When folding memory operands, preserve existing MachineMemOperands.

This comes into play with patchpoint, which can fold multiple
operands. Since the patchpoint is already treated as a call, the
machine mem operands won't affect anything, and there's nothing to
test. But we still want to do the right thing here to be sure that our
MIs obey the rules.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194750 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/TargetInstrInfo.cpp b/lib/CodeGen/TargetInstrInfo.cpp
index 5e6162fbc311d2e42410966346d3786df546689d..edeca3d5b83ea64b0a80f732781202f4fcbdba20 100644 (file)
--- a/lib/CodeGen/TargetInstrInfo.cpp
+++ b/lib/CodeGen/TargetInstrInfo.cpp
@@ -364,6 +364,7 @@ TargetInstrInfo::foldMemoryOperand(MachineBasicBlock::iterator MI,
 
   // Ask the target to do the actual folding.
   if (MachineInstr *NewMI = foldMemoryOperandImpl(MF, MI, Ops, FI)) {
+    NewMI->setMemRefs(MI->memoperands_begin(), MI->memoperands_end());
     // Add a memory operand, foldMemoryOperandImpl doesn't do that.
     assert((!(Flags & MachineMemOperand::MOStore) ||
             NewMI->mayStore()) &&
@@ -424,9 +425,19 @@ TargetInstrInfo::foldMemoryOperand(MachineBasicBlock::iterator MI,
   NewMI = MBB.insert(MI, NewMI);
 
   // Copy the memoperands from the load to the folded instruction.
-  NewMI->setMemRefs(LoadMI->memoperands_begin(),
-                    LoadMI->memoperands_end());
-
+  if (MI->memoperands_empty()) {
+    NewMI->setMemRefs(LoadMI->memoperands_begin(),
+                      LoadMI->memoperands_end());
+  }
+  else {
+    // Handle the rare case of folding multiple loads.
+    NewMI->setMemRefs(MI->memoperands_begin(),
+                      MI->memoperands_end());
+    for (MachineInstr::mmo_iterator I = LoadMI->memoperands_begin(),
+           E = LoadMI->memoperands_end(); I != E; ++I) {
+      NewMI->addMemOperand(MF, *I);
+    }
+  }
   return NewMI;
 }