[llvm] [DSE] Apply initializes attribute to DSE (PR #107282)

[Nikita Popov via llvm-commits]

================
@@ -1147,13 +1262,26 @@ struct DSEState {
     return MemoryLocation::getOrNone(I);
   }
 
-  std::optional<MemoryLocation> getLocForInst(Instruction *I) {
+  // Returns a list of <MemoryLocation, bool> pairs wrote by I.
+  // The bool means whether the write is from Initializes attr.
+  SmallVector<std::pair<MemoryLocation, bool>, 1>
+  getLocForInst(Instruction *I, bool ConsiderInitializesAttr) {
+    SmallVector<std::pair<MemoryLocation, bool>, 1> Locations;
     if (isMemTerminatorInst(I)) {
-      if (auto Loc = getLocForTerminator(I)) {
-        return Loc->first;
+      if (auto Loc = getLocForTerminator(I))
+        Locations.push_back(std::make_pair(Loc->first, false));
+      return Locations;
+    }
+
+    if (auto Loc = getLocForWrite(I))
+      Locations.push_back(std::make_pair(*Loc, false));
----------------
nikic wrote:

Can we return here or does this need to fall through?

https://github.com/llvm/llvm-project/pull/107282