Part one of switching to using a more sane heuristic for determining if-conversion profitability.

Rather than having arbitrary cutoffs, actually try to cost model the conversion.

For now, the constants are tuned to more or less match our existing behavior, but these will be
changed to reflect realistic values as this work proceeds.

llvm-svn: 114973

1 files changed, 0 insertions, 25 deletions

diff --git a/llvm/lib/Target/ARM/Thumb2InstrInfo.cpp b/llvm/lib/Target/ARM/Thumb2InstrInfo.cpp
index 09abf1d2484..49f5e4a9509 100644
--- a/llvm/lib/Target/ARM/Thumb2InstrInfo.cpp
+++ b/llvm/lib/Target/ARM/Thumb2InstrInfo.cpp
@@ -28,16 +28,6 @@
 
 using namespace llvm;
 
-static cl::opt<unsigned>
-IfCvtLimit("thumb2-ifcvt-limit", cl::Hidden,
-           cl::desc("Thumb2 if-conversion limit (default 3)"),
-           cl::init(3));
-
-static cl::opt<unsigned>
-IfCvtDiamondLimit("thumb2-ifcvt-diamond-limit", cl::Hidden,
-                  cl::desc("Thumb2 diamond if-conversion limit (default 3)"),
-                  cl::init(3));
-
 Thumb2InstrInfo::Thumb2InstrInfo(const ARMSubtarget &STI)
   : ARMBaseInstrInfo(STI), RI(*this, STI) {
 }
@@ -105,21 +95,6 @@ Thumb2InstrInfo::isLegalToSplitMBBAt(MachineBasicBlock &MBB,
   return llvm::getITInstrPredicate(MBBI, PredReg) == ARMCC::AL;
 }
 
-bool Thumb2InstrInfo::isProfitableToIfCvt(MachineBasicBlock &MBB,
-                                          unsigned NumInstrs) const {
-  return NumInstrs && NumInstrs <= IfCvtLimit;
-}
-  
-bool Thumb2InstrInfo::
-isProfitableToIfCvt(MachineBasicBlock &TMBB, unsigned NumT,
-                    MachineBasicBlock &FMBB, unsigned NumF) const {
-  // FIXME: Catch optimization such as:
-  //        r0 = movne
-  //        r0 = moveq
-  return NumT && NumF &&
-    NumT <= (IfCvtDiamondLimit) && NumF <= (IfCvtDiamondLimit);
-}
-
 void Thumb2InstrInfo::copyPhysReg(MachineBasicBlock &MBB,
                                   MachineBasicBlock::iterator I, DebugLoc DL,
                                   unsigned DestReg, unsigned SrcReg,