[PATCH] D139359: Scalarizer: fix an opaque pointer bug

[Nicolai Hähnle via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rG6c379cb318d7: Scalarizer: fix an opaque pointer bug (authored by nhaehnle).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D139359/new/

https://reviews.llvm.org/D139359

Files:
  llvm/lib/Transforms/Scalar/Scalarizer.cpp
  llvm/test/Transforms/Scalarizer/opaque-ptr-bug.ll


Index: llvm/test/Transforms/Scalarizer/opaque-ptr-bug.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/Scalarizer/opaque-ptr-bug.ll
@@ -0,0 +1,28 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt %s -passes='scalarizer,dce' -S -scalarize-load-store -o - | FileCheck %s
+
+; This used to crash because the same (pointer) value was scattered by
+; different amounts.
+
+define void @test1(ptr %p) {
+; CHECK-LABEL: @test1(
+; CHECK-NEXT:    [[P_I12:%.*]] = getelementptr i16, ptr [[P:%.*]], i32 1
+; CHECK-NEXT:    [[P_I11:%.*]] = getelementptr i32, ptr [[P]], i32 1
+; CHECK-NEXT:    [[P_I2:%.*]] = getelementptr i32, ptr [[P]], i32 2
+; CHECK-NEXT:    [[P_I3:%.*]] = getelementptr i32, ptr [[P]], i32 3
+; CHECK-NEXT:    store i32 0, ptr [[P]], align 8
+; CHECK-NEXT:    [[P_I1:%.*]] = getelementptr i32, ptr [[P]], i32 1
+; CHECK-NEXT:    store i32 0, ptr [[P_I1]], align 4
+; CHECK-NEXT:    store i32 0, ptr [[P]], align 16
+; CHECK-NEXT:    store i32 0, ptr [[P_I11]], align 4
+; CHECK-NEXT:    store i32 0, ptr [[P_I2]], align 8
+; CHECK-NEXT:    store i32 0, ptr [[P_I3]], align 4
+; CHECK-NEXT:    store i16 0, ptr [[P]], align 4
+; CHECK-NEXT:    store i16 0, ptr [[P_I12]], align 2
+; CHECK-NEXT:    ret void
+;
+  store <2 x i32> zeroinitializer, ptr %p
+  store <4 x i32> zeroinitializer, ptr %p
+  store <2 x i16> zeroinitializer, ptr %p
+  ret void
+}
Index: llvm/lib/Transforms/Scalar/Scalarizer.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/Scalarizer.cpp
+++ llvm/lib/Transforms/Scalar/Scalarizer.cpp
@@ -76,10 +76,13 @@
 // Used to store the scattered form of a vector.
 using ValueVector = SmallVector<Value *, 8>;
 
-// Used to map a vector Value to its scattered form.  We use std::map
-// because we want iterators to persist across insertion and because the
-// values are relatively large.
-using ScatterMap = std::map<Value *, ValueVector>;
+// Used to map a vector Value and associated type to its scattered form.
+// The associated type is only non-null for pointer values that are "scattered"
+// when used as pointer operands to load or store.
+//
+// We use std::map because we want iterators to persist across insertion and
+// because the values are relatively large.
+using ScatterMap = std::map<std::pair<Value *, Type *>, ValueVector>;
 
 // Lists Instructions that have been replaced with scalar implementations,
 // along with a pointer to their scattered forms.
@@ -389,7 +392,7 @@
     // so that it can be used everywhere.
     Function *F = VArg->getParent();
     BasicBlock *BB = &F->getEntryBlock();
-    return Scatterer(BB, BB->begin(), V, PtrElemTy, &Scattered[V]);
+    return Scatterer(BB, BB->begin(), V, PtrElemTy, &Scattered[{V, PtrElemTy}]);
   }
   if (Instruction *VOp = dyn_cast<Instruction>(V)) {
     // When scalarizing PHI nodes we might try to examine/rewrite InsertElement
@@ -406,7 +409,7 @@
     BasicBlock *BB = VOp->getParent();
     return Scatterer(
         BB, skipPastPhiNodesAndDbg(std::next(BasicBlock::iterator(VOp))), V,
-        PtrElemTy, &Scattered[V]);
+        PtrElemTy, &Scattered[{V, PtrElemTy}]);
   }
   // In the fallback case, just put the scattered before Point and
   // keep the result local to Point.
@@ -422,7 +425,7 @@
 
   // If we already have a scattered form of Op (created from ExtractElements
   // of Op itself), replace them with the new form.
-  ValueVector &SV = Scattered[Op];
+  ValueVector &SV = Scattered[{Op, nullptr}];
   if (!SV.empty()) {
     for (unsigned I = 0, E = SV.size(); I != E; ++I) {
       Value *V = SV[I];


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