From 2ad40d34947ced36d96f351f6c2a4d57a044e2a4 Mon Sep 17 00:00:00 2001 From: Bob Wilson Date: Tue, 26 Oct 2010 00:02:21 +0000 Subject: Change if-conversion to keep track of the extra cost due to microcoded instructions separately from the count of non-predicated instructions. The instruction count is used in places to determine how many instructions to copy, predicate, etc. and things get confused if that count includes the extra cost for microcoded ops. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117332 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/IfConversion.cpp | 36 +++++++++++++++++++++++++----------- 1 file changed, 25 insertions(+), 11 deletions(-) (limited to 'lib/CodeGen/IfConversion.cpp') diff --git a/lib/CodeGen/IfConversion.cpp b/lib/CodeGen/IfConversion.cpp index 1ee27f0e38..ce3eda7891 100644 --- a/lib/CodeGen/IfConversion.cpp +++ b/lib/CodeGen/IfConversion.cpp @@ -93,6 +93,7 @@ namespace { /// ClobbersPred - True if BB could modify predicates (e.g. has /// cmp, call, etc.) /// NonPredSize - Number of non-predicated instructions. + /// ExtraCost - Extra cost for microcoded instructions. /// BB - Corresponding MachineBasicBlock. /// TrueBB / FalseBB- See AnalyzeBranch(). /// BrCond - Conditions for end of block conditional branches. @@ -108,6 +109,7 @@ namespace { bool CannotBeCopied : 1; bool ClobbersPred : 1; unsigned NonPredSize; + unsigned ExtraCost; MachineBasicBlock *BB; MachineBasicBlock *TrueBB; MachineBasicBlock *FalseBB; @@ -117,7 +119,7 @@ namespace { IsAnalyzed(false), IsEnqueued(false), IsBrAnalyzable(false), HasFallThrough(false), IsUnpredicable(false), CannotBeCopied(false), ClobbersPred(false), NonPredSize(0), - BB(0), TrueBB(0), FalseBB(0) {} + ExtraCost(0), BB(0), TrueBB(0), FalseBB(0) {} }; /// IfcvtToken - Record information about pending if-conversions to attempt: @@ -652,6 +654,7 @@ void IfConverter::ScanInstructions(BBInfo &BBI) { // Then scan all the instructions. BBI.NonPredSize = 0; + BBI.ExtraCost = 0; BBI.ClobbersPred = false; for (MachineBasicBlock::iterator I = BBI.BB->begin(), E = BBI.BB->end(); I != E; ++I) { @@ -667,8 +670,10 @@ void IfConverter::ScanInstructions(BBInfo &BBI) { if (!isCondBr) { if (!isPredicated) { + BBI.NonPredSize++; unsigned NumOps = TII->getNumMicroOps(&*I, InstrItins); - BBI.NonPredSize += NumOps; + if (NumOps > 1) + BBI.ExtraCost += NumOps-1; } else if (!AlreadyPredicated) { // FIXME: This instruction is already predicated before the // if-conversion pass. It's probably something like a conditional move. @@ -815,8 +820,10 @@ IfConverter::BBInfo &IfConverter::AnalyzeBlock(MachineBasicBlock *BB, } if (CanRevCond && ValidDiamond(TrueBBI, FalseBBI, Dups, Dups2) && - MeetIfcvtSizeLimit(*TrueBBI.BB, TrueBBI.NonPredSize - (Dups + Dups2), - *FalseBBI.BB, FalseBBI.NonPredSize - (Dups + Dups2), + MeetIfcvtSizeLimit(*TrueBBI.BB, (TrueBBI.NonPredSize - (Dups + Dups2) + + TrueBBI.ExtraCost), + *FalseBBI.BB, (FalseBBI.NonPredSize - (Dups + Dups2) + + FalseBBI.ExtraCost), Prediction, Confidence) && FeasibilityAnalysis(TrueBBI, BBI.BrCond) && FeasibilityAnalysis(FalseBBI, RevCond)) { @@ -834,7 +841,7 @@ IfConverter::BBInfo &IfConverter::AnalyzeBlock(MachineBasicBlock *BB, } if (ValidTriangle(TrueBBI, FalseBBI, false, Dups, Prediction, Confidence) && - MeetIfcvtSizeLimit(*TrueBBI.BB, TrueBBI.NonPredSize, + MeetIfcvtSizeLimit(*TrueBBI.BB, TrueBBI.NonPredSize + TrueBBI.ExtraCost, Prediction, Confidence) && FeasibilityAnalysis(TrueBBI, BBI.BrCond, true)) { // Triangle: @@ -849,7 +856,7 @@ IfConverter::BBInfo &IfConverter::AnalyzeBlock(MachineBasicBlock *BB, } if (ValidTriangle(TrueBBI, FalseBBI, true, Dups, Prediction, Confidence) && - MeetIfcvtSizeLimit(*TrueBBI.BB, TrueBBI.NonPredSize, + MeetIfcvtSizeLimit(*TrueBBI.BB, TrueBBI.NonPredSize + TrueBBI.ExtraCost, Prediction, Confidence) && FeasibilityAnalysis(TrueBBI, BBI.BrCond, true, true)) { Tokens.push_back(new IfcvtToken(BBI, ICTriangleRev, TNeedSub, Dups)); @@ -857,7 +864,7 @@ IfConverter::BBInfo &IfConverter::AnalyzeBlock(MachineBasicBlock *BB, } if (ValidSimple(TrueBBI, Dups, Prediction, Confidence) && - MeetIfcvtSizeLimit(*TrueBBI.BB, TrueBBI.NonPredSize, + MeetIfcvtSizeLimit(*TrueBBI.BB, TrueBBI.NonPredSize + TrueBBI.ExtraCost, Prediction, Confidence) && FeasibilityAnalysis(TrueBBI, BBI.BrCond)) { // Simple (split, no rejoin): @@ -875,7 +882,8 @@ IfConverter::BBInfo &IfConverter::AnalyzeBlock(MachineBasicBlock *BB, // Try the other path... if (ValidTriangle(FalseBBI, TrueBBI, false, Dups, 1.0-Prediction, Confidence) && - MeetIfcvtSizeLimit(*FalseBBI.BB, FalseBBI.NonPredSize, + MeetIfcvtSizeLimit(*FalseBBI.BB, + FalseBBI.NonPredSize + FalseBBI.ExtraCost, 1.0-Prediction, Confidence) && FeasibilityAnalysis(FalseBBI, RevCond, true)) { Tokens.push_back(new IfcvtToken(BBI, ICTriangleFalse, FNeedSub, Dups)); @@ -884,7 +892,8 @@ IfConverter::BBInfo &IfConverter::AnalyzeBlock(MachineBasicBlock *BB, if (ValidTriangle(FalseBBI, TrueBBI, true, Dups, 1.0-Prediction, Confidence) && - MeetIfcvtSizeLimit(*FalseBBI.BB, FalseBBI.NonPredSize, + MeetIfcvtSizeLimit(*FalseBBI.BB, + FalseBBI.NonPredSize + FalseBBI.ExtraCost, 1.0-Prediction, Confidence) && FeasibilityAnalysis(FalseBBI, RevCond, true, true)) { Tokens.push_back(new IfcvtToken(BBI, ICTriangleFRev, FNeedSub, Dups)); @@ -892,7 +901,8 @@ IfConverter::BBInfo &IfConverter::AnalyzeBlock(MachineBasicBlock *BB, } if (ValidSimple(FalseBBI, Dups, 1.0-Prediction, Confidence) && - MeetIfcvtSizeLimit(*FalseBBI.BB, FalseBBI.NonPredSize, + MeetIfcvtSizeLimit(*FalseBBI.BB, + FalseBBI.NonPredSize + FalseBBI.ExtraCost, 1.0-Prediction, Confidence) && FeasibilityAnalysis(FalseBBI, RevCond)) { Tokens.push_back(new IfcvtToken(BBI, ICSimpleFalse, FNeedSub, Dups)); @@ -1422,8 +1432,10 @@ void IfConverter::CopyAndPredicateBlock(BBInfo &ToBBI, BBInfo &FromBBI, MachineInstr *MI = MF.CloneMachineInstr(I); ToBBI.BB->insert(ToBBI.BB->end(), MI); + ToBBI.NonPredSize++; unsigned NumOps = TII->getNumMicroOps(MI, InstrItins); - ToBBI.NonPredSize += NumOps; + if (NumOps > 1) + ToBBI.ExtraCost += NumOps-1; if (!TII->isPredicated(I) && !MI->isDebugValue()) { if (!TII->PredicateInstruction(MI, Cond)) { @@ -1497,7 +1509,9 @@ void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI, bool AddEdges) { FromBBI.Predicate.clear(); ToBBI.NonPredSize += FromBBI.NonPredSize; + ToBBI.ExtraCost += FromBBI.ExtraCost; FromBBI.NonPredSize = 0; + FromBBI.ExtraCost = 0; ToBBI.ClobbersPred |= FromBBI.ClobbersPred; ToBBI.HasFallThrough = FromBBI.HasFallThrough; -- cgit v1.2.3