i386: Use generic division to generate INEXACT exception

Introduce math_force_eval_div to use generic division to generate
INEXACT as well as INVALID and DIVZERO exceptions.

libgcc/ChangeLog:

	* config/i386/sfp-exceptions.c (__math_force_eval): Remove.
	(__math_force_eval_div): New define.
	(__sfp_handle_exceptions): Use __math_force_eval_div to use
	generic division to generate INVALID, DIVZERO and INEXACT
	exceptions.

libatomic/ChangeLog:

	* config/x86/fenv.c (__math_force_eval): Remove.
	(__math_force_eval_div): New define.
	(__atomic_deraiseexcept): Use __math_force_eval_div to use
	generic division to generate INVALID, DIVZERO and INEXACT
	exceptions.

libgfortran/ChangeLog:

	* config/fpu-387.h (__math_force_eval): Remove.
	(__math_force_eval_div): New define.
	(local_feraiseexcept): Use __math_force_eval_div to use
	generic division to generate INVALID, DIVZERO and INEXACT
	exceptions.
	(struct fenv): Define named struct instead of typedef.

2 files changed, 18 insertions, 14 deletions

diff --git a/libatomic/ChangeLog b/libatomic/ChangeLog
index 48c115de49f..e8ab8ecb047 100644
--- a/libatomic/ChangeLog
+++ b/libatomic/ChangeLog
@@ -1,7 +1,15 @@
+2020-05-06  Uroš Bizjak  <ubizjak@gmail.com>
+
+	* config/x86/fenv.c (__math_force_eval): Remove.
+	(__math_force_eval_div): New define.
+	(__atomic_deraiseexcept): Use __math_force_eval_div to use
+	generic division to generate INVALID, DIVZERO and INEXACT
+	exceptions.
+
 2020-05-01  Uroš Bizjak  <ubizjak@gmail.com>
 
 	* config/x86/fenv.c (__math_force_eval): New define.
-	(__atomic_feraiseexcept): Use __math_force_eval to evaluete
+	(__atomic_feraiseexcept): Use __math_force_eval to evaluate
 	generic division to generate INVALID and DIVZERO exceptions.
 
 2020-04-19  Uroš Bizjak  <ubizjak@gmail.com>
diff --git a/libatomic/config/x86/fenv.c b/libatomic/config/x86/fenv.c
index d972a99f594..88622c613f3 100644
--- a/libatomic/config/x86/fenv.c
+++ b/libatomic/config/x86/fenv.c
@@ -48,9 +48,11 @@ struct fenv
 };
 
 #ifdef __SSE_MATH__
-# define __math_force_eval(x) asm volatile ("" : : "x" (x));
+# define __math_force_eval_div(x, y) \
+  do { asm ("" : "+x" (x)); asm volatile ("" : : "x" (x / y)); } while (0)
 #else
-# define __math_force_eval(x) asm volatile ("" : : "f" (x));
+# define __math_force_eval_div(x, y) \
+  do { asm ("" : "+t" (x)); asm volatile ("" : : "f" (x / y)); } while (0)
 #endif
 
 /* Raise the supported floating-point exceptions from EXCEPTS.  Other
@@ -59,14 +61,15 @@ struct fenv
 void
 __atomic_feraiseexcept (int excepts)
 {
+  struct fenv temp;
+
   if (excepts & FE_INVALID)
     {
       float f = 0.0f;
-      __math_force_eval (f / f);
+      __math_force_eval_div (f, f);
     }
   if (excepts & FE_DENORM)
     {
-      struct fenv temp;
       asm volatile ("fnstenv\t%0" : "=m" (temp));
       temp.__status_word |= FE_DENORM;
       asm volatile ("fldenv\t%0" : : "m" (temp));
@@ -75,11 +78,10 @@ __atomic_feraiseexcept (int excepts)
   if (excepts & FE_DIVBYZERO)
     {
       float f = 1.0f, g = 0.0f;
-      __math_force_eval (f / g);
+      __math_force_eval_div (f, g);
     }
   if (excepts & FE_OVERFLOW)
     {
-      struct fenv temp;
       asm volatile ("fnstenv\t%0" : "=m" (temp));
       temp.__status_word |= FE_OVERFLOW;
       asm volatile ("fldenv\t%0" : : "m" (temp));
@@ -87,7 +89,6 @@ __atomic_feraiseexcept (int excepts)
     }
   if (excepts & FE_UNDERFLOW)
     {
-      struct fenv temp;
       asm volatile ("fnstenv\t%0" : "=m" (temp));
       temp.__status_word |= FE_UNDERFLOW;
       asm volatile ("fldenv\t%0" : : "m" (temp));
@@ -96,11 +97,6 @@ __atomic_feraiseexcept (int excepts)
   if (excepts & FE_INEXACT)
     {
       float f = 1.0f, g = 3.0f;
-#ifdef __SSE_MATH__
-      asm volatile ("%vdivss\t{%1, %d0|%d0, %1}" : "+x" (f) : "xm" (g));
-#else
-      asm volatile ("fdivs\t%1" : "+t" (f) : "m" (g));
-      /* No need for fwait, exception is triggered by emitted fstp.  */
-#endif
+      __math_force_eval_div (f, g);
     }
 }