[PATCH, libgfortran]: Use __get_cpud to check for SSE

Uros Bizjak ubizjak@gmail.com
Fri Sep 7 09:19:00 GMT 2007


Hello!

There is open-coded use of cpuid in config/fpu-387.h that can be
substituted with __get_cpuid from new cpuid.h header.

The patch was boostrapped and regression tested on i686-pc-linux-gnu.
Before that,  conifg/fpu-387.h was copied into config/fpu-glibc.h to
be sure that configure system picked new file. OK for mainline?

2007-09-07  Uros Bizjak  <ubizjak@gmail.com>

	* config/fpu-387.h: Include cpuid.h.
	(set_fpu): Use __get_cpuid to check for SSE.

Uros.
-------------- next part --------------
Index: config/fpu-387.h
===================================================================
--- config/fpu-387.h	(revision 128228)
+++ config/fpu-387.h	(working copy)
@@ -28,79 +28,68 @@
 write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 Boston, MA 02110-1301, USA.  */
 
-#define SSE	(1 << 25)
+#ifndef __x86_64__
+#include "cpuid.h"
+#endif
 
 static int
 has_sse (void)
 {
-#ifdef __x86_64__
-  return 1;
-#else
+#ifndef __x86_64__
   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)
+  if (!__get_cpuid (1, &eax, &ebx, &ecx, &edx))
     return 0;
 
-  /* 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 0;
-
-  asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1"
-		: "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx)
-		: "0" (1));
-
-  if (edx & SSE)
-    return 1;
-
-  return 0;
+  return edx & bit_SSE;
+#else
+  return 1;
 #endif
 }
 
-void set_fpu (void)
-{
-  unsigned short cw;
-  unsigned int cw_sse;
-
-  /* i387 -- see linux <fpu_control.h> header file for details.  */
+/* i387 -- see linux <fpu_control.h> header file for details.  */
 #define _FPU_MASK_IM  0x01
 #define _FPU_MASK_DM  0x02
 #define _FPU_MASK_ZM  0x04
 #define _FPU_MASK_OM  0x08
 #define _FPU_MASK_UM  0x10
 #define _FPU_MASK_PM  0x20
+
+void set_fpu (void)
+{
+  unsigned short cw;
+
   asm volatile ("fnstcw %0" : "=m" (cw));
-  cw |= _FPU_MASK_IM | _FPU_MASK_DM | _FPU_MASK_ZM | _FPU_MASK_OM | _FPU_MASK_UM | _FPU_MASK_PM;
+
+  cw |= (_FPU_MASK_IM | _FPU_MASK_DM | _FPU_MASK_ZM | _FPU_MASK_OM
+	 | _FPU_MASK_UM | _FPU_MASK_PM);
+
   if (options.fpe & GFC_FPE_INVALID) cw &= ~_FPU_MASK_IM;
   if (options.fpe & GFC_FPE_DENORMAL) cw &= ~_FPU_MASK_DM;
   if (options.fpe & GFC_FPE_ZERO) cw &= ~_FPU_MASK_ZM;
   if (options.fpe & GFC_FPE_OVERFLOW) cw &= ~_FPU_MASK_OM;
   if (options.fpe & GFC_FPE_UNDERFLOW) cw &= ~_FPU_MASK_UM;
   if (options.fpe & GFC_FPE_PRECISION) cw &= ~_FPU_MASK_PM;
+
   asm volatile ("fldcw %0" : : "m" (cw));
 
   if (has_sse())
     {
-      /* SSE */
+      unsigned int cw_sse;
+
       asm volatile ("stmxcsr %0" : "=m" (cw_sse));
-      cw_sse &= 0xFFFF0000;
+
+      cw_sse &= 0xffff0000;
       cw_sse |= (_FPU_MASK_IM | _FPU_MASK_DM | _FPU_MASK_ZM | _FPU_MASK_OM
 		 | _FPU_MASK_UM | _FPU_MASK_PM ) << 7;
+
       if (options.fpe & GFC_FPE_INVALID) cw_sse &= ~(_FPU_MASK_IM << 7);
       if (options.fpe & GFC_FPE_DENORMAL) cw_sse &= ~(_FPU_MASK_DM << 7);
       if (options.fpe & GFC_FPE_ZERO) cw_sse &= ~(_FPU_MASK_ZM << 7);
       if (options.fpe & GFC_FPE_OVERFLOW) cw_sse &= ~(_FPU_MASK_OM << 7);
       if (options.fpe & GFC_FPE_UNDERFLOW) cw_sse &= ~(_FPU_MASK_UM << 7);
       if (options.fpe & GFC_FPE_PRECISION) cw_sse &= ~(_FPU_MASK_PM << 7);
+
       asm volatile ("ldmxcsr %0" : : "m" (cw_sse));
     }
 }


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