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-rw-r--r--lib/Transforms/Utils/SimplifyIndVar.cpp4
-rw-r--r--test/Transforms/IndVarSimplify/2011-11-17-selfphi.ll29
2 files changed, 31 insertions, 2 deletions
diff --git a/lib/Transforms/Utils/SimplifyIndVar.cpp b/lib/Transforms/Utils/SimplifyIndVar.cpp
index 76289c055b..6732a789d5 100644
--- a/lib/Transforms/Utils/SimplifyIndVar.cpp
+++ b/lib/Transforms/Utils/SimplifyIndVar.cpp
@@ -107,8 +107,8 @@ Value *SimplifyIndvar::foldIVUser(Instruction *UseInst, Instruction *IVOperand)
// Attempt to fold a binary operator with constant operand.
// e.g. ((I + 1) >> 2) => I >> 2
- if (IVOperand->getNumOperands() != 2 ||
- !isa<ConstantInt>(IVOperand->getOperand(1)))
+ if (!isa<BinaryOperator>(IVOperand)
+ || !isa<ConstantInt>(IVOperand->getOperand(1)))
return 0;
IVSrc = IVOperand->getOperand(0);
diff --git a/test/Transforms/IndVarSimplify/2011-11-17-selfphi.ll b/test/Transforms/IndVarSimplify/2011-11-17-selfphi.ll
new file mode 100644
index 0000000000..ccf259597e
--- /dev/null
+++ b/test/Transforms/IndVarSimplify/2011-11-17-selfphi.ll
@@ -0,0 +1,29 @@
+; RUN: opt < %s -indvars -S | FileCheck %s
+; PR11350: Check that SimplifyIndvar handles a cycle of useless self-phis.
+
+; CHECK: @test
+; CHECK-NOT: lcssa = phi
+define void @test() nounwind {
+entry:
+ br label %for.cond.preheader
+
+for.cond.preheader: ; preds = %entry
+ br label %for.cond.outer
+
+for.cond.outer: ; preds = %for.cond.preheader, %for.end
+ %p_41.addr.0.ph = phi i32 [ %p_41.addr.1.lcssa, %for.end ], [ 1, %for.cond.preheader ]
+ br label %for.cond
+
+for.cond:
+ br i1 true, label %for.end, label %for.ph
+
+for.ph: ; preds = %for.cond4.preheader
+ br label %for.end
+
+for.end:
+ %p_41.addr.1.lcssa = phi i32 [ undef, %for.ph ], [ %p_41.addr.0.ph, %for.cond ]
+ %p_68.lobit.i = lshr i32 %p_41.addr.1.lcssa, 31
+ %cmp7 = icmp eq i32 %p_41.addr.1.lcssa, 0
+ %conv8 = zext i1 %cmp7 to i32
+ br label %for.cond.outer
+}