Add commutable attribute to opcodes for ARC

[marksl]

Summary

This is a very trivial change I'd like to use to go through the process of creating a patch for the ARC code generator.

This patch sets the isCommutable attribute for several opcodes that have the "reg = OPCODE reg, reg" format.

[danilaml]

LGTM

llvm/lib/Target/ARC/ARCInstrInfo.td

 //===----------------------------------------------------------------------===//
 // Instruction Generation multiclasses.
 // Generate many variants of a single instruction with a single defining
 // multiclass.  These classes do not contain Selection DAG patterns.
 //===----------------------------------------------------------------------===//
 
 // Generic 3 operand binary instructions (i.e., add r0, r1, r2).
 multiclass ArcBinaryInst<bits<5> major, bits<6> mincode,
-                       string opasm> {
+                       string opasm, bit Commutable> {
   // 3 register variant.
   def _rrr : F32_DOP_RR<major, mincode, 0, (outs GPR32:$A),
                         (ins GPR32:$B, GPR32:$C),
                         !strconcat(opasm, "\t$A, $B, $C"),
-                        []>;
+                        []>
+  { let isCommutable = Commutable; }
   def _f_rrr : F32_DOP_RR<major, mincode, 1, (outs GPR32:$A),
                           (ins GPR32:$B, GPR32:$C),
                           !strconcat(opasm, ".f\t$A, $B, $C"),
                           []>
   { let Defs = [STATUS32]; }
 
   // 2 register with unsigned 6-bit immediate variant.
   def _rru6 : F32_DOP_RU6<major, mincode, 0, (outs GPR32:$A),
def _rr : F32_SOP_RR<major, subop, 0, (outs GPR32:$B), (ins GPR32:$C),
                        !strconcat(opasm, "\t$B, $C"), []>;
 
   def _f_rr : F32_SOP_RR<major, subop, 1, (outs GPR32:$B), (ins GPR32:$C),
                        !strconcat(opasm, ".f\t$B, $C"), []>
   { let Defs = [STATUS32]; }
 }
 
 
-multiclass ArcBinaryGEN4Inst<bits<6> mincode, string opasm> :
-  ArcBinaryInst<0b00100, mincode, opasm>;
+multiclass ArcBinaryGEN4Inst<bits<6> mincode, string opasm, bit Commutable = 0> :
+  ArcBinaryInst<0b00100, mincode, opasm, Commutable>;
 multiclass ArcBinaryEXT5Inst<bits<6> mincode, string opasm> :
-  ArcBinaryInst<0b00101, mincode, opasm>;
+  ArcBinaryInst<0b00101, mincode, opasm, 0>;
 
 multiclass ArcUnaryGEN4Inst<bits<6> mincode, string opasm> :
   ArcUnaryInst<0b00100, mincode, opasm>;
 
 // Pattern generation for different instruction variants.
 multiclass MultiPat<SDPatternOperator InFrag,
                Instruction RRR, Instruction RRU6, Instruction RRLImm> {
   def _rrr : Pat<(InFrag i32:$B, i32:$C), (RRR i32:$B, i32:$C)>;
   def _rru6 : Pat<(InFrag i32:$B, immU6:$U6), (RRU6 i32:$B, immU6:$U6)>;
   def _rrlimm : Pat<(InFrag i32:$B, imm32:$LImm), (RRLImm i32:$B, imm32:$LImm)>;
 }
 
 // ---------------------------------------------------------------------------
 // Instruction definitions and patterns for 3 operand binary instructions.
 // ---------------------------------------------------------------------------
 
 // Definitions for 3 operand binary instructions.
-defm ADD : ArcBinaryGEN4Inst<0b000000, "add">;
+defm ADD : ArcBinaryGEN4Inst<0b000000, "add",1>;
 defm SUB : ArcBinaryGEN4Inst<0b000010, "sub">;
 defm SUB1 : ArcBinaryGEN4Inst<0b010111, "sub1">;
 defm SUB2 : ArcBinaryGEN4Inst<0b011000, "sub2">;
 defm SUB3 : ArcBinaryGEN4Inst<0b011001, "sub3">;
-defm OR  : ArcBinaryGEN4Inst<0b000101, "or">;
-defm AND : ArcBinaryGEN4Inst<0b000100, "and">;
-defm XOR : ArcBinaryGEN4Inst<0b000111, "xor">;
-defm MAX : ArcBinaryGEN4Inst<0b001000, "max">;
-defm MIN : ArcBinaryGEN4Inst<0b001001, "min">;
+defm OR  : ArcBinaryGEN4Inst<0b000101, "or",1>;
+defm AND : ArcBinaryGEN4Inst<0b000100, "and",1>;
+defm XOR : ArcBinaryGEN4Inst<0b000111, "xor",1>;
+defm MAX : ArcBinaryGEN4Inst<0b001000, "max",1>;
+defm MIN : ArcBinaryGEN4Inst<0b001001, "min",1>;
 defm ASL : ArcBinaryEXT5Inst<0b000000, "asl">;
 defm LSR : ArcBinaryEXT5Inst<0b000001, "lsr">;
 defm ASR : ArcBinaryEXT5Inst<0b000010, "asr">;
 defm ROR : ArcBinaryEXT5Inst<0b000011, "ror">;
-defm MPY  : ArcBinaryGEN4Inst<0b011010, "mpy">;
-defm MPYM : ArcBinaryGEN4Inst<0b011011, "mpym">;
-defm MPYMU : ArcBinaryGEN4Inst<0b011100, "mpymu">;
-defm SETEQ : ArcBinaryGEN4Inst<0b111000, "seteq">;
+defm MPY  : ArcBinaryGEN4Inst<0b011010, "mpy",1>;
+defm MPYM : ArcBinaryGEN4Inst<0b011011, "mpym",1>;
+defm MPYMU : ArcBinaryGEN4Inst<0b011100, "mpymu",1>;
+defm SETEQ : ArcBinaryGEN4Inst<0b111000, "seteq",1>;
 
 // Patterns for 3 operand binary instructions.
 defm : MultiPat<add, ADD_rrr, ADD_rru6, ADD_rrlimm>;
 defm : MultiPat<sub, SUB_rrr, SUB_rru6, SUB_rrlimm>;
 defm : MultiPat<or, OR_rrr, OR_rru6, OR_rrlimm>;
 defm : MultiPat<and, AND_rrr, AND_rru6, AND_rrlimm>;
 defm : MultiPat<xor, XOR_rrr, XOR_rru6, XOR_rrlimm>;
 defm : MultiPat<smax, MAX_rrr, MAX_rru6, MAX_rrlimm>;