//
//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "phielim"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/SSARegMap.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
-#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/Compiler.h"
#include <algorithm>
using namespace llvm;
+STATISTIC(NumAtomic, "Number of atomic phis lowered");
+//STATISTIC(NumSimple, "Number of simple phis lowered");
+
namespace {
- static Statistic NumAtomic("phielim", "Number of atomic phis lowered");
- static Statistic NumSimple("phielim", "Number of simple phis lowered");
-
struct VISIBILITY_HIDDEN PNE : public MachineFunctionPass {
+ static char ID; // Pass identification, replacement for typeid
+ PNE() : MachineFunctionPass((intptr_t)&ID) {}
+
bool runOnMachineFunction(MachineFunction &Fn) {
analyzePHINodes(Fn);
VRegPHIUse VRegPHIUseCount;
};
+ char PNE::ID = 0;
RegisterPass<PNE> X("phi-node-elimination",
"Eliminate PHI nodes for register allocation");
}
// into the phi node destination.
//
const MRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
- RegInfo->copyRegToReg(MBB, AfterPHIsIt, DestReg, IncomingReg, RC);
+ RegInfo->copyRegToReg(MBB, AfterPHIsIt, DestReg, IncomingReg, RC, RC);
// Update live variable information if there is any...
LiveVariables *LV = getAnalysisToUpdate<LiveVariables>();
if (LV) {
MachineInstr *PHICopy = prior(AfterPHIsIt);
+ // Increment use count of the newly created virtual register.
+ LV->getVarInfo(IncomingReg).NumUses++;
+
// Add information to LiveVariables to know that the incoming value is
// killed. Note that because the value is defined in several places (once
// each for each incoming block), the "def" block and instruction fields
// Realize that the destination register is defined by the PHI copy now, not
// the PHI itself.
LV->getVarInfo(DestReg).DefInst = PHICopy;
+
+ LV->getVarInfo(IncomingReg).UsedBlocks[MBB.getNumber()] = true;
}
// Adjust the VRegPHIUseCount map to account for the removal of this PHI
MachineBasicBlock::iterator I = opBlock.getFirstTerminator();
// Insert the copy.
- RegInfo->copyRegToReg(opBlock, I, IncomingReg, SrcReg, RC);
+ RegInfo->copyRegToReg(opBlock, I, IncomingReg, SrcReg, RC, RC);
// Now update live variable information if we have it. Otherwise we're done
if (!LV) continue;
// instruction kills the incoming value.
//
LiveVariables::VarInfo &InRegVI = LV->getVarInfo(SrcReg);
+ InRegVI.UsedBlocks[opBlock.getNumber()] = true;
// Loop over all of the successors of the basic block, checking to see
// if the value is either live in the block, or if it is killed in the