Bob Wilson
74b0ccc577
Fix pr4195: When iterating through predecessor blocks, break out of the loop
...
after finding the (unique) layout predecessor. Sometimes a block may be listed
more than once, and processing it more than once in this loop can lead to
inconsistent values for FtTBB/FtFBB, since the AnalyzeBranch method does not
clear these values. There's no point in continuing the loop regardless.
The testcase for this is reduced from the 2003-05-02-DependentPHI SingleSource
test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71536 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-12 03:48:10 +00:00
Evan Cheng
5374405dc1
Oops. Don't forget to align single bb loops.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71363 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-09 19:18:01 +00:00
Evan Cheng
f045f80ba9
Enable loop bb placement optimization.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71291 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 23:35:49 +00:00
Evan Cheng
0269d3cbf3
Don't align loop header unless the loop back edge is below the header.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71242 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 19:01:44 +00:00
Evan Cheng
4b7f7a6e1f
Reverse branch condition only when there is a conditional branch.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71214 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 09:35:53 +00:00
Nick Lewycky
0ab2dcee5b
Add explicit braces to disambiguate nested if/else. Removes a warning.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71211 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 06:57:41 +00:00
Evan Cheng
45e0010e14
Optimize code placement in loop to eliminate unconditional branches or move unconditional branch to the outside of the loop. e.g.
...
/// A:
/// ...
/// <fallthrough to B>
///
/// B: --> loop header
/// ...
/// jcc <cond> C, [exit]
///
/// C:
/// ...
/// jmp B
///
/// ==>
///
/// A:
/// ...
/// jmp B
///
/// C: --> new loop header
/// ...
/// <fallthough to B>
///
/// B:
/// ...
/// jcc <cond> C, [exit]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71209 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 06:34:09 +00:00
Evan Cheng
7132e12ee5
Code refactoring.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71151 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-07 05:49:39 +00:00
Evan Cheng
bbf1db7213
Rename "loop aligner" pass to "code placement optimization" pass.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71150 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-07 05:42:24 +00:00
