[mips][micromips] Initial support for micrmomips DSP instructions and addu.qb implementation

[zoran.jovanovic]

Test files renamed and changed usage of predicates.

[dsanders]

LGTM with a few nits.

I noticed you don't actually use DSPR3 yet but I expect will change in the next few patches.

lib/Target/Mips/MicroMipsDSPInstrFormats.td

1–2

Unfortunately, this has to be a single line and we have to fit into 80 cols as well. The '-*- tablegen -*-' is used by editors to configure for the specified language.

The 'Micromips DSP' part is probably the best bit to remove.

13

HasDSP is not an encoding predicate, it belongs in InsnPredicates.

lib/Target/Mips/MipsSEISelLowering.cpp

935–936

!hasDSPR3() is redundant here. The predicates are cumulative so you have have DSPR3 without also having DSPR2.

948–949

!hasDSPR3() is redundant here. The predicates are cumulative so you have have DSPR3 without also having DSPR2.

lib/Target/Mips/AsmParser/MipsAsmParser.cpp

bool hasMips32r6() const {
     return STI.getFeatureBits()[Mips::FeatureMips32r6];
   }
   bool hasMips64r6() const {
     return STI.getFeatureBits()[Mips::FeatureMips64r6];
   }
 
   bool hasDSP() const { return STI.getFeatureBits()[Mips::FeatureDSP]; }
   bool hasDSPR2() const { return STI.getFeatureBits()[Mips::FeatureDSPR2]; }
+  bool hasDSPR3() const { return STI.getFeatureBits()[Mips::FeatureDSPR3]; }
   bool hasMSA() const { return STI.getFeatureBits()[Mips::FeatureMSA]; }
   bool hasCnMips() const {
     return (STI.getFeatureBits()[Mips::FeatureCnMips]);
   }
 
   bool inPicMode() {
     return IsPicEnabled;
   }

lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp

if (isMicroMips(STI)) {
     if (isMips32r6(STI)) {
       NewOpcode = Mips::MipsR62MicroMipsR6(Opcode, Mips::Arch_micromipsr6);
       if (NewOpcode == -1)
         NewOpcode = Mips::Std2MicroMipsR6(Opcode, Mips::Arch_micromipsr6);
     }
     else
       NewOpcode = Mips::Std2MicroMips(Opcode, Mips::Arch_micromips);
 
+    // Check whether it is Dsp instruction.
+    if (NewOpcode == -1)
+      NewOpcode = Mips::Dsp2MicroMips(Opcode, Mips::Arch_mmdsp);
+
     if (NewOpcode != -1) {
       if (Fixups.size() > N)
         Fixups.pop_back();
 
       Opcode = NewOpcode;
       TmpInst.setOpcode (NewOpcode);
       Binary = getBinaryCodeForInstr(TmpInst, Fixups, STI);
     }

lib/Target/Mips/MicroMipsDSPInstrFormats.td

+//===-- MicroMipsDSPInstrFormats.td - Micromips DSP Instruction Formats -*-
+//tablegen -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+class MMDSPInst<string opstr = "">
+    : MipsInst<(outs), (ins), "", [], NoItinerary, FrmOther>, PredicateControl {
+  let EncodingPredicates = [HasDSP];
+  string BaseOpcode = opstr;
+  string Arch = "mmdsp";
+  let DecoderNamespace = "MicroMips";
+}
+
+class POOL32A_3R_FMT<bits<11> op> : MMDSPInst {
+  bits<5> rd;
+  bits<5> rs;
+  bits<5> rt;
+
+  let Inst{31-26} = 0b000000;
+  let Inst{25-21} = rt;
+  let Inst{20-16} = rs;
+  let Inst{15-11} = rd;
+  let Inst{10-0}  = op;
+}

lib/Target/Mips/MicroMipsDSPInstrInfo.td

+//===- MicroMipsDSPInstrInfo.td - Micromips DSP instructions -*- tablegen *-=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file describes MicroMips DSP instructions.
+//
+//===----------------------------------------------------------------------===//
+
+// Instruction encoding.
+class ADDU_QB_MM_ENC : POOL32A_3R_FMT<0b00011001101>;
+
+// Instruction defs.
+// MIPS DSP Rev 1
+def ADDU_QB_MM : DspMMRel, ADDU_QB_MM_ENC, ADDU_QB_DESC, ISA_MICROMIPS;

lib/Target/Mips/Mips.td

def FeatureMips64r6    : SubtargetFeature<"mips64r6", "MipsArchVersion",
                                  FeatureNaN2008]>;
 
 def FeatureMips16  : SubtargetFeature<"mips16", "InMips16Mode", "true",
                                       "Mips16 mode">;
 
 def FeatureDSP : SubtargetFeature<"dsp", "HasDSP", "true", "Mips DSP ASE">;
 def FeatureDSPR2 : SubtargetFeature<"dspr2", "HasDSPR2", "true",
                                     "Mips DSP-R2 ASE", [FeatureDSP]>;
+def FeatureDSPR3
+    : SubtargetFeature<"dspr3", "HasDSPR3", "true", "Mips DSP-R3 ASE",
+                       [ FeatureDSP, FeatureDSPR2 ]>;
 
 def FeatureMSA : SubtargetFeature<"msa", "HasMSA", "true", "Mips MSA ASE">;
 
 def FeatureEVA : SubtargetFeature<"eva", "HasEVA", "true", "Mips EVA ASE">;
 
 def FeatureMicroMips  : SubtargetFeature<"micromips", "InMicroMipsMode", "true",
                                          "microMips mode">;
 

lib/Target/Mips/MipsDSPInstrFormats.td

 //===- MipsDSPInstrFormats.td - Mips Instruction Formats ---*- tablegen -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
+class DspMMRel;
+
+def Dsp2MicroMips : InstrMapping {
+  let FilterClass = "DspMMRel";
+  // Instructions with the same BaseOpcode and isNVStore values form a row.
+  let RowFields = ["BaseOpcode"];
+  // Instructions with the same predicate sense form a column.
+  let ColFields = ["Arch"];
+  // The key column is the unpredicated instructions.
+  let KeyCol = ["dsp"];
+  // Value columns are PredSense=true and PredSense=false
+  let ValueCols = [["dsp"], ["mmdsp"]];
+}
+
 def HasDSP : Predicate<"Subtarget->hasDSP()">,
              AssemblerPredicate<"FeatureDSP">;
 def HasDSPR2 : Predicate<"Subtarget->hasDSPR2()">,
                AssemblerPredicate<"FeatureDSPR2">;
+def HasDSPR3 : Predicate<"Subtarget->hasDSPR3()">,
+               AssemblerPredicate<"FeatureDSPR3">;
 
 // Fields.
 class Field6<bits<6> val> {
   bits<6> V = val;
 }
 
 def SPECIAL3_OPCODE : Field6<0b011111>;
 def REGIMM_OPCODE : Field6<0b000001>;
 
-class DSPInst : MipsInst<(outs), (ins), "", [], NoItinerary, FrmOther> {
+class DSPInst<string opstr = "">
+    : MipsInst<(outs), (ins), "", [], NoItinerary, FrmOther> {
   let Predicates = [HasDSP];
+  string BaseOpcode = opstr;
+  string Arch = "dsp";
 }
 
 class PseudoDSP<dag outs, dag ins, list<dag> pattern,
                 InstrItinClass itin = IIPseudo>:
   MipsPseudo<outs, ins, pattern, itin> {
   let Predicates = [HasDSP];
 }
 

lib/Target/Mips/MipsDSPInstrInfo.td

class PREPEND_DESC : APPEND_DESC_BASE<"prepend", int_mips_prepend, immZExt5,
                                       NoItinerary>;
 
 // Pseudos.
 def BPOSGE32_PSEUDO : BPOSGE32_PSEUDO_DESC_BASE<int_mips_bposge32,
                                                 NoItinerary>, Uses<[DSPPos]>;
 
 // Instruction defs.
 // MIPS DSP Rev 1
-def ADDU_QB : ADDU_QB_ENC, ADDU_QB_DESC;
+def ADDU_QB : DspMMRel, ADDU_QB_ENC, ADDU_QB_DESC;
 def ADDU_S_QB : ADDU_S_QB_ENC, ADDU_S_QB_DESC;
 def SUBU_QB : SUBU_QB_ENC, SUBU_QB_DESC;
 def SUBU_S_QB : SUBU_S_QB_ENC, SUBU_S_QB_DESC;
 def ADDQ_PH : ADDQ_PH_ENC, ADDQ_PH_DESC;
 def ADDQ_S_PH : ADDQ_S_PH_ENC, ADDQ_S_PH_DESC;
 def SUBQ_PH : SUBQ_PH_ENC, SUBQ_PH_DESC;
 def SUBQ_S_PH : SUBQ_S_PH_ENC, SUBQ_S_PH_DESC;
 def ADDQ_S_W : ADDQ_S_W_ENC, ADDQ_S_W_DESC;

lib/Target/Mips/MipsInstrInfo.td

 
 // Micromips r6
 include "MicroMips32r6InstrFormats.td"
 include "MicroMips32r6InstrInfo.td"
 
 // Micromips64 r6
 include "MicroMips64r6InstrFormats.td"
 include "MicroMips64r6InstrInfo.td"
+
+// Micromips DSP
+include "MicroMipsDSPInstrFormats.td"
+include "MicroMipsDSPInstrInfo.td"

lib/Target/Mips/MipsSEISelLowering.cpp

if (Op0->getOpcode() == ISD::SHL && Op1 == Op0->getOperand(1)) {
                           Op0Op0->getOperand(2) };
         return DAG.getNode(MipsISD::VEXTRACT_SEXT_ELT, SDLoc(Op0Op0),
                            Op0Op0->getVTList(),
                            makeArrayRef(Ops, Op0Op0->getNumOperands()));
       }
     }
   }
 
-  if ((Ty != MVT::v2i16) && ((Ty != MVT::v4i8) || !Subtarget.hasDSPR2()))
+  if ((Ty != MVT::v2i16) && ((Ty != MVT::v4i8) || (!Subtarget.hasDSPR2() &&
+                                                   !Subtarget.hasDSPR3())))
     return SDValue();
 
   return performDSPShiftCombine(MipsISD::SHRA_DSP, N, Ty, DAG, Subtarget);
 }
 
 
 static SDValue performSRLCombine(SDNode *N, SelectionDAG &DAG,
                                  TargetLowering::DAGCombinerInfo &DCI,
                                  const MipsSubtarget &Subtarget) {
   EVT Ty = N->getValueType(0);
 
-  if (((Ty != MVT::v2i16) || !Subtarget.hasDSPR2()) && (Ty != MVT::v4i8))
+  if (((Ty != MVT::v2i16) || (!Subtarget.hasDSPR2() &&
+                              !Subtarget.hasDSPR3())) && (Ty != MVT::v4i8))
     return SDValue();
 
   return performDSPShiftCombine(MipsISD::SHRL_DSP, N, Ty, DAG, Subtarget);
 }
 
 static bool isLegalDSPCondCode(EVT Ty, ISD::CondCode CC) {
   bool IsV216 = (Ty == MVT::v2i16);
 

lib/Target/Mips/MipsSubtarget.h

class MipsSubtarget : public MipsGenSubtargetInfo {
   bool InMips16HardFloat;
 
   // PreviousInMips16 -- the function we just processed was in Mips 16 Mode
   bool PreviousInMips16Mode;
 
   // InMicroMips -- can process MicroMips instructions
   bool InMicroMipsMode;
 
-  // HasDSP, HasDSPR2 -- supports DSP ASE.
-  bool HasDSP, HasDSPR2;
+  // HasDSP, HasDSPR2, HasDSPR3 -- supports DSP ASE.
+  bool HasDSP, HasDSPR2, HasDSPR3;
 
   // Allow mixed Mips16 and Mips32 in one source file
   bool AllowMixed16_32;
 
   // Optimize for space by compiling all functions as Mips 16 unless
   // it needs floating point. Functions needing floating point are
   // compiled as Mips32
   bool Os16;
public:
   bool inMips16HardFloat() const {
     return inMips16Mode() && InMips16HardFloat;
   }
   bool inMicroMipsMode() const { return InMicroMipsMode; }
   bool inMicroMips32r6Mode() const { return InMicroMipsMode && hasMips32r6(); }
   bool inMicroMips64r6Mode() const { return InMicroMipsMode && hasMips64r6(); }
   bool hasDSP() const { return HasDSP; }
   bool hasDSPR2() const { return HasDSPR2; }
+  bool hasDSPR3() const { return HasDSPR3; }
   bool hasMSA() const { return HasMSA; }
   bool hasEVA() const { return HasEVA; }
   bool useSmallSection() const { return UseSmallSection; }
 
   bool hasStandardEncoding() const { return !inMips16Mode(); }
 
   bool useSoftFloat() const { return IsSoftFloat; }
 

lib/Target/Mips/MipsSubtarget.cpp

MipsSubtarget::MipsSubtarget(const Triple &TT, const std::string &CPU,
                              const MipsTargetMachine &TM)
     : MipsGenSubtargetInfo(TT, CPU, FS), MipsArchVersion(MipsDefault),
       IsLittle(little), IsSoftFloat(false), IsSingleFloat(false), IsFPXX(false),
       NoABICalls(false), IsFP64bit(false), UseOddSPReg(true),
       IsNaN2008bit(false), IsGP64bit(false), HasVFPU(false), HasCnMips(false),
       HasMips3_32(false), HasMips3_32r2(false), HasMips4_32(false),
       HasMips4_32r2(false), HasMips5_32r2(false), InMips16Mode(false),
       InMips16HardFloat(Mips16HardFloat), InMicroMipsMode(false), HasDSP(false),
-      HasDSPR2(false), AllowMixed16_32(Mixed16_32 | Mips_Os16), Os16(Mips_Os16),
-      HasMSA(false), UseTCCInDIV(false), HasEVA(false), TM(TM),
+      HasDSPR2(false), HasDSPR3(false), AllowMixed16_32(Mixed16_32 | Mips_Os16),
+      Os16(Mips_Os16), HasMSA(false), UseTCCInDIV(false), HasEVA(false), TM(TM),
       TargetTriple(TT), TSInfo(),
       InstrInfo(
           MipsInstrInfo::create(initializeSubtargetDependencies(CPU, FS, TM))),
       FrameLowering(MipsFrameLowering::create(*this)),
       TLInfo(MipsTargetLowering::create(TM, *this)) {
 
   PreviousInMips16Mode = InMips16Mode;
 

test/MC/Disassembler/Mips/micromips_dsp.txt

+# RUN: llvm-mc --disassemble %s -triple=mips-unknown-linux -mcpu=mips32r6 -mattr=micromips  -mattr=+dsp | FileCheck %s
+
+0x00 0xa4 0x18 0xcd # CHECK: addu.qb $3, $4, $5
+

test/MC/Mips/micromips32r6/micromips-dsp-instructions.s

+# RUN: llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips32r6 -mattr=micromips -mattr=+dsp | FileCheck %s
+
+  .set noat
+  addu.qb $3, $4, $5           # CHECK: addu.qb $3, $4, $5      # encoding: [0x00,0xa4,0x18,0xcd]
+