fix PR5837 by having SSAUpdate reuse phi nodes for the
'GetValueInMiddleOfBlock' case, instead of inserting
duplicates.
A similar fix is almost certainly needed by the machine-level
SSAUpdate implementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91820 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Transforms/LoopRotate/phi-duplicate.ll b/test/Transforms/LoopRotate/phi-duplicate.ll
new file mode 100644
index 0000000..cac00f8
--- /dev/null
+++ b/test/Transforms/LoopRotate/phi-duplicate.ll
@@ -0,0 +1,35 @@
+; RUN: opt -S %s -loop-rotate | FileCheck %s
+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-n8:16:32:64"
+target triple = "x86_64-apple-darwin10.0"
+
+; PR5837
+define void @test(i32 %N, double* %G) nounwind ssp {
+entry:
+ br label %for.cond
+
+for.cond: ; preds = %for.body, %entry
+ %j.0 = phi i64 [ 1, %entry ], [ %inc, %for.body ] ; <i64> [#uses=5]
+ %cmp = icmp slt i64 %j.0, 1000 ; <i1> [#uses=1]
+ br i1 %cmp, label %for.body, label %for.end
+
+for.body: ; preds = %for.cond
+ %arrayidx = getelementptr inbounds double* %G, i64 %j.0 ; <double*> [#uses=1]
+ %tmp3 = load double* %arrayidx ; <double> [#uses=1]
+ %sub = sub i64 %j.0, 1 ; <i64> [#uses=1]
+ %arrayidx6 = getelementptr inbounds double* %G, i64 %sub ; <double*> [#uses=1]
+ %tmp7 = load double* %arrayidx6 ; <double> [#uses=1]
+ %add = fadd double %tmp3, %tmp7 ; <double> [#uses=1]
+ %arrayidx10 = getelementptr inbounds double* %G, i64 %j.0 ; <double*> [#uses=1]
+ store double %add, double* %arrayidx10
+ %inc = add nsw i64 %j.0, 1 ; <i64> [#uses=1]
+ br label %for.cond
+
+for.end: ; preds = %for.cond
+ ret void
+}
+; Should only end up with one phi.
+; CHECK: for.body:
+; CHECK-NEXT: %j.02 = phi i64
+; CHECK-NOT phi
+; CHECK: ret void
+