[CodeGen] Split out the notions of MI invariance and MI dereferenceability.

Summary:
An IR load can be invariant, dereferenceable, neither, or both.  But
currently, MI's notion of invariance is IR-invariant &&
IR-dereferenceable.

This patch splits up the notions of invariance and dereferenceability at
the MI level.  It's NFC, so adds some probably-unnecessary
"is-dereferenceable" checks, which we can remove later if desired.

Reviewers: chandlerc, tstellarAMD

Subscribers: jholewinski, arsenm, nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D23371

llvm-svn: 281151

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/MIRParser/MILexer.h b/llvm/lib/CodeGen/MIRParser/MILexer.h
index c0d9561b2e8..6911700b4c8 100644
--- a/llvm/lib/CodeGen/MIRParser/MILexer.h
+++ b/llvm/lib/CodeGen/MIRParser/MILexer.h
@@ -54,6 +54,7 @@ struct MIToken {
     kw_implicit_define,
     kw_def,
     kw_dead,
+    kw_dereferenceable,
     kw_killed,
     kw_undef,
     kw_internal,
@@ -166,7 +167,7 @@ public:
 
   bool isMemoryOperandFlag() const {
     return Kind == kw_volatile || Kind == kw_non_temporal ||
-           Kind == kw_invariant;
+           Kind == kw_dereferenceable || Kind == kw_invariant;
   }
 
   bool is(TokenKind K) const { return Kind == K; }