Let MachineVerifier be aware of mem-to-mem instructions.
A mem-to-mem instruction (that both loads and stores), which store to an
FI, cannot pass the verifier since it thinks it is loading from the FI.
For the mem-to-mem instruction, do a looser check in visitMachineOperand()
and only check liveness at the reg-slot while analyzing a frame index operand.
Needed to make CodeGen/SystemZ/xor-01.ll pass with -verify-machineinstrs,
which now runs with this flag.
Reviewed by Evan Cheng and Quentin Colombet.
llvm-svn: 250885
diff --git a/llvm/lib/CodeGen/MachineVerifier.cpp b/llvm/lib/CodeGen/MachineVerifier.cpp
index c21b875..b9ca0c5 100644
--- a/llvm/lib/CodeGen/MachineVerifier.cpp
+++ b/llvm/lib/CodeGen/MachineVerifier.cpp
@@ -994,11 +994,17 @@
LiveInts && !LiveInts->isNotInMIMap(MI)) {
LiveInterval &LI = LiveStks->getInterval(MO->getIndex());
SlotIndex Idx = LiveInts->getInstructionIndex(MI);
- if (MI->mayLoad() && !LI.liveAt(Idx.getRegSlot(true))) {
+
+ // 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))) {
report("Instruction loads from dead spill slot", MO, MONum);
errs() << "Live stack: " << LI << '\n';
}
- if (MI->mayStore() && !LI.liveAt(Idx.getRegSlot())) {
+ if (stores && !LI.liveAt(Idx.getRegSlot())) {
report("Instruction stores to dead spill slot", MO, MONum);
errs() << "Live stack: " << LI << '\n';
}