[llvm-commits] [llvm] r135724 - /llvm/trunk/lib/CodeGen/IfConversion.cpp
Jakub Staszak
jstaszak at apple.com
Thu Jul 21 16:48:55 PDT 2011
Author: kuba
Date: Thu Jul 21 18:48:55 2011
New Revision: 135724
URL: http://llvm.org/viewvc/llvm-project?rev=135724&view=rev
Log:
Use MachineBranchProbabilityInfo instead of MachineLoopInfo in IfConversion.
Modified:
llvm/trunk/lib/CodeGen/IfConversion.cpp
Modified: llvm/trunk/lib/CodeGen/IfConversion.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/IfConversion.cpp?rev=135724&r1=135723&r2=135724&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/IfConversion.cpp (original)
+++ llvm/trunk/lib/CodeGen/IfConversion.cpp Thu Jul 21 18:48:55 2011
@@ -16,14 +16,13 @@
#include "llvm/Function.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/Codegen/MachineBranchProbabilityInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/MC/MCInstrItineraries.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
-#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
@@ -154,7 +153,8 @@
const TargetInstrInfo *TII;
const TargetRegisterInfo *TRI;
const InstrItineraryData *InstrItins;
- const MachineLoopInfo *MLI;
+ const MachineBranchProbabilityInfo *MBPI;
+
bool MadeChange;
int FnNum;
public:
@@ -162,9 +162,9 @@
IfConverter() : MachineFunctionPass(ID), FnNum(-1) {
initializeIfConverterPass(*PassRegistry::getPassRegistry());
}
-
+
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<MachineLoopInfo>();
+ AU.addRequired<MachineBranchProbabilityInfo>();
MachineFunctionPass::getAnalysisUsage(AU);
}
@@ -252,7 +252,7 @@
}
INITIALIZE_PASS_BEGIN(IfConverter, "if-converter", "If Converter", false, false)
-INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
+INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
INITIALIZE_PASS_END(IfConverter, "if-converter", "If Converter", false, false)
FunctionPass *llvm::createIfConverterPass() { return new IfConverter(); }
@@ -261,7 +261,7 @@
TLI = MF.getTarget().getTargetLowering();
TII = MF.getTarget().getInstrInfo();
TRI = MF.getTarget().getRegisterInfo();
- MLI = &getAnalysis<MachineLoopInfo>();
+ MBPI = &getAnalysis<MachineBranchProbabilityInfo>();
InstrItins = MF.getTarget().getInstrItineraryData();
if (!TII) return false;
@@ -790,28 +790,9 @@
bool TNeedSub = TrueBBI.Predicate.size() > 0;
bool FNeedSub = FalseBBI.Predicate.size() > 0;
bool Enqueued = false;
-
- // Try to predict the branch, using loop info to guide us.
- // General heuristics are:
- // - backedge -> 90% taken
- // - early exit -> 20% taken
- // - branch predictor confidence -> 90%
- BranchProbability Prediction(5, 10);
- MachineLoop *Loop = MLI->getLoopFor(BB);
- if (Loop) {
- if (TrueBBI.BB == Loop->getHeader())
- Prediction = BranchProbability(9, 10);
- else if (FalseBBI.BB == Loop->getHeader())
- Prediction = BranchProbability(1, 10);
-
- MachineLoop *TrueLoop = MLI->getLoopFor(TrueBBI.BB);
- MachineLoop *FalseLoop = MLI->getLoopFor(FalseBBI.BB);
- if (!TrueLoop || TrueLoop->getParentLoop() == Loop)
- Prediction = BranchProbability(2, 10);
- else if (!FalseLoop || FalseLoop->getParentLoop() == Loop)
- Prediction = BranchProbability(8, 10);
- }
-
+
+ BranchProbability Prediction = MBPI->getEdgeProbability(BB, TrueBBI.BB);
+
if (CanRevCond && ValidDiamond(TrueBBI, FalseBBI, Dups, Dups2) &&
MeetIfcvtSizeLimit(*TrueBBI.BB, (TrueBBI.NonPredSize - (Dups + Dups2) +
TrueBBI.ExtraCost), TrueBBI.ExtraCost2,
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