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author | Dimitry Andric <dim@FreeBSD.org> | 2017-12-20 14:16:56 +0000 |
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committer | Dimitry Andric <dim@FreeBSD.org> | 2017-12-20 14:16:56 +0000 |
commit | 2cab237b5dbfe1b3e9c7aa7a3c02d2b98fcf7462 (patch) | |
tree | 524fe828571f81358bba62fdb6d04c6e5e96a2a4 /contrib/llvm/lib/CodeGen/MachineCSE.cpp | |
parent | 6c7828a2807ea5e50c79ca42dbedf2b589ce63b2 (diff) | |
parent | 044eb2f6afba375a914ac9d8024f8f5142bb912e (diff) | |
download | src-2cab237b5dbfe1b3e9c7aa7a3c02d2b98fcf7462.tar.gz src-2cab237b5dbfe1b3e9c7aa7a3c02d2b98fcf7462.zip |
Notes
Diffstat (limited to 'contrib/llvm/lib/CodeGen/MachineCSE.cpp')
-rw-r--r-- | contrib/llvm/lib/CodeGen/MachineCSE.cpp | 67 |
1 files changed, 46 insertions, 21 deletions
diff --git a/contrib/llvm/lib/CodeGen/MachineCSE.cpp b/contrib/llvm/lib/CodeGen/MachineCSE.cpp index 582ff139f886..53c0d840ac84 100644 --- a/contrib/llvm/lib/CodeGen/MachineCSE.cpp +++ b/contrib/llvm/lib/CodeGen/MachineCSE.cpp @@ -1,4 +1,4 @@ -//===-- MachineCSE.cpp - Machine Common Subexpression Elimination Pass ----===// +//===- MachineCSE.cpp - Machine Common Subexpression Elimination Pass -----===// // // The LLVM Compiler Infrastructure // @@ -15,18 +15,35 @@ #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/ScopedHashTable.h" +#include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/SmallSet.h" +#include "llvm/ADT/SmallVector.h" #include "llvm/ADT/Statistic.h" #include "llvm/Analysis/AliasAnalysis.h" +#include "llvm/CodeGen/MachineBasicBlock.h" #include "llvm/CodeGen/MachineDominators.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineFunctionPass.h" #include "llvm/CodeGen/MachineInstr.h" +#include "llvm/CodeGen/MachineOperand.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/Passes.h" +#include "llvm/CodeGen/TargetInstrInfo.h" +#include "llvm/CodeGen/TargetOpcodes.h" +#include "llvm/CodeGen/TargetRegisterInfo.h" +#include "llvm/CodeGen/TargetSubtargetInfo.h" +#include "llvm/MC/MCInstrDesc.h" +#include "llvm/MC/MCRegisterInfo.h" +#include "llvm/Pass.h" +#include "llvm/Support/Allocator.h" #include "llvm/Support/Debug.h" #include "llvm/Support/RecyclingAllocator.h" #include "llvm/Support/raw_ostream.h" -#include "llvm/Target/TargetInstrInfo.h" -#include "llvm/Target/TargetSubtargetInfo.h" +#include <cassert> +#include <iterator> +#include <utility> +#include <vector> + using namespace llvm; #define DEBUG_TYPE "machine-cse" @@ -40,15 +57,18 @@ STATISTIC(NumCrossBBCSEs, STATISTIC(NumCommutes, "Number of copies coalesced after commuting"); namespace { + class MachineCSE : public MachineFunctionPass { const TargetInstrInfo *TII; const TargetRegisterInfo *TRI; AliasAnalysis *AA; MachineDominatorTree *DT; MachineRegisterInfo *MRI; + public: static char ID; // Pass identification - MachineCSE() : MachineFunctionPass(ID), LookAheadLimit(0), CurrVN(0) { + + MachineCSE() : MachineFunctionPass(ID) { initializeMachineCSEPass(*PassRegistry::getPassRegistry()); } @@ -69,16 +89,18 @@ namespace { } private: - unsigned LookAheadLimit; - typedef RecyclingAllocator<BumpPtrAllocator, - ScopedHashTableVal<MachineInstr*, unsigned> > AllocatorTy; - typedef ScopedHashTable<MachineInstr*, unsigned, - MachineInstrExpressionTrait, AllocatorTy> ScopedHTType; - typedef ScopedHTType::ScopeTy ScopeType; - DenseMap<MachineBasicBlock*, ScopeType*> ScopeMap; + using AllocatorTy = RecyclingAllocator<BumpPtrAllocator, + ScopedHashTableVal<MachineInstr *, unsigned>>; + using ScopedHTType = + ScopedHashTable<MachineInstr *, unsigned, MachineInstrExpressionTrait, + AllocatorTy>; + using ScopeType = ScopedHTType::ScopeTy; + + unsigned LookAheadLimit = 0; + DenseMap<MachineBasicBlock *, ScopeType *> ScopeMap; ScopedHTType VNT; - SmallVector<MachineInstr*, 64> Exps; - unsigned CurrVN; + SmallVector<MachineInstr *, 64> Exps; + unsigned CurrVN = 0; bool PerformTrivialCopyPropagation(MachineInstr *MI, MachineBasicBlock *MBB); @@ -104,10 +126,13 @@ namespace { DenseMap<MachineDomTreeNode*, unsigned> &OpenChildren); bool PerformCSE(MachineDomTreeNode *Node); }; + } // end anonymous namespace char MachineCSE::ID = 0; + char &llvm::MachineCSEID = MachineCSE::ID; + INITIALIZE_PASS_BEGIN(MachineCSE, DEBUG_TYPE, "Machine Common Subexpression Elimination", false, false) INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree) @@ -225,8 +250,8 @@ bool MachineCSE::hasLivePhysRegDefUses(const MachineInstr *MI, continue; if (TargetRegisterInfo::isVirtualRegister(Reg)) continue; - // Reading constant physregs is ok. - if (!MRI->isConstantPhysReg(Reg)) + // Reading either caller preserved or constant physregs is ok. + if (!MRI->isCallerPreservedOrConstPhysReg(Reg)) for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) PhysRefs.insert(*AI); } @@ -598,12 +623,12 @@ bool MachineCSE::ProcessBlock(MachineBasicBlock *MBB) { // Go through implicit defs of CSMI and MI, and clear the kill flags on // their uses in all the instructions between CSMI and MI. // We might have made some of the kill flags redundant, consider: - // subs ... %NZCV<imp-def> <- CSMI - // csinc ... %NZCV<imp-use,kill> <- this kill flag isn't valid anymore - // subs ... %NZCV<imp-def> <- MI, to be eliminated - // csinc ... %NZCV<imp-use,kill> + // subs ... implicit-def %nzcv <- CSMI + // csinc ... implicit killed %nzcv <- this kill flag isn't valid anymore + // subs ... implicit-def %nzcv <- MI, to be eliminated + // csinc ... implicit killed %nzcv // Since we eliminated MI, and reused a register imp-def'd by CSMI - // (here %NZCV), that register, if it was killed before MI, should have + // (here %nzcv), that register, if it was killed before MI, should have // that kill flag removed, because it's lifetime was extended. if (CSMI->getParent() == MI->getParent()) { for (MachineBasicBlock::iterator II = CSMI, IE = MI; II != IE; ++II) @@ -702,7 +727,7 @@ bool MachineCSE::PerformCSE(MachineDomTreeNode *Node) { } bool MachineCSE::runOnMachineFunction(MachineFunction &MF) { - if (skipFunction(*MF.getFunction())) + if (skipFunction(MF.getFunction())) return false; TII = MF.getSubtarget().getInstrInfo(); |