[GlobalISel] Add a localizer pass for target to use

This reverts commit r299287 plus clean-ups.

The localizer pass is a helper pass that could be run at O0 in the GISel
pipeline to work around the deficiency of the fast register allocator.
It basically shortens the live-ranges of the constants so that the
allocator does not spill all over the place.

Long term fix would be to make the greedy allocator fast.

llvm-svn: 304051

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/GlobalISel.cpp b/llvm/lib/CodeGen/GlobalISel/GlobalISel.cpp
index fcd2722f1c2..29d1209bb02 100644
--- a/llvm/lib/CodeGen/GlobalISel/GlobalISel.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/GlobalISel.cpp
@@ -26,6 +26,7 @@ void llvm::initializeGlobalISel(PassRegistry &Registry) {
 void llvm::initializeGlobalISel(PassRegistry &Registry) {
   initializeIRTranslatorPass(Registry);
   initializeLegalizerPass(Registry);
+  initializeLocalizerPass(Registry);
   initializeRegBankSelectPass(Registry);
   initializeInstructionSelectPass(Registry);
 }