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Re: Processor-specific code
On Thu, Apr 14, 2005 at 05:27:16PM +0200, François-Xavier Coudert wrote:
> No, since reading GFORTRAN_FPU_* variables changes the FPU mode when the
> library is loaded, while TR 15580 commands will be ran afterwards (during
> execution).
You'll find that globally changing the rounding mode will screw up
libm functions. Which is pretty much going to make this useless.
Further, when folks need rounding modes other than round-to-nearest,
they tend to need to switch rounding modes during the program too.
For instance, to perform the same calculation with both round-up and
round-down to get error bounds on the calculation.
Thus I think an environment variable to do this is doubly useless.
All that said, C99 has <fenv.h> to control just about anything you
could want about the fpu.
r~