82acc31fd4
OPC_Decode is a specialized OPC_TryDecode. The difference between them is that OPC_TryDecode performs a "completeness check", while OPC_Decode asserts that the check passes. The check is just a boolean test, which is nothing compared to the complexity of the decoding process, so there is no point in having a special opcode that optimizes the check.
72 lines
2.9 KiB
TableGen
72 lines
2.9 KiB
TableGen
// RUN: llvm-tblgen -gen-disassembler -I %p/../../../include %s | FileCheck %s
|
|
|
|
include "llvm/Target/Target.td"
|
|
|
|
class Enc {
|
|
int Size = 2;
|
|
bits<16> Inst;
|
|
}
|
|
|
|
class EncSHIFT<bits<2> opc> : Enc {
|
|
bits<6> shamt;
|
|
let Inst{15...14} = {0, 0};
|
|
let Inst{13...12} = opc;
|
|
let Inst{11...6} = shamt;
|
|
}
|
|
|
|
class EncNOP<bits<2> opc> : Enc {
|
|
let Inst{15...14} = {0, 0};
|
|
let Inst{13...12} = opc;
|
|
let Inst{11...6} = {0, 0, 0, 0, 0, 0};
|
|
}
|
|
|
|
def ShAmtOp : Operand<i32> {
|
|
let DecoderMethod = "decodeShAmt";
|
|
let hasCompleteDecoder = false;
|
|
}
|
|
|
|
class I<dag out_ops, dag in_ops> : Instruction {
|
|
let InOperandList = in_ops;
|
|
let OutOperandList = out_ops;
|
|
}
|
|
|
|
// CHECK: /* 0 */ OPC_ExtractField, 12, 4, // Field = Inst{15-12}
|
|
// CHECK-NEXT: /* 3 */ OPC_FilterValueOrSkip, 0, 15, 0, // if Field != 0x0 skip to 22
|
|
// CHECK-NEXT: /* 7 */ OPC_Scope, 8, 0, // end scope at 18
|
|
// CHECK-NEXT: /* 10 */ OPC_CheckField, 6, 6, 0, // if Inst{11-6} != 0x0
|
|
// CHECK-NEXT: /* 14 */ OPC_Decode, {{[0-9]+}}, 2, 0, // Opcode: {{.*}}:NOP, DecodeIdx: 0
|
|
// CHECK-NEXT: /* 18 */ OPC_Decode, {{[0-9]+}}, 2, 1, // Opcode: SHIFT0, DecodeIdx: 1
|
|
// CHECK-NEXT: /* 22 */ OPC_FilterValueOrSkip, 1, 15, 0, // if Field != 0x1 skip to 41
|
|
// CHECK-NEXT: /* 26 */ OPC_Scope, 8, 0, // end scope at 37
|
|
// CHECK-NEXT: /* 29 */ OPC_CheckField, 6, 6, 0, // if Inst{11-6} != 0x0
|
|
// CHECK-NEXT: /* 33 */ OPC_Decode, {{[0-9]+}}, 2, 0, // Opcode: {{.*}}:NOP, DecodeIdx: 0
|
|
// CHECK-NEXT: /* 37 */ OPC_Decode, {{[0-9]+}}, 2, 1, // Opcode: SHIFT1, DecodeIdx: 1
|
|
// CHECK-NEXT: /* 41 */ OPC_FilterValueOrSkip, 2, 15, 0, // if Field != 0x2 skip to 60
|
|
// CHECK-NEXT: /* 45 */ OPC_Scope, 8, 0, // end scope at 56
|
|
// CHECK-NEXT: /* 48 */ OPC_CheckField, 6, 6, 0, // if Inst{11-6} != 0x0
|
|
// CHECK-NEXT: /* 52 */ OPC_Decode, {{[0-9]+}}, 2, 0, // Opcode: {{.*}}:NOP, DecodeIdx: 0
|
|
// CHECK-NEXT: /* 56 */ OPC_Decode, {{[0-9]+}}, 2, 1, // Opcode: SHIFT2, DecodeIdx: 1
|
|
// CHECK-NEXT: /* 60 */ OPC_FilterValue, 3, // if Field != 0x3
|
|
// CHECK-NEXT: /* 62 */ OPC_Scope, 8, 0, // end scope at 73
|
|
// CHECK-NEXT: /* 65 */ OPC_CheckField, 6, 6, 0, // if Inst{11-6} != 0x0
|
|
// CHECK-NEXT: /* 69 */ OPC_Decode, {{[0-9]+}}, 2, 0, // Opcode: {{.*}}:NOP, DecodeIdx: 0
|
|
// CHECK-NEXT: /* 73 */ OPC_Decode, {{[0-9]+}}, 2, 1, // Opcode: SHIFT3, DecodeIdx: 1
|
|
|
|
|
|
class SHIFT<bits<2> opc> : I<(outs), (ins ShAmtOp:$shamt)>, EncSHIFT<opc>;
|
|
def SHIFT0 : SHIFT<0>;
|
|
def SHIFT1 : SHIFT<1>;
|
|
def SHIFT2 : SHIFT<2>;
|
|
def SHIFT3 : SHIFT<3>;
|
|
|
|
def NOP : I<(outs), (ins)>, EncNOP<0>;
|
|
def : AdditionalEncoding<NOP>, EncNOP<1>;
|
|
def : AdditionalEncoding<NOP>, EncNOP<2>;
|
|
def : AdditionalEncoding<NOP>, EncNOP<3>;
|
|
|
|
def II : InstrInfo;
|
|
|
|
def MyTarget : Target {
|
|
let InstructionSet = II;
|
|
}
|