Update copyright years.

[thirdparty/gcc.git] / libgfortran / config / fpu-glibc.h

diff --git a/libgfortran/config/fpu-glibc.h b/libgfortran/config/fpu-glibc.h
index 695b9d3fbb0e1c55de5a386dfcf0724ff5848052..ff5f2f2b1a83f0443bbf57e5a6197757abdd45a7 100644 (file)
--- a/libgfortran/config/fpu-glibc.h
+++ b/libgfortran/config/fpu-glibc.h
@@ -1,5 +1,5 @@
 /* FPU-related code for systems with GNU libc.
-   Copyright (C) 2005-2014 Free Software Foundation, Inc.
+   Copyright (C) 2005-2024 Free Software Foundation, Inc.
    Contributed by Francois-Xavier Coudert <coudert@clipper.ens.fr>
 
 This file is part of the GNU Fortran runtime library (libgfortran).
@@ -27,57 +27,68 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
    feenableexcept function in fenv.h to set individual exceptions
    (there's nothing to do that in C99).  */
 
-#include <assert.h>
-
 #ifdef HAVE_FENV_H
 #include <fenv.h>
 #endif
 
 
+/* Check we can actually store the FPU state in the allocated size.  */
+_Static_assert (sizeof(fenv_t) <= (size_t) GFC_FPE_STATE_BUFFER_SIZE,
+               "GFC_FPE_STATE_BUFFER_SIZE is too small");
+
+
 void set_fpu_trap_exceptions (int trap, int notrap)
 {
+  int mode_set = 0, mode_clr = 0;
+
 #ifdef FE_INVALID
   if (trap & GFC_FPE_INVALID)
-    feenableexcept (FE_INVALID);
+    mode_set |= FE_INVALID;
   if (notrap & GFC_FPE_INVALID)
-    fedisableexcept (FE_INVALID);
+    mode_clr |= FE_INVALID;
 #endif
 
-/* glibc does never have a FE_DENORMAL.  */
+/* Some glibc targets (like alpha) have FE_DENORMAL, but not many.  */
 #ifdef FE_DENORMAL
   if (trap & GFC_FPE_DENORMAL)
-    feenableexcept (FE_DENORMAL);
+    mode_set |= FE_DENORMAL;
   if (notrap & GFC_FPE_DENORMAL)
-    fedisableexcept (FE_DENORMAL);
+    mode_clr |= FE_DENORMAL;
 #endif
 
 #ifdef FE_DIVBYZERO
   if (trap & GFC_FPE_ZERO)
-    feenableexcept (FE_DIVBYZERO);
+    mode_set |= FE_DIVBYZERO;
   if (notrap & GFC_FPE_ZERO)
-    fedisableexcept (FE_DIVBYZERO);
+    mode_clr |= FE_DIVBYZERO;
 #endif
 
 #ifdef FE_OVERFLOW
   if (trap & GFC_FPE_OVERFLOW)
-    feenableexcept (FE_OVERFLOW);
+    mode_set |= FE_OVERFLOW;
   if (notrap & GFC_FPE_OVERFLOW)
-    fedisableexcept (FE_OVERFLOW);
+    mode_clr |= FE_OVERFLOW;
 #endif
 
 #ifdef FE_UNDERFLOW
   if (trap & GFC_FPE_UNDERFLOW)
-    feenableexcept (FE_UNDERFLOW);
+    mode_set |= FE_UNDERFLOW;
   if (notrap & GFC_FPE_UNDERFLOW)
-    fedisableexcept (FE_UNDERFLOW);
+    mode_clr |= FE_UNDERFLOW;
 #endif
 
 #ifdef FE_INEXACT
   if (trap & GFC_FPE_INEXACT)
-    feenableexcept (FE_INEXACT);
+    mode_set |= FE_INEXACT;
   if (notrap & GFC_FPE_INEXACT)
-    fedisableexcept (FE_INEXACT);
+    mode_clr |= FE_INEXACT;
 #endif
+
+  /* Clear stalled exception flags.  */
+  feclearexcept (FE_ALL_EXCEPT);
+
+  feenableexcept (mode_set);
+  fedisableexcept (mode_clr);
 }
 
 
@@ -130,7 +141,6 @@ void set_fpu (void)
                "exception not supported.\n");
 #endif
 
-/* glibc does never have a FE_DENORMAL.  */
 #ifndef FE_DENORMAL
   if (options.fpe & GFC_FPE_DENORMAL)
     estr_write ("Fortran runtime warning: Floating point 'denormal operand' "
@@ -331,8 +341,14 @@ get_fpu_rounding_mode (void)
       case FE_TOWARDZERO:
        return GFC_FPE_TOWARDZERO;
 #endif
+
+#ifdef FE_TONEARESTFROMZERO
+      case FE_TONEARESTFROMZERO:
+       return GFC_FPE_AWAY;
+#endif
+
       default:
-       return GFC_FPE_INVALID;
+       return 0; /* Should be unreachable.  */
     }
 }
 
@@ -367,8 +383,15 @@ set_fpu_rounding_mode (int mode)
        rnd_mode = FE_TOWARDZERO;
        break;
 #endif
+
+#ifdef FE_TONEARESTFROMZERO
+      case GFC_FPE_AWAY:
+       rnd_mode = FE_TONEARESTFROMZERO;
+       break;
+#endif
+
       default:
-       return;
+       return; /* Should be unreachable.  */
     }
 
   fesetround (rnd_mode);
@@ -387,26 +410,36 @@ support_fpu_rounding_mode (int mode)
        return 0;
 #endif
 
+      case GFC_FPE_UPWARD:
 #ifdef FE_UPWARD
        return 1;
 #else
        return 0;
 #endif
 
+      case GFC_FPE_DOWNWARD:
 #ifdef FE_DOWNWARD
        return 1;
 #else
        return 0;
 #endif
 
+      case GFC_FPE_TOWARDZERO:
 #ifdef FE_TOWARDZERO
        return 1;
 #else
        return 0;
 #endif
 
-      default:
+      case GFC_FPE_AWAY:
+#ifdef FE_TONEARESTFROMZERO
+       return 1;
+#else
        return 0;
+#endif
+
+      default:
+       return 0; /* Should be unreachable.  */
     }
 }
 
@@ -414,9 +447,6 @@ support_fpu_rounding_mode (int mode)
 void
 get_fpu_state (void *state)
 {
-  /* Check we can actually store the FPU state in the allocated size.  */
-  assert (sizeof(fenv_t) <= GFC_FPE_STATE_BUFFER_SIZE);
-
   fegetenv (state);
 }
 
@@ -424,9 +454,56 @@ get_fpu_state (void *state)
 void
 set_fpu_state (void *state)
 {
-  /* Check we can actually store the FPU state in the allocated size.  */
-  assert (sizeof(fenv_t) <= GFC_FPE_STATE_BUFFER_SIZE);
-
   fesetenv (state);
 }
 
+
+/* Underflow in glibc is currently only supported on alpha, through
+   the FE_MAP_UMZ macro and __ieee_set_fp_control() function call.  */
+
+int
+support_fpu_underflow_control (int kind __attribute__((unused)))
+{
+#if defined(__alpha__) && defined(FE_MAP_UMZ)
+  return (kind == 4 || kind == 8) ? 1 : 0;
+#else
+  return 0;
+#endif
+}
+
+
+int
+get_fpu_underflow_mode (void)
+{
+#if defined(__alpha__) && defined(FE_MAP_UMZ)
+
+  fenv_t state = __ieee_get_fp_control ();
+
+  /* Return 0 for abrupt underflow (flush to zero), 1 for gradual underflow.  */
+  return (state & FE_MAP_UMZ) ? 0 : 1;
+
+#else
+
+  return 0;
+
+#endif
+}
+
+
+void
+set_fpu_underflow_mode (int gradual __attribute__((unused)))
+{
+#if defined(__alpha__) && defined(FE_MAP_UMZ)
+
+  fenv_t state = __ieee_get_fp_control ();
+
+  if (gradual)
+    state &= ~FE_MAP_UMZ;
+  else
+    state |= FE_MAP_UMZ;
+
+  __ieee_set_fp_control (state);
+
+#endif
+}
+