1 files changed, 41 insertions, 12 deletions

diff --git a/llvm/lib/Analysis/CFLAliasAnalysis.cpp b/llvm/lib/Analysis/CFLAliasAnalysis.cpp
index 84b31dff055..c262b9ea2ad 100644
--- a/llvm/lib/Analysis/CFLAliasAnalysis.cpp
+++ b/llvm/lib/Analysis/CFLAliasAnalysis.cpp
@@ -539,6 +539,19 @@ public:
     Output.push_back(Edge(&Inst, From1, EdgeType::Assign, AttrNone));
     Output.push_back(Edge(&Inst, From2, EdgeType::Assign, AttrNone));
   }
+
+  void visitConstantExpr(ConstantExpr *CE) {
+    switch (CE->getOpcode()) {
+    default:
+      llvm_unreachable("Unknown instruction type encountered!");
+// Build the switch statement using the Instruction.def file.
+#define HANDLE_INST(NUM, OPCODE, CLASS)                                        \
+  case Instruction::OPCODE:                                                    \
+    visit##OPCODE(*(CLASS *)CE);                                               \
+    break;
+#include "llvm/IR/Instruction.def"
+    }
+  }
 };
 
 // For a given instruction, we need to know which Value* to get the
@@ -741,6 +754,10 @@ static EdgeType flipWeight(EdgeType);
 static void argsToEdges(CFLAliasAnalysis &, Instruction *,
                         SmallVectorImpl<Edge> &);
 
+// Gets edges of the given ConstantExpr*, writing them to the SmallVector*.
+static void argsToEdges(CFLAliasAnalysis &, ConstantExpr *,
+                        SmallVectorImpl<Edge> &);
+
 // Gets the "Level" that one should travel in StratifiedSets
 // given an EdgeType.
 static Level directionOfEdgeType(EdgeType);
@@ -807,6 +824,13 @@ static bool hasUsefulEdges(Instruction *Inst) {
   return !isa<CmpInst>(Inst) && !isa<FenceInst>(Inst) && !IsNonInvokeTerminator;
 }
 
+static bool hasUsefulEdges(ConstantExpr *CE) {
+  // ConstantExpr doens't have terminators, invokes, or fences, so only needs
+  // to check for compares.
+  return CE->getOpcode() != Instruction::ICmp &&
+         CE->getOpcode() != Instruction::FCmp;
+}
+
 static Optional<StratifiedAttr> valueToAttrIndex(Value *Val) {
   if (isa<GlobalValue>(Val))
     return AttrGlobalIndex;
@@ -846,6 +870,13 @@ static void argsToEdges(CFLAliasAnalysis &Analysis, Instruction *Inst,
   v.visit(Inst);
 }
 
+static void argsToEdges(CFLAliasAnalysis &Analysis, ConstantExpr *CE,
+                        SmallVectorImpl<Edge> &Output) {
+  assert(hasUsefulEdges(CE) && "Expected constant expr to have 'useful' edges");
+  GetEdgesVisitor v(Analysis, Output);
+  v.visitConstantExpr(CE);
+}
+
 static Level directionOfEdgeType(EdgeType Weight) {
   switch (Weight) {
   case EdgeType::Reference:
@@ -865,25 +896,23 @@ static void constexprToEdges(CFLAliasAnalysis &Analysis,
   Worklist.push_back(&CExprToCollapse);
 
   SmallVector<Edge, 8> ConstexprEdges;
+  SmallPtrSet<ConstantExpr *, 4> Visited;
   while (!Worklist.empty()) {
     auto *CExpr = Worklist.pop_back_val();
-    std::unique_ptr<Instruction> Inst(CExpr->getAsInstruction());
 
-    if (!hasUsefulEdges(Inst.get()))
+    if (!hasUsefulEdges(CExpr))
       continue;
 
     ConstexprEdges.clear();
-    argsToEdges(Analysis, Inst.get(), ConstexprEdges);
+    argsToEdges(Analysis, CExpr, ConstexprEdges);
     for (auto &Edge : ConstexprEdges) {
-      if (Edge.From == Inst.get())
-        Edge.From = CExpr;
-      else if (auto *Nested = dyn_cast<ConstantExpr>(Edge.From))
-        Worklist.push_back(Nested);
-
-      if (Edge.To == Inst.get())
-        Edge.To = CExpr;
-      else if (auto *Nested = dyn_cast<ConstantExpr>(Edge.To))
-        Worklist.push_back(Nested);
+      if (auto *Nested = dyn_cast<ConstantExpr>(Edge.From))
+        if (Visited.insert(Nested).second)
+          Worklist.push_back(Nested);
+
+      if (auto *Nested = dyn_cast<ConstantExpr>(Edge.To))
+        if (Visited.insert(Nested).second)
+          Worklist.push_back(Nested);
     }
 
     Results.append(ConstexprEdges.begin(), ConstexprEdges.end());