[MachineVerifier] Analyze MachineMemOperands for mem-to-mem moves.
Since the verifier will give false reports if it incorrectly thinks MI is
loading or storing using an FI, it is necessary to scan memoperands and
find out how the FI is used in the instruction. This should be relatively
rare.
Needed to make CodeGen/SystemZ/spill-01.ll pass, which now runs with this flag.
Reviewed by Quentin Colombet.
llvm-svn: 251620
diff --git a/llvm/lib/CodeGen/MachineVerifier.cpp b/llvm/lib/CodeGen/MachineVerifier.cpp
index b9ca0c5..25035fd 100644
--- a/llvm/lib/CodeGen/MachineVerifier.cpp
+++ b/llvm/lib/CodeGen/MachineVerifier.cpp
@@ -992,15 +992,34 @@
case MachineOperand::MO_FrameIndex:
if (LiveStks && LiveStks->hasInterval(MO->getIndex()) &&
LiveInts && !LiveInts->isNotInMIMap(MI)) {
- LiveInterval &LI = LiveStks->getInterval(MO->getIndex());
+ int FI = MO->getIndex();
+ LiveInterval &LI = LiveStks->getInterval(FI);
SlotIndex Idx = LiveInts->getInstructionIndex(MI);
- // For a memory-to-memory move, we don't know if MI is using
- // this frame index for loading or storing, so check for
- // liveness at reg-slot only in the simple load case.
bool stores = MI->mayStore();
- bool simpleLoad = (MI->mayLoad() && !stores);
- if (simpleLoad && !LI.liveAt(Idx.getRegSlot(true))) {
+ bool loads = MI->mayLoad();
+ // For a memory-to-memory move, we need to check if the frame
+ // index is used for storing or loading, by inspecting the
+ // memory operands.
+ if (stores && loads) {
+ for (auto *MMO : MI->memoperands()) {
+ const PseudoSourceValue *PSV = MMO->getPseudoValue();
+ if (PSV == nullptr) continue;
+ const FixedStackPseudoSourceValue *Value =
+ dyn_cast<FixedStackPseudoSourceValue>(PSV);
+ if (Value == nullptr) continue;
+ if (Value->getFrameIndex() != FI) continue;
+
+ if (MMO->isStore())
+ loads = false;
+ else
+ stores = false;
+ break;
+ }
+ if (loads == stores)
+ report("Missing fixed stack memoperand.", MI);
+ }
+ if (loads && !LI.liveAt(Idx.getRegSlot(true))) {
report("Instruction loads from dead spill slot", MO, MONum);
errs() << "Live stack: " << LI << '\n';
}