[llvm-commits] [llvm] r76688 - in /llvm/trunk/lib/CodeGen: PHIElimination.cpp PHIElimination.h
Lang Hames
lhames at gmail.com
Tue Jul 21 16:47:33 PDT 2009
Author: lhames
Date: Tue Jul 21 18:47:33 2009
New Revision: 76688
URL: http://llvm.org/viewvc/llvm-project?rev=76688&view=rev
Log:
Exposed PHIElimination pass within CodeGen.
Added:
llvm/trunk/lib/CodeGen/PHIElimination.h
Modified:
llvm/trunk/lib/CodeGen/PHIElimination.cpp
Modified: llvm/trunk/lib/CodeGen/PHIElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PHIElimination.cpp?rev=76688&r1=76687&r2=76688&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PHIElimination.cpp (original)
+++ llvm/trunk/lib/CodeGen/PHIElimination.cpp Tue Jul 21 18:47:33 2009
@@ -14,6 +14,7 @@
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "phielim"
+#include "PHIElimination.h"
#include "llvm/BasicBlock.h"
#include "llvm/Instructions.h"
#include "llvm/CodeGen/LiveVariables.h"
@@ -22,7 +23,6 @@
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/STLExtras.h"
@@ -34,76 +34,20 @@
STATISTIC(NumAtomic, "Number of atomic phis lowered");
-namespace {
- class VISIBILITY_HIDDEN PNE : public MachineFunctionPass {
- MachineRegisterInfo *MRI; // Machine register information
-
- public:
- static char ID; // Pass identification, replacement for typeid
- PNE() : MachineFunctionPass(&ID) {}
-
- virtual bool runOnMachineFunction(MachineFunction &Fn);
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addPreserved<LiveVariables>();
- AU.addPreservedID(MachineLoopInfoID);
- AU.addPreservedID(MachineDominatorsID);
- MachineFunctionPass::getAnalysisUsage(AU);
- }
-
- private:
- /// EliminatePHINodes - Eliminate phi nodes by inserting copy instructions
- /// in predecessor basic blocks.
- ///
- bool EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB);
- void LowerAtomicPHINode(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator AfterPHIsIt);
-
- /// analyzePHINodes - Gather information about the PHI nodes in
- /// here. In particular, we want to map the number of uses of a virtual
- /// register which is used in a PHI node. We map that to the BB the
- /// vreg is coming from. This is used later to determine when the vreg
- /// is killed in the BB.
- ///
- void analyzePHINodes(const MachineFunction& Fn);
-
- // FindCopyInsertPoint - Find a safe place in MBB to insert a copy from
- // SrcReg. This needs to be after any def or uses of SrcReg, but before
- // any subsequent point where control flow might jump out of the basic
- // block.
- MachineBasicBlock::iterator FindCopyInsertPoint(MachineBasicBlock &MBB,
- unsigned SrcReg);
-
- // SkipPHIsAndLabels - Copies need to be inserted after phi nodes and
- // also after any exception handling labels: in landing pads execution
- // starts at the label, so any copies placed before it won't be executed!
- MachineBasicBlock::iterator SkipPHIsAndLabels(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I) {
- // Rather than assuming that EH labels come before other kinds of labels,
- // just skip all labels.
- while (I != MBB.end() &&
- (I->getOpcode() == TargetInstrInfo::PHI || I->isLabel()))
- ++I;
- return I;
- }
-
- typedef std::pair<const MachineBasicBlock*, unsigned> BBVRegPair;
- typedef std::map<BBVRegPair, unsigned> VRegPHIUse;
-
- VRegPHIUse VRegPHIUseCount;
-
- // Defs of PHI sources which are implicit_def.
- SmallPtrSet<MachineInstr*, 4> ImpDefs;
- };
-}
-
-char PNE::ID = 0;
-static RegisterPass<PNE>
+char PHIElimination::ID = 0;
+static RegisterPass<PHIElimination>
X("phi-node-elimination", "Eliminate PHI nodes for register allocation");
const PassInfo *const llvm::PHIEliminationID = &X;
-bool PNE::runOnMachineFunction(MachineFunction &Fn) {
+void llvm::PHIElimination::getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addPreserved<LiveVariables>();
+ AU.addPreservedID(MachineLoopInfoID);
+ AU.addPreservedID(MachineDominatorsID);
+ MachineFunctionPass::getAnalysisUsage(AU);
+ }
+
+bool llvm::PHIElimination::runOnMachineFunction(MachineFunction &Fn) {
MRI = &Fn.getRegInfo();
analyzePHINodes(Fn);
@@ -132,7 +76,8 @@
/// EliminatePHINodes - Eliminate phi nodes by inserting copy instructions in
/// predecessor basic blocks.
///
-bool PNE::EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB) {
+bool llvm::PHIElimination::EliminatePHINodes(MachineFunction &MF,
+ MachineBasicBlock &MBB) {
if (MBB.empty() || MBB.front().getOpcode() != TargetInstrInfo::PHI)
return false; // Quick exit for basic blocks without PHIs.
@@ -162,8 +107,9 @@
// FindCopyInsertPoint - Find a safe place in MBB to insert a copy from SrcReg.
// This needs to be after any def or uses of SrcReg, but before any subsequent
// point where control flow might jump out of the basic block.
-MachineBasicBlock::iterator PNE::FindCopyInsertPoint(MachineBasicBlock &MBB,
- unsigned SrcReg) {
+MachineBasicBlock::iterator
+llvm::PHIElimination::FindCopyInsertPoint(MachineBasicBlock &MBB,
+ unsigned SrcReg) {
// Handle the trivial case trivially.
if (MBB.empty())
return MBB.begin();
@@ -206,9 +152,10 @@
/// under the assuption that it needs to be lowered in a way that supports
/// atomic execution of PHIs. This lowering method is always correct all of the
/// time.
-///
-void PNE::LowerAtomicPHINode(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator AfterPHIsIt) {
+///
+void llvm::PHIElimination::LowerAtomicPHINode(
+ MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator AfterPHIsIt) {
// Unlink the PHI node from the basic block, but don't delete the PHI yet.
MachineInstr *MPhi = MBB.remove(MBB.begin());
@@ -420,7 +367,7 @@
/// used in a PHI node. We map that to the BB the vreg is coming from. This is
/// used later to determine when the vreg is killed in the BB.
///
-void PNE::analyzePHINodes(const MachineFunction& Fn) {
+void llvm::PHIElimination::analyzePHINodes(const MachineFunction& Fn) {
for (MachineFunction::const_iterator I = Fn.begin(), E = Fn.end();
I != E; ++I)
for (MachineBasicBlock::const_iterator BBI = I->begin(), BBE = I->end();
Added: llvm/trunk/lib/CodeGen/PHIElimination.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PHIElimination.h?rev=76688&view=auto
==============================================================================
--- llvm/trunk/lib/CodeGen/PHIElimination.h (added)
+++ llvm/trunk/lib/CodeGen/PHIElimination.h Tue Jul 21 18:47:33 2009
@@ -0,0 +1,80 @@
+//===-- lib/CodeGen/PHIElimination.h ----------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_PHIELIMINATION_HPP
+#define LLVM_CODEGEN_PHIELIMINATION_HPP
+
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/Target/TargetInstrInfo.h"
+
+#include <map>
+
+namespace llvm {
+
+ /// Lower PHI instructions to copies.
+ class PHIElimination : public MachineFunctionPass {
+ MachineRegisterInfo *MRI; // Machine register information
+
+ public:
+ static char ID; // Pass identification, replacement for typeid
+ PHIElimination() : MachineFunctionPass(&ID) {}
+
+ virtual bool runOnMachineFunction(MachineFunction &Fn);
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const;
+
+ private:
+ /// EliminatePHINodes - Eliminate phi nodes by inserting copy instructions
+ /// in predecessor basic blocks.
+ ///
+ bool EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB);
+ void LowerAtomicPHINode(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator AfterPHIsIt);
+
+ /// analyzePHINodes - Gather information about the PHI nodes in
+ /// here. In particular, we want to map the number of uses of a virtual
+ /// register which is used in a PHI node. We map that to the BB the
+ /// vreg is coming from. This is used later to determine when the vreg
+ /// is killed in the BB.
+ ///
+ void analyzePHINodes(const MachineFunction& Fn);
+
+ // FindCopyInsertPoint - Find a safe place in MBB to insert a copy from
+ // SrcReg. This needs to be after any def or uses of SrcReg, but before
+ // any subsequent point where control flow might jump out of the basic
+ // block.
+ MachineBasicBlock::iterator FindCopyInsertPoint(MachineBasicBlock &MBB,
+ unsigned SrcReg);
+
+ // SkipPHIsAndLabels - Copies need to be inserted after phi nodes and
+ // also after any exception handling labels: in landing pads execution
+ // starts at the label, so any copies placed before it won't be executed!
+ MachineBasicBlock::iterator SkipPHIsAndLabels(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I) {
+ // Rather than assuming that EH labels come before other kinds of labels,
+ // just skip all labels.
+ while (I != MBB.end() &&
+ (I->getOpcode() == TargetInstrInfo::PHI || I->isLabel()))
+ ++I;
+ return I;
+ }
+
+ typedef std::pair<const MachineBasicBlock*, unsigned> BBVRegPair;
+ typedef std::map<BBVRegPair, unsigned> VRegPHIUse;
+
+ VRegPHIUse VRegPHIUseCount;
+
+ // Defs of PHI sources which are implicit_def.
+ SmallPtrSet<MachineInstr*, 4> ImpDefs;
+ };
+
+}
+
+#endif /* PHIELIMINATION_H */
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