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.

6 files changed, 67 insertions, 50 deletions

diff --git a/libatomic/ChangeLog b/libatomic/ChangeLog
index 48c115d..e8ab8ec 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 d972a99..88622c6 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);
     }
 }
diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index 8e63e43..33e8929 100644
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,11 @@
+2020-05-06  Uroš Bizjak  <ubizjak@gmail.com>
+
+	* 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.
+
 2020-05-06  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* config/aarch64/lse-init.c (init_have_lse_atomics): Use __getauxval
@@ -54,7 +62,7 @@
 2020-05-01  Uroš Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/sfp-exceptions.c (__math_force_eval): New define.
-	(__sfp_handle_exceptions): Use __math_force_eval to evaluete
+	(__sfp_handle_exceptions): Use __math_force_eval to evaluate
 	generic division to generate INVALID and DIVZERO exceptions.
 
 2020-04-27  Sebastian Huber  <sebastian.huber@embedded-brains.de>
diff --git a/libgcc/config/i386/sfp-exceptions.c b/libgcc/config/i386/sfp-exceptions.c
index 4b3a7a0..72cb0f4 100644
--- a/libgcc/config/i386/sfp-exceptions.c
+++ b/libgcc/config/i386/sfp-exceptions.c
@@ -42,22 +42,25 @@ 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
 
 void
 __sfp_handle_exceptions (int _fex)
 {
+  struct fenv temp;
+
   if (_fex & FP_EX_INVALID)
     {
       float f = 0.0f;
-      __math_force_eval (f / f);
+      __math_force_eval_div (f, f);
     }
   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));
@@ -66,11 +69,10 @@ __sfp_handle_exceptions (int _fex)
   if (_fex & FP_EX_DIVZERO)
     {
       float f = 1.0f, g = 0.0f;
-      __math_force_eval (f / g);
+      __math_force_eval_div (f, g);
     }
   if (_fex & FP_EX_OVERFLOW)
     {
-      struct fenv temp;
       asm volatile ("fnstenv\t%0" : "=m" (temp));
       temp.__status_word |= FP_EX_OVERFLOW;
       asm volatile ("fldenv\t%0" : : "m" (temp));
@@ -78,7 +80,6 @@ __sfp_handle_exceptions (int _fex)
     }
   if (_fex & FP_EX_UNDERFLOW)
     {
-      struct fenv temp;
       asm volatile ("fnstenv\t%0" : "=m" (temp));
       temp.__status_word |= FP_EX_UNDERFLOW;
       asm volatile ("fldenv\t%0" : : "m" (temp));
@@ -87,12 +88,7 @@ __sfp_handle_exceptions (int _fex)
   if (_fex & FP_EX_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);
     }
 }
 #endif
diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index eecfb90..94c7e0f 100644
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,7 +1,16 @@
+2020-05-06  Uroš Bizjak  <ubizjak@gmail.com>
+
+	* 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.
+
 2020-05-01  Uroš Bizjak  <ubizjak@gmail.com>
 
 	* config/fpu-387.h (__math_force_eval): New define.
-	(local_feraiseexcept): Use __math_force_eval to evaluete
+	(local_feraiseexcept): Use __math_force_eval to evaluate
 	generic division to generate INVALID and DIVZERO exceptions.
 
 2020-04-22  Fritz Reese  <foreese@gcc.gnu.org>
diff --git a/libgfortran/config/fpu-387.h b/libgfortran/config/fpu-387.h
index 41b82bc..8b5e758 100644
--- a/libgfortran/config/fpu-387.h
+++ b/libgfortran/config/fpu-387.h
@@ -69,7 +69,7 @@ has_sse (void)
 
 /* This structure corresponds to the layout of the block
    written by FSTENV.  */
-typedef struct
+struct fenv
 {
   unsigned short int __control_word;
   unsigned short int __unused1;
@@ -79,22 +79,28 @@ typedef struct
   unsigned short int __unused3;
   unsigned int __eip;
   unsigned short int __cs_selector;
-  unsigned short int __opcode;
+  unsigned int __opcode:11;
+  unsigned int __unused4:5;
   unsigned int __data_offset;
   unsigned short int __data_selector;
   unsigned short int __unused5;
   unsigned int __mxcsr;
-}
-my_fenv_t;
+};
 
 /* Check we can actually store the FPU state in the allocated size.  */
-_Static_assert (sizeof(my_fenv_t) <= (size_t) GFC_FPE_STATE_BUFFER_SIZE,
+_Static_assert (sizeof(struct fenv) <= (size_t) GFC_FPE_STATE_BUFFER_SIZE,
 		"GFC_FPE_STATE_BUFFER_SIZE is too small");
 
 #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
@@ -104,14 +110,15 @@ _Static_assert (sizeof(my_fenv_t) <= (size_t) GFC_FPE_STATE_BUFFER_SIZE,
 static void
 local_feraiseexcept (int excepts)
 {
+  struct fenv temp;
+
   if (excepts & _FPU_MASK_IM)
     {
       float f = 0.0f;
-      __math_force_eval (f / f);
+      __math_force_eval_div (f, f);
     }
   if (excepts & _FPU_MASK_DM)
     {
-      my_fenv_t temp;
       __asm__ __volatile__ ("fnstenv\t%0" : "=m" (temp));
       temp.__status_word |= _FPU_MASK_DM;
       __asm__ __volatile__ ("fldenv\t%0" : : "m" (temp));
@@ -120,11 +127,10 @@ local_feraiseexcept (int excepts)
   if (excepts & _FPU_MASK_ZM)
     {
       float f = 1.0f, g = 0.0f;
-      __math_force_eval (f / g);
+      __math_force_eval_div (f, g);
     }
   if (excepts & _FPU_MASK_OM)
     {
-      my_fenv_t temp;
       __asm__ __volatile__ ("fnstenv\t%0" : "=m" (temp));
       temp.__status_word |= _FPU_MASK_OM;
       __asm__ __volatile__ ("fldenv\t%0" : : "m" (temp));
@@ -132,7 +138,6 @@ local_feraiseexcept (int excepts)
     }
   if (excepts & _FPU_MASK_UM)
     {
-      my_fenv_t temp;
       __asm__ __volatile__ ("fnstenv\t%0" : "=m" (temp));
       temp.__status_word |= _FPU_MASK_UM;
       __asm__ __volatile__ ("fldenv\t%0" : : "m" (temp));
@@ -141,12 +146,7 @@ local_feraiseexcept (int excepts)
   if (excepts & _FPU_MASK_PM)
     {
       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);
     }
 }
 
@@ -272,7 +272,7 @@ get_fpu_except_flags (void)
 void
 set_fpu_except_flags (int set, int clear)
 {
-  my_fenv_t temp;
+  struct fenv temp;
   int exc_set = 0, exc_clr = 0;
 
   /* Translate from GFC_PE_* values to _FPU_MASK_* values.  */
@@ -426,7 +426,7 @@ support_fpu_rounding_mode (int mode __attribute__((unused)))
 void
 get_fpu_state (void *state)
 {
-  my_fenv_t *envp = state;
+  struct fenv *envp = state;
 
   __asm__ __volatile__ ("fnstenv\t%0" : "=m" (*envp));
 
@@ -441,7 +441,7 @@ get_fpu_state (void *state)
 void
 set_fpu_state (void *state)
 {
-  my_fenv_t *envp = state;
+  struct fenv *envp = state;
 
   /* glibc sources (sysdeps/x86_64/fpu/fesetenv.c) do something more
      complex than this, but I think it suffices in our case.  */