Fix PR6283.
When coalescing with a physreg, remember to add imp-def and imp-kill when
dealing with sub-registers.
Also fix a related bug in VirtRegRewriter where substitutePhysReg may
reallocate the operand list on an instruction and invalidate the reg_iterator.
This can happen when a register is mentioned twice on the same instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96072 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/VirtRegRewriter.cpp b/lib/CodeGen/VirtRegRewriter.cpp
index ce62594..84e0398 100644
--- a/lib/CodeGen/VirtRegRewriter.cpp
+++ b/lib/CodeGen/VirtRegRewriter.cpp
@@ -62,6 +62,7 @@
/// substitutePhysReg - Replace virtual register in MachineOperand with a
/// physical register. Do the right thing with the sub-register index.
+/// Note that operands may be added, so the MO reference is no longer valid.
static void substitutePhysReg(MachineOperand &MO, unsigned Reg,
const TargetRegisterInfo &TRI) {
if (unsigned SubIdx = MO.getSubReg()) {
@@ -123,14 +124,15 @@
continue;
unsigned pReg = VRM.getPhys(reg);
mri->setPhysRegUsed(pReg);
- for (MachineRegisterInfo::reg_iterator regItr = mri->reg_begin(reg),
- regEnd = mri->reg_end(); regItr != regEnd;) {
- MachineOperand &mop = regItr.getOperand();
- assert(mop.isReg() && mop.getReg() == reg && "reg_iterator broken?");
- ++regItr;
- substitutePhysReg(mop, pReg, *tri);
- changed = true;
- }
+ // Copy the register use-list before traversing it.
+ SmallVector<std::pair<MachineInstr*, unsigned>, 32> reglist;
+ for (MachineRegisterInfo::reg_iterator I = mri->reg_begin(reg),
+ E = mri->reg_end(); I != E; ++I)
+ reglist.push_back(std::make_pair(&*I, I.getOperandNo()));
+ for (unsigned N=0; N != reglist.size(); ++N)
+ substitutePhysReg(reglist[N].first->getOperand(reglist[N].second),
+ pReg, *tri);
+ changed |= !reglist.empty();
}
}
@@ -1850,19 +1852,18 @@
KilledMIRegs.clear();
for (unsigned j = 0, e = VirtUseOps.size(); j != e; ++j) {
unsigned i = VirtUseOps[j];
- MachineOperand &MO = MI.getOperand(i);
- unsigned VirtReg = MO.getReg();
+ unsigned VirtReg = MI.getOperand(i).getReg();
assert(TargetRegisterInfo::isVirtualRegister(VirtReg) &&
"Not a virtual register?");
- unsigned SubIdx = MO.getSubReg();
+ unsigned SubIdx = MI.getOperand(i).getSubReg();
if (VRM.isAssignedReg(VirtReg)) {
// This virtual register was assigned a physreg!
unsigned Phys = VRM.getPhys(VirtReg);
RegInfo->setPhysRegUsed(Phys);
- if (MO.isDef())
+ if (MI.getOperand(i).isDef())
ReusedOperands.markClobbered(Phys);
- substitutePhysReg(MO, Phys, *TRI);
+ substitutePhysReg(MI.getOperand(i), Phys, *TRI);
if (VRM.isImplicitlyDefined(VirtReg))
// FIXME: Is this needed?
BuildMI(MBB, &MI, MI.getDebugLoc(),
@@ -1871,10 +1872,10 @@
}
// This virtual register is now known to be a spilled value.
- if (!MO.isUse())
+ if (!MI.getOperand(i).isUse())
continue; // Handle defs in the loop below (handle use&def here though)
- bool AvoidReload = MO.isUndef();
+ bool AvoidReload = MI.getOperand(i).isUndef();
// Check if it is defined by an implicit def. It should not be spilled.
// Note, this is for correctness reason. e.g.
// 8 %reg1024<def> = IMPLICIT_DEF