Commit Graph

4 Commits

Author SHA1 Message Date
Bill Wendling
2aae6ae572 Micro-optimization:
If we have this situation:

    jCC  L1
    jmp  L2
L1:
  ...
L2:
  ...

We can get a small performance boost by emitting this instead:

    jnCC L2
L1:
  ...
L2:
  ...

This testcase shows an example of this:

float func(float x, float y) {
    double product = (double)x * y;
    if (product == 0.0)
        return product;
    return product - 1.0;
}



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101075 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-12 22:19:57 +00:00
Chris Lattner
09987f73f6 allow this to work on linux hosts.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92407 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02 00:22:15 +00:00
Chris Lattner
133ce871df Teach codegen to handle:
(X != null) | (Y != null) --> (X|Y) != 0
 (X == null) & (Y == null) --> (X|Y) == 0

so that instcombine can stop doing this for pointers.  This is part of PR3351,
which is a case where instcombine doing this for pointers (inserting ptrtoint)
is pessimizing code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92406 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02 00:00:03 +00:00
Chris Lattner
aac00392c3 rename file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92405 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-01 23:55:04 +00:00