[llvm] [MISched] Make `getUnderlyingObjectsForInstr()` preserve unidentified objects (PR #225085)

[Nathan Corbyn via llvm-commits]

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@@ -120,57 +120,52 @@ ScheduleDAGInstrs::ScheduleDAGInstrs(MachineFunction &mf,
   SchedModel.init(&ST, EnableSchedModel, EnableSchedItins);
 }
 
-/// If this machine instr has memory reference information and it can be
-/// tracked to a normal reference to a known object, return the Value
-/// for that object. This function returns false the memory location is
-/// unknown or may alias anything.
+/// If this machine instruction has memory reference information, collect the
+/// list of underlying objects in \p Objects. If any of these objects are
+/// unknown or may alias anything, return false. Atomic and volatile memory
+/// operands are skipped.
 static bool getUnderlyingObjectsForInstr(const MachineInstr *MI,
                                          const MachineFrameInfo &MFI,
                                          UnderlyingObjectsVector &Objects,
                                          const DataLayout &DL) {
-  auto AllMMOsOkay = [&]() {
-    for (const MachineMemOperand *MMO : MI->memoperands()) {
-      // TODO: Figure out whether isAtomic is really necessary (see D57601).
-      if (MMO->isVolatile() || MMO->isAtomic())
-        return false;
+  bool AllObjectsIdentified = true;
 
-      if (const PseudoSourceValue *PSV = MMO->getPseudoValue()) {
+  for (const MachineMemOperand *MMO : MI->memoperands()) {
+    // TODO: Figure out whether isAtomic is really necessary (see D57601).
+    if (MMO->isVolatile() || MMO->isAtomic()) {
+      AllObjectsIdentified = false;
+      continue;
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cofibrant wrote:

This branch is different and it's the only one that continues. This is the 'volatile and atomic operands are skipped in the comment'.

https://github.com/llvm/llvm-project/pull/225085