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[RISCV] Add a PseudoVSETVLIX0X0 pseudo for the x0,x0 vsetvli. NFC #141875

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Merged
merged 4 commits into from
May 29, 2025
Merged

[RISCV] Add a PseudoVSETVLIX0X0 pseudo for the x0,x0 vsetvli. NFC #141875

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5b6ad97
[RISCV] Add a PseudoVSETVLIX0X0 pseudo for the x0,x0 vsetvli. NFC
topperc May 28, 2025
d79e351
Merge remote-tracking branch 'origin/main' into pr/PseudoVSETVLIX0X0
topperc May 29, 2025
29c4bcc
fixup! Remove CheckAll
topperc May 29, 2025
f69749d
fixup! Update getInfoForVSETVLI.
topperc May 29, 2025
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3 changes: 0 additions & 3 deletions llvm/lib/Target/RISCV/RISCVDeadRegisterDefinitions.cpp
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Expand Up @@ -74,9 +74,6 @@ bool RISCVDeadRegisterDefinitions::runOnMachineFunction(MachineFunction &MF) {
MI.getOpcode() != RISCV::PseudoVSETVLI &&
MI.getOpcode() != RISCV::PseudoVSETIVLI)
continue;
// For PseudoVSETVLIX0, Rd = X0 has special meaning.
if (MI.getOpcode() == RISCV::PseudoVSETVLIX0)
continue;
for (int I = 0, E = Desc.getNumDefs(); I != E; ++I) {
MachineOperand &MO = MI.getOperand(I);
if (!MO.isReg() || !MO.isDef() || MO.isEarlyClobber())
Expand Down
21 changes: 10 additions & 11 deletions llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
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Expand Up @@ -941,15 +941,13 @@ RISCVInsertVSETVLI::getInfoForVSETVLI(const MachineInstr &MI) const {
} else {
assert(MI.getOpcode() == RISCV::PseudoVSETVLI ||
MI.getOpcode() == RISCV::PseudoVSETVLIX0);
Register AVLReg = MI.getOperand(1).getReg();
assert((AVLReg != RISCV::X0 || MI.getOperand(0).getReg() != RISCV::X0) &&
"Can't handle X0, X0 vsetvli yet");
if (AVLReg == RISCV::X0)
if (MI.getOpcode() == RISCV::PseudoVSETVLIX0)
NewInfo.setAVLVLMAX();
else if (MI.getOperand(1).isUndef())
// Otherwise use an AVL of 1 to avoid depending on previous vl.
NewInfo.setAVLImm(1);
else {
Register AVLReg = MI.getOperand(1).getReg();
VNInfo *VNI = getVNInfoFromReg(AVLReg, MI, LIS);
NewInfo.setAVLRegDef(VNI, AVLReg);
}
Expand Down Expand Up @@ -1056,7 +1054,7 @@ void RISCVInsertVSETVLI::insertVSETVLI(MachineBasicBlock &MBB,
// Use X0, X0 form if the AVL is the same and the SEW+LMUL gives the same
// VLMAX.
if (Info.hasSameAVL(PrevInfo) && Info.hasSameVLMAX(PrevInfo)) {
auto MI = BuildMI(MBB, InsertPt, DL, TII->get(RISCV::PseudoVSETVLIX0))
auto MI = BuildMI(MBB, InsertPt, DL, TII->get(RISCV::PseudoVSETVLIX0X0))
.addReg(RISCV::X0, RegState::Define | RegState::Dead)
.addReg(RISCV::X0, RegState::Kill)
.addImm(Info.encodeVTYPE())
Expand All @@ -1074,11 +1072,12 @@ void RISCVInsertVSETVLI::insertVSETVLI(MachineBasicBlock &MBB,
DefMI && RISCVInstrInfo::isVectorConfigInstr(*DefMI)) {
VSETVLIInfo DefInfo = getInfoForVSETVLI(*DefMI);
if (DefInfo.hasSameAVL(PrevInfo) && DefInfo.hasSameVLMAX(PrevInfo)) {
auto MI = BuildMI(MBB, InsertPt, DL, TII->get(RISCV::PseudoVSETVLIX0))
.addReg(RISCV::X0, RegState::Define | RegState::Dead)
.addReg(RISCV::X0, RegState::Kill)
.addImm(Info.encodeVTYPE())
.addReg(RISCV::VL, RegState::Implicit);
auto MI =
BuildMI(MBB, InsertPt, DL, TII->get(RISCV::PseudoVSETVLIX0X0))
.addReg(RISCV::X0, RegState::Define | RegState::Dead)
.addReg(RISCV::X0, RegState::Kill)
.addImm(Info.encodeVTYPE())
.addReg(RISCV::VL, RegState::Implicit);
if (LIS)
LIS->InsertMachineInstrInMaps(*MI);
return;
Expand All @@ -1098,7 +1097,7 @@ void RISCVInsertVSETVLI::insertVSETVLI(MachineBasicBlock &MBB,
}

if (Info.hasAVLVLMAX()) {
Register DestReg = MRI->createVirtualRegister(&RISCV::GPRRegClass);
Register DestReg = MRI->createVirtualRegister(&RISCV::GPRNoX0RegClass);
auto MI = BuildMI(MBB, InsertPt, DL, TII->get(RISCV::PseudoVSETVLIX0))
.addReg(DestReg, RegState::Define | RegState::Dead)
.addReg(RISCV::X0, RegState::Kill)
Expand Down
7 changes: 5 additions & 2 deletions llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td
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Expand Up @@ -6056,7 +6056,7 @@ let hasSideEffects = 0, mayLoad = 0, mayStore = 0, isCodeGenOnly = 1 in {
PseudoInstExpansion<(CSRRS GPR:$rd, SysRegVLENB.Encoding, X0)>,
Sched<[WriteRdVLENB]>;
let Defs = [VL, VTYPE] in {
def PseudoReadVLENBViaVSETVLIX0 : Pseudo<(outs GPR:$rd), (ins uimm5:$shamt),
def PseudoReadVLENBViaVSETVLIX0 : Pseudo<(outs GPRNoX0:$rd), (ins uimm5:$shamt),
[]>,
Sched<[WriteVSETVLI, ReadVSETVLI]>;
}
Expand Down Expand Up @@ -6096,9 +6096,12 @@ let hasSideEffects = 0, mayLoad = 0, mayStore = 0, Defs = [VL, VTYPE] in {
def PseudoVSETVLI : Pseudo<(outs GPR:$rd), (ins GPRNoX0:$rs1, VTypeIOp11:$vtypei), []>,
PseudoInstExpansion<(VSETVLI GPR:$rd, GPR:$rs1, VTypeIOp11:$vtypei)>,
Sched<[WriteVSETVLI, ReadVSETVLI]>;
def PseudoVSETVLIX0 : Pseudo<(outs GPR:$rd), (ins GPRX0:$rs1, VTypeIOp11:$vtypei), []>,
def PseudoVSETVLIX0 : Pseudo<(outs GPRNoX0:$rd), (ins GPRX0:$rs1, VTypeIOp11:$vtypei), []>,
PseudoInstExpansion<(VSETVLI GPR:$rd, GPR:$rs1, VTypeIOp11:$vtypei)>,
Sched<[WriteVSETVLI, ReadVSETVLI]>;
def PseudoVSETVLIX0X0 : Pseudo<(outs GPRX0:$rd), (ins GPRX0:$rs1, VTypeIOp11:$vtypei), []>,
PseudoInstExpansion<(VSETVLI GPR:$rd, GPR:$rs1, VTypeIOp11:$vtypei)>,
Sched<[WriteVSETVLI, ReadVSETVLI]>;
def PseudoVSETIVLI : Pseudo<(outs GPR:$rd), (ins uimm5:$rs1, VTypeIOp10:$vtypei), []>,
PseudoInstExpansion<(VSETIVLI GPR:$rd, uimm5:$rs1, VTypeIOp10:$vtypei)>,
Sched<[WriteVSETIVLI]>;
Expand Down
7 changes: 2 additions & 5 deletions llvm/lib/Target/RISCV/RISCVInstrPredicates.td
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Expand Up @@ -70,18 +70,15 @@ def isVectorConfigInstr
CheckOpcode<[
PseudoVSETVLI,
PseudoVSETVLIX0,
PseudoVSETVLIX0X0,
PseudoVSETIVLI
]>>>;

// Return true if this is 'vsetvli x0, x0, vtype' which preserves
// VL and only sets VTYPE.
def isVLPreservingConfig
: TIIPredicate<"isVLPreservingConfig",
MCReturnStatement<
CheckAll<[
CheckOpcode<[PseudoVSETVLIX0]>,
CheckRegOperand<0, X0>
]>>>;
MCReturnStatement<CheckOpcode<[PseudoVSETVLIX0X0]>>>;

def isFloatScalarMoveOrScalarSplatInstr
: TIIPredicate<"isFloatScalarMoveOrScalarSplatInstr",
Expand Down
20 changes: 10 additions & 10 deletions llvm/test/CodeGen/RISCV/rvv/vmv-copy.mir
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Expand Up @@ -98,14 +98,14 @@ body: |
; CHECK-NEXT: $v28m4 = PseudoVLE32_V_M4 undef $v28m4, killed $x16, $noreg, 5 /* e32 */, 0 /* tu, mu */, implicit $vl, implicit $vtype
; CHECK-NEXT: $x15 = PseudoVSETVLI $x17, 73 /* e16, m2, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $v0m2 = PseudoVLE32_V_M2 undef $v0m2, $x18, $noreg, 4 /* e16 */, 0 /* tu, mu */, implicit $vl, implicit $vtype
; CHECK-NEXT: $x0 = PseudoVSETVLIX0 $x0, 82 /* e32, m4, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $x0 = PseudoVSETVLIX0X0 $x0, 82 /* e32, m4, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $v4m4 = PseudoVLE32_V_M4 undef $v4m4, killed $x18, $noreg, 5 /* e32 */, 0 /* tu, mu */, implicit $vl, implicit $vtype
; CHECK-NEXT: $v12m4 = VMV4R_V $v28m4, implicit $vtype
$x15 = PseudoVSETVLI $x14, 82, implicit-def $vl, implicit-def $vtype
$v28m4 = PseudoVLE32_V_M4 undef $v28m4, killed $x16, $noreg, 5, 0, implicit $vl, implicit $vtype
$x15 = PseudoVSETVLI $x17, 73, implicit-def $vl, implicit-def $vtype
$v0m2 = PseudoVLE32_V_M2 undef $v0m2, $x18, $noreg, 4, 0, implicit $vl, implicit $vtype
$x0 = PseudoVSETVLIX0 $x0, 82, implicit-def $vl, implicit-def $vtype
$x0 = PseudoVSETVLIX0X0 $x0, 82, implicit-def $vl, implicit-def $vtype
$v4m4 = PseudoVLE32_V_M4 undef $v4m4, killed $x18, $noreg, 5, 0, implicit $vl, implicit $vtype
$v12m4 = COPY $v28m4
...
Expand All @@ -120,16 +120,16 @@ body: |
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: $x15 = PseudoVSETVLI $x14, 82 /* e32, m4, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $v28m4 = PseudoVLE32_V_M4 undef $v28m4, killed $x16, $noreg, 5 /* e32 */, 0 /* tu, mu */, implicit $vl, implicit $vtype
; CHECK-NEXT: $x0 = PseudoVSETVLIX0 $x0, 73 /* e16, m2, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $x0 = PseudoVSETVLIX0X0 $x0, 73 /* e16, m2, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $v0m2 = PseudoVLE32_V_M2 undef $v0m2, $x18, $noreg, 4 /* e16 */, 0 /* tu, mu */, implicit $vl, implicit $vtype
; CHECK-NEXT: $x0 = PseudoVSETVLIX0 $x0, 82 /* e32, m4, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $x0 = PseudoVSETVLIX0X0 $x0, 82 /* e32, m4, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $v4m4 = PseudoVLE32_V_M4 undef $v4m4, killed $x18, $noreg, 5 /* e32 */, 0 /* tu, mu */, implicit $vl, implicit $vtype
; CHECK-NEXT: $v12m4 = PseudoVMV_V_V_M4 undef $v12m4, $v28m4, $noreg, 5 /* e32 */, 0 /* tu, mu */, implicit $vl, implicit $vtype
$x15 = PseudoVSETVLI $x14, 82, implicit-def $vl, implicit-def $vtype
$v28m4 = PseudoVLE32_V_M4 undef $v28m4, killed $x16, $noreg, 5, 0, implicit $vl, implicit $vtype
$x0 = PseudoVSETVLIX0 $x0, 73, implicit-def $vl, implicit-def $vtype
$x0 = PseudoVSETVLIX0X0 $x0, 73, implicit-def $vl, implicit-def $vtype
$v0m2 = PseudoVLE32_V_M2 undef $v0m2, $x18, $noreg, 4, 0, implicit $vl, implicit $vtype
$x0 = PseudoVSETVLIX0 $x0, 82, implicit-def $vl, implicit-def $vtype
$x0 = PseudoVSETVLIX0X0 $x0, 82, implicit-def $vl, implicit-def $vtype
$v4m4 = PseudoVLE32_V_M4 undef $v4m4, killed $x18, $noreg, 5, 0, implicit $vl, implicit $vtype
$v12m4 = COPY $v28m4
...
Expand All @@ -144,12 +144,12 @@ body: |
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: $x15 = PseudoVSETVLI $x14, 82 /* e32, m4, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $v28m4 = PseudoVLE32_V_M4 undef $v28m4, killed $x16, $noreg, 5 /* e32 */, 0 /* tu, mu */, implicit $vl, implicit $vtype
; CHECK-NEXT: $x0 = PseudoVSETVLIX0 $x0, 73 /* e16, m2, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $x0 = PseudoVSETVLIX0X0 $x0, 73 /* e16, m2, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $v0m2 = PseudoVLE32_V_M2 undef $v0m2, $x18, $noreg, 4 /* e16 */, 0 /* tu, mu */, implicit $vl, implicit $vtype
; CHECK-NEXT: $v12m4 = VMV4R_V $v28m4, implicit $vtype
$x15 = PseudoVSETVLI $x14, 82, implicit-def $vl, implicit-def $vtype
$v28m4 = PseudoVLE32_V_M4 undef $v28m4, killed $x16, $noreg, 5, 0, implicit $vl, implicit $vtype
$x0 = PseudoVSETVLIX0 $x0, 73, implicit-def $vl, implicit-def $vtype
$x0 = PseudoVSETVLIX0X0 $x0, 73, implicit-def $vl, implicit-def $vtype
$v0m2 = PseudoVLE32_V_M2 undef $v0m2, $x18, $noreg, 4, 0, implicit $vl, implicit $vtype
$v12m4 = COPY $v28m4
...
Expand Down Expand Up @@ -185,11 +185,11 @@ body: |
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: $x15 = PseudoVSETVLI $x14, 82 /* e32, m4, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $v28m4 = PseudoVLE32_V_M4 undef $v28m4, killed $x16, $noreg, 5 /* e32 */, 0 /* tu, mu */, implicit $vl, implicit $vtype
; CHECK-NEXT: $x0 = PseudoVSETVLIX0 $x0, 74 /* e16, m4, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $x0 = PseudoVSETVLIX0X0 $x0, 74 /* e16, m4, ta, mu */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: $v12m4 = VMV4R_V $v28m4, implicit $vtype
$x15 = PseudoVSETVLI $x14, 82, implicit-def $vl, implicit-def $vtype
$v28m4 = PseudoVLE32_V_M4 undef $v28m4, killed $x16, $noreg, 5, 0, implicit $vl, implicit $vtype
$x0 = PseudoVSETVLIX0 $x0, 74, implicit-def $vl, implicit-def $vtype
$x0 = PseudoVSETVLIX0X0 $x0, 74, implicit-def $vl, implicit-def $vtype
$v12m4 = COPY $v28m4
...
---
Expand Down
2 changes: 1 addition & 1 deletion llvm/test/CodeGen/RISCV/rvv/vsetvli-insert-coalesce.mir
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Expand Up @@ -15,7 +15,7 @@ body: |
; CHECK-NEXT: bb.1:
; CHECK-NEXT: successors: %bb.2(0x80000000)
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: dead [[PseudoVSETVLIX0_:%[0-9]+]]:gpr = PseudoVSETVLIX0 killed $x0, 209 /* e32, m2, ta, ma */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: dead [[PseudoVSETVLIX0_:%[0-9]+]]:gprnox0 = PseudoVSETVLIX0 killed $x0, 209 /* e32, m2, ta, ma */, implicit-def $vl, implicit-def $vtype
; CHECK-NEXT: renamable $v10m2 = PseudoVMV_V_I_M2 undef renamable $v10m2, 0, -1, 5 /* e32 */, 0 /* tu, mu */, implicit $vl, implicit $vtype
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: bb.2:
Expand Down
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