[llvm-dev] Where to find the list of passes run by clang/opt with -O3

Davide Italiano via llvm-dev llvm-dev at lists.llvm.org
Tue Sep 5 12:53:41 PDT 2017


On Tue, Sep 5, 2017 at 12:51 PM, Davide Italiano <davide at freebsd.org> wrote:
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>
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> On Tue, Sep 5, 2017 at 8:16 AM, Nitish Srivastava via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>>
>> Hi,
>>
>>   I am trying to locate the passes run by clang/opt when it is passed the option -O3. Can someone point me where to look at? Eventually, I want to turn off just the LoopStrengthReduction pass in the -O3 set of default passes.
>>

Also, the easiest hack to turn off LSR is that of probably just
commenting out the line that adds the pass in PassManagerBuilder.cpp.
If you use `opt` + the new pass manager there's a flag for testing to
specify a custom pipeline, but that will be more work.


-- 
Davide

"There are no solved problems; there are only problems that are more
or less solved" -- Henri Poincare


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