R600/SI: Remove explicit m0 operand from DS instructions
Instead add m0 as an implicit operand. This helps avoid spills
of the m0 register in some cases.
llvm-svn: 237141
diff --git a/llvm/lib/Target/R600/SILoadStoreOptimizer.cpp b/llvm/lib/Target/R600/SILoadStoreOptimizer.cpp
index a927ad8..9b1d256 100644
--- a/llvm/lib/Target/R600/SILoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/R600/SILoadStoreOptimizer.cpp
@@ -213,7 +213,6 @@
// Be careful, since the addresses could be subregisters themselves in weird
// cases, like vectors of pointers.
const MachineOperand *AddrReg = TII->getNamedOperand(*I, AMDGPU::OpName::addr);
- const MachineOperand *M0Reg = TII->getNamedOperand(*I, AMDGPU::OpName::m0);
unsigned DestReg0 = TII->getNamedOperand(*I, AMDGPU::OpName::vdst)->getReg();
unsigned DestReg1
@@ -254,37 +253,24 @@
.addImm(NewOffset0) // offset0
.addImm(NewOffset1) // offset1
.addImm(0) // gds
- .addOperand(*M0Reg) // M0
.addMemOperand(*I->memoperands_begin())
.addMemOperand(*Paired->memoperands_begin());
- LIS->InsertMachineInstrInMaps(Read2);
-
unsigned SubRegIdx0 = (EltSize == 4) ? AMDGPU::sub0 : AMDGPU::sub0_sub1;
unsigned SubRegIdx1 = (EltSize == 4) ? AMDGPU::sub1 : AMDGPU::sub2_sub3;
updateRegDefsUses(DestReg0, DestReg, SubRegIdx0);
updateRegDefsUses(DestReg1, DestReg, SubRegIdx1);
LIS->RemoveMachineInstrFromMaps(I);
- LIS->RemoveMachineInstrFromMaps(Paired);
+ // Replacing Paired in the maps with Read2 allows us to avoid updating the
+ // live range for the m0 register.
+ LIS->ReplaceMachineInstrInMaps(Paired, Read2);
I->eraseFromParent();
Paired->eraseFromParent();
LiveInterval &AddrRegLI = LIS->getInterval(AddrReg->getReg());
LIS->shrinkToUses(&AddrRegLI);
- LiveInterval &M0RegLI = LIS->getInterval(M0Reg->getReg());
- LIS->shrinkToUses(&M0RegLI);
-
- // Currently m0 is treated as a register class with one member instead of an
- // implicit physical register. We are using the virtual register for the first
- // one, but we still need to update the live range of the now unused second m0
- // virtual register to avoid verifier errors.
- const MachineOperand *PairedM0Reg
- = TII->getNamedOperand(*Paired, AMDGPU::OpName::m0);
- LiveInterval &PairedM0RegLI = LIS->getInterval(PairedM0Reg->getReg());
- LIS->shrinkToUses(&PairedM0RegLI);
-
LIS->getInterval(DestReg); // Create new LI
DEBUG(dbgs() << "Inserted read2: " << *Read2 << '\n');
@@ -300,7 +286,6 @@
// Be sure to use .addOperand(), and not .addReg() with these. We want to be
// sure we preserve the subregister index and any register flags set on them.
const MachineOperand *Addr = TII->getNamedOperand(*I, AMDGPU::OpName::addr);
- const MachineOperand *M0Reg = TII->getNamedOperand(*I, AMDGPU::OpName::m0);
const MachineOperand *Data0 = TII->getNamedOperand(*I, AMDGPU::OpName::data0);
const MachineOperand *Data1
= TII->getNamedOperand(*Paired, AMDGPU::OpName::data0);
@@ -331,6 +316,13 @@
const MCInstrDesc &Write2Desc = TII->get(Opc);
DebugLoc DL = I->getDebugLoc();
+ // repairLiveintervalsInRange() doesn't handle physical register, so we have
+ // to update the M0 range manually.
+ SlotIndex PairedIndex = LIS->getInstructionIndex(Paired);
+ LiveRange &M0Range = LIS->getRegUnit(*MCRegUnitIterator(AMDGPU::M0, TRI));
+ LiveRange::Segment *M0Segment = M0Range.getSegmentContaining(PairedIndex);
+ bool UpdateM0Range = M0Segment->end == PairedIndex.getRegSlot();
+
MachineInstrBuilder Write2
= BuildMI(*MBB, I, DL, Write2Desc)
.addOperand(*Addr) // addr
@@ -339,21 +331,25 @@
.addImm(NewOffset0) // offset0
.addImm(NewOffset1) // offset1
.addImm(0) // gds
- .addOperand(*M0Reg) // m0
.addMemOperand(*I->memoperands_begin())
.addMemOperand(*Paired->memoperands_begin());
// XXX - How do we express subregisters here?
- unsigned OrigRegs[] = { Data0->getReg(), Data1->getReg(), Addr->getReg(),
- M0Reg->getReg()};
+ unsigned OrigRegs[] = { Data0->getReg(), Data1->getReg(), Addr->getReg() };
LIS->RemoveMachineInstrFromMaps(I);
LIS->RemoveMachineInstrFromMaps(Paired);
I->eraseFromParent();
Paired->eraseFromParent();
+ // This doesn't handle physical registers like M0
LIS->repairIntervalsInRange(MBB, Write2, Write2, OrigRegs);
+ if (UpdateM0Range) {
+ SlotIndex Write2Index = LIS->getInstructionIndex(Write2);
+ M0Segment->end = Write2Index.getRegSlot();
+ }
+
DEBUG(dbgs() << "Inserted write2 inst: " << *Write2 << '\n');
return Write2.getInstr();
}