Add method to update livevar when an instruction moves

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11625 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-02-19 18:28:02 +00:00
parent 7c955fdb44
commit 5ed001b6af

View File

@ -33,6 +33,7 @@
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/CFG.h"
#include "Support/DepthFirstIterator.h"
#include "Support/STLExtras.h"
using namespace llvm;
static RegisterAnalysis<LiveVariables> X("livevars", "Live Variable Analysis");
@ -313,3 +314,36 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &MF) {
return false;
}
/// instructionChanged - When the address of an instruction changes, this
/// method should be called so that live variables can update its internal
/// data structures. This removes the records for OldMI, transfering them to
/// the records for NewMI.
void LiveVariables::instructionChanged(MachineInstr *OldMI,
MachineInstr *NewMI) {
// If the instruction defines any virtual registers, update the VarInfo for
// the instruction.
for (unsigned i = 0, e = NewMI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = NewMI->getOperand(i);
if (MO.isRegister() && MO.isDef() &&
MRegisterInfo::isVirtualRegister(MO.getReg())) {
unsigned Reg = MO.getReg();
VarInfo &VI = getVarInfo(Reg);
if (VI.DefInst == OldMI)
VI.DefInst = NewMI;
}
}
// Move the killed information over...
killed_iterator I, E;
tie(I, E) = killed_range(OldMI);
for (killed_iterator A = I; A != E; ++A)
RegistersKilled.insert(std::make_pair(NewMI, A->second));
RegistersKilled.erase(I, E);
// Move the dead information over...
tie(I, E) = dead_range(OldMI);
for (killed_iterator A = I; A != E; ++A)
RegistersDead.insert(std::make_pair(NewMI, A->second));
RegistersDead.erase(I, E);
}