sfp-exceptions.c (__sfp_handle_exceptions): Handle FP_EX_DENORM.

	* config/i386/sfp-exceptions.c (__sfp_handle_exceptions): Handle
	FP_EX_DENORM.  Store result to volatile location after SSE division
	to close interrupt window.  Remove unneeded fwait after x87
	division since interrupt window will be closed by emitted fstp.

From-SVN: r204540

libgcc/ChangeLog

+2013-11-07  Uros Bizjak  <ubizjak@gmail.com>
+
+	* config/i386/sfp-exceptions.c (__sfp_handle_exceptions): Handle
+	FP_EX_DENORM.  Store result to volatile location after SSE division
+	to close interrupt window.  Remove unneeded fwait after x87
+	division since interrupt window will be closed by emitted fstp.
+
 2013-11-06  Joseph Myers  <joseph@codesourcery.com>
 
 	* soft-fp/README: Update.

libgcc/config/i386/sfp-exceptions.c

@@ -48,20 +48,32 @@ __sfp_handle_exceptions (int _fex)
     {
       float f = 0.0f;
 #ifdef __x86_64__
+      volatile float r;
       asm volatile ("%vdivss\t{%0, %d0|%d0, %0}" : "+x" (f));
+      r = f; /* Needed to trigger exception.   */
 #else
       asm volatile ("fdiv\t{%y0, %0|%0, %y0}" : "+t" (f));
-      asm volatile ("fwait");
+      /* No need for fwait, exception is triggered by emitted fstp.  */
 #endif
     }
+  if (_fex & FP_EX_DENORM)
+    {
+      struct fenv temp;
+      asm volatile ("fnstenv\t%0" : "=m" (temp));
+      temp.__status_word |= FP_EX_DENORM;
+      asm volatile ("fldenv\t%0" : : "m" (temp));
+      asm volatile ("fwait");
+    }
   if (_fex & FP_EX_DIVZERO)
     {
       float f = 1.0f, g = 0.0f;
 #ifdef __x86_64__
+      volatile float r;
       asm volatile ("%vdivss\t{%1, %d0|%d0, %1}" : "+x" (f) : "xm" (g));
+      r = f; /* Needed to trigger exception.   */
 #else
       asm volatile ("fdivs\t%1" : "+t" (f) : "m" (g));
-      asm volatile ("fwait");
+      /* No need for fwait, exception is triggered by emitted fstp.  */
 #endif
     }
   if (_fex & FP_EX_OVERFLOW)