PR9604; try to deal with RAUW updates correctly in the AST. I'm not convinced

it's completely safe to cache the AST across LICM runs even with this fix,
but this fix can't hurt.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129198 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 54 insertions, 0 deletions

diff --git a/include/llvm/Analysis/AliasSetTracker.h b/include/llvm/Analysis/AliasSetTracker.h
index 4efa3963b6..03149c662e 100644
--- a/include/llvm/Analysis/AliasSetTracker.h
+++ b/include/llvm/Analysis/AliasSetTracker.h
@@ -284,6 +284,7 @@ class AliasSetTracker {
   class ASTCallbackVH : public CallbackVH {
     AliasSetTracker *AST;
     virtual void deleted();
+    virtual void allUsesReplacedWith(Value *);
   public:
     ASTCallbackVH(Value *V, AliasSetTracker *AST = 0);
     ASTCallbackVH &operator=(Value *V);
diff --git a/lib/Analysis/AliasSetTracker.cpp b/lib/Analysis/AliasSetTracker.cpp
index 3a46976d66..2ed6949412 100644
--- a/lib/Analysis/AliasSetTracker.cpp
+++ b/lib/Analysis/AliasSetTracker.cpp
@@ -602,6 +602,10 @@ void AliasSetTracker::ASTCallbackVH::deleted() {
   // this now dangles!
 }
 
+void AliasSetTracker::ASTCallbackVH::allUsesReplacedWith(Value *V) {
+  AST->copyValue(getValPtr(), V);
+}
+
 AliasSetTracker::ASTCallbackVH::ASTCallbackVH(Value *V, AliasSetTracker *ast)
   : CallbackVH(V), AST(ast) {}
 
diff --git a/test/Transforms/LICM/2011-04-09-RAUW-AST.ll b/test/Transforms/LICM/2011-04-09-RAUW-AST.ll
new file mode 100644
index 0000000000..4285bd19e5
--- /dev/null
+++ b/test/Transforms/LICM/2011-04-09-RAUW-AST.ll
@@ -0,0 +1,49 @@
+; RUN: opt < %s -loop-rotate -licm -S | FileCheck %s
+; PR9604
+
+@g_3 = global i32 0, align 4
+@.str = private unnamed_addr constant [4 x i8] c"%d\0A\00"
+
+define i32 @main() nounwind {
+entry:
+  %tmp = load i32* @g_3, align 4
+  %tobool = icmp eq i32 %tmp, 0
+  br i1 %tobool, label %for.cond, label %if.then
+
+if.then:                                          ; preds = %entry
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc10, %if.then, %entry
+  %g.0 = phi i32* [ %g.0, %for.inc10 ], [ @g_3, %entry ], [ null, %if.then ]
+  %x.0 = phi i32 [ %inc12, %for.inc10 ], [ 0, %entry ], [ 0, %if.then ]
+  %cmp = icmp slt i32 %x.0, 5
+  br i1 %cmp, label %for.cond4, label %for.end13
+
+for.cond4:                                        ; preds = %for.body7, %for.cond
+  %y.0 = phi i32 [ %inc, %for.body7 ], [ 0, %for.cond ]
+  %cmp6 = icmp slt i32 %y.0, 5
+  br i1 %cmp6, label %for.body7, label %for.inc10
+
+; CHECK: for.body7:
+; CHECK-NEXT: phi
+; CHECK-NEXT: store i32 0
+; CHECK-NEXT: store i32 1
+
+for.body7:                                        ; preds = %for.cond4
+  store i32 0, i32* @g_3, align 4
+  store i32 1, i32* %g.0, align 4
+  %inc = add nsw i32 %y.0, 1
+  br label %for.cond4
+
+for.inc10:                                        ; preds = %for.cond4
+  %inc12 = add nsw i32 %x.0, 1
+  br label %for.cond
+
+for.end13:                                        ; preds = %for.cond
+  %tmp14 = load i32* @g_3, align 4
+  %call = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([4 x i8]* @.str, i64 0, i64 0), i32 %tmp14) nounwind
+  ret i32 0
+}
+
+declare i32 @printf(i8* nocapture, ...) nounwind
+