[llvm-commits] CVS: llvm/lib/CodeGen/VirtRegMap.cpp
Chris Lattner
lattner at cs.uiuc.edu
Wed Sep 29 19:34:00 PDT 2004
Changes in directory llvm/lib/CodeGen:
VirtRegMap.cpp updated: 1.21 -> 1.22
---
Log message:
Don't use a densemap for keeping track of which vregs are already loaded, just
use a simple vector. This speeds up -spiller=simple from taking 22s to taking
.1s on povray (debug build). This change does not modify the generated code.
---
Diffs of the changes: (+10 -6)
Index: llvm/lib/CodeGen/VirtRegMap.cpp
diff -u llvm/lib/CodeGen/VirtRegMap.cpp:1.21 llvm/lib/CodeGen/VirtRegMap.cpp:1.22
--- llvm/lib/CodeGen/VirtRegMap.cpp:1.21 Wed Sep 29 21:15:18 2004
+++ llvm/lib/CodeGen/VirtRegMap.cpp Wed Sep 29 21:33:48 2004
@@ -133,25 +133,29 @@
const TargetMachine& TM = MF.getTarget();
const MRegisterInfo& MRI = *TM.getRegisterInfo();
- DenseMap<bool, VirtReg2IndexFunctor> Loaded;
+ // LoadedRegs - Keep track of which vregs are loaded, so that we only load
+ // each vreg once (in the case where a spilled vreg is used by multiple
+ // operands). This is always smaller than the number of operands to the
+ // current machine instr, so it should be small.
+ std::vector<unsigned> LoadedRegs;
for (MachineFunction::iterator mbbi = MF.begin(), E = MF.end();
mbbi != E; ++mbbi) {
DEBUG(std::cerr << mbbi->getBasicBlock()->getName() << ":\n");
for (MachineBasicBlock::iterator mii = mbbi->begin(),
mie = mbbi->end(); mii != mie; ++mii) {
- Loaded.grow(MF.getSSARegMap()->getLastVirtReg());
- for (unsigned i = 0,e = mii->getNumOperands(); i != e; ++i){
+ for (unsigned i = 0, e = mii->getNumOperands(); i != e; ++i) {
MachineOperand& mop = mii->getOperand(i);
if (mop.isRegister() && mop.getReg() &&
MRegisterInfo::isVirtualRegister(mop.getReg())) {
unsigned virtReg = mop.getReg();
unsigned physReg = VRM.getPhys(virtReg);
if (mop.isUse() && VRM.hasStackSlot(mop.getReg()) &&
- !Loaded[virtReg]) {
+ std::find(LoadedRegs.begin(), LoadedRegs.end(),
+ virtReg) == LoadedRegs.end()) {
MRI.loadRegFromStackSlot(*mbbi, mii, physReg,
VRM.getStackSlot(virtReg));
- Loaded[virtReg] = true;
+ LoadedRegs.push_back(virtReg);
DEBUG(std::cerr << '\t';
prior(mii)->print(std::cerr, &TM));
++NumLoads;
@@ -166,7 +170,7 @@
}
}
DEBUG(std::cerr << '\t'; mii->print(std::cerr, &TM));
- Loaded.clear();
+ LoadedRegs.clear();
}
}
return true;
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