Do not track subregister liveness when it brings no benefits

Some subregisters are only to indicate different access sizes, while not
providing any way to actually divide the register up into multiple
disjunct parts. Avoid tracking subregister liveness in these cases as it
is not beneficial.

Differential Revision: http://reviews.llvm.org/D8429

llvm-svn: 232695

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/VirtRegMap.cpp b/llvm/lib/CodeGen/VirtRegMap.cpp
index 7d3b0cea1c1..d9adfdf7b2e 100644
--- a/llvm/lib/CodeGen/VirtRegMap.cpp
+++ b/llvm/lib/CodeGen/VirtRegMap.cpp
@@ -286,7 +286,7 @@ void VirtRegRewriter::addMBBLiveIns() {
 }
 
 void VirtRegRewriter::rewrite() {
-  bool NoSubRegLiveness = !MRI->tracksSubRegLiveness();
+  bool NoSubRegLiveness = !MRI->subRegLivenessEnabled();
   SmallVector<unsigned, 8> SuperDeads;
   SmallVector<unsigned, 8> SuperDefs;
   SmallVector<unsigned, 8> SuperKills;