[mips][microMIPSr6] Implement DIV, DIVU, MOD and MODU instructions

[jkolek]

LGTM with a nit.

test/MC/Disassembler/Mips/micromips32r6.txt

18

Use the single-line style.

lib/Target/Mips/MicroMips32r6InstrInfo.td

 // Instruction Encodings
 //
 //===----------------------------------------------------------------------===//
 class ADD_MMR6_ENC : ARITH_FM_MMR6<"add", 0x110>;
 class ADDIU_MMR6_ENC : ADDI_FM_MMR6<"addiu", 0xc>;
 class ADDU_MMR6_ENC : ARITH_FM_MMR6<"addu", 0x150>;
 class BALC_MMR6_ENC  : BRANCH_OFF26_FM<0b101101>;
 class BC_MMR6_ENC : BRANCH_OFF26_FM<0b100101>;
+class DIV_MMR6_ENC : ARITH_FM_MMR6<"div", 0x118>;
+class DIVU_MMR6_ENC : ARITH_FM_MMR6<"divu", 0x198>;
+class MOD_MMR6_ENC : ARITH_FM_MMR6<"mod", 0x158>;
+class MODU_MMR6_ENC : ARITH_FM_MMR6<"modu", 0x1d8>;
 
 //===----------------------------------------------------------------------===//
 //
 // Instruction Descriptions
 //
 //===----------------------------------------------------------------------===//
 
 class ADD_MMR6_DESC : ArithLogicR<"add", GPR32Opnd>;
 class ADDIU_MMR6_DESC : ArithLogicI<"addiu", simm16, GPR32Opnd>;
 class ADDU_MMR6_DESC : ArithLogicR<"addu", GPR32Opnd>;
 
 class BC_MMR6_DESC_BASE<string instr_asm, DAGOperand opnd>
     : BRANCH_DESC_BASE, MMR6Arch<instr_asm> {
   dag InOperandList = (ins opnd:$offset);
   dag OutOperandList = (outs);
   string AsmString = !strconcat(instr_asm, "\t$offset");
   bit isBarrier = 1;
 }
 
 class BALC_MMR6_DESC : BC_MMR6_DESC_BASE<"balc", brtarget26> {
   bit isCall = 1;
   list<Register> Defs = [RA];
 }
 class BC_MMR6_DESC : BC_MMR6_DESC_BASE<"bc", brtarget26>;
+class DIV_MMR6_DESC : ArithLogicR<"div", GPR32Opnd>;
+class DIVU_MMR6_DESC : ArithLogicR<"divu", GPR32Opnd>;
+class MOD_MMR6_DESC : ArithLogicR<"mod", GPR32Opnd>;
+class MODU_MMR6_DESC : ArithLogicR<"modu", GPR32Opnd>;
 
 //===----------------------------------------------------------------------===//
 //
 // Instruction Definitions
 //
 //===----------------------------------------------------------------------===//
 
 let DecoderNamespace = "MicroMips32r6" in {
 def ADD_MMR6 : StdMMR6Rel, ADD_MMR6_DESC, ADD_MMR6_ENC, ISA_MICROMIPS32R6;
 def ADDIU_MMR6 : StdMMR6Rel, ADDIU_MMR6_DESC, ADDIU_MMR6_ENC, ISA_MICROMIPS32R6;
 def ADDU_MMR6 : StdMMR6Rel, ADDU_MMR6_DESC, ADDU_MMR6_ENC, ISA_MICROMIPS32R6;
 def BALC_MMR6 : R6MMR6Rel, BALC_MMR6_ENC, BALC_MMR6_DESC, ISA_MICROMIPS32R6;
 def BC_MMR6 : R6MMR6Rel, BC_MMR6_ENC, BC_MMR6_DESC, ISA_MICROMIPS32R6;
+def DIV_MMR6 : R6MMR6Rel, DIV_MMR6_DESC, DIV_MMR6_ENC, ISA_MICROMIPS32R6;
+def DIVU_MMR6 : R6MMR6Rel, DIVU_MMR6_DESC, DIVU_MMR6_ENC, ISA_MICROMIPS32R6;
+def MOD_MMR6 : R6MMR6Rel, MOD_MMR6_DESC, MOD_MMR6_ENC, ISA_MICROMIPS32R6;
+def MODU_MMR6 : R6MMR6Rel, MODU_MMR6_DESC, MODU_MMR6_ENC, ISA_MICROMIPS32R6;
 }

lib/Target/Mips/Mips32r6InstrInfo.td

class BITSWAP_DESC_BASE<string instr_asm, RegisterOperand GPROpnd> {
   dag InOperandList = (ins GPROpnd:$rt);
   string AsmString = !strconcat(instr_asm, "\t$rd, $rt");
   list<dag> Pattern = [];
 }
 
 class BITSWAP_DESC : BITSWAP_DESC_BASE<"bitswap", GPR32Opnd>;
 
 class DIVMOD_DESC_BASE<string instr_asm, RegisterOperand GPROpnd,
-                       SDPatternOperator Op=null_frag> {
+                       SDPatternOperator Op=null_frag>
+    : MipsR6Arch<instr_asm> {
   dag OutOperandList = (outs GPROpnd:$rd);
   dag InOperandList = (ins GPROpnd:$rs, GPROpnd:$rt);
   string AsmString = !strconcat(instr_asm, "\t$rd, $rs, $rt");
   list<dag> Pattern = [(set GPROpnd:$rd, (Op GPROpnd:$rs, GPROpnd:$rt))];
 
   // This instruction doesn't trap division by zero itself. We must insert
   // teq instructions as well.
   bit usesCustomInserter = 1;

 def BOVC : BOVC_ENC, BOVC_DESC, ISA_MIPS32R6;
 def CACHE_R6 : CACHE_ENC, CACHE_DESC, ISA_MIPS32R6;
 def CLASS_D : CLASS_D_ENC, CLASS_D_DESC, ISA_MIPS32R6;
 def CLASS_S : CLASS_S_ENC, CLASS_S_DESC, ISA_MIPS32R6;
 def CLO_R6 : CLO_R6_ENC, CLO_R6_DESC, ISA_MIPS32R6;
 def CLZ_R6 : CLZ_R6_ENC, CLZ_R6_DESC, ISA_MIPS32R6;
 defm S : CMP_CC_M<FIELD_CMP_FORMAT_S, "s", FGR32Opnd>;
 defm D : CMP_CC_M<FIELD_CMP_FORMAT_D, "d", FGR64Opnd>;
-def DIV : DIV_ENC, DIV_DESC, ISA_MIPS32R6;
-def DIVU : DIVU_ENC, DIVU_DESC, ISA_MIPS32R6;
+def DIV : R6MMR6Rel, DIV_ENC, DIV_DESC, ISA_MIPS32R6;
+def DIVU : R6MMR6Rel, DIVU_ENC, DIVU_DESC, ISA_MIPS32R6;
 def JIALC : JIALC_ENC, JIALC_DESC, ISA_MIPS32R6;
 def JIC : JIC_ENC, JIC_DESC, ISA_MIPS32R6;
 def JR_HB_R6 : JR_HB_R6_ENC, JR_HB_R6_DESC, ISA_MIPS32R6;
 def LDC2_R6 : LDC2_R6_ENC, LDC2_R6_DESC, ISA_MIPS32R6;
 def LL_R6 : LL_R6_ENC, LL_R6_DESC, ISA_MIPS32R6;
 def LSA_R6 : LSA_R6_ENC, LSA_R6_DESC, ISA_MIPS32R6;
 def LWC2_R6 : LWC2_R6_ENC, LWC2_R6_DESC, ISA_MIPS32R6;
 def LWPC : LWPC_ENC, LWPC_DESC, ISA_MIPS32R6;
 def LWUPC : LWUPC_ENC, LWUPC_DESC, ISA_MIPS32R6;
 def MADDF_S : MADDF_S_ENC, MADDF_S_DESC, ISA_MIPS32R6;
 def MADDF_D : MADDF_D_ENC, MADDF_D_DESC, ISA_MIPS32R6;
 def MAXA_D : MAXA_D_ENC, MAXA_D_DESC, ISA_MIPS32R6;
 def MAXA_S : MAXA_S_ENC, MAXA_S_DESC, ISA_MIPS32R6;
 def MAX_D : MAX_D_ENC, MAX_D_DESC, ISA_MIPS32R6;
 def MAX_S : MAX_S_ENC, MAX_S_DESC, ISA_MIPS32R6;
 def MINA_D : MINA_D_ENC, MINA_D_DESC, ISA_MIPS32R6;
 def MINA_S : MINA_S_ENC, MINA_S_DESC, ISA_MIPS32R6;
 def MIN_D : MIN_D_ENC, MIN_D_DESC, ISA_MIPS32R6;
 def MIN_S : MIN_S_ENC, MIN_S_DESC, ISA_MIPS32R6;
-def MOD : MOD_ENC, MOD_DESC, ISA_MIPS32R6;
-def MODU : MODU_ENC, MODU_DESC, ISA_MIPS32R6;
+def MOD : R6MMR6Rel, MOD_ENC, MOD_DESC, ISA_MIPS32R6;
+def MODU : R6MMR6Rel, MODU_ENC, MODU_DESC, ISA_MIPS32R6;
 def MSUBF_S : MSUBF_S_ENC, MSUBF_S_DESC, ISA_MIPS32R6;
 def MSUBF_D : MSUBF_D_ENC, MSUBF_D_DESC, ISA_MIPS32R6;
 def MUH    : MUH_ENC, MUH_DESC, ISA_MIPS32R6;
 def MUHU   : MUHU_ENC, MUHU_DESC, ISA_MIPS32R6;
 def MUL_R6 : MUL_R6_ENC, MUL_R6_DESC, ISA_MIPS32R6;
 def MULU   : MULU_ENC, MULU_DESC, ISA_MIPS32R6;
 def NAL; // BAL with rd=0
 def PREF_R6 : PREF_ENC, PREF_DESC, ISA_MIPS32R6;

test/MC/Disassembler/Mips/micromips32r6.txt

 # RUN: llvm-mc --disassemble %s -triple=mips-unknown-linux -mcpu=mips32r6 -mattr=micromips32r6 | FileCheck %s
 
 # CHECK: add $3, $4, $5
 0x00 0xa4 0x19 0x10
 
 # CHECK: addiu $3, $4, 1234
 0x30 0x64 0x04 0xd2
 
 # CHECK: addu $3, $4, $5
 0x00 0xa4 0x19 0x50
 
 # CHECK: balc 14572256
 0xb4 0x37 0x96 0xb8
 
 # CHECK: bc 14572256
 0x94 0x37 0x96 0xb8
+
+# CHECK: div $3, $4, $5
+0x00 0xa4 0x19 0x18
+
+# CHECK: divu $3, $4, $5
+0x00 0xa4 0x19 0x98
+
+# CHECK: mod $3, $4, $5
+0x00 0xa4 0x19 0x58
+
+# CHECK: modu $3, $4, $5
+0x00 0xa4 0x19 0xd8

test/MC/Mips/micromips32r6/valid.s

 # RUN: llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips32r6 -mattr=micromips32r6 | FileCheck %s
 
   .set noat
   add $3, $4, $5           # CHECK: add $3, $4, $5      # encoding: [0x00,0xa4,0x19,0x10]
   addiu $3, $4, 1234       # CHECK: addiu $3, $4, 1234  # encoding: [0x30,0x64,0x04,0xd2]
   addu $3, $4, $5          # CHECK: addu $3, $4, $5     # encoding: [0x00,0xa4,0x19,0x50]
   balc 14572256            # CHECK: balc 14572256       # encoding: [0xb4,0x37,0x96,0xb8]
   bc 14572256              # CHECK: bc 14572256         # encoding: [0x94,0x37,0x96,0xb8]
+  div $3, $4, $5           # CHECK: div $3, $4, $5      # encoding: [0x00,0xa4,0x19,0x18]
+  divu $3, $4, $5          # CHECK: divu $3, $4, $5     # encoding: [0x00,0xa4,0x19,0x98]
+  mod $3, $4, $5           # CHECK: mod $3, $4, $5      # encoding: [0x00,0xa4,0x19,0x58]
+  modu $3, $4, $5          # CHECK: modu $3, $4, $5     # encoding: [0x00,0xa4,0x19,0xd8]