Consistently use MemoryLocation::UnknownSize to indicate unknown access size

1. Change the software pipeliner to use unknown size instead of dropping
   memory operands. It used to do it before, but MachineInstr::mayAlias
   did not handle it correctly.
2. Recognize UnknownSize in MachineInstr::mayAlias.
3. Print and parse UnknownSize in MIR.

Differential Revision: https://reviews.llvm.org/D50339

llvm-svn: 340208

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/MachineOperand.cpp b/llvm/lib/CodeGen/MachineOperand.cpp
index 8098333832b..a116d8fe877 100644
--- a/llvm/lib/CodeGen/MachineOperand.cpp
+++ b/llvm/lib/CodeGen/MachineOperand.cpp
@@ -14,6 +14,7 @@
 #include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Analysis/Loads.h"
+#include "llvm/Analysis/MemoryLocation.h"
 #include "llvm/CodeGen/MIRPrinter.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineJumpTableInfo.h"
@@ -1078,7 +1079,11 @@ void MachineMemOperand::print(raw_ostream &OS, ModuleSlotTracker &MST,
   if (getFailureOrdering() != AtomicOrdering::NotAtomic)
     OS << toIRString(getFailureOrdering()) << ' ';
 
-  OS << getSize();
+  if (getSize() == MemoryLocation::UnknownSize)
+    OS << "unknown-size";
+  else
+    OS << getSize();
+
   if (const Value *Val = getValue()) {
     OS << ((isLoad() && isStore()) ? " on " : isLoad() ? " from " : " into ");
     printIRValueReference(OS, *Val, MST);