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Re: How to replace -O1 with corresponding -f's?


Sergei Organov wrote:
> Andrew Haley <aph@redhat.com> writes:
> 
> 
>>Sergei Organov writes:
>> > Hi,
>> > 
>> > Using gcc compiled from gcc-4_0-branch, in an attempt to see which
>> > particular optimization option makes my test case to be mis-optimized, I
>> > try to replace -O1 (which toggles on the problem) with corresponding set
>> > of -fxxx optimization options.
>>
>>In general you can't do this.  You can turn some optimization passes
>>off, though.
> 
> 
> Sigh :(

To be clear - there are a number of optimizations which have no corresponding
-f switch, being enabled or disabled solely by "if (optimize)" constructs; the
global 'optimize' flag is set by -On (n>0).  Similarly, there are places where
"if (optimize >= 2)" is the sole trigger.

This could be construed a bug, and I do not think there would be objection to
patches that add -f options for every such optimization.

zw


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