[PATCH] D120077: [EarlyCSE][OpaquePtr] Check access type when performing DSE

[Arthur Eubanks via Phabricator via llvm-commits]

aeubanks created this revision.
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This will bail out on target specific intrinsics. If those are deemed
important enough for EarlyCSE to handle, we can augment MemIntrinsicInfo
with an access type for TargetTransformInfo::getTgtMemIntrinsic() to
handle.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D120077

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


Index: llvm/test/Transforms/EarlyCSE/opaque-ptr.ll
===================================================================
--- llvm/test/Transforms/EarlyCSE/opaque-ptr.ll
+++ llvm/test/Transforms/EarlyCSE/opaque-ptr.ll
@@ -30,3 +30,14 @@
   %sub = sub i32 %a, %v2.c
   ret i32 %sub
 }
+
+define void @dse(ptr %p, i32 %i1, i8 %i2) {
+; CHECK-LABEL: @dse(
+; CHECK-NEXT:    store i32 [[I1:%.*]], ptr [[P:%.*]], align 4
+; CHECK-NEXT:    store i8 [[I2:%.*]], ptr [[P]], align 1
+; CHECK-NEXT:    ret void
+;
+  store i32 %i1, ptr %p
+  store i8 %i2, ptr %p
+  ret void
+}
Index: llvm/lib/Transforms/Scalar/EarlyCSE.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/EarlyCSE.cpp
+++ llvm/lib/Transforms/Scalar/EarlyCSE.cpp
@@ -781,6 +781,21 @@
       return getLoadStorePointerOperand(Inst);
     }
 
+    Type *getValueType() const {
+      // TODO: handle target-specific intrinsics.
+      if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst)) {
+        switch (II->getIntrinsicID()) {
+        case Intrinsic::masked_load:
+          return II->getType();
+        case Intrinsic::masked_store:
+          return II->getArgOperand(0)->getType();
+        default:
+          return nullptr;
+        }
+      }
+      return getLoadStoreType(Inst);
+    }
+
     bool mayReadFromMemory() const {
       if (IntrID != 0)
         return Info.ReadMem;
@@ -1162,6 +1177,9 @@
          "Violated invariant");
   if (Earlier.getPointerOperand() != Later.getPointerOperand())
     return false;
+  if (!Earlier.getValueType() || !Later.getValueType() ||
+      Earlier.getValueType() != Later.getValueType())
+    return false;
   if (Earlier.getMatchingId() != Later.getMatchingId())
     return false;
   // At the moment, we don't remove ordered stores, but do remove


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