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| author | Chris Lattner <sabre@nondot.org> | 2009-01-26 02:18:20 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2009-01-26 02:18:20 +0000 |
| commit | 18f02318a65e176cb165ccff97478a7967aeef86 (patch) | |
| tree | 0b13bcb3d3bdd3c45db20e742ae650313c647d15 | |
| parent | 3796a262c50e0b04c1a5a9571f12bb9bc4936c25 (diff) | |
| download | llvm-18f02318a65e176cb165ccff97478a7967aeef86.tar.gz llvm-18f02318a65e176cb165ccff97478a7967aeef86.tar.bz2 llvm-18f02318a65e176cb165ccff97478a7967aeef86.tar.xz | |
Handle single-entry phi nodes gracefully in condprop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62985 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Scalar/CondPropagate.cpp | 8 | ||||
| -rw-r--r-- | test/Transforms/CondProp/2009-01-25-SingleEntryPHI.ll | 37 |
2 files changed, 45 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/CondPropagate.cpp b/lib/Transforms/Scalar/CondPropagate.cpp index 2e89943290..f68fb292e4 100644 --- a/lib/Transforms/Scalar/CondPropagate.cpp +++ b/lib/Transforms/Scalar/CondPropagate.cpp @@ -126,6 +126,14 @@ void CondProp::SimplifyPredecessors(BranchInst *BI) { // one use (the branch), and is the only instruction besides the branch in the // block. PHINode *PN = cast<PHINode>(BI->getCondition()); + + if (PN->getNumIncomingValues() == 1) { + // Eliminate single-entry PHI nodes. + FoldSingleEntryPHINodes(PN->getParent()); + return; + } + + if (!PN->hasOneUse()) return; BasicBlock *BB = BI->getParent(); diff --git a/test/Transforms/CondProp/2009-01-25-SingleEntryPHI.ll b/test/Transforms/CondProp/2009-01-25-SingleEntryPHI.ll new file mode 100644 index 0000000000..d14ce38f3d --- /dev/null +++ b/test/Transforms/CondProp/2009-01-25-SingleEntryPHI.ll @@ -0,0 +1,37 @@ +; RUN: llvm-as < %s | opt -condprop | llvm-dis +; PR3405 +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128" +target triple = "x86_64-unknown-linux-gnu" + +define i32 @main(i32 %argc, i8** %argv) nounwind { +entry: + br label %bb2 + +bb2: ; preds = %bb.bb2_crit_edge, %entry + br i1 false, label %bb5.thread2, label %bb + +bb: ; preds = %bb2 + br i1 false, label %bb3, label %bb.bb2_crit_edge + +bb.bb2_crit_edge: ; preds = %bb + br label %bb2 + +bb3: ; preds = %bb + %.lcssa4 = phi i1 [ false, %bb ] ; <i1> [#uses=1] + br i1 %.lcssa4, label %bb5.thread, label %bb6 + +bb5.thread: ; preds = %bb3 + br label %bb7 + +bb7: ; preds = %bb5.thread2, %bb5.thread + br label %UnifiedReturnBlock + +bb6: ; preds = %bb3 + br label %UnifiedReturnBlock + +bb5.thread2: ; preds = %bb2 + br label %bb7 + +UnifiedReturnBlock: ; preds = %bb6, %bb7 + ret i32 0 +} |