Fix pr4195: When iterating through predecessor blocks, break out of the loop
after finding the (unique) layout predecessor. Sometimes a block may be listed
more than once, and processing it more than once in this loop can lead to
inconsistent values for FtTBB/FtFBB, since the AnalyzeBranch method does not
clear these values. There's no point in continuing the loop regardless.
The testcase for this is reduced from the 2003-05-02-DependentPHI SingleSource
test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71536 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/ARM/2009-05-11-CodePlacementCrash.ll b/test/CodeGen/ARM/2009-05-11-CodePlacementCrash.ll
new file mode 100644
index 0000000..35d4306
--- /dev/null
+++ b/test/CodeGen/ARM/2009-05-11-CodePlacementCrash.ll
@@ -0,0 +1,30 @@
+; RUN: llvm-as < %s | llc -march=arm
+ %struct.List = type { %struct.List*, i32 }
+@Node5 = external constant %struct.List ; <%struct.List*> [#uses=1]
+@"\01LC" = external constant [7 x i8] ; <[7 x i8]*> [#uses=1]
+
+define i32 @main() nounwind {
+entry:
+ br label %bb
+
+bb: ; preds = %bb3, %entry
+ %CurL.02 = phi %struct.List* [ @Node5, %entry ], [ %2, %bb3 ] ; <%struct.List*> [#uses=1]
+ %PrevL.01 = phi %struct.List* [ null, %entry ], [ %CurL.02, %bb3 ] ; <%struct.List*> [#uses=1]
+ %0 = icmp eq %struct.List* %PrevL.01, null ; <i1> [#uses=1]
+ br i1 %0, label %bb3, label %bb1
+
+bb1: ; preds = %bb
+ br label %bb3
+
+bb3: ; preds = %bb1, %bb
+ %iftmp.0.0 = phi i32 [ 0, %bb1 ], [ -1, %bb ] ; <i32> [#uses=1]
+ %1 = tail call i32 (i8*, ...)* @printf(i8* getelementptr ([7 x i8]* @"\01LC", i32 0, i32 0), i32 0, i32 %iftmp.0.0) nounwind ; <i32> [#uses=0]
+ %2 = load %struct.List** null, align 4 ; <%struct.List*> [#uses=2]
+ %phitmp = icmp eq %struct.List* %2, null ; <i1> [#uses=1]
+ br i1 %phitmp, label %bb5, label %bb
+
+bb5: ; preds = %bb3
+ ret i32 0
+}
+
+declare i32 @printf(i8* nocapture, ...) nounwind