pushfl; popl %0; popfl"
+		: "=&r" (eax), "=&r" (ebx)
+		: "i" (0x00200000));
+
+  if (((eax ^ ebx) & 0x00200000) == 0)
+    return;
+
+  /* Check the highest input value for eax.  */
+  asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1"
+		: "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx)
+		: "0" (0));
+
+  if (eax == 0)
+    return;
+
+  asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1"
+		: "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx)
+		: "0" (1));
+
+  if (edx & (1 << 25))
+#endif
+    {
+      unsigned int mxcsr = __builtin_ia32_stmxcsr ();
+      mxcsr |= MXCSR_DAZ | MXCSR_FTZ;
+      __builtin_ia32_ldmxcsr (mxcsr);
+    }
+}