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| author | Christopher Lamb <christopher.lamb@gmail.com> | 2007-12-10 07:24:06 +0000 |
|---|---|---|
| committer | Christopher Lamb <christopher.lamb@gmail.com> | 2007-12-10 07:24:06 +0000 |
| commit | d202e03fe56ca9c95ee20060f293f77cc2d77160 (patch) | |
| tree | fe2ba577968d536779164c0d7a7197c4c1d0edcd /llvm/lib/CodeGen/BranchFolding.cpp | |
| parent | b6a8cfea24b0ab70a5d04e1feab8fb8501026d69 (diff) | |
| download | bcm5719-llvm-d202e03fe56ca9c95ee20060f293f77cc2d77160.tar.gz bcm5719-llvm-d202e03fe56ca9c95ee20060f293f77cc2d77160.zip | |
Improve branch folding by recgonizing that explict successor relationships impact the value of fall-through choices.
llvm-svn: 44785
Diffstat (limited to 'llvm/lib/CodeGen/BranchFolding.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/BranchFolding.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index d4b1e90fd54..0f8c6629bae 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -775,6 +775,11 @@ static bool IsBetterFallthrough(MachineBasicBlock *MBB1, // optimize branches that branch to either a return block or an assert block // into a fallthrough to the return. if (MBB1->empty() || MBB2->empty()) return false; + + // If there is a clear successor ordering we make sure that one block + // will fall through to the next + if (MBB1->isSuccessor(MBB2)) return true; + if (MBB2->isSuccessor(MBB1)) return false; MachineInstr *MBB1I = --MBB1->end(); MachineInstr *MBB2I = --MBB2->end(); |
