Move handing of GlobalValues from getReg() to copyConstantToRegister(), this

will avoid extra register-to-register copies.  Thanks to Chris for the idea.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15019 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Misha Brukman 2004-07-20 00:59:38 +00:00
parent bee7e7644b
commit ba1c1da36a
2 changed files with 22 additions and 38 deletions

View File

@ -397,23 +397,7 @@ static AllocaInst *dyn_castFixedAlloca(Value *V) {
///
unsigned ISel::getReg(Value *V, MachineBasicBlock *MBB,
MachineBasicBlock::iterator IPt) {
// If this operand is a constant, emit the code to copy the constant into
// the register here...
//
if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// GV is located at PC + distance
unsigned CurPC = makeAnotherReg(Type::IntTy);
unsigned Reg1 = makeAnotherReg(V->getType());
unsigned Reg2 = makeAnotherReg(V->getType());
// Move PC to destination reg
BuildMI(*MBB, IPt, PPC32::MovePCtoLR, 0, CurPC);
// Move value at PC + distance into return reg
BuildMI(*MBB, IPt, PPC32::LOADHiAddr, 2, Reg1).addReg(CurPC)
.addGlobalAddress(GV);
BuildMI(*MBB, IPt, PPC32::LOADLoAddr, 2, Reg2).addReg(Reg1)
.addGlobalAddress(GV);
return Reg2;
} else if (Constant *C = dyn_cast<Constant>(V)) {
if (Constant *C = dyn_cast<Constant>(V)) {
unsigned Reg = makeAnotherReg(V->getType());
copyConstantToRegister(MBB, IPt, C, Reg);
return Reg;
@ -542,8 +526,16 @@ void ISel::copyConstantToRegister(MachineBasicBlock *MBB,
// Copy zero (null pointer) to the register.
BuildMI(*MBB, IP, PPC32::LI, 1, R).addImm(0);
} else if (GlobalValue *GV = dyn_cast<GlobalValue>(C)) {
unsigned AddrReg = getReg(GV, MBB, IP);
BuildMI(*MBB, IP, PPC32::OR, 2, R).addReg(AddrReg).addReg(AddrReg);
// GV is located at PC + distance
unsigned CurPC = makeAnotherReg(Type::IntTy);
unsigned TmpReg = makeAnotherReg(GV->getType());
// Move PC to destination reg
BuildMI(*MBB, IP, PPC32::MovePCtoLR, 0, CurPC);
// Move value at PC + distance into return reg
BuildMI(*MBB, IP, PPC32::LOADHiAddr, 2, TmpReg).addReg(CurPC)
.addGlobalAddress(GV);
BuildMI(*MBB, IP, PPC32::LOADLoAddr, 2, R).addReg(TmpReg)
.addGlobalAddress(GV);
} else {
std::cerr << "Offending constant: " << *C << "\n";
assert(0 && "Type not handled yet!");

View File

@ -397,23 +397,7 @@ static AllocaInst *dyn_castFixedAlloca(Value *V) {
///
unsigned ISel::getReg(Value *V, MachineBasicBlock *MBB,
MachineBasicBlock::iterator IPt) {
// If this operand is a constant, emit the code to copy the constant into
// the register here...
//
if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// GV is located at PC + distance
unsigned CurPC = makeAnotherReg(Type::IntTy);
unsigned Reg1 = makeAnotherReg(V->getType());
unsigned Reg2 = makeAnotherReg(V->getType());
// Move PC to destination reg
BuildMI(*MBB, IPt, PPC32::MovePCtoLR, 0, CurPC);
// Move value at PC + distance into return reg
BuildMI(*MBB, IPt, PPC32::LOADHiAddr, 2, Reg1).addReg(CurPC)
.addGlobalAddress(GV);
BuildMI(*MBB, IPt, PPC32::LOADLoAddr, 2, Reg2).addReg(Reg1)
.addGlobalAddress(GV);
return Reg2;
} else if (Constant *C = dyn_cast<Constant>(V)) {
if (Constant *C = dyn_cast<Constant>(V)) {
unsigned Reg = makeAnotherReg(V->getType());
copyConstantToRegister(MBB, IPt, C, Reg);
return Reg;
@ -542,8 +526,16 @@ void ISel::copyConstantToRegister(MachineBasicBlock *MBB,
// Copy zero (null pointer) to the register.
BuildMI(*MBB, IP, PPC32::LI, 1, R).addImm(0);
} else if (GlobalValue *GV = dyn_cast<GlobalValue>(C)) {
unsigned AddrReg = getReg(GV, MBB, IP);
BuildMI(*MBB, IP, PPC32::OR, 2, R).addReg(AddrReg).addReg(AddrReg);
// GV is located at PC + distance
unsigned CurPC = makeAnotherReg(Type::IntTy);
unsigned TmpReg = makeAnotherReg(GV->getType());
// Move PC to destination reg
BuildMI(*MBB, IP, PPC32::MovePCtoLR, 0, CurPC);
// Move value at PC + distance into return reg
BuildMI(*MBB, IP, PPC32::LOADHiAddr, 2, TmpReg).addReg(CurPC)
.addGlobalAddress(GV);
BuildMI(*MBB, IP, PPC32::LOADLoAddr, 2, R).addReg(TmpReg)
.addGlobalAddress(GV);
} else {
std::cerr << "Offending constant: " << *C << "\n";
assert(0 && "Type not handled yet!");