Disable the PPC CTR-Loops pass by default.

The pass itself works well, but the something in the Machine* infrastructure
does not understand terminators which define registers. Without the ability
to use the block-placement pass, etc. this causes performance regressions (and
so is turned off by default). Turning off the analysis turns off the problems
with the Machine* infrastructure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158206 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 4 deletions

diff --git a/lib/Target/PowerPC/PPCTargetMachine.cpp b/lib/Target/PowerPC/PPCTargetMachine.cpp
index 6f7fc4bb39..bcab83c5cf 100644
--- a/lib/Target/PowerPC/PPCTargetMachine.cpp
+++ b/lib/Target/PowerPC/PPCTargetMachine.cpp
@@ -23,8 +23,8 @@
 using namespace llvm;
 
 static cl::
-opt<bool> DisableCTRLoops("disable-ppc-ctrloops", cl::Hidden,
-                        cl::desc("Disable CTR loops for PPC"));
+opt<bool> EnableCTRLoops("enable-ppc-ctrloops", cl::Hidden,
+                        cl::desc("Enable CTR loops for PPC"));
 
 extern "C" void LLVMInitializePowerPCTarget() {
   // Register the targets
@@ -103,9 +103,10 @@ TargetPassConfig *PPCTargetMachine::createPassConfig(PassManagerBase &PM) {
 }
 
 bool PPCPassConfig::addPreRegAlloc() {
-  if (!DisableCTRLoops && getOptLevel() != CodeGenOpt::None) {
+  // FIXME: Once this can be enabled by default, this condition should read:
+  // if (!DisableCTRLoops && getOptLevel() != CodeGenOpt::None)
+  if (EnableCTRLoops)
     PM->add(createPPCCTRLoops());
-  }
 
   return false;
 }