@c %**start of header
@setfilename g77.info
-@set last-update 1999-06-06
-@set copyrights-g77 1995-1999
+@set last-update 2000-12-21
+@set copyrights-g77 1995,1996,1997,1998,1999,2000
@include root.texi
@smallexample
@var{one line to give the program's name and a brief idea of what it does.}
-Copyright (C) 19@var{yy} @var{name of author}
+Copyright (C) @var{year} @var{name of author}
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
when it starts in an interactive mode:
@smallexample
-Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author}
+Gnomovision version 69, Copyright (C) @var{year} @var{name of author}
Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
type `show w'.
This is free software, and you are welcome to redistribute it
-malign-double
-ffloat-store -fforce-mem -fforce-addr -fno-inline
-ffast-math -fstrength-reduce -frerun-cse-after-loop
+-funsafe-math-optimizations -fno-trapping-math
-fexpensive-optimizations -fdelayed-branch
-fschedule-insns -fschedule-insn2 -fcaller-saves
-funroll-loops -funroll-all-loops
@cindex options, -fset-g77-defaults
@item -fset-g77-defaults
@emph{Version info:}
-This option is obsolete in @code{egcs}
-as of version 1.1.
+This option was obsolete as of @code{egcs}
+version 1.1.
The effect is instead achieved
by the @code{lang_init_options} routine
in @file{gcc/gcc/f/com.c}.
@cindex conformance, IEEE 754
Might allow some programs designed to not be too dependent
on IEEE behavior for floating-point to run faster, or die trying.
+Sets @samp{-funsafe-math-optimizations}, and
+@samp{-fno-trapping-math}.
+
+@cindex -funsafe-math-optimizations option
+@cindex options, -funsafe-math-optimizations
+@item -funsafe-math-optimizations
+Allow optimizations that may be give incorrect results
+for certain IEEE inputs.
+
+@cindex -fno-trapping-math option
+@cindex options, -fno-trapping-math
+@item -fno-trapping-math
+Allow the compiler to assume that floating-point arithmetic
+will not generate traps on any inputs. This is useful, for
+example, when running a program using IEEE "non-stop"
+floating-point arithmetic.
@cindex -fstrength-reduce option
@cindex options, -fstrength-reduce
and m68k GNU systems you can do this with a technique similar to that
for turning on floating-point exceptions
(@pxref{Floating-point Exception Handling}).
-The control word could be set to double precision by
-replacing the @code{__setfpucw} call with one like this:
+The control word could be set to double precision by some code like this
+one:
@smallexample
- __setfpucw ((_FPU_DEFAULT & ~_FPU_EXTENDED) | _FPU_DOUBLE);
+#include <fpu_control.h>
+@{
+ fpu_control_t cw = (_FPU_DEFAULT & ~_FPU_EXTENDED) | _FPU_DOUBLE;
+ _FPU_SETCW(cw);
+@}
@end smallexample
(It is not clear whether this has any effect on the operation of the GNU
maths library, but we have no evidence of it causing trouble.)
be invoked at startup using @code{gcc}'s @code{constructor} attribute.
For example, just compiling and linking the following C code with your
program will turn on exception trapping for the ``common'' exceptions
-on an x86-based GNU system:
+on a GNU system using glibc 2.2 or newer:
@smallexample
-#include <fpu_control.h>
+#define _GNU_SOURCE 1
+#include <fenv.h>
static void __attribute__ ((constructor))
trapfpe ()
@{
- fpu_control_t cw =
- _FPU_DEFAULT &
- ~(_FPU_MASK_IM | _FPU_MASK_ZM | _FPU_MASK_OM);
- _FPU_SETCW(cw);
+ /* Enable some exceptions. At startup all exceptions are masked. */
+
+ feenableexcept (FE_INVALID|FE_DIVBYZERO|FE_OVERFLOW);
@}
@end smallexample
which is used during the build of @code{gcc} to
build a list of all options that are accepted by
at least one language's compiler.
-This list goes into the @code{lang_options} array
+This list goes into the @code{documented_lang_options} array
in @file{gcc/toplev.c}, which uses this array to
determine whether a particular option should be
offered to the linked-in front end for processing
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