Make tail merging the default, except on powerPC.  There was no prior art
for a target-dependent default with a command-line override; this way
should be generally usable.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37285 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 34c45f3..41f7e19 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -78,7 +78,7 @@
   
   // Branch folding must be run after regalloc and prolog/epilog insertion.
   if (!Fast)
-    PM.add(createBranchFoldingPass());
+    PM.add(createBranchFoldingPass(DoTailMergeDefault()));
     
   // Fold redundant debug labels.
   PM.add(createDebugLabelFoldingPass());
@@ -181,7 +181,7 @@
   
   // Branch folding must be run after regalloc and prolog/epilog insertion.
   if (!Fast)
-    PM.add(createBranchFoldingPass());
+    PM.add(createBranchFoldingPass(DoTailMergeDefault()));
   
   if (addPreEmitPass(PM, Fast) && PrintMachineCode)
     PM.add(createMachineFunctionPrinterPass(cerr));