[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
diff --git a/llvm/lib/CodeGen/MachinePipeliner.cpp b/llvm/lib/CodeGen/MachinePipeliner.cpp
index dc61eba..45e9d50 100644
--- a/llvm/lib/CodeGen/MachinePipeliner.cpp
+++ b/llvm/lib/CodeGen/MachinePipeliner.cpp
@@ -3082,7 +3082,8 @@
MachineInstr::mmo_iterator NewMemRefs = MF.allocateMemRefsArray(NumRefs);
unsigned Refs = 0;
for (MachineMemOperand *MMO : NewMI.memoperands()) {
- if (MMO->isVolatile() || MMO->isInvariant() || (!MMO->getValue())) {
+ if (MMO->isVolatile() || (MMO->isInvariant() && MMO->isDereferenceable()) ||
+ (!MMO->getValue())) {
NewMemRefs[Refs++] = MMO;
continue;
}