diff options
Diffstat (limited to 'gcc/f/g77.texi')
| -rw-r--r-- | gcc/f/g77.texi | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/gcc/f/g77.texi b/gcc/f/g77.texi index 72a793c..842f4e4 100644 --- a/gcc/f/g77.texi +++ b/gcc/f/g77.texi @@ -10475,9 +10475,10 @@ mode and not take the performance hit of @samp{-ffloat-store}. On x86 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 or the @code{_FPU_SETCW} macro with one like this: +The control word could be set to double precision by some code like this +one: @smallexample +#include <fpu_control.h> @{ fpu_control_t cw = (_FPU_DEFAULT & ~_FPU_EXTENDED) | _FPU_DOUBLE; _FPU_SETCW(cw); @@ -12150,17 +12151,17 @@ Most systems provide some C-callable mechanism to change this; this can 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 |