[llvm-commits] CVS: llvm/lib/Transforms/Scalar/PRE.cpp

[Chris Lattner]

Changes in directory llvm/lib/Transforms/Scalar:

PRE.cpp added (r1.1)

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Log message:

Initial checkin of PRE on LLVM.  This implementation is still lacking in 
several ways:

 * Load expressions are not PRE'd well.  Alias Analysis should be used to
   get accurate information when computing anticipatibility.
 * The expression collection implementation does not handle PHI nodes properly,
   thus the implementation misses many opportunities to PRE.
 * This code could be sped up quite a bit

Despite these flaws, the code seems to work well, and handles PR's as one 
would expect.



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Diffs of the changes: