Convert INSERT_SUBREG to COPY in TwoAddressInstructionPass.
INSERT_SUBREG will now only appear in SSA machine instructions.
Fix the handling of partial redefs in ProcessImplicitDefs. This is now relevant
since partial redef COPY instructions appear.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107726 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index fc65f86..a626fc0 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -265,7 +265,7 @@
if (MO.getReg() == Reg && MO.isDef()) {
assert(MI.getOperand(MOIdx).getSubReg() != MO.getSubReg() &&
MI.getOperand(MOIdx).getSubReg() &&
- MO.getSubReg());
+ (MO.getSubReg() || MO.isImplicit()));
return true;
}
}
diff --git a/lib/CodeGen/ProcessImplicitDefs.cpp b/lib/CodeGen/ProcessImplicitDefs.cpp
index 0195918..80121ca 100644
--- a/lib/CodeGen/ProcessImplicitDefs.cpp
+++ b/lib/CodeGen/ProcessImplicitDefs.cpp
@@ -117,10 +117,24 @@
}
}
+ // Eliminate %reg1032:sub<def> = COPY undef.
+ if (MI->isCopy() && MI->getOperand(0).getSubReg()) {
+ MachineOperand &MO = MI->getOperand(1);
+ if (ImpDefRegs.count(MO.getReg())) {
+ if (MO.isKill()) {
+ LiveVariables::VarInfo& vi = lv_->getVarInfo(MO.getReg());
+ vi.removeKill(MI);
+ }
+ MI->eraseFromParent();
+ Changed = true;
+ continue;
+ }
+ }
+
bool ChangedToImpDef = false;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand& MO = MI->getOperand(i);
- if (!MO.isReg() || !MO.isUse() || MO.isUndef())
+ if (!MO.isReg() || (MO.isDef() && !MO.getSubReg()) || MO.isUndef())
continue;
unsigned Reg = MO.getReg();
if (!Reg)
@@ -145,6 +159,12 @@
Changed = true;
MO.setIsUndef();
+ // This is a partial register redef of an implicit def.
+ // Make sure the whole register is defined by the instruction.
+ if (MO.isDef()) {
+ MI->addRegisterDefined(Reg);
+ continue;
+ }
if (MO.isKill() || MI->isRegTiedToDefOperand(i)) {
// Make sure other uses of
for (unsigned j = i+1; j != e; ++j) {
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index 4d4318d..efe14e6 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -1218,6 +1218,19 @@
DEBUG(dbgs() << "\t\trewrite to:\t" << *mi);
}
+ // Rewrite INSERT_SUBREG as COPY now that we no longer need SSA form.
+ if (mi->isInsertSubreg()) {
+ // From %reg = INSERT_SUBREG %reg, %subreg, subidx
+ // To %reg:subidx = COPY %subreg
+ unsigned SubIdx = mi->getOperand(3).getImm();
+ mi->RemoveOperand(3);
+ assert(mi->getOperand(0).getSubReg() == 0 && "Unexpected subreg idx");
+ mi->getOperand(0).setSubReg(SubIdx);
+ mi->RemoveOperand(1);
+ mi->setDesc(TII->get(TargetOpcode::COPY));
+ DEBUG(dbgs() << "\t\tconvert to:\t" << *mi);
+ }
+
// Clear TiedOperands here instead of at the top of the loop
// since most instructions do not have tied operands.
TiedOperands.clear();