diff options
Diffstat (limited to 'llvm/lib/Target/RISCV/GISel/RISCVLegalizerInfo.cpp')
-rw-r--r-- | llvm/lib/Target/RISCV/GISel/RISCVLegalizerInfo.cpp | 184 |
1 files changed, 177 insertions, 7 deletions
diff --git a/llvm/lib/Target/RISCV/GISel/RISCVLegalizerInfo.cpp b/llvm/lib/Target/RISCV/GISel/RISCVLegalizerInfo.cpp index 7f35107..38c1f9868 100644 --- a/llvm/lib/Target/RISCV/GISel/RISCVLegalizerInfo.cpp +++ b/llvm/lib/Target/RISCV/GISel/RISCVLegalizerInfo.cpp @@ -139,20 +139,21 @@ RISCVLegalizerInfo::RISCVLegalizerInfo(const RISCVSubtarget &ST) .clampScalar(0, s32, sXLen) .minScalarSameAs(1, 0); + auto &ExtActions = + getActionDefinitionsBuilder({G_ZEXT, G_SEXT, G_ANYEXT}) + .legalIf(all(typeIsLegalIntOrFPVec(0, IntOrFPVecTys, ST), + typeIsLegalIntOrFPVec(1, IntOrFPVecTys, ST))); if (ST.is64Bit()) { - getActionDefinitionsBuilder({G_ZEXT, G_SEXT, G_ANYEXT}) - .legalFor({{sXLen, s32}}) - .maxScalar(0, sXLen); - + ExtActions.legalFor({{sXLen, s32}}); getActionDefinitionsBuilder(G_SEXT_INREG) .customFor({sXLen}) .maxScalar(0, sXLen) .lower(); } else { - getActionDefinitionsBuilder({G_ZEXT, G_SEXT, G_ANYEXT}).maxScalar(0, sXLen); - getActionDefinitionsBuilder(G_SEXT_INREG).maxScalar(0, sXLen).lower(); } + ExtActions.customIf(typeIsLegalBoolVec(1, BoolVecTys, ST)) + .maxScalar(0, sXLen); // Merge/Unmerge for (unsigned Op : {G_MERGE_VALUES, G_UNMERGE_VALUES}) { @@ -235,7 +236,9 @@ RISCVLegalizerInfo::RISCVLegalizerInfo(const RISCVSubtarget &ST) getActionDefinitionsBuilder(G_ICMP) .legalFor({{sXLen, sXLen}, {sXLen, p0}}) - .widenScalarToNextPow2(1) + .legalIf(all(typeIsLegalBoolVec(0, BoolVecTys, ST), + typeIsLegalIntOrFPVec(1, IntOrFPVecTys, ST))) + .widenScalarOrEltToNextPow2OrMinSize(1, 8) .clampScalar(1, sXLen, sXLen) .clampScalar(0, sXLen, sXLen); @@ -418,6 +421,29 @@ RISCVLegalizerInfo::RISCVLegalizerInfo(const RISCVSubtarget &ST) .clampScalar(0, sXLen, sXLen) .customFor({sXLen}); + auto &SplatActions = + getActionDefinitionsBuilder(G_SPLAT_VECTOR) + .legalIf(all(typeIsLegalIntOrFPVec(0, IntOrFPVecTys, ST), + typeIs(1, sXLen))) + .customIf(all(typeIsLegalBoolVec(0, BoolVecTys, ST), typeIs(1, s1))); + // Handle case of s64 element vectors on RV32. If the subtarget does not have + // f64, then try to lower it to G_SPLAT_VECTOR_SPLIT_64_VL. If the subtarget + // does have f64, then we don't know whether the type is an f64 or an i64, + // so mark the G_SPLAT_VECTOR as legal and decide later what to do with it, + // depending on how the instructions it consumes are legalized. They are not + // legalized yet since legalization is in reverse postorder, so we cannot + // make the decision at this moment. + if (XLen == 32) { + if (ST.hasVInstructionsF64() && ST.hasStdExtD()) + SplatActions.legalIf(all( + typeInSet(0, {nxv1s64, nxv2s64, nxv4s64, nxv8s64}), typeIs(1, s64))); + else if (ST.hasVInstructionsI64()) + SplatActions.customIf(all( + typeInSet(0, {nxv1s64, nxv2s64, nxv4s64, nxv8s64}), typeIs(1, s64))); + } + + SplatActions.clampScalar(1, sXLen, sXLen); + getLegacyLegalizerInfo().computeTables(); } @@ -576,7 +602,145 @@ bool RISCVLegalizerInfo::legalizeVScale(MachineInstr &MI, auto VScale = MIB.buildLShr(XLenTy, VLENB, MIB.buildConstant(XLenTy, 3)); MIB.buildMul(Dst, VScale, MIB.buildConstant(XLenTy, Val)); } + MI.eraseFromParent(); + return true; +} + +// Custom-lower extensions from mask vectors by using a vselect either with 1 +// for zero/any-extension or -1 for sign-extension: +// (vXiN = (s|z)ext vXi1:vmask) -> (vXiN = vselect vmask, (-1 or 1), 0) +// Note that any-extension is lowered identically to zero-extension. +bool RISCVLegalizerInfo::legalizeExt(MachineInstr &MI, + MachineIRBuilder &MIB) const { + + unsigned Opc = MI.getOpcode(); + assert(Opc == TargetOpcode::G_ZEXT || Opc == TargetOpcode::G_SEXT || + Opc == TargetOpcode::G_ANYEXT); + + MachineRegisterInfo &MRI = *MIB.getMRI(); + Register Dst = MI.getOperand(0).getReg(); + Register Src = MI.getOperand(1).getReg(); + + LLT DstTy = MRI.getType(Dst); + int64_t ExtTrueVal = Opc == TargetOpcode::G_SEXT ? -1 : 1; + LLT DstEltTy = DstTy.getElementType(); + auto SplatZero = MIB.buildSplatVector(DstTy, MIB.buildConstant(DstEltTy, 0)); + auto SplatTrue = + MIB.buildSplatVector(DstTy, MIB.buildConstant(DstEltTy, ExtTrueVal)); + MIB.buildSelect(Dst, Src, SplatTrue, SplatZero); + + MI.eraseFromParent(); + return true; +} + +/// Return the type of the mask type suitable for masking the provided +/// vector type. This is simply an i1 element type vector of the same +/// (possibly scalable) length. +static LLT getMaskTypeFor(LLT VecTy) { + assert(VecTy.isVector()); + ElementCount EC = VecTy.getElementCount(); + return LLT::vector(EC, LLT::scalar(1)); +} + +/// Creates an all ones mask suitable for masking a vector of type VecTy with +/// vector length VL. +static MachineInstrBuilder buildAllOnesMask(LLT VecTy, const SrcOp &VL, + MachineIRBuilder &MIB, + MachineRegisterInfo &MRI) { + LLT MaskTy = getMaskTypeFor(VecTy); + return MIB.buildInstr(RISCV::G_VMSET_VL, {MaskTy}, {VL}); +} + +/// Gets the two common "VL" operands: an all-ones mask and the vector length. +/// VecTy is a scalable vector type. +static std::pair<MachineInstrBuilder, Register> +buildDefaultVLOps(const DstOp &Dst, MachineIRBuilder &MIB, + MachineRegisterInfo &MRI) { + LLT VecTy = Dst.getLLTTy(MRI); + assert(VecTy.isScalableVector() && "Expecting scalable container type"); + Register VL(RISCV::X0); + MachineInstrBuilder Mask = buildAllOnesMask(VecTy, VL, MIB, MRI); + return {Mask, VL}; +} + +static MachineInstrBuilder +buildSplatPartsS64WithVL(const DstOp &Dst, const SrcOp &Passthru, Register Lo, + Register Hi, Register VL, MachineIRBuilder &MIB, + MachineRegisterInfo &MRI) { + // TODO: If the Hi bits of the splat are undefined, then it's fine to just + // splat Lo even if it might be sign extended. I don't think we have + // introduced a case where we're build a s64 where the upper bits are undef + // yet. + + // Fall back to a stack store and stride x0 vector load. + // TODO: need to lower G_SPLAT_VECTOR_SPLIT_I64. This is done in + // preprocessDAG in SDAG. + return MIB.buildInstr(RISCV::G_SPLAT_VECTOR_SPLIT_I64_VL, {Dst}, + {Passthru, Lo, Hi, VL}); +} + +static MachineInstrBuilder +buildSplatSplitS64WithVL(const DstOp &Dst, const SrcOp &Passthru, + const SrcOp &Scalar, Register VL, + MachineIRBuilder &MIB, MachineRegisterInfo &MRI) { + assert(Scalar.getLLTTy(MRI) == LLT::scalar(64) && "Unexpected VecTy!"); + auto Unmerge = MIB.buildUnmerge(LLT::scalar(32), Scalar); + return buildSplatPartsS64WithVL(Dst, Passthru, Unmerge.getReg(0), + Unmerge.getReg(1), VL, MIB, MRI); +} + +// Lower splats of s1 types to G_ICMP. For each mask vector type, we have a +// legal equivalently-sized i8 type, so we can use that as a go-between. +// Splats of s1 types that have constant value can be legalized as VMSET_VL or +// VMCLR_VL. +bool RISCVLegalizerInfo::legalizeSplatVector(MachineInstr &MI, + MachineIRBuilder &MIB) const { + assert(MI.getOpcode() == TargetOpcode::G_SPLAT_VECTOR); + + MachineRegisterInfo &MRI = *MIB.getMRI(); + + Register Dst = MI.getOperand(0).getReg(); + Register SplatVal = MI.getOperand(1).getReg(); + + LLT VecTy = MRI.getType(Dst); + LLT XLenTy(STI.getXLenVT()); + + // Handle case of s64 element vectors on rv32 + if (XLenTy.getSizeInBits() == 32 && + VecTy.getElementType().getSizeInBits() == 64) { + auto [_, VL] = buildDefaultVLOps(Dst, MIB, MRI); + buildSplatSplitS64WithVL(Dst, MIB.buildUndef(VecTy), SplatVal, VL, MIB, + MRI); + MI.eraseFromParent(); + return true; + } + + // All-zeros or all-ones splats are handled specially. + MachineInstr &SplatValMI = *MRI.getVRegDef(SplatVal); + if (isAllOnesOrAllOnesSplat(SplatValMI, MRI)) { + auto VL = buildDefaultVLOps(VecTy, MIB, MRI).second; + MIB.buildInstr(RISCV::G_VMSET_VL, {Dst}, {VL}); + MI.eraseFromParent(); + return true; + } + if (isNullOrNullSplat(SplatValMI, MRI)) { + auto VL = buildDefaultVLOps(VecTy, MIB, MRI).second; + MIB.buildInstr(RISCV::G_VMCLR_VL, {Dst}, {VL}); + MI.eraseFromParent(); + return true; + } + // Handle non-constant mask splat (i.e. not sure if it's all zeros or all + // ones) by promoting it to an s8 splat. + LLT InterEltTy = LLT::scalar(8); + LLT InterTy = VecTy.changeElementType(InterEltTy); + auto ZExtSplatVal = MIB.buildZExt(InterEltTy, SplatVal); + auto And = + MIB.buildAnd(InterEltTy, ZExtSplatVal, MIB.buildConstant(InterEltTy, 1)); + auto LHS = MIB.buildSplatVector(InterTy, And); + auto ZeroSplat = + MIB.buildSplatVector(InterTy, MIB.buildConstant(InterEltTy, 0)); + MIB.buildICmp(CmpInst::Predicate::ICMP_NE, Dst, LHS, ZeroSplat); MI.eraseFromParent(); return true; } @@ -640,6 +804,12 @@ bool RISCVLegalizerInfo::legalizeCustom( return legalizeVAStart(MI, MIRBuilder); case TargetOpcode::G_VSCALE: return legalizeVScale(MI, MIRBuilder); + case TargetOpcode::G_ZEXT: + case TargetOpcode::G_SEXT: + case TargetOpcode::G_ANYEXT: + return legalizeExt(MI, MIRBuilder); + case TargetOpcode::G_SPLAT_VECTOR: + return legalizeSplatVector(MI, MIRBuilder); } llvm_unreachable("expected switch to return"); |