[mips][microMIPS] Implement SDBBP and RDHWR instructions

[jkolek]

Summary

Implement microMIPS SDBBP and RDHWR instructions.

[sstankovic]

lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp

91

gcc uses ".set mips32r2" here, even when compiled with --mmicromips.

lib/Target/Mips/MipsInstrInfo.td

1355

Is HasStdEnc needed here?

test/MC/Mips/micromips-control-instructions.s

79

sdbbp has integer operand (which I suppose defaults to 0 if omitted), so you should also test the case when operand is specified.

[sstankovic]

LGTM

[jkolek]

Closed by commit rL222347 (authored by @jkolek).

lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp

void MipsInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
   switch (MI->getOpcode()) {
   default:
     break;
   case Mips::RDHWR:
   case Mips::RDHWR64:
     O << "\t.set\tpush\n";
     O << "\t.set\tmips32r2\n";
     break;
+  case Mips::RDHWR_MM:
+    O << "\t.set\tpush\n";
+    O << "\t.set\tmicromips\n";
+    break;
   case Mips::Save16:
     O << "\tsave\t";
     printSaveRestore(MI, O);
     O << " # 16 bit inst\n";
     return;
   case Mips::SaveX16:
     O << "\tsave\t";
     printSaveRestore(MI, O);
if (!printAliasInstr(MI, O) && !printAlias(*MI, O))
     printInstruction(MI, O);
   printAnnotation(O, Annot);
 
   switch (MI->getOpcode()) {
   default:
     break;
   case Mips::RDHWR:
   case Mips::RDHWR64:
+  case Mips::RDHWR_MM:
     O << "\n\t.set\tpop";
   }
 }
 
 static void printExpr(const MCExpr *Expr, raw_ostream &OS) {
   int Offset = 0;
   const MCSymbolRefExpr *SRE;
 

lib/Target/Mips/MicroMipsInstrFormats.td

class BARRIER_FM_MM<bits<5> op> : MMArch {
 
   let Inst{31-26} = 0x0;
   let Inst{25-21} = 0x0;
   let Inst{20-16} = 0x0;
   let Inst{15-11} = op;
   let Inst{10-6}  = 0x0;
   let Inst{5-0}   = 0x0;
 }
+
+class SDBBP_FM_MM : MMArch {
+  bits<10> code_;
+
+  bits<32> Inst;
+
+  let Inst{31-26} = 0x0;
+  let Inst{25-16} = code_;
+  let Inst{15-6}  = 0x36d;
+  let Inst{5-0}   = 0x3c;
+}
+
+class RDHWR_FM_MM {
+  bits<5> rt;
+  bits<5> rd;
+
+  bits<32> Inst;
+
+  let Inst{31-26} = 0x0;
+  let Inst{25-21} = rt;
+  let Inst{20-16} = rd;
+  let Inst{15-6}  = 0x1ac;
+  let Inst{5-0}   = 0x3c;
+}

lib/Target/Mips/MicroMipsInstrInfo.td

let DecoderNamespace = "MicroMips", Predicates = [InMicroMips] in {
   def SSNOP_MM : MMRel, Barrier<"ssnop">, BARRIER_FM_MM<0x1>;
   def EHB_MM   : MMRel, Barrier<"ehb">, BARRIER_FM_MM<0x2>;
   def PAUSE_MM : MMRel, Barrier<"pause">, BARRIER_FM_MM<0x5>;
 
   def TLBP_MM : MMRel, TLB<"tlbp">, COP0_TLB_FM_MM<0x0d>;
   def TLBR_MM : MMRel, TLB<"tlbr">, COP0_TLB_FM_MM<0x4d>;
   def TLBWI_MM : MMRel, TLB<"tlbwi">, COP0_TLB_FM_MM<0x8d>;
   def TLBWR_MM : MMRel, TLB<"tlbwr">, COP0_TLB_FM_MM<0xcd>;
+
+  def SDBBP_MM : MMRel, SYS_FT<"sdbbp">, SDBBP_FM_MM;
+  def RDHWR_MM : ReadHardware<GPR32Opnd, HWRegsOpnd>, RDHWR_FM_MM;
 }
 
 //===----------------------------------------------------------------------===//
 // MicroMips instruction aliases
 //===----------------------------------------------------------------------===//
 
 let Predicates = [InMicroMips] in {
   def : MipsInstAlias<"wait", (WAIT_MM 0x0), 1>;
 }

lib/Target/Mips/MipsInstrInfo.td

 def TTLTIU : MMRel, TEQI_FT<"tltiu", GPR32Opnd>, TEQI_FM<0xb>,
            ISA_MIPS2_NOT_32R6_64R6;
 def TNEI : MMRel, TEQI_FT<"tnei", GPR32Opnd>, TEQI_FM<0xe>,
            ISA_MIPS2_NOT_32R6_64R6;
 
 def BREAK : MMRel, BRK_FT<"break">, BRK_FM<0xd>;
 def SYSCALL : MMRel, SYS_FT<"syscall">, SYS_FM<0xc>;
 def TRAP : TrapBase<BREAK>;
-def SDBBP : SYS_FT<"sdbbp">, SDBBP_FM, ISA_MIPS32_NOT_32R6_64R6;
+def SDBBP : MMRel, SYS_FT<"sdbbp">, SDBBP_FM, ISA_MIPS32_NOT_32R6_64R6;
 
 def ERET : MMRel, ER_FT<"eret">, ER_FM<0x18>, INSN_MIPS3_32;
 def DERET : MMRel, ER_FT<"deret">, ER_FM<0x1f>, ISA_MIPS32;
 
 def EI : MMRel, DEI_FT<"ei", GPR32Opnd>, EI_FM<1>, ISA_MIPS32R2;
 def DI : MMRel, DEI_FT<"di", GPR32Opnd>, EI_FM<0>, ISA_MIPS32R2;
 
 let EncodingPredicates = []<Predicate>, // FIXME: Lack of HasStdEnc is probably a bug
def PseudoMSUBU : MAddSubPseudo<MSUBU, MipsMSubu, II_MSUBU>,
                   ISA_MIPS32_NOT_32R6_64R6;
 }
 
 def PseudoSDIV : MultDivPseudo<SDIV, ACC64, GPR32Opnd, MipsDivRem, II_DIV,
                                0, 1, 1>, ISA_MIPS1_NOT_32R6_64R6;
 def PseudoUDIV : MultDivPseudo<UDIV, ACC64, GPR32Opnd, MipsDivRemU, II_DIVU,
                                0, 1, 1>, ISA_MIPS1_NOT_32R6_64R6;
 
+let AdditionalPredicates = [HasStdEnc, NotInMicroMips] in {
 def RDHWR : ReadHardware<GPR32Opnd, HWRegsOpnd>, RDHWR_FM;
-
+}
 def EXT : MMRel, ExtBase<"ext", GPR32Opnd, uimm5, MipsExt>, EXT_FM<0>;
 def INS : MMRel, InsBase<"ins", GPR32Opnd, uimm5, MipsIns>, EXT_FM<4>;
 
 /// Move Control Registers From/To CPU Registers
 def MFC0 : MFC3OP<"mfc0", GPR32Opnd>, MFC3OP_FM<0x10, 0>, ISA_MIPS32;
 def MTC0 : MFC3OP<"mtc0", GPR32Opnd>, MFC3OP_FM<0x10, 4>, ISA_MIPS32;
 def MFC2 : MFC3OP<"mfc2", GPR32Opnd>, MFC3OP_FM<0x12, 0>;
 def MTC2 : MFC3OP<"mtc2", GPR32Opnd>, MFC3OP_FM<0x12, 4>;

lib/Target/Mips/MipsSEISelDAGToDAG.cpp

case ISD::INTRINSIC_VOID: {
     break;
   }
 
   case MipsISD::ThreadPointer: {
     EVT PtrVT = getTargetLowering()->getPointerTy();
     unsigned RdhwrOpc, DestReg;
 
     if (PtrVT == MVT::i32) {
-      RdhwrOpc = Mips::RDHWR;
+      RdhwrOpc = Subtarget->inMicroMipsMode() ? Mips::RDHWR_MM : Mips::RDHWR;
       DestReg = Mips::V1;
     } else {
       RdhwrOpc = Mips::RDHWR64;
       DestReg = Mips::V1_64;
     }
 
     SDNode *Rdhwr =
       CurDAG->getMachineNode(RdhwrOpc, SDLoc(Node),

test/CodeGen/Mips/micromips-rdhwr-directives.ll

+; RUN: llc -march=mipsel -mcpu=mips32 -relocation-model=static < %s \
+; RUN:   -mattr=+micromips | FileCheck %s
+
+@a = external thread_local global i32
+
+define i32 @foo() nounwind readonly {
+entry:
+; CHECK: .set  push
+; CHECK: .set  micromips
+; CHECK: rdhwr
+; CHECK: .set  pop
+
+  %0 = load i32* @a, align 4
+  ret i32 %0
+}
+

test/MC/Mips/micromips-control-instructions.s

 # RUN: llvm-mc %s -triple=mipsel -show-encoding -mcpu=mips32r2 -mattr=micromips \
 # RUN: | FileCheck -check-prefix=CHECK-EL %s
 # RUN: llvm-mc %s -triple=mips -show-encoding -mcpu=mips32r2 -mattr=micromips \
 # RUN: | FileCheck -check-prefix=CHECK-EB %s
 # Check that the assembler can handle the documented syntax
 # for control instructions.
 #------------------------------------------------------------------------------
 # microMIPS Control Instructions
 #------------------------------------------------------------------------------
 # Little endian
 #------------------------------------------------------------------------------
 # CHECK-EL:    cache 1, 8($5)             # encoding: [0x25,0x20,0x08,0x60]
 # CHECK-EL:    pref 1, 8($5)              # encoding: [0x25,0x60,0x08,0x20]
 # CHECK-EL:    ssnop                      # encoding: [0x00,0x00,0x00,0x08]
 # CHECK-EL:    ehb                        # encoding: [0x00,0x00,0x00,0x10]
 # CHECK-EL:    pause                      # encoding: [0x00,0x00,0x00,0x28]
+# CHECK-EL:    sdbbp                      # encoding: [0x00,0x00,0x7c,0xdb]
+# CHECK-EL:    .set push
+# CHECK-EL:    .set micromips
+# CHECK-EL:    rdhwr $5, $29
+# CHECK-EL:    .set pop                   # encoding: [0xbd,0x00,0x3c,0x6b]
 # CHECK-EL:    break                      # encoding: [0x00,0x00,0x07,0x00]
 # CHECK-EL:    break 7                    # encoding: [0x07,0x00,0x07,0x00]
 # CHECK-EL:    break 7, 5                 # encoding: [0x07,0x00,0x47,0x01]
 # CHECK-EL:    syscall                    # encoding: [0x00,0x00,0x7c,0x8b]
 # CHECK-EL:    syscall 396                # encoding: [0x8c,0x01,0x7c,0x8b]
 # CHECK-EL:    eret                       # encoding: [0x00,0x00,0x7c,0xf3]
 # CHECK-EL:    deret                      # encoding: [0x00,0x00,0x7c,0xe3]
 # CHECK-EL:    di                         # encoding: [0x00,0x00,0x7c,0x47]

 #------------------------------------------------------------------------------
 # Big endian
 #------------------------------------------------------------------------------
 # CHECK-EB:   cache 1, 8($5)              # encoding: [0x20,0x25,0x60,0x08]
 # CHECK-EB:   pref 1, 8($5)               # encoding: [0x60,0x25,0x20,0x08]
 # CHECK-EB:   ssnop                       # encoding: [0x00,0x00,0x08,0x00]
 # CHECK-EB:   ehb                         # encoding: [0x00,0x00,0x10,0x00]
 # CHECK-EB:   pause                       # encoding: [0x00,0x00,0x28,0x00]
+# CHECK-EB:   sdbbp                       # encoding: [0x00,0x00,0xdb,0x7c]
+# CHECK-EB:   .set push
+# CHECK-EB:   .set micromips
+# CHECK-EB:   rdhwr $5, $29
+# CHECK-EB:   .set pop                    # encoding: [0x00,0xbd,0x6b,0x3c]
 # CHECK-EB:   break                       # encoding: [0x00,0x00,0x00,0x07]
 # CHECK-EB:   break 7                     # encoding: [0x00,0x07,0x00,0x07]
 # CHECK-EB:   break 7, 5                  # encoding: [0x00,0x07,0x01,0x47]
 # CHECK-EB:   syscall                     # encoding: [0x00,0x00,0x8b,0x7c]
 # CHECK-EB:   syscall 396                 # encoding: [0x01,0x8c,0x8b,0x7c]
 # CHECK-EB:   eret                        # encoding: [0x00,0x00,0xf3,0x7c]
 # CHECK-EB:   deret                       # encoding: [0x00,0x00,0xe3,0x7c]
 # CHECK-EB:   di                          # encoding: [0x00,0x00,0x47,0x7c]

 # CHECK-EB:   tlbwi                       # encoding: [0x00,0x00,0x23,0x7c]
 # CHECK-EB:   tlbwr                       # encoding: [0x00,0x00,0x33,0x7c]
 
     cache 1, 8($5)
     pref 1, 8($5)
     ssnop
     ehb
     pause
+    sdbbp
+    rdhwr $5, $29
     break
     break 7
     break 7,5
     syscall
     syscall 0x18c
     eret
     deret
     di