Rewrite the global merge pass to be subprogram agnostic for now.

It was previously using the subtarget to get values for the global
offset without actually checking each function as it was generating
code. Go ahead and solidify the current behavior and make the
existing FIXMEs more prominent.

As a note the ARM backend previously had a thumb1 and non-thumb1
set of defaults. Only the former was tested so I've changed the
behavior to only use that for now.

llvm-svn: 230245

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/lib/Target/ARM/ARMTargetMachine.cpp b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
index 11fbb5c..a97a058 100644
--- a/llvm/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
@@ -326,7 +326,12 @@ void ARMPassConfig::addIRPasses() {
 
 bool ARMPassConfig::addPreISel() {
   if (TM->getOptLevel() != CodeGenOpt::None)
-    addPass(createGlobalMergePass(TM));
+    // FIXME: This is using the thumb1 only constant value for
+    // maximal global offset for merging globals. We may want
+    // to look into using the old value for non-thumb1 code of
+    // 4095 based on the TargetMachine, but this starts to become
+    // tricky when doing code gen per function.
+    addPass(createGlobalMergePass(TM, 127));
 
   return false;
 }