forked from OSchip/llvm-project
[MIPS GlobalISel] Select count trailing zeros
llvm.cttz.<type> intrinsic has additional i1 argument is_zero_undef, it tells whether zero as the first argument produces a defined result. G_CTTZ is generated from llvm.cttz.<type> (<type> <src>, i1 false) intrinsics, clang generates these intrinsics from __builtin_ctz and __builtin_ctzll. G_CTTZ_ZERO_UNDEF comes from llvm.cttz.<type> (<type> <src>, i1 true). Clang generates such intrinsics as parts of expansion of builtin_ffs and builtin_ffsll. It is also traditionally part of and many algorithms that are now predicated on avoiding zero-value inputs. Add narrow scalar (algorithm uses G_CTTZ_ZERO_UNDEF) for G_CTTZ. Lower G_CTTZ and G_CTTZ_ZERO_UNDEF for MIPS32. Differential Revision: https://reviews.llvm.org/D73215
This commit is contained in:
Petar Avramovic
parent
2b66d32f3f
commit
8bc7ba5b9e
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@ -242,6 +242,7 @@ public:
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LegalizeResult narrowScalarExt(MachineInstr &MI, unsigned TypeIdx, LLT Ty);
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LegalizeResult narrowScalarSelect(MachineInstr &MI, unsigned TypeIdx, LLT Ty);
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LegalizeResult narrowScalarCTLZ(MachineInstr &MI, unsigned TypeIdx, LLT Ty);
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LegalizeResult narrowScalarCTTZ(MachineInstr &MI, unsigned TypeIdx, LLT Ty);
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LegalizeResult lowerBitcast(MachineInstr &MI);
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LegalizeResult lowerBitCount(MachineInstr &MI, unsigned TypeIdx, LLT Ty);
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@ -981,6 +981,8 @@ LegalizerHelper::LegalizeResult LegalizerHelper::narrowScalar(MachineInstr &MI,
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switch (MI.getOpcode()) {
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case TargetOpcode::G_CTLZ:
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return narrowScalarCTLZ(MI, TypeIdx, NarrowTy);
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case TargetOpcode::G_CTTZ:
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return narrowScalarCTTZ(MI, TypeIdx, NarrowTy);
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default:
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return UnableToLegalize;
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}
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@ -3885,6 +3887,37 @@ LegalizerHelper::narrowScalarCTLZ(MachineInstr &MI, unsigned TypeIdx,
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return UnableToLegalize;
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}
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LegalizerHelper::LegalizeResult
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LegalizerHelper::narrowScalarCTTZ(MachineInstr &MI, unsigned TypeIdx,
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LLT NarrowTy) {
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if (TypeIdx != 1)
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return UnableToLegalize;
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LLT SrcTy = MRI.getType(MI.getOperand(1).getReg());
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unsigned NarrowSize = NarrowTy.getSizeInBits();
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if (SrcTy.isScalar() && SrcTy.getSizeInBits() == 2 * NarrowSize) {
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MachineIRBuilder &B = MIRBuilder;
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auto UnmergeSrc = B.buildUnmerge(NarrowTy, MI.getOperand(1));
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// cttz(Hi:Lo) -> Lo == 0 ? (cttz(Hi) + NarrowSize) : cttz(Lo)
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auto C_0 = B.buildConstant(NarrowTy, 0);
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auto LoIsZero = B.buildICmp(CmpInst::ICMP_EQ, LLT::scalar(1),
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UnmergeSrc.getReg(0), C_0);
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auto HiCTTZ = B.buildCTTZ(NarrowTy, UnmergeSrc.getReg(1));
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auto C_NarrowSize = B.buildConstant(NarrowTy, NarrowSize);
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auto LoIsZeroCTTZ = B.buildAdd(NarrowTy, HiCTTZ, C_NarrowSize);
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auto LoCTTZ = B.buildCTTZ_ZERO_UNDEF(NarrowTy, UnmergeSrc.getReg(0));
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auto LoOut = B.buildSelect(NarrowTy, LoIsZero, LoIsZeroCTTZ, LoCTTZ);
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B.buildMerge(MI.getOperand(0), {LoOut.getReg(0), C_0.getReg(0)});
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MI.eraseFromParent();
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return Legalized;
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}
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return UnableToLegalize;
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}
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LegalizerHelper::LegalizeResult
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LegalizerHelper::lowerBitCount(MachineInstr &MI, unsigned TypeIdx, LLT Ty) {
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unsigned Opc = MI.getOpcode();
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@ -208,6 +208,12 @@ MipsLegalizerInfo::MipsLegalizerInfo(const MipsSubtarget &ST) {
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getActionDefinitionsBuilder(G_CTLZ_ZERO_UNDEF)
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.lowerFor({{s32, s32}});
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getActionDefinitionsBuilder(G_CTTZ)
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.lowerFor({{s32, s32}})
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.maxScalar(1, s32);
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getActionDefinitionsBuilder(G_CTTZ_ZERO_UNDEF)
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.lowerFor({{s32, s32}, {s64, s64}});
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// FP instructions
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getActionDefinitionsBuilder(G_FCONSTANT)
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.legalFor({s32, s64});
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@ -0,0 +1,175 @@
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# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
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# RUN: llc -O0 -mtriple=mipsel-linux-gnu -run-pass=legalizer -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=MIPS32
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---
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name: cttz_i32
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alignment: 4
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tracksRegLiveness: true
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body: |
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bb.1.entry:
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liveins: $a0
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; MIPS32-LABEL: name: cttz_i32
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; MIPS32: liveins: $a0
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; MIPS32: [[COPY:%[0-9]+]]:_(s32) = COPY $a0
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; MIPS32: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 -1
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; MIPS32: [[XOR:%[0-9]+]]:_(s32) = G_XOR [[COPY]], [[C]]
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; MIPS32: [[ADD:%[0-9]+]]:_(s32) = G_ADD [[COPY]], [[C]]
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; MIPS32: [[AND:%[0-9]+]]:_(s32) = G_AND [[XOR]], [[ADD]]
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; MIPS32: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 32
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; MIPS32: [[CTLZ:%[0-9]+]]:_(s32) = G_CTLZ [[AND]](s32)
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; MIPS32: [[SUB:%[0-9]+]]:_(s32) = G_SUB [[C1]], [[CTLZ]]
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; MIPS32: $v0 = COPY [[SUB]](s32)
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; MIPS32: RetRA implicit $v0
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%0:_(s32) = COPY $a0
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%1:_(s32) = G_CTTZ %0(s32)
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$v0 = COPY %1(s32)
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RetRA implicit $v0
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...
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---
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name: cttz_i64
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alignment: 4
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tracksRegLiveness: true
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body: |
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bb.1.entry:
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liveins: $a0, $a1
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; MIPS32-LABEL: name: cttz_i64
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; MIPS32: liveins: $a0, $a1
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; MIPS32: [[COPY:%[0-9]+]]:_(s32) = COPY $a0
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; MIPS32: [[COPY1:%[0-9]+]]:_(s32) = COPY $a1
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; MIPS32: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
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; MIPS32: [[ICMP:%[0-9]+]]:_(s32) = G_ICMP intpred(eq), [[COPY]](s32), [[C]]
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; MIPS32: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 -1
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; MIPS32: [[XOR:%[0-9]+]]:_(s32) = G_XOR [[COPY1]], [[C1]]
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; MIPS32: [[ADD:%[0-9]+]]:_(s32) = G_ADD [[COPY1]], [[C1]]
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; MIPS32: [[AND:%[0-9]+]]:_(s32) = G_AND [[XOR]], [[ADD]]
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; MIPS32: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 32
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; MIPS32: [[CTLZ:%[0-9]+]]:_(s32) = G_CTLZ [[AND]](s32)
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; MIPS32: [[SUB:%[0-9]+]]:_(s32) = G_SUB [[C2]], [[CTLZ]]
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; MIPS32: [[ADD1:%[0-9]+]]:_(s32) = G_ADD [[SUB]], [[C2]]
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; MIPS32: [[XOR1:%[0-9]+]]:_(s32) = G_XOR [[COPY]], [[C1]]
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; MIPS32: [[ADD2:%[0-9]+]]:_(s32) = G_ADD [[COPY]], [[C1]]
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; MIPS32: [[AND1:%[0-9]+]]:_(s32) = G_AND [[XOR1]], [[ADD2]]
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; MIPS32: [[CTLZ1:%[0-9]+]]:_(s32) = G_CTLZ [[AND1]](s32)
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; MIPS32: [[SUB1:%[0-9]+]]:_(s32) = G_SUB [[C2]], [[CTLZ1]]
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; MIPS32: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
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; MIPS32: [[COPY2:%[0-9]+]]:_(s32) = COPY [[ICMP]](s32)
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; MIPS32: [[AND2:%[0-9]+]]:_(s32) = G_AND [[COPY2]], [[C3]]
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; MIPS32: [[SELECT:%[0-9]+]]:_(s32) = G_SELECT [[AND2]](s32), [[ADD1]], [[SUB1]]
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; MIPS32: $v0 = COPY [[SELECT]](s32)
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; MIPS32: $v1 = COPY [[C]](s32)
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; MIPS32: RetRA implicit $v0, implicit $v1
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%1:_(s32) = COPY $a0
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%2:_(s32) = COPY $a1
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%0:_(s64) = G_MERGE_VALUES %1(s32), %2(s32)
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%3:_(s64) = G_CTTZ %0(s64)
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%4:_(s32), %5:_(s32) = G_UNMERGE_VALUES %3(s64)
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$v0 = COPY %4(s32)
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$v1 = COPY %5(s32)
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RetRA implicit $v0, implicit $v1
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...
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---
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name: ffs_i32_expansion
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alignment: 4
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tracksRegLiveness: true
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body: |
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bb.1.entry:
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liveins: $a0
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; MIPS32-LABEL: name: ffs_i32_expansion
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; MIPS32: liveins: $a0
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; MIPS32: [[COPY:%[0-9]+]]:_(s32) = COPY $a0
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; MIPS32: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
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; MIPS32: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
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; MIPS32: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 -1
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; MIPS32: [[XOR:%[0-9]+]]:_(s32) = G_XOR [[COPY]], [[C2]]
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; MIPS32: [[ADD:%[0-9]+]]:_(s32) = G_ADD [[COPY]], [[C2]]
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; MIPS32: [[AND:%[0-9]+]]:_(s32) = G_AND [[XOR]], [[ADD]]
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; MIPS32: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 32
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; MIPS32: [[CTLZ:%[0-9]+]]:_(s32) = G_CTLZ [[AND]](s32)
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; MIPS32: [[SUB:%[0-9]+]]:_(s32) = G_SUB [[C3]], [[CTLZ]]
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; MIPS32: [[ADD1:%[0-9]+]]:_(s32) = nuw nsw G_ADD [[SUB]], [[C]]
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; MIPS32: [[ICMP:%[0-9]+]]:_(s32) = G_ICMP intpred(eq), [[COPY]](s32), [[C1]]
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; MIPS32: [[COPY1:%[0-9]+]]:_(s32) = COPY [[ICMP]](s32)
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; MIPS32: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C]]
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; MIPS32: [[SELECT:%[0-9]+]]:_(s32) = G_SELECT [[AND1]](s32), [[C1]], [[ADD1]]
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; MIPS32: $v0 = COPY [[SELECT]](s32)
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; MIPS32: RetRA implicit $v0
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%0:_(s32) = COPY $a0
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%2:_(s32) = G_CONSTANT i32 1
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%4:_(s32) = G_CONSTANT i32 0
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%1:_(s32) = G_CTTZ_ZERO_UNDEF %0(s32)
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%3:_(s32) = nuw nsw G_ADD %1, %2
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%5:_(s1) = G_ICMP intpred(eq), %0(s32), %4
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%6:_(s32) = G_SELECT %5(s1), %4, %3
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$v0 = COPY %6(s32)
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RetRA implicit $v0
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...
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---
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name: ffs_i64_expansion
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alignment: 4
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tracksRegLiveness: true
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body: |
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bb.1.entry:
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liveins: $a0, $a1
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; MIPS32-LABEL: name: ffs_i64_expansion
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; MIPS32: liveins: $a0, $a1
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; MIPS32: [[COPY:%[0-9]+]]:_(s32) = COPY $a0
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; MIPS32: [[COPY1:%[0-9]+]]:_(s32) = COPY $a1
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; MIPS32: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
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; MIPS32: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
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; MIPS32: [[MV:%[0-9]+]]:_(s64) = G_MERGE_VALUES [[C1]](s32), [[C1]](s32)
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; MIPS32: [[ICMP:%[0-9]+]]:_(s32) = G_ICMP intpred(eq), [[COPY]](s32), [[C1]]
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; MIPS32: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 -1
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; MIPS32: [[XOR:%[0-9]+]]:_(s32) = G_XOR [[COPY1]], [[C2]]
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; MIPS32: [[ADD:%[0-9]+]]:_(s32) = G_ADD [[COPY1]], [[C2]]
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; MIPS32: [[AND:%[0-9]+]]:_(s32) = G_AND [[XOR]], [[ADD]]
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; MIPS32: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 32
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; MIPS32: [[CTLZ:%[0-9]+]]:_(s32) = G_CTLZ [[AND]](s32)
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; MIPS32: [[SUB:%[0-9]+]]:_(s32) = G_SUB [[C3]], [[CTLZ]]
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; MIPS32: [[ADD1:%[0-9]+]]:_(s32) = G_ADD [[SUB]], [[C3]]
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; MIPS32: [[XOR1:%[0-9]+]]:_(s32) = G_XOR [[COPY]], [[C2]]
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; MIPS32: [[ADD2:%[0-9]+]]:_(s32) = G_ADD [[COPY]], [[C2]]
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; MIPS32: [[AND1:%[0-9]+]]:_(s32) = G_AND [[XOR1]], [[ADD2]]
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; MIPS32: [[CTLZ1:%[0-9]+]]:_(s32) = G_CTLZ [[AND1]](s32)
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; MIPS32: [[SUB1:%[0-9]+]]:_(s32) = G_SUB [[C3]], [[CTLZ1]]
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; MIPS32: [[COPY2:%[0-9]+]]:_(s32) = COPY [[ICMP]](s32)
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; MIPS32: [[AND2:%[0-9]+]]:_(s32) = G_AND [[COPY2]], [[C]]
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; MIPS32: [[SELECT:%[0-9]+]]:_(s32) = G_SELECT [[AND2]](s32), [[ADD1]], [[SUB1]]
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; MIPS32: [[ADD3:%[0-9]+]]:_(s32) = G_ADD [[SELECT]], [[C]]
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; MIPS32: [[ICMP1:%[0-9]+]]:_(s32) = G_ICMP intpred(ult), [[ADD3]](s32), [[C]]
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; MIPS32: [[ADD4:%[0-9]+]]:_(s32) = G_ADD [[C1]], [[C1]]
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; MIPS32: [[COPY3:%[0-9]+]]:_(s32) = COPY [[ICMP1]](s32)
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; MIPS32: [[AND3:%[0-9]+]]:_(s32) = G_AND [[COPY3]], [[C]]
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; MIPS32: [[ADD5:%[0-9]+]]:_(s32) = G_ADD [[ADD4]], [[AND3]]
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; MIPS32: [[MV1:%[0-9]+]]:_(s64) = G_MERGE_VALUES [[ADD3]](s32), [[ADD5]](s32)
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; MIPS32: [[XOR2:%[0-9]+]]:_(s32) = G_XOR [[COPY]], [[C1]]
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; MIPS32: [[XOR3:%[0-9]+]]:_(s32) = G_XOR [[COPY1]], [[C1]]
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; MIPS32: [[OR:%[0-9]+]]:_(s32) = G_OR [[XOR2]], [[XOR3]]
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; MIPS32: [[ICMP2:%[0-9]+]]:_(s32) = G_ICMP intpred(eq), [[OR]](s32), [[C1]]
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; MIPS32: [[COPY4:%[0-9]+]]:_(s32) = COPY [[ICMP2]](s32)
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; MIPS32: [[AND4:%[0-9]+]]:_(s32) = G_AND [[COPY4]], [[C]]
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; MIPS32: [[SELECT1:%[0-9]+]]:_(s64) = G_SELECT [[AND4]](s32), [[MV]], [[MV1]]
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; MIPS32: [[UV:%[0-9]+]]:_(s32), [[UV1:%[0-9]+]]:_(s32) = G_UNMERGE_VALUES [[SELECT1]](s64)
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; MIPS32: $v0 = COPY [[UV]](s32)
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; MIPS32: $v1 = COPY [[UV1]](s32)
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; MIPS32: RetRA implicit $v0, implicit $v1
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%1:_(s32) = COPY $a0
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%2:_(s32) = COPY $a1
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%0:_(s64) = G_MERGE_VALUES %1(s32), %2(s32)
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%4:_(s64) = G_CONSTANT i64 1
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%6:_(s64) = G_CONSTANT i64 0
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%3:_(s64) = G_CTTZ_ZERO_UNDEF %0(s64)
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%5:_(s64) = nuw nsw G_ADD %3, %4
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%7:_(s1) = G_ICMP intpred(eq), %0(s64), %6
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%8:_(s64) = G_SELECT %7(s1), %6, %5
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%9:_(s32), %10:_(s32) = G_UNMERGE_VALUES %8(s64)
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$v0 = COPY %9(s32)
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$v1 = COPY %10(s32)
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RetRA implicit $v0, implicit $v1
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...
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@ -0,0 +1,116 @@
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; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
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; RUN: llc -O0 -mtriple=mipsel-linux-gnu -global-isel -verify-machineinstrs %s -o -| FileCheck %s -check-prefixes=MIPS32
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define i32 @cttz_i32(i32 %a) {
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; MIPS32-LABEL: cttz_i32:
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; MIPS32: # %bb.0: # %entry
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; MIPS32-NEXT: not $1, $4
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; MIPS32-NEXT: addiu $2, $4, -1
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; MIPS32-NEXT: and $1, $1, $2
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; MIPS32-NEXT: ori $2, $zero, 32
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; MIPS32-NEXT: clz $1, $1
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; MIPS32-NEXT: subu $2, $2, $1
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; MIPS32-NEXT: jr $ra
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; MIPS32-NEXT: nop
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entry:
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%0 = call i32 @llvm.cttz.i32(i32 %a, i1 false)
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ret i32 %0
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}
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declare i32 @llvm.cttz.i32(i32, i1 immarg)
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define i64 @cttz_i64(i64 %a) {
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; MIPS32-LABEL: cttz_i64:
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; MIPS32: # %bb.0: # %entry
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; MIPS32-NEXT: ori $3, $zero, 0
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; MIPS32-NEXT: sltiu $1, $4, 1
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; MIPS32-NEXT: not $2, $5
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; MIPS32-NEXT: addiu $5, $5, -1
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; MIPS32-NEXT: and $2, $2, $5
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; MIPS32-NEXT: ori $5, $zero, 32
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; MIPS32-NEXT: clz $2, $2
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; MIPS32-NEXT: subu $2, $5, $2
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; MIPS32-NEXT: addiu $2, $2, 32
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; MIPS32-NEXT: not $6, $4
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; MIPS32-NEXT: addiu $4, $4, -1
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; MIPS32-NEXT: and $4, $6, $4
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; MIPS32-NEXT: clz $4, $4
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; MIPS32-NEXT: subu $4, $5, $4
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; MIPS32-NEXT: andi $1, $1, 1
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; MIPS32-NEXT: movn $4, $2, $1
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; MIPS32-NEXT: move $2, $4
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; MIPS32-NEXT: jr $ra
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; MIPS32-NEXT: nop
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entry:
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%0 = call i64 @llvm.cttz.i64(i64 %a, i1 false)
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ret i64 %0
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}
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declare i64 @llvm.cttz.i64(i64, i1 immarg)
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define i32 @ffs_i32_expansion(i32 %a) {
|
||||
; MIPS32-LABEL: ffs_i32_expansion:
|
||||
; MIPS32: # %bb.0: # %entry
|
||||
; MIPS32-NEXT: ori $1, $zero, 0
|
||||
; MIPS32-NEXT: not $2, $4
|
||||
; MIPS32-NEXT: addiu $3, $4, -1
|
||||
; MIPS32-NEXT: and $2, $2, $3
|
||||
; MIPS32-NEXT: ori $3, $zero, 32
|
||||
; MIPS32-NEXT: clz $2, $2
|
||||
; MIPS32-NEXT: subu $2, $3, $2
|
||||
; MIPS32-NEXT: addiu $2, $2, 1
|
||||
; MIPS32-NEXT: sltiu $3, $4, 1
|
||||
; MIPS32-NEXT: andi $3, $3, 1
|
||||
; MIPS32-NEXT: movn $2, $1, $3
|
||||
; MIPS32-NEXT: jr $ra
|
||||
; MIPS32-NEXT: nop
|
||||
entry:
|
||||
%0 = call i32 @llvm.cttz.i32(i32 %a, i1 true)
|
||||
%1 = add nuw nsw i32 %0, 1
|
||||
%iszero = icmp eq i32 %a, 0
|
||||
%ffs = select i1 %iszero, i32 0, i32 %1
|
||||
ret i32 %ffs
|
||||
}
|
||||
|
||||
define i64 @ffs_i64_expansion(i64 %a) {
|
||||
; MIPS32-LABEL: ffs_i64_expansion:
|
||||
; MIPS32: # %bb.0: # %entry
|
||||
; MIPS32-NEXT: ori $1, $zero, 1
|
||||
; MIPS32-NEXT: ori $2, $zero, 0
|
||||
; MIPS32-NEXT: sltiu $3, $4, 1
|
||||
; MIPS32-NEXT: not $6, $5
|
||||
; MIPS32-NEXT: addiu $7, $5, -1
|
||||
; MIPS32-NEXT: and $6, $6, $7
|
||||
; MIPS32-NEXT: ori $7, $zero, 32
|
||||
; MIPS32-NEXT: clz $6, $6
|
||||
; MIPS32-NEXT: subu $6, $7, $6
|
||||
; MIPS32-NEXT: addiu $6, $6, 32
|
||||
; MIPS32-NEXT: not $8, $4
|
||||
; MIPS32-NEXT: addiu $9, $4, -1
|
||||
; MIPS32-NEXT: and $8, $8, $9
|
||||
; MIPS32-NEXT: clz $8, $8
|
||||
; MIPS32-NEXT: subu $7, $7, $8
|
||||
; MIPS32-NEXT: andi $3, $3, 1
|
||||
; MIPS32-NEXT: movn $7, $6, $3
|
||||
; MIPS32-NEXT: addiu $3, $7, 1
|
||||
; MIPS32-NEXT: sltu $1, $3, $1
|
||||
; MIPS32-NEXT: addiu $6, $2, 0
|
||||
; MIPS32-NEXT: andi $1, $1, 1
|
||||
; MIPS32-NEXT: addu $1, $6, $1
|
||||
; MIPS32-NEXT: xori $4, $4, 0
|
||||
; MIPS32-NEXT: xori $5, $5, 0
|
||||
; MIPS32-NEXT: or $4, $4, $5
|
||||
; MIPS32-NEXT: sltiu $4, $4, 1
|
||||
; MIPS32-NEXT: andi $4, $4, 1
|
||||
; MIPS32-NEXT: movn $3, $2, $4
|
||||
; MIPS32-NEXT: movn $1, $2, $4
|
||||
; MIPS32-NEXT: move $2, $3
|
||||
; MIPS32-NEXT: move $3, $1
|
||||
; MIPS32-NEXT: jr $ra
|
||||
; MIPS32-NEXT: nop
|
||||
entry:
|
||||
%0 = call i64 @llvm.cttz.i64(i64 %a, i1 true)
|
||||
%1 = add nuw nsw i64 %0, 1
|
||||
%iszero = icmp eq i64 %a, 0
|
||||
%ffs = select i1 %iszero, i64 0, i64 %1
|
||||
ret i64 %ffs
|
||||
}
|
||||
Loading…
Reference in New Issue