diff options
| author | Chris Lattner <sabre@nondot.org> | 2010-11-30 18:12:52 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-11-30 18:12:52 +0000 |
| commit | de189be53f5831737f38e720f10dbcdcce6876c6 (patch) | |
| tree | b8217c6ad3e6ff091ec902a43be517d90415ccd4 /lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | |
| parent | 21d8b9bcad1f058a4f2571dbc5a677e0ed95643e (diff) | |
add TLI support indicating that jumps are more expensive than logical operations
and use this to disable a specific optimization. Patch by Micah Villmow!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120435 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index d00643f1f1..6dfc6b53c7 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -1403,6 +1403,7 @@ void SelectionDAGBuilder::visitBr(const BranchInst &I) { // If this is a series of conditions that are or'd or and'd together, emit // this as a sequence of branches instead of setcc's with and/or operations. + // As long as jumps are not expensive, this should improve performance. // For example, instead of something like: // cmp A, B // C = seteq @@ -1417,7 +1418,8 @@ void SelectionDAGBuilder::visitBr(const BranchInst &I) { // jle foo // if (const BinaryOperator *BOp = dyn_cast<BinaryOperator>(CondVal)) { - if (BOp->hasOneUse() && + if (!TLI.isJumpExpensive() && + BOp->hasOneUse() && (BOp->getOpcode() == Instruction::And || BOp->getOpcode() == Instruction::Or)) { FindMergedConditions(BOp, Succ0MBB, Succ1MBB, BrMBB, BrMBB, |