From bcbb032d557db28b221ac0b1992413de2b653454 Mon Sep 17 00:00:00 2001
From: Dean Michael Berris <dberris@google.com>
Date: Thu, 26 Jul 2018 00:02:54 +0000
Subject: [PATCH] [MCA] Avoid an InstrDesc copy in mca::LSUnit::reserve.

Summary:
InstrDesc contains 4 vectors (as well as some other data), so it's
expensive to copy.

Authored By: orodley

Reviewers: andreadb, mattd, dberris

Reviewed By: mattd, dberris

Subscribers: dberris, gbedwell, llvm-commits

Differential Revision: https://reviews.llvm.org/D49775

llvm-svn: 337985
---
 llvm/tools/llvm-mca/LSUnit.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/tools/llvm-mca/LSUnit.cpp b/llvm/tools/llvm-mca/LSUnit.cpp
index 4406e30..9ee3b61 100644
--- a/llvm/tools/llvm-mca/LSUnit.cpp
+++ b/llvm/tools/llvm-mca/LSUnit.cpp
@@ -52,7 +52,7 @@ void LSUnit::assignSQSlot(unsigned Index) {
 }
 
 bool LSUnit::reserve(const InstRef &IR) {
-  const InstrDesc Desc = IR.getInstruction()->getDesc();
+  const InstrDesc &Desc = IR.getInstruction()->getDesc();
   unsigned MayLoad = Desc.MayLoad;
   unsigned MayStore = Desc.MayStore;
   unsigned IsMemBarrier = Desc.HasSideEffects;
-- 
2.7.4