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Remove AsmThatEarlyClobber etc. from LiveIntervalAnalysis

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and redo as linked list walk.  Logic moved into RA.
Per review feedback.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56326 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dale Johannesen
2008-09-19 01:02:35 +00:00
parent 4fe0fe8b49
commit fa48f94130
5 changed files with 86 additions and 96 deletions
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lib/CodeGen/LiveIntervalAnalysis.cpp
+4 -71
View File
@@ -674,8 +674,6 @@ exit:
/// live interval is an interval [i, j) where 1 <= i <= j < N for
/// which a variable is live
void LiveIntervals::computeIntervals() {
AsmsThatEarlyClobber.clear();
AsmsWithEarlyClobberConflict.clear();
DOUT << "********** COMPUTING LIVE INTERVALS **********\n"
<< "********** Function: "
@@ -716,13 +714,15 @@ void LiveIntervals::computeIntervals() {
if (MO.isRegister() && MO.getReg() && MO.isDef()) {
handleRegisterDef(MBB, MI, MIIndex, MO, i);
if (MO.isEarlyClobber()) {
AsmsThatEarlyClobber.insert(std::make_pair(MO.getReg(), MI));
LiveInterval &interval = getOrCreateInterval(MO.getReg());
interval.isEarlyClobber = true;
}
}
if (MO.isRegister() && !MO.isDef() &&
MO.getReg() && TargetRegisterInfo::isVirtualRegister(MO.getReg()) &&
MO.overlapsEarlyClobber()) {
AsmsWithEarlyClobberConflict.insert(std::make_pair(MO.getReg(), MI));
LiveInterval &interval = getOrCreateInterval(MO.getReg());
interval.overlapsEarlyClobber = true;
}
}
@@ -752,73 +752,6 @@ bool LiveIntervals::findLiveInMBBs(const LiveRange &LR,
return ResVal;
}
/// noEarlyclobberConflict - see whether virtual reg VReg has a conflict with
/// hard reg HReg because of earlyclobbers.
///
/// Earlyclobber operands may not be assigned the same register as
/// each other, or as earlyclobber-conflict operands (i.e. those that
/// are non-earlyclobbered inputs to an asm that also has earlyclobbers).
///
/// Thus there are two cases to check for:
/// 1. VReg is an earlyclobber-conflict register and HReg is an earlyclobber
/// register in some asm that also has VReg as an input.
/// 2. VReg is an earlyclobber register and HReg is an earlyclobber-conflict
/// input elsewhere in some asm.
/// In both cases HReg can be assigned by the user, or assigned early in
/// register allocation.
///
/// Dropping the distinction between earlyclobber and earlyclobber-conflict,
/// keeping only one multimap, looks promising, but two earlyclobber-conflict
/// operands may be assigned the same register if they happen to contain the
/// same value, and that implementation would prevent this.
///
bool LiveIntervals::noEarlyclobberConflict(unsigned VReg, VirtRegMap &vrm,
unsigned HReg) {
typedef std::multimap<unsigned, MachineInstr*>::iterator It;
// Short circuit the most common case.
if (AsmsWithEarlyClobberConflict.size()!=0) {
std::pair<It, It> x = AsmsWithEarlyClobberConflict.equal_range(VReg);
for (It I = x.first; I!=x.second; I++) {
MachineInstr* MI = I->second;
for (int i = MI->getNumOperands() - 1; i >= 0; --i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isRegister() && MO.isEarlyClobber()) {
unsigned PhysReg = MO.getReg();
if (PhysReg && TargetRegisterInfo::isVirtualRegister(PhysReg)) {
if (!vrm.hasPhys(PhysReg))
continue;
PhysReg = vrm.getPhys(PhysReg);
}
if (PhysReg==HReg)
return false;
}
}
}
}
// Short circuit the most common case.
if (AsmsThatEarlyClobber.size()!=0) {
std::pair<It, It> x = AsmsThatEarlyClobber.equal_range(VReg);
for (It I = x.first; I!=x.second; I++) {
MachineInstr* MI = I->second;
for (int i = MI->getNumOperands() - 1; i >= 0; --i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isRegister() && MO.overlapsEarlyClobber()) {
unsigned PhysReg = MO.getReg();
if (PhysReg && TargetRegisterInfo::isVirtualRegister(PhysReg)) {
if (!vrm.hasPhys(PhysReg))
continue;
PhysReg = vrm.getPhys(PhysReg);
}
if (PhysReg==HReg)
return false;
}
}
}
}
return true;
}
LiveInterval* LiveIntervals::createInterval(unsigned reg) {
float Weight = TargetRegisterInfo::isPhysicalRegister(reg) ?
HUGE_VALF : 0.0F;