Add the long awaited memory operand folding support for linear scan
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12058 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index e517cb3..1238a2c 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -19,6 +19,7 @@
#include "VirtRegMap.h"
#include "llvm/Function.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "Support/Statistic.h"
@@ -49,6 +50,24 @@
return frameIndex;
}
+void VirtRegMap::virtFolded(unsigned virtReg,
+ MachineInstr* oldMI,
+ MachineInstr* newMI)
+{
+ // move previous memory references folded to new instruction
+ MI2VirtMap::iterator i, e;
+ std::vector<MI2VirtMap::mapped_type> regs;
+ for (tie(i, e) = mi2vMap_.equal_range(oldMI); i != e; ) {
+ regs.push_back(i->second);
+ mi2vMap_.erase(i++);
+ }
+ for (unsigned i = 0, e = regs.size(); i != e; ++i)
+ mi2vMap_.insert(std::make_pair(newMI, i));
+
+ // add new memory reference
+ mi2vMap_.insert(std::make_pair(newMI, virtReg));
+}
+
std::ostream& llvm::operator<<(std::ostream& os, const VirtRegMap& vrm)
{
const MRegisterInfo* mri = vrm.mf_->getTarget().getRegisterInfo();
@@ -129,9 +148,9 @@
vrm_.getStackSlot(virtReg),
mri_.getRegClass(physReg));
++numStores;
- DEBUG(std::cerr << "\t\tadded: ";
+ DEBUG(std::cerr << "added: ";
prior(nextLastRef)->print(std::cerr, tm_);
- std::cerr << "\t\tafter: ";
+ std::cerr << "after: ";
lastDef->print(std::cerr, tm_));
lastDef_[virtReg] = 0;
}
@@ -161,10 +180,8 @@
vrm_.getStackSlot(virtReg),
mri_.getRegClass(physReg));
++numLoads;
- DEBUG(std::cerr << "\t\tadded: ";
- prior(mii)->print(std::cerr,tm_);
- std::cerr << "\t\tbefore: ";
- mii->print(std::cerr, tm_));
+ DEBUG(std::cerr << "added: ";
+ prior(mii)->print(std::cerr,tm_));
lastDef_[virtReg] = mii;
}
}
@@ -186,6 +203,16 @@
void eliminateVirtRegsInMbb(MachineBasicBlock& mbb) {
for (MachineBasicBlock::iterator mii = mbb.begin(),
mie = mbb.end(); mii != mie; ++mii) {
+
+ // if we have references to memory operands make sure
+ // we clear all physical registers that may contain
+ // the value of the spilled virtual register
+ VirtRegMap::MI2VirtMap::const_iterator i, e;
+ for (tie(i, e) = vrm_.getFoldedVirts(mii); i != e; ++i) {
+ unsigned physReg = vrm_.getPhys(i->second);
+ if (physReg) vacateJustPhysReg(mbb, mii, physReg);
+ }
+
// rewrite all used operands
for (unsigned i = 0, e = mii->getNumOperands(); i != e; ++i) {
MachineOperand& op = mii->getOperand(i);