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Re: What is acceptable for -ffast-math? (Was: associative law in combine)
- To: aoliva at redhat dot com, jsm28 at cam dot ac dot uk
- Subject: Re: What is acceptable for -ffast-math? (Was: associative law in combine)
- From: dewar at gnat dot com
- Date: Mon, 30 Jul 2001 21:08:46 -0400 (EDT)
- Cc: gcc at gcc dot gnu dot org
<<I'd rather you use #pragma STDC FP_CONTRACT OFF - while this seems to be
intended to disable optimisations that give more accurate results, it
should probably disable optimisations here that may give less accurate
results as well.
>>
Well to be fair, Alexandre is trying to provide a mechanism for very
specifically controlling on an operation by operation basis whether
"optimizations" of the type we are discussing are permitted.
My own view is that, if you absolutely must persue this, then just use
parentheses as in Fortran. So what if some PP output is unnecessarily
signalled as not being optimizable, this is a second order effect (my
own guess is that even the first order effect of such optimizations is
small in any case).