Philip Reames 521c9dc7d8 Factor check for the assume intrinsic out of checks in computeKnownBitsFromAssume ...

We were matching against the assume intrinsic in every check.  Since we know that it must be an assume, this is just wasted work.  Somewhat surprisingly, matching an intrinsic id is actually relatively expensive.  It devolves to a string construction and comparison in Function::isIntrinsic.

I originally spotted this because it showed up in a performance profile of my compiler.  I've since discovered a separate issue which seems to be the actual root cause, but this is minor perf goodness regardless.  

I'm likely to follow up with another change to factor out the comparison matching.  There's no need to match the compare instruction in every single one of the tests.

Differential Revision: http://reviews.llvm.org/D6312



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222709 91177308-0d34-0410-b5e6-96231b3b80d8

2014-11-24 23:44:28 +00:00

103 KiB

Raw Blame History

View Raw