From 365c9f1ff55bef134c6b9707f7df44d680ddabea Mon Sep 17 00:00:00 2001
From: Andrew Trick <atrick@apple.com>
Date: Sat, 15 Oct 2011 06:19:55 +0000
Subject: [PATCH] Fix SCEVExpander assert during LSR: "argument of incompatible
 type".

Just because we're dealing with a GEP doesn't mean we can assert the
SCEV has a pointer type. The fix is simply to ignore the SCEV pointer
type, which we really didn't need.
Fixes PR11138 webkit crash.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142058 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Analysis/ScalarEvolutionExpander.h    |  3 +--
 lib/Analysis/ScalarEvolutionExpander.cpp           | 11 ++++-----
 .../LoopStrengthReduce/2011-10-14-IntPtr.ll        | 27 ++++++++++++++++++++++
 3 files changed, 33 insertions(+), 8 deletions(-)
 create mode 100644 test/Transforms/LoopStrengthReduce/2011-10-14-IntPtr.ll

diff --git a/include/llvm/Analysis/ScalarEvolutionExpander.h b/include/llvm/Analysis/ScalarEvolutionExpander.h
index 1080580c960..a4ad1451d41 100644
--- a/include/llvm/Analysis/ScalarEvolutionExpander.h
+++ b/include/llvm/Analysis/ScalarEvolutionExpander.h
@@ -237,8 +237,7 @@ namespace llvm {
 
     bool isNormalAddRecExprPHI(PHINode *PN, Instruction *IncV, const Loop *L);
 
-    bool isExpandedAddRecExprPHI(PHINode *PN, Instruction *IncV, const Loop *L,
-                                 Type *ExpandTy);
+    bool isExpandedAddRecExprPHI(PHINode *PN, Instruction *IncV, const Loop *L);
 
     Value *expandAddRecExprLiterally(const SCEVAddRecExpr *);
     PHINode *getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized,
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index e76b6b10cf9..47f0f321161 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -881,7 +881,7 @@ bool SCEVExpander::isNormalAddRecExprPHI(PHINode *PN, Instruction *IncV,
 /// should match any patterns generated by getAddRecExprPHILiterally and
 /// expandAddtoGEP.
 bool SCEVExpander::isExpandedAddRecExprPHI(PHINode *PN, Instruction *IncV,
-                                           const Loop *L, Type *ExpandTy) {
+                                           const Loop *L) {
   switch (IncV->getOpcode()) {
   // Check for a simple Add/Sub or GEP of a loop invariant step.
   case Instruction::Add:
@@ -904,7 +904,7 @@ bool SCEVExpander::isExpandedAddRecExprPHI(PHINode *PN, Instruction *IncV,
       // i1* is used by the expander to represent an address-size element.
       if (IncV->getNumOperands() != 2)
         return false;
-      unsigned AS = cast<PointerType>(ExpandTy)->getAddressSpace();
+      unsigned AS = cast<PointerType>(IncV->getType())->getAddressSpace();
       if (IncV->getType() != Type::getInt1PtrTy(SE.getContext(), AS)
           && IncV->getType() != Type::getInt8PtrTy(SE.getContext(), AS))
         return false;
@@ -954,7 +954,7 @@ SCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized,
         cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock));
 
       if (LSRMode) {
-        if (!isExpandedAddRecExprPHI(PN, IncV, L, ExpandTy))
+        if (!isExpandedAddRecExprPHI(PN, IncV, L))
           continue;
       }
       else {
@@ -1547,9 +1547,8 @@ unsigned SCEVExpander::replaceCongruentIVs(Loop *L, const DominatorTree *DT,
         cast<Instruction>(Phi->getIncomingValueForBlock(LatchBlock));
 
       // If this phi is more canonical, swap it with the original.
-      if (!isExpandedAddRecExprPHI(OrigPhiRef, OrigInc, L,
-                                   OrigPhiRef->getType())
-          && isExpandedAddRecExprPHI(Phi, IsomorphicInc, L, Phi->getType())) {
+      if (!isExpandedAddRecExprPHI(OrigPhiRef, OrigInc, L)
+          && isExpandedAddRecExprPHI(Phi, IsomorphicInc, L)) {
         std::swap(OrigPhiRef, Phi);
         std::swap(OrigInc, IsomorphicInc);
       }
diff --git a/test/Transforms/LoopStrengthReduce/2011-10-14-IntPtr.ll b/test/Transforms/LoopStrengthReduce/2011-10-14-IntPtr.ll
new file mode 100644
index 00000000000..60cc7a51632
--- /dev/null
+++ b/test/Transforms/LoopStrengthReduce/2011-10-14-IntPtr.ll
@@ -0,0 +1,27 @@
+; RUN: opt -loop-reduce -S < %s | FileCheck %s
+;
+; Test SCEVExpander reusing a phi->gep->phi IV when SCEV "wrongly"
+; reports the expression as an IntegerTy.
+
+target triple = "x86_64-apple-darwin"
+
+; CHECK: @test
+; CHECK: phi
+; CHECK-NOT: phi
+define void @test(i32 %rowStride) ssp align 2 {
+entry:
+  %cond = select i1 undef, i32 %rowStride, i32 4
+  br label %for.end
+
+for.end.critedge:                                 ; preds = %for.end
+  br label %for.end
+
+for.end:                                          ; preds = %for.end.critedge, %entry
+  br i1 undef, label %for.body83, label %for.end.critedge
+
+for.body83:                                       ; preds = %for.body83, %for.end
+  %ptr.0157 = phi i8* [ %add.ptr96, %for.body83 ], [ null, %for.end ]
+  store i8 undef, i8* %ptr.0157, align 1
+  %add.ptr96 = getelementptr inbounds i8* %ptr.0157, i32 %cond
+  br label %for.body83
+}
-- 
2.11.0