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[MachineSink] Remove subrange of live-ins from super register as well. #159145

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Merged
merged 2 commits into from
Sep 26, 2025
Merged

[MachineSink] Remove subrange of live-ins from super register as well. #159145

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d40d5de
[MachineSink] Remove subrange of live-ins from super register as well.
petechou Sep 16, 2025
d000334
Add a subreg-aware removeLiveIn variant.
petechou Sep 19, 2025
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5 changes: 5 additions & 0 deletions llvm/include/llvm/CodeGen/MachineBasicBlock.h
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Original file line number Diff line number Diff line change
Expand Up @@ -505,6 +505,11 @@ class MachineBasicBlock
LLVM_ABI void removeLiveIn(MCRegister Reg,
LaneBitmask LaneMask = LaneBitmask::getAll());

/// Remove the specified register from any overlapped live in. The method is
/// subreg-aware and removes Reg and its subregs from the live in set. It also
/// clears the corresponding bitmask from its live-in super registers.
LLVM_ABI void removeLiveInOverlappedWith(MCRegister Reg);

/// Return true if the specified register is in the live in set.
LLVM_ABI bool isLiveIn(MCRegister Reg,
LaneBitmask LaneMask = LaneBitmask::getAll()) const;
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20 changes: 20 additions & 0 deletions llvm/lib/CodeGen/MachineBasicBlock.cpp
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Expand Up @@ -606,6 +606,26 @@ void MachineBasicBlock::removeLiveIn(MCRegister Reg, LaneBitmask LaneMask) {
LiveIns.erase(I);
}

void MachineBasicBlock::removeLiveInOverlappedWith(MCRegister Reg) {
const MachineFunction *MF = getParent();
const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
// Remove Reg and its subregs from live in set.
for (MCPhysReg S : TRI->subregs_inclusive(Reg))
removeLiveIn(S);

// Remove live-in bitmask in super registers as well.
for (MCPhysReg Super : TRI->superregs(Reg)) {
for (MCSubRegIndexIterator SRI(Super, TRI); SRI.isValid(); ++SRI) {
if (Reg == SRI.getSubReg()) {
unsigned SubRegIndex = SRI.getSubRegIndex();
LaneBitmask SubRegLaneMask = TRI->getSubRegIndexLaneMask(SubRegIndex);
removeLiveIn(Super, SubRegLaneMask);
break;
}
}
}
}

MachineBasicBlock::livein_iterator
MachineBasicBlock::removeLiveIn(MachineBasicBlock::livein_iterator I) {
// Get non-const version of iterator.
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6 changes: 2 additions & 4 deletions llvm/lib/CodeGen/MachineSink.cpp
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Expand Up @@ -2187,11 +2187,9 @@ static void clearKillFlags(MachineInstr *MI, MachineBasicBlock &CurBB,
static void updateLiveIn(MachineInstr *MI, MachineBasicBlock *SuccBB,
const SmallVectorImpl<unsigned> &UsedOpsInCopy,
const SmallVectorImpl<Register> &DefedRegsInCopy) {
MachineFunction &MF = *SuccBB->getParent();
const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
for (Register DefReg : DefedRegsInCopy)
for (MCPhysReg S : TRI->subregs_inclusive(DefReg))
SuccBB->removeLiveIn(S);
SuccBB->removeLiveInOverlappedWith(DefReg);

for (auto U : UsedOpsInCopy)
SuccBB->addLiveIn(MI->getOperand(U).getReg());
SuccBB->sortUniqueLiveIns();
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2 changes: 1 addition & 1 deletion llvm/test/CodeGen/AMDGPU/av_spill_cross_bb_usage.mir
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Expand Up @@ -49,7 +49,7 @@ body: |
; GCN-NEXT: {{ $}}
; GCN-NEXT: bb.1:
; GCN-NEXT: successors: %bb.2(0x80000000)
; GCN-NEXT: liveins: $exec, $sgpr30, $sgpr31, $vgpr0, $vgpr1, $vgpr2, $vgpr3, $vgpr4, $vgpr5, $vgpr6, $vgpr7, $vgpr8, $vgpr9, $vgpr40, $sgpr30_sgpr31, $vgpr10_vgpr11:0x000000000000000F, $vgpr14_vgpr15:0x000000000000000F, $vgpr41_vgpr42:0x000000000000000F, $vgpr43_vgpr44:0x000000000000000F, $vgpr45_vgpr46:0x000000000000000F, $vgpr56_vgpr57:0x000000000000000F, $vgpr58_vgpr59:0x000000000000000F, $vgpr60_vgpr61:0x000000000000000F
; GCN-NEXT: liveins: $exec, $sgpr30, $sgpr31, $vgpr0, $vgpr1, $vgpr2, $vgpr3, $vgpr4, $vgpr5, $vgpr6, $vgpr7, $vgpr8, $vgpr9, $vgpr40, $sgpr30_sgpr31, $vgpr10_vgpr11:0x000000000000000F, $vgpr14_vgpr15:0x000000000000000F, $vgpr43_vgpr44:0x000000000000000F
; GCN-NEXT: {{ $}}
; GCN-NEXT: renamable $vgpr57 = COPY $vgpr9, implicit $exec
; GCN-NEXT: renamable $vgpr56 = COPY $vgpr8, implicit $exec
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113 changes: 113 additions & 0 deletions llvm/test/CodeGen/AMDGPU/postra-machine-sink-livein-subrange.mir
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@@ -0,0 +1,113 @@
# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 6
# RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx908 -run-pass=postra-machine-sink -verify-machineinstrs -o - %s | FileCheck --check-prefixes=GCN %s

# Test live-in with subrange is updated accordingly in postra-machine-sink.
---
name: test_postra_machine_sink_livein_update
tracksRegLiveness: true
frameInfo:
adjustsStack: true
stack:
- { id: 0, name: '', type: spill-slot, offset: 0, size: 4, alignment: 4,
stack-id: default, callee-saved-register: '', callee-saved-restored: true,
debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
- { id: 1, name: '', type: spill-slot, offset: 0, size: 8, alignment: 4,
stack-id: default, callee-saved-register: '', callee-saved-restored: true,
debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
- { id: 2, name: '', type: spill-slot, offset: 0, size: 8, alignment: 4,
stack-id: default, callee-saved-register: '', callee-saved-restored: true,
debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
machineFunctionInfo:
scratchRSrcReg: '$sgpr0_sgpr1_sgpr2_sgpr3'
stackPtrOffsetReg: '$sgpr32'
body: |
; GCN-LABEL: name: test_postra_machine_sink_livein_update
; GCN: bb.0:
; GCN-NEXT: successors: %bb.2(0x40000000), %bb.1(0x40000000)
; GCN-NEXT: liveins: $sgpr30, $sgpr31, $vgpr0, $vgpr1, $vgpr2, $vgpr3, $vgpr4, $vgpr5, $vgpr6, $vgpr7, $vgpr8, $vgpr9, $vgpr10, $vgpr11, $vgpr12, $vgpr13, $vgpr14, $vgpr15, $vgpr40, $sgpr30_sgpr31
; GCN-NEXT: {{ $}}
; GCN-NEXT: renamable $vgpr44 = COPY $vgpr13, implicit $exec
; GCN-NEXT: renamable $vgpr43 = COPY $vgpr12, implicit $exec
; GCN-NEXT: S_CBRANCH_SCC1 %bb.2, implicit undef $scc
; GCN-NEXT: S_BRANCH %bb.1
; GCN-NEXT: {{ $}}
; GCN-NEXT: bb.1:
; GCN-NEXT: successors: %bb.2(0x80000000)
; GCN-NEXT: liveins: $exec, $sgpr30, $sgpr31, $vgpr0, $vgpr1, $vgpr2, $vgpr3, $vgpr4, $vgpr5, $vgpr6, $vgpr7, $vgpr8, $vgpr9, $vgpr40, $sgpr30_sgpr31, $vgpr10_vgpr11:0x000000000000000F, $vgpr14_vgpr15:0x000000000000000F, $vgpr43_vgpr44:0x000000000000000F
; GCN-NEXT: {{ $}}
; GCN-NEXT: renamable $vgpr57 = COPY $vgpr9, implicit $exec
; GCN-NEXT: renamable $vgpr56 = COPY $vgpr8, implicit $exec
; GCN-NEXT: renamable $vgpr59 = COPY $vgpr7, implicit $exec
; GCN-NEXT: renamable $vgpr58 = COPY $vgpr6, implicit $exec
; GCN-NEXT: renamable $vgpr61 = COPY $vgpr5, implicit $exec
; GCN-NEXT: renamable $vgpr60 = COPY $vgpr4, implicit $exec
; GCN-NEXT: renamable $vgpr42 = COPY $vgpr3, implicit $exec
; GCN-NEXT: renamable $vgpr41 = COPY $vgpr2, implicit $exec
; GCN-NEXT: renamable $vgpr46 = COPY $vgpr1, implicit $exec
; GCN-NEXT: renamable $vgpr45 = COPY $vgpr0, implicit $exec
; GCN-NEXT: ADJCALLSTACKUP 0, 0, implicit-def dead $scc, implicit-def $sgpr32, implicit $sgpr32
; GCN-NEXT: renamable $sgpr16_sgpr17 = IMPLICIT_DEF
; GCN-NEXT: $vgpr40 = SI_SPILL_S32_TO_VGPR $sgpr30, 0, $vgpr40, implicit-def $sgpr30_sgpr31, implicit $sgpr30_sgpr31
; GCN-NEXT: $vgpr40 = SI_SPILL_S32_TO_VGPR $sgpr31, 1, $vgpr40, implicit $sgpr30_sgpr31
; GCN-NEXT: SI_SPILL_AV64_SAVE killed $vgpr14_vgpr15, %stack.1, $sgpr32, 0, implicit $exec :: (store (s64) into %stack.1, align 4, addrspace 5)
; GCN-NEXT: SI_SPILL_AV64_SAVE killed $vgpr10_vgpr11, %stack.2, $sgpr32, 0, implicit $exec :: (store (s64) into %stack.2, align 4, addrspace 5)
; GCN-NEXT: dead $sgpr30_sgpr31 = SI_CALL killed renamable $sgpr16_sgpr17, 0, csr_amdgpu, implicit-def dead $vgpr0
; GCN-NEXT: renamable $vgpr14_vgpr15 = SI_SPILL_AV64_RESTORE %stack.1, $sgpr32, 0, implicit $exec :: (load (s64) from %stack.1, align 4, addrspace 5)
; GCN-NEXT: renamable $vgpr0_vgpr1 = nofpexcept V_FMA_F64_e64 0, killed $vgpr45_vgpr46, 0, killed $vgpr41_vgpr42, 0, killed $vgpr60_vgpr61, 0, 0, implicit $mode, implicit $exec
; GCN-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def dead $scc, implicit-def $sgpr32, implicit $sgpr32
; GCN-NEXT: FLAT_STORE_DWORDX2 killed renamable $vgpr58_vgpr59, killed renamable $vgpr0_vgpr1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s64))
; GCN-NEXT: renamable $vgpr0_vgpr1 = SI_SPILL_AV64_RESTORE %stack.2, $sgpr32, 0, implicit $exec :: (load (s64) from %stack.2, align 4, addrspace 5)
; GCN-NEXT: FLAT_STORE_DWORDX2 killed renamable $vgpr0_vgpr1, killed renamable $vgpr56_vgpr57, 0, 0, implicit $exec, implicit $flat_scr :: (store (s64))
; GCN-NEXT: {{ $}}
; GCN-NEXT: bb.2:
; GCN-NEXT: liveins: $vgpr40, $vgpr14_vgpr15:0x000000000000000F, $vgpr43_vgpr44:0x000000000000000F
; GCN-NEXT: {{ $}}
; GCN-NEXT: renamable $vgpr0_vgpr1 = V_MOV_B64_PSEUDO 0, implicit $exec
; GCN-NEXT: FLAT_STORE_DWORDX2 undef renamable $vgpr0_vgpr1, killed renamable $vgpr43_vgpr44, 0, 0, implicit $exec, implicit $flat_scr :: (store (s64))
; GCN-NEXT: FLAT_STORE_DWORDX2 killed renamable $vgpr0_vgpr1, killed renamable $vgpr14_vgpr15, 0, 0, implicit $exec, implicit $flat_scr :: (store (s64))
; GCN-NEXT: S_SETPC_B64_return undef $sgpr30_sgpr31
bb.0:
successors: %bb.2(0x40000000), %bb.1(0x40000000)
liveins: $sgpr30, $sgpr31, $vgpr0, $vgpr1, $vgpr2, $vgpr3, $vgpr4, $vgpr5, $vgpr6, $vgpr7, $vgpr8, $vgpr9, $vgpr10, $vgpr11, $vgpr12, $vgpr13, $vgpr14, $vgpr15, $vgpr40, $sgpr30_sgpr31
renamable $vgpr44 = COPY $vgpr13, implicit $exec
renamable $vgpr43 = COPY $vgpr12, implicit $exec
renamable $vgpr57 = COPY $vgpr9, implicit $exec
renamable $vgpr56 = COPY $vgpr8, implicit $exec
renamable $vgpr59 = COPY $vgpr7, implicit $exec
renamable $vgpr58 = COPY $vgpr6, implicit $exec
renamable $vgpr61 = COPY $vgpr5, implicit $exec
renamable $vgpr60 = COPY $vgpr4, implicit $exec
renamable $vgpr42 = COPY $vgpr3, implicit $exec
renamable $vgpr41 = COPY $vgpr2, implicit $exec
renamable $vgpr46 = COPY $vgpr1, implicit $exec
renamable $vgpr45 = COPY $vgpr0, implicit $exec
S_CBRANCH_SCC1 %bb.2, implicit undef $scc
S_BRANCH %bb.1
bb.1:
successors: %bb.2(0x80000000)
liveins: $sgpr30, $sgpr31, $vgpr40, $sgpr30_sgpr31, $vgpr10_vgpr11:0x000000000000000F, $vgpr14_vgpr15:0x000000000000000F, $vgpr41_vgpr42:0x000000000000000F, $vgpr43_vgpr44:0x000000000000000F, $vgpr45_vgpr46:0x000000000000000F, $vgpr56_vgpr57:0x000000000000000F, $vgpr58_vgpr59:0x000000000000000F, $vgpr60_vgpr61:0x000000000000000F
ADJCALLSTACKUP 0, 0, implicit-def dead $scc, implicit-def $sgpr32, implicit $sgpr32
renamable $sgpr16_sgpr17 = IMPLICIT_DEF
$vgpr40 = SI_SPILL_S32_TO_VGPR $sgpr30, 0, $vgpr40, implicit-def $sgpr30_sgpr31, implicit $sgpr30_sgpr31
$vgpr40 = SI_SPILL_S32_TO_VGPR $sgpr31, 1, $vgpr40, implicit $sgpr30_sgpr31
SI_SPILL_AV64_SAVE killed $vgpr14_vgpr15, %stack.1, $sgpr32, 0, implicit $exec :: (store (s64) into %stack.1, align 4, addrspace 5)
SI_SPILL_AV64_SAVE killed $vgpr10_vgpr11, %stack.2, $sgpr32, 0, implicit $exec :: (store (s64) into %stack.2, align 4, addrspace 5)
dead $sgpr30_sgpr31 = SI_CALL killed renamable $sgpr16_sgpr17, 0, csr_amdgpu, implicit-def dead $vgpr0
renamable $vgpr14_vgpr15 = SI_SPILL_AV64_RESTORE %stack.1, $sgpr32, 0, implicit $exec :: (load (s64) from %stack.1, align 4, addrspace 5)
renamable $vgpr0_vgpr1 = nofpexcept V_FMA_F64_e64 0, killed $vgpr45_vgpr46, 0, killed $vgpr41_vgpr42, 0, killed $vgpr60_vgpr61, 0, 0, implicit $mode, implicit $exec
ADJCALLSTACKDOWN 0, 0, implicit-def dead $scc, implicit-def $sgpr32, implicit $sgpr32
FLAT_STORE_DWORDX2 killed renamable $vgpr58_vgpr59, killed renamable $vgpr0_vgpr1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s64))
renamable $vgpr0_vgpr1 = SI_SPILL_AV64_RESTORE %stack.2, $sgpr32, 0, implicit $exec :: (load (s64) from %stack.2, align 4, addrspace 5)
FLAT_STORE_DWORDX2 killed renamable $vgpr0_vgpr1, killed renamable $vgpr56_vgpr57, 0, 0, implicit $exec, implicit $flat_scr :: (store (s64))
bb.2:
liveins: $vgpr40, $vgpr14_vgpr15:0x000000000000000F, $vgpr43_vgpr44:0x000000000000000F
renamable $vgpr0_vgpr1 = V_MOV_B64_PSEUDO 0, implicit $exec
FLAT_STORE_DWORDX2 undef renamable $vgpr0_vgpr1, killed renamable $vgpr43_vgpr44, 0, 0, implicit $exec, implicit $flat_scr :: (store (s64))
FLAT_STORE_DWORDX2 killed renamable $vgpr0_vgpr1, killed renamable $vgpr14_vgpr15, 0, 0, implicit $exec, implicit $flat_scr :: (store (s64))
S_SETPC_B64_return undef $sgpr30_sgpr31
...