gfortran.h: Add bitmasks for different FPE traps.

	* gfortran.h: Add bitmasks for different FPE traps. Add fpe
	member to options_t.
	* invoke.texi: Document the new -ffpe-trap option.
	* lang.opt: Add -ffpe-trap option.
	* options.c (gfc_init_options): Initialize the FPE option.
	(gfc_handle_fpe_trap_option): New function to parse the argument
	of the -ffpe-trap option.
	(gfc_handle_option): Add case for -ffpe-trap.
	* trans-decl.c: Declare a tree for the set_fpe library function.
	(gfc_build_builtin_function_decls): Build this tree.
	(gfc_generate_function_code): Generate a call to set_fpe at
	the beginning of the main program.
	* trans.h: New tree for the set_fpe library function.

	* Makefile.am: Add fpu.c to the build process, and
	target-dependent code as fpu-target.h.
	* Makefile.in: Regenerate.
	* configure.ac: Add call to configure.host to set
	FPU_HOST_HEADER.
	* configure: Regenerate.
	* config.h.in: Regenerate.
	* aclocal.m4: Regenerate.
	* configure.host: New script to determine which host-dependent
	code should go in.
	* libgfortran.h: Add fpe option, remove previous fpu_ options.
	Add bitmasks for different FPE traps. Add prototype for set_fpu.
	* runtime/environ.c: Remove environment variables to control
	fpu behaviour.
	* runtime/fpu.c (set_fpe): New function for the front-end.
	* runtime/main.c (init): Set FPU state.
	* config: New directory to store host-dependent code.
	* config/fpu-387.h: New file with code handling the i387 FPU.
	* config/fpu-glibc.h: New file with code for glibc systems.
	* config/fpu-generic.h: Fallback for the most generic host. Issue
	warnings.

From-SVN: r105328

3 files changed, 253 insertions, 0 deletions

diff --git a/libgfortran/config/fpu-387.h b/libgfortran/config/fpu-387.h
new file mode 100644
index 0000000..06c02ea
--- /dev/null
+++ b/libgfortran/config/fpu-387.h
@@ -0,0 +1,103 @@
+/* FPU-related code for x86 and x86_64 processors.
+   Copyright 2005 Free Software Foundation, Inc.
+   Contributed by Francois-Xavier Coudert <coudert@clipper.ens.fr>
+
+This file is part of the GNU Fortran 95 runtime library (libgfortran).
+
+Libgfortran is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public
+License as published by the Free Software Foundation; either
+version 2 of the License, or (at your option) any later version.
+
+In addition to the permissions in the GNU General Public License, the
+Free Software Foundation gives you unlimited permission to link the
+compiled version of this file into combinations with other programs,
+and to distribute those combinations without any restriction coming
+from the use of this file.  (The General Public License restrictions
+do apply in other respects; for example, they cover modification of
+the file, and distribution when not linked into a combine
+executable.)
+
+Libgfortran is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public
+License along with libgfortran; see the file COPYING.  If not,
+write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+
+static int
+has_sse (void)
+{
+#ifdef __x86_64__
+  return 1;
+#else
+  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)
+    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 & (1 << 25))
+    return 1;
+
+  return 0;
+#endif
+}
+
+void set_fpu (void)
+{
+  short cw;
+  int cw_sse;
+
+  /* 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
+  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;
+  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 */
+      asm volatile ("stmxcsr %0" : : "m" (cw_sse));
+      cw_sse &= 0xFFFF0000;
+      if (options.fpe & GFC_FPE_INVALID) cw_sse |= 1 << 7;
+      if (options.fpe & GFC_FPE_DENORMAL) cw_sse |= 1 << 8;
+      if (options.fpe & GFC_FPE_ZERO) cw_sse |= 1 << 9;
+      if (options.fpe & GFC_FPE_OVERFLOW) cw_sse |= 1 << 10;
+      if (options.fpe & GFC_FPE_UNDERFLOW) cw_sse |= 1 << 11;
+      if (options.fpe & GFC_FPE_PRECISION) cw_sse |= 1 << 12;
+      asm volatile ("ldmxcsr %0" : : "m" (cw_sse));
+    }
+}
diff --git a/libgfortran/config/fpu-generic.h b/libgfortran/config/fpu-generic.h
new file mode 100644
index 0000000..9e043d7
--- /dev/null
+++ b/libgfortran/config/fpu-generic.h
@@ -0,0 +1,57 @@
+/* Fallback FPU-related code (for systems not otherwise supported).
+   Copyright 2005 Free Software Foundation, Inc.
+   Contributed by Francois-Xavier Coudert <coudert@clipper.ens.fr>
+
+This file is part of the GNU Fortran 95 runtime library (libgfortran).
+
+Libgfortran is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public
+License as published by the Free Software Foundation; either
+version 2 of the License, or (at your option) any later version.
+
+In addition to the permissions in the GNU General Public License, the
+Free Software Foundation gives you unlimited permission to link the
+compiled version of this file into combinations with other programs,
+and to distribute those combinations without any restriction coming
+from the use of this file.  (The General Public License restrictions
+do apply in other respects; for example, they cover modification of
+the file, and distribution when not linked into a combine
+executable.)
+
+Libgfortran is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public
+License along with libgfortran; see the file COPYING.  If not,
+write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+
+/* Fallback FPU-related code for systems not otherwise supported. This
+   is mainly telling the user that we will not be able to do what he
+   requested.  */
+
+void
+set_fpu (void)
+{
+  if (options.fpe & GFC_FPE_INVALID)
+    st_printf ("Fortran runtime warning: IEEE 'invalid operation' "
+	       "exception not supported.\n");
+  if (options.fpe & GFC_FPE_DENORMAL)
+    st_printf ("Fortran runtime warning: IEEE 'denormal number' "
+	       "exception not supported.\n");
+  if (options.fpe & GFC_FPE_ZERO)
+    st_printf ("Fortran runtime warning: IEEE 'division by zero' "
+	       "exception not supported.\n");
+  if (options.fpe & GFC_FPE_OVERFLOW)
+    st_printf ("Fortran runtime warning: IEEE 'overflow' "
+	       "exception not supported.\n");
+  if (options.fpe & GFC_FPE_UNDERFLOW)
+    st_printf ("Fortran runtime warning: IEEE 'underflow' "
+	       "exception not supported.\n");
+  if (options.fpe & GFC_FPE_PRECISION)
+    st_printf ("Fortran runtime warning: IEEE 'loss of precision' "
+	       "exception not supported.\n");
+}
diff --git a/libgfortran/config/fpu-glibc.h b/libgfortran/config/fpu-glibc.h
new file mode 100644
index 0000000..0a6c9df1
--- /dev/null
+++ b/libgfortran/config/fpu-glibc.h
@@ -0,0 +1,93 @@
+/* FPU-related code for systems with GNU libc.
+   Copyright 2005 Free Software Foundation, Inc.
+   Contributed by Francois-Xavier Coudert <coudert@clipper.ens.fr>
+
+This file is part of the GNU Fortran 95 runtime library (libgfortran).
+
+Libgfortran is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public
+License as published by the Free Software Foundation; either
+version 2 of the License, or (at your option) any later version.
+
+In addition to the permissions in the GNU General Public License, the
+Free Software Foundation gives you unlimited permission to link the
+compiled version of this file into combinations with other programs,
+and to distribute those combinations without any restriction coming
+from the use of this file.  (The General Public License restrictions
+do apply in other respects; for example, they cover modification of
+the file, and distribution when not linked into a combine
+executable.)
+
+Libgfortran is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public
+License along with libgfortran; see the file COPYING.  If not,
+write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+
+/* FPU-related code for systems with the GNU libc, providing the
+   feenableexcept function in fenv.h to set individual exceptions
+   (there's nothing to do that in C99).  */
+
+#define __USE_GNU
+#ifdef HAVE_FENV_H
+#include <fenv.h>
+#endif
+
+void set_fpu (void)
+{
+  fedisableexcept (FE_ALL_EXCEPT);
+
+  if (options.fpe & GFC_FPE_INVALID)
+#ifdef FE_INVALID
+    feenableexcept (FE_INVALID);
+#else
+    st_printf ("Fortran runtime warning: IEEE 'invalid operation' "
+	       "exception not supported.\n");
+#endif
+
+/* glibc does never have a FE_DENORMAL.  */
+  if (options.fpe & GFC_FPE_DENORMAL)
+#ifdef FE_DENORMAL
+    feenableexcept (FE_DENORMAL);
+#else
+    st_printf ("Fortran runtime warning: IEEE 'denormal number' "
+	       "exception not supported.\n");
+#endif
+
+  if (options.fpe & GFC_FPE_ZERO)
+#ifdef FE_DIVBYZERO
+    feenableexcept (FE_DIVBYZERO);
+#else
+    st_printf ("Fortran runtime warning: IEEE 'division by zero' "
+	       "exception not supported.\n");
+#endif
+
+  if (options.fpe & GFC_FPE_OVERFLOW)
+#ifdef FE_OVERFLOW
+    feenableexcept (FE_OVERFLOW);
+#else
+    st_printf ("Fortran runtime warning: IEEE 'overflow' "
+	       "exception not supported.\n");
+#endif
+
+  if (options.fpe & GFC_FPE_UNDERFLOW)
+#ifdef FE_UNDERFLOW
+    feenableexcept (FE_UNDERFLOW);
+#else
+    st_printf ("Fortran runtime warning: IEEE 'underflow' "
+	       "exception not supported.\n");
+#endif
+
+  if (options.fpe & GFC_FPE_PRECISION)
+#ifdef FE_INEXACT
+    feenableexcept (FE_INEXACT);
+#else
+    st_printf ("Fortran runtime warning: IEEE 'loss of precision' "
+	       "exception not supported.\n");
+#endif
+}