How to get GCC on par with ICC?

Joseph Myers joseph@codesourcery.com
Fri Jun 15 18:01:00 GMT 2018


On Fri, 15 Jun 2018, Jeff Law wrote:

> And resolution on -fno-math-errno as the default.  Setting errno can be
> more expensive than people realize.

I don't think I saw any version of the -fno-math-errno patch proposal that 
included the testsuite updates I'd expect.  Certainly 
gcc.dg/torture/pr68264.c tests libm functions setting errno and would need 
to use -fmath-errno explicitly, but it seems likely there are other tests 
involving built-in functions that in fact only test what they're intended 
to test given -fmath-errno; tests using libm functions without explicit 
-ffast-math / -fmath-errno / -fno-math-errno would need review (and there 
should be new tests for optimizations that are only valid given 
-fno-math-errno).

-- 
Joseph S. Myers
joseph@codesourcery.com



More information about the Gcc mailing list