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Decoder.sv
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Decoder.sv
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module Decoder(
output logic[3:0] byte_incr,
/* verilator lint_off UNDRIVEN */ /* verilator lint_off UNUSED */
Sysbus bus
/* verilator lint_on UNUSED */ /* verilator lint_on UNDRIVEN */
,
output logic[191:0] opcode_stream,
output logic[255:0] mnemonic_stream,
input logic[63:0] current_addr,
input logic[0:15*8-1] buffer,
input logic[63:0] op[0:255],
input logic[63:0] op2[0:255],
input logic[255:0] ModRM,
input logic[255:0] ModRM2
);
logic signed[31:0] displacement;
logic[4:0] dispsize;
logic[31:0] ereg;
logic[31:0] greg;
logic[1:0] mod;
logic[2:0] reg1;
logic[2:0] rm;
//logic[255:0] immediate;
logic[0:15*8-1] buffer;
logic[7:0] instr;
logic [3:0] rex_bits;
logic[7:0] modrm;
//logic [0:0] RR_addr;
logic [0:0] RM;
// Output strings
logic [7:0] optr;
logic [7:0] mptr;
logic [1:0] num_inst_bytes;
typedef enum {
UNDEFINED=3'b000,
LEGACY_PREFIX=3'b001, REX_PREFIX=3'b010, OPCODE=3'b011,
MOD_RM=3'b100, SIB=3'b101, DISPLACEMENT=3'b110, IMMEDIATE=3'b111
} inst_field_t;
task check_legacy_prefix;
output logic[3:0] next_byte_offset;
output inst_field_t next_field_type;
input logic[3:0] inst_byte_offset;
logic[3:0] inc;
begin
inc = 4'd1;
// $display("Byte: 0x%x", buffer[inst_byte_offset*8 +: 8]);
case (buffer[inst_byte_offset*8 +: 8])
8'hF0: /* $display("Group 1: lock prefix") */ ;
8'hF2: /* $display("Group 1: REPNE/REPNZ") */ ;
8'hF3: /* $display("Group 1: REPE/REPZ") */ ;
8'h2E: /* $display("Group 2: CS segement override prefix / branch not taken") */ ;
8'h36: /* $display("Group 2: SS segment override prefix") */ ;
8'h3E: /* $display("Group 2: DS segment override prefix") */ ;
8'h26: /* $display("Group 2: ES segment override prefix / branch taken hint") */ ;
8'h64: /* $display("Group 2: FS segment override prefix") */ ;
8'h65: /* $display("Group 2: GS segment override prefix") */ ;
8'h66: /* $display("Group 3: operand size override prefix") */ ;
8'h67: /* $display("Group 4: address override prefix") */ ;
default: begin
/* $display("Not a legacy instruction prefix") */ ;
inc = 4'd0;
end
endcase
next_byte_offset = inst_byte_offset + inc;
next_field_type = REX_PREFIX | OPCODE;
end
endtask
task check_rex_prefix;
output logic[3:0] next_byte_offset;
output inst_field_t next_field_type;
input logic[3:0] inst_byte_offset;
logic[7:0] ibyte;
logic[15:0] out;
logic[3:0] inc;
begin
inc = 4'd1;
// $display("Byte: 0x%x", buffer[inst_byte_offset*8 +: 8]);
ibyte[7:0] = buffer[inst_byte_offset*8 +: 8];
if (ibyte[7:4] == 4'b0100) begin
// $display("REX prefix");
// if (rex_bits[3] == 1'b1)
// $display("REX: 64 bit operand size");
// if (rex_bits[2] == 1'b1)
// $display("REX: Mod R/M reg field");
// if (rex_bits[1] == 1'b1)
// $display("REX: SIB extension field present");
// if (rex_bits[0] == 1'b1)
// $display("REX: ModR/M or SIB or Opcode reg");
rex_bits[3:0] = ibyte[3:0];
inc = 4'd1;
toascii(out,ibyte[7:0]);
opcode_stream[191-optr*8 -: 16] = out;
optr = optr + 3;
end
else begin
// $display("Not a REX prefix");
inc = 4'd0;
rex_bits[3:0] = 4'b0;
end
next_byte_offset = inst_byte_offset + inc;
next_field_type = OPCODE;
if (rex_bits[3] == 0);
end
endtask
task check_opcode;
output logic[3:0] next_byte_offset;
output inst_field_t next_field_type;
input logic[3:0] inst_byte_offset;
logic[3:0] inc;
logic[15:0] out1;
logic[15:0] out2;
begin
inc = 1;
if (buffer[inst_byte_offset*8 +: 8]==8'h00) begin
if (buffer[inst_byte_offset*8 +: 24]==24'h00) begin
opcode_stream[191-optr*8 -: 64] = "00 00 00";
optr = optr + 8;
next_field_type = LEGACY_PREFIX;
end
end
else if (buffer[inst_byte_offset*8 +: 8]==8'h0f) begin
inst_byte_offset=inst_byte_offset+1;
inc = inc + 1;
//$display("Opcode 2: 0x%x", buffer[inst_byte_offset*8 +: 8]);
//$display("Opcode 2: %s", op2[buffer[inst_byte_offset*8 +: 8]]);
num_inst_bytes[1:0] = 2'b10;
instr[7:0] = buffer[inst_byte_offset*8 +: 8];
toascii(out1,8'h0f);
opcode_stream[191-optr*8 -: 16] = out1;
optr = optr + 3;
toascii(out2,buffer[inst_byte_offset*8 +: 8]);
opcode_stream[191-optr*8 -: 16] = out2;
mnemonic_stream[255-mptr*8 -: 64] = op2[buffer[inst_byte_offset*8 +: 8]] ;
optr = optr + 3;
mptr = mptr + 8;
RM = ModRM2[255-buffer[inst_byte_offset*8 +: 8]];
end
else begin
//$display("Opcode 1: 0x%x", buffer[inst_byte_offset*8 +: 8]);
//$display("Opcode 1: %s", op[buffer[inst_byte_offset*8 +: 8]]);
num_inst_bytes[1:0] = 2'b01;
instr[7:0] = buffer[inst_byte_offset*8 +: 8];
toascii(out1,buffer[inst_byte_offset*8 +: 8]);
opcode_stream[191-optr*8 -: 16] = out1;
mnemonic_stream[255-mptr*8 -: 64] = op[buffer[inst_byte_offset*8 +: 8]] ;
optr = optr + 3;
mptr = mptr + 8;
RM = ModRM[255-buffer[inst_byte_offset*8 +: 8]];
end
if (RM) begin
//$display("ModRM present");
next_field_type = MOD_RM;
end
else begin
//$display("ModRM absent");
next_field_type = LEGACY_PREFIX;
end
next_byte_offset = inst_byte_offset + inc;
end
endtask
task check_modrm;
output logic[3:0] next_byte_offset;
output inst_field_t next_field_type;
input logic[3:0] inst_byte_offset;
logic[3:0] inc;
logic[15:0] out1;
begin
inc = 1;
modrm=buffer[inst_byte_offset*8 +: 8];
toascii(out1,modrm);
opcode_stream[191-optr*8 -: 16] = out1;
optr = optr + 3;
/* if(modrm[7:6] == 2'b11) begin
// $display("Register Register Addressing (No Memory Operand); REX.X not used");
//RR_addr[0] = 1'b1;
end
else begin
// $display("Memory Addressing without an SIB Byte, REX.X Not Used");
//RR_addr[0] = 1'b0;
end
*/ //$display("Register Name : %x",{rex_bits[2],modrm[5:3]});
mod[1:0]=modrm[7:6];
reg1[2:0]=modrm[5:3];
rm[2:0]=modrm[2:0];
get_reg();
if(mod[1:0]==2'b00) begin
if(rm[2:0]==3'b110) begin
dispsize[4:0]=5'd16;
end
else begin
dispsize[4:0]=5'd16;
end
end
else if(mod[1:0]==2'b01) begin
dispsize[4:0]=5'd8;
end
else if(mod[1:0]==2'b10) begin
dispsize[4:0]=5'd16;
end
else begin
dispsize[4:0]=5'd0;
end
if(reg1[2:0]==3'b000); //
if(rex_bits[2:0]==3'b000); //
next_field_type=LEGACY_PREFIX;
if(mod[1:0]!=2'b11 && modrm[2:0] == 3'b100) begin
next_field_type = next_field_type | SIB;
end
/* if(dispsize[4:0]!=5'd0) begin
$display("bye");
next_field_type = next_field_type | DISPLACEMENT;
end
*/
next_byte_offset = inst_byte_offset + inc;
end
endtask
task check_sib;
output logic[3:0] next_byte_offset;
output inst_field_t next_field_type;
input logic[3:0] inst_byte_offset;
logic[3:0] inc;
logic[7:0] sib;
logic[1:0] scale;
logic[3:0] index;
logic[3:0] base;
logic[2:0] num_disp_bytes;
logic[31:0] disp;
logic[31:0] scale_factor;
logic[31:0] byte_off;
logic[15:0] out1;
begin
inc = 1;
byte_off[31:0]={28'b0,inst_byte_offset};
sib = buffer[inst_byte_offset*8 +: 8];
toascii(out1,sib);
opcode_stream[191-optr*8 -: 16] = out1;
optr = optr + 3;
inc = inc + 1;
scale[1:0] = (1 << sib[7:6]);
index[3:0] = {rex_bits[1], sib[5:3]};
base[3:0] = {rex_bits[0], sib[2:0]};
// $display("scale: b%b", scale);
// $display("index: b%b", index);
// $display("base : b%b", base);
if(base[3]==0); // TO be removed
if (modrm[7:6] == 2'b00 ) begin
if (index[3:0] == 4'b0100 ) begin
if (base[2:0] == 3'b101 ) begin
num_disp_bytes[2:0] = 3'b100;
disp[31:0] = buffer[(byte_off+32'b1)*8 +: 32];
scale_factor = disp[31:0];
inc = inc + num_disp_bytes;
end
else begin
num_disp_bytes[2:0] = 3'b000;
disp[31:0] = 0;
scale_factor[31:0] = {29'b0,base[2:0]};
inc = inc + num_disp_bytes;
end
end
else begin
if (base[2:0] == 3'b101 ) begin
num_disp_bytes[2:0] = 3'b100;
disp[31:0] = buffer[(byte_off+32'b1)*8 +: 32];
scale_factor[31:0] = (index[2:0] * scale[1:0]) + disp[31:0];
inc = inc + num_disp_bytes;
end
else begin
num_disp_bytes[2:0] = 3'b000;
disp[31:0] = 32'b0;
scale_factor[31:0] = (index[2:0] * scale[1:0]) + {29'b0,base[2:0]};
inc = inc + num_disp_bytes;
end
end
end
else if (modrm[7:6] == 2'b01 ) begin
if (index[3:0] == 4'b0100 ) begin
num_disp_bytes[2:0] = 3'b001;
disp[31:0] = {24'b0, buffer[(byte_off+32'b1)*8 +: 8]};
scale_factor[31:0] = disp[31:0] + {29'b0,base[2:0]};
inc = inc + num_disp_bytes;
end
else begin
num_disp_bytes[2:0] = 3'b001;
disp[31:0] = {24'b0, buffer[(byte_off+32'b1)*8 +: 8]};
scale_factor[31:0] = disp[31:0] + {29'b0,base[2:0]} +(index[2:0] * scale[1:0]) ;
inc = inc + num_disp_bytes;
end
end
else if (modrm[7:6] == 2'b10 ) begin
if (index[3:0] == 4'b0100 ) begin
num_disp_bytes[2:0] = 3'b100;
disp[31:0] = buffer[(byte_off+1)*8 +: 32];
scale_factor[31:0] = disp[31:0] + {29'b0,base[2:0]};
inc = inc + num_disp_bytes;
end
else begin
num_disp_bytes[2:0] = 3'b100;
disp[31:0] = buffer[(byte_off+1)*8 +: 32];
scale_factor[31:0] = disp[31:0] + {29'b0,base[2:0]} + (index[2:0] * scale[1:0]) ;
inc = inc + num_disp_bytes;
end
end
else begin
end
if (scale_factor == 0);
next_byte_offset = inst_byte_offset + inc;
next_field_type = LEGACY_PREFIX;
// $display("Next Byte Offset: %d , Inst_byte_offset: %d, inc:%d ",next_byte_offset,inst_byte_offset,inc);
// $display("Scale factor: 0x%x", scale_factor[31:0]);
end
endtask
task check_disp;
output logic[3:0] next_byte_offset;
output inst_field_t next_field_type;
input logic[3:0] inst_byte_offset;
logic[3:0] inc;
logic[15:0] disp16_bytes;
logic[7:0] disp8_bytes;
logic[7:0] disp_opcode;
logic[15:0] out1;
//logic[7:0] imm64_bytes;
begin
inc=0;
disp_opcode = buffer[inst_byte_offset*8 +: 8];
toascii(out1,disp_opcode);
opcode_stream[191-optr*8 -: 16] = out1;
if(dispsize==5'd16) begin
optr = optr + 6;
disp16_bytes[15:0]=$signed(buffer[inst_byte_offset*8 +: 16]);
displacement[31:0] ={ {16{disp16_bytes[15]}} , disp16_bytes[15:0] };
inc = inc + 4;
next_byte_offset = inst_byte_offset + inc;
end
else if(dispsize==5'd8) begin
optr = optr + 3;
disp8_bytes[7:0]=$signed(buffer[inst_byte_offset*8 +: 8]);
displacement[31:0] ={ {24{disp8_bytes[7]}} , disp8_bytes[7:0] };
inc = inc + 1;
next_byte_offset = inst_byte_offset + inc;
end
next_field_type=IMMEDIATE | LEGACY_PREFIX;
//if(next_field_type[2:0]==3'b000) ;
if(displacement[31:0]==32'd0) ;
end
endtask
task decode_instr;
logic [63:0] immediate;
logic [39:0] imm64_bytes;
logic [63:0] imm;
logic [7:0] imm_1byte;
logic [15:0] out1;
logic [15:0] out2;
begin
case (instr[7:0])
8'h00: ;
8'h01: ;
8'h02: ;
8'h03: ;
8'h04: ;
8'h05: ;
8'h06: ;
8'h07: ;
8'h08: ;
8'h09: ;
8'h0a: ;
8'h0b: ;
8'h0c: ;
8'h0d: ;
8'h0e: ;
8'h0f: ;
8'h10: ;
8'h11: ;
8'h12: ;
8'h13: ;
8'h14: ;
8'h15: ;
8'h16: ;
8'h17: ;
8'h18: ;
8'h19: ;
8'h1a: ;
8'h1b: ;
8'h1c: ;
8'h1d: ;
8'h1e: ;
8'h1f: ;
8'h20: ;
8'h21: ;
8'h22: ;
8'h23: ;
8'h24: ;
8'h25: ;
8'h26: ;
8'h27: ;
8'h28: ;
8'h29: ;
8'h2a: ;
8'h2b: ;
8'h2c: ;
8'h2d: ;
8'h2e: ;
8'h2f: ;
8'h30: ;
8'h31:
begin
mptr = mptr + 4;
mnemonic_stream[255-mptr*8 -: 32] = ereg[31:0];
mptr = mptr + 4;
mnemonic_stream[255-mptr*8 -: 8] = ",";
mptr = mptr + 1;
mnemonic_stream[255-mptr*8 -: 32] = greg[31:0];
mptr = mptr + 4;
if (dispsize[4:0] != 5'b0) begin
end
end
8'h32: ;
8'h33: ;
8'h34: ;
8'h35: ;
8'h36: ;
8'h37: ;
8'h38: ;
8'h39: ;
8'h3a: ;
8'h3b: ;
8'h3c: ;
8'h3d: ;
8'h3e: ;
8'h3f: ;
8'h40: ;
8'h41: ;
8'h42: ;
8'h43: ;
8'h44: ;
8'h45: ;
8'h46: ;
8'h47: ;
8'h48: ;
8'h49: ;
8'h4a: ;
8'h4b: ;
8'h4c: ;
8'h4d: ;
8'h4e: ;
8'h4f: ;
8'h50:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rax";
mptr = mptr + 5;
end
8'h51:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rcx";
mptr = mptr + 5;
end
8'h52:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rdx";
mptr = mptr + 5;
end
8'h53:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rbx";
mptr = mptr + 5;
end
8'h54:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rsp";
mptr = mptr + 5;
end
8'h55:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rbp";
mptr = mptr + 5;
end
8'h56:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rsi";
mptr = mptr + 5;
end
8'h57:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rdi";
mptr = mptr + 5;
end
8'h58:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rax";
mptr = mptr + 5;
end
8'h59:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rcx";
mptr = mptr + 5;
end
8'h5a:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rdx";
mptr = mptr + 5;
end
8'h5b:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rbx";
mptr = mptr + 5;
end
8'h5c:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rsp";
mptr = mptr + 5;
end
8'h5d:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rbp";
mptr = mptr + 5;
end
8'h5e:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rsi";
mptr = mptr + 5;
end
8'h5f:
begin
mnemonic_stream[255-mptr*8 -: 40] = " %rdi";
mptr = mptr + 5;
end
8'h60: ;
8'h61: ;
8'h62: ;
8'h63: ;
8'h64: ;
8'h65: ;
8'h66: ;
8'h67: ;
8'h68: ;
8'h69: ;
8'h6a: ;
8'h6b: ;
8'h6c: ;
8'h6d: ;
8'h6e: ;
8'h6f: ;
8'h70:
begin
mnemonic_stream[255-mptr*8 -: 8] = "O";
mptr = mptr + 1;
mptr = mptr + 1;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h71:
begin
mnemonic_stream[255-mptr*8 -: 16] = "NO";
mptr = mptr + 2;
mptr = mptr + 1;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h72:
begin
mnemonic_stream[255-mptr*8 -: 24] = "NAE";
mptr = mptr + 3;
mptr = mptr + 1;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h73:
begin
mnemonic_stream[255-mptr*8 -: 16] = "AE";
mptr = mptr + 2;
mptr = mptr + 1;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h74:
begin
mnemonic_stream[255-mptr*8 -: 8] = "E";
mptr = mptr + 1;
mptr = mptr + 1;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h75:
begin
mnemonic_stream[255-mptr*8 -: 16] = "NE";
mptr = mptr + 2;
mptr = mptr + 1;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h76:
begin
mnemonic_stream[255-mptr*8 -: 16] = "NA";
mptr = mptr + 2;
mptr = mptr + 1;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h77:
begin
mnemonic_stream[255-mptr*8 -: 8] = "A";
mptr = mptr + 1;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h78:
begin
mnemonic_stream[255-mptr*8 -: 8] = "S";
mptr = mptr + 1;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h79:
begin
mnemonic_stream[255-mptr*8 -: 16] = "NS";
mptr = mptr + 2;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h7a:
begin
mnemonic_stream[255-mptr*8 -: 16] = "PE";
mptr = mptr + 2;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h7b:
begin
mnemonic_stream[255-mptr*8 -: 16] = "PO";
mptr = mptr + 2;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h7c:
begin
mnemonic_stream[255-mptr*8 -: 24] = "NGE";
mptr = mptr + 3;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h7d:
begin
mnemonic_stream[255-mptr*8 -: 16] = "GE";
mptr = mptr + 2;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h7e:
begin
mnemonic_stream[255-mptr*8 -: 16] = "LE";
mptr = mptr + 2;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h7f:
begin
mnemonic_stream[255-mptr*8 -: 24] = "NLE";
mptr = mptr + 3;
imm[63:0] = current_addr[63:0] + 64'd4;
for (int i=8 ; i> 0 ; i--) begin
toascii(mnemonic_stream[255-mptr*8 -: 16],imm[8*i-1 -: 8]);
mptr = mptr + 2;
end
end
8'h80: ;
8'h81: ;
8'h82: ;
8'h83:
begin
handle_immediate(3'b001);
end
8'h84: ;
8'h85: ;
8'h86: ;
8'h87: ;
8'h88: ;
8'h89:
begin
mptr = mptr + 4;
mnemonic_stream[255-mptr*8 -: 32] = ereg[31:0];
mptr = mptr + 4;
mnemonic_stream[255-mptr*8 -: 8] = ",";
mptr = mptr + 1;
mnemonic_stream[255-mptr*8 -: 32] = greg[31:0];
mptr = mptr + 4;
if (dispsize[4:0] != 5'b0) begin
end
end
8'h8a: ;
8'h8b: ;
8'h8c: ;
8'h8d: ;
8'h8e: ;
8'h8f: ;
/* NOP */ 8'h90: ;
8'h91: ;
8'h92: ;
8'h93: ;
8'h94: ;
8'h95: ;
8'h96: ;
8'h97: ;
8'h98: ;
8'h99: ;
8'h9a: ;
8'h9b: ;
8'h9c: ;
8'h9d: ;
8'h9e: ;
8'h9f: ;
8'ha0: ;
8'ha1: ;
8'ha2: ;
8'ha3: ;
8'ha4: ;
8'ha5: ;
8'ha6: ;
8'ha7: ;
8'ha8: ;
8'ha9: ;
8'haa: ;
8'hab: ;
8'hac: ;
8'had: ;
8'hae: ;
8'haf: ;
8'hb0: ;
8'hb1: ;
8'hb2: ;
8'hb3: ;
8'hb4: ;
8'hb5: ;
8'hb6: ;
8'hb7: ;
8'hb8:
begin
end
8'hb9: ;
8'hba: ;
8'hbb: ;
8'hbc: ;
8'hbd: ;
8'hbe: ;
8'hbf:
begin
mnemonic_stream[255-mptr*8 -: 24] = "$0x";
mptr = mptr + 3;
imm64_bytes[39:0]=$signed(buffer[byte_incr*8 +: 40]);
immediate[63:0] ={ {24{imm64_bytes[39]}} , imm64_bytes[39:0] };
for(int i=0;i<=4;i++) begin
toascii(out2,immediate[8*i +: 8]);
mnemonic_stream[255-mptr*8 -: 16]=out2[15:0];
mptr = mptr + 2;
end
mnemonic_stream[255-mptr*8 -: 8] = ",";
mptr = mptr + 1;
mnemonic_stream[255-mptr*8 -: 32] = "%rdi";
mptr = mptr + 4;
for(int i=0;i<=4;i++) begin
imm_1byte[7:0] = buffer[byte_incr*8 +: 8];
toascii(out1,imm_1byte);
opcode_stream[191-optr*8 -: 16] = out1[15:0];
optr = optr + 3;
byte_incr = byte_incr + 1;
end
end
8'hc0: ;
8'hc1: ;
8'hc2: ;
/* retq */ 8'hc3: ;
8'hc4: ;
8'hc5: ;
8'hc6: ;
8'hc7: ;
8'hc8: ;
8'hc9: ;
8'hca: ;
8'hcb: ;
8'hcc: ;
8'hcd: ;
8'hce: ;
8'hcf: ;
8'hd0: ;
8'hd1: ;
8'hd2: ;
8'hd3: ;
8'hd4: ;
8'hd5: ;
8'hd6: ;
8'hd7: ;
8'hd8: ;
8'hd9: ;
8'hda: ;
8'hdb: ;
8'hdc: ;
8'hdd: ;
8'hde: ;
8'hdf: ;
8'he0: ;
8'he1: ;
8'he2: ;
8'he3: ;
8'he4: ;
8'he5: ;
8'he6: ;
8'he7: ;
8'he8: ;
8'he9: ;
8'hea: ;
8'heb: ;
8'hec: ;
8'hed: ;
8'hee: ;
8'hef: ;
8'hf0: ;
8'hf1: ;
8'hf2: ;
8'hf3: ;
8'hf4: ;
8'hf5: ;
8'hf6: ;
8'hf7: ;
8'hf8: ;
8'hf9: ;
8'hfa: ;
8'hfb: ;
8'hfc: ;
8'hfd: ;
8'hfe: ;
8'hff: ;
endcase
end
endtask
task decode;
output logic[3:0] increment_by;
logic[3:0] offs;
logic[3:0] offs2;
logic[3:0] offs3;
logic[3:0] offs4;
logic[3:0] offs5;
logic[3:0] offs6;
logic[3:0] offs7;
logic[3:0] offs8;
inst_field_t next_fld_type;
begin
instr[7:0] = 0;
opcode_stream[191:0] = " ";
mnemonic_stream[255:0] = " ";
optr[7:0] = 8'b0;
mptr[7:0] = 8'b0;
next_fld_type = LEGACY_PREFIX;
offs = 0;
offs2=offs;
if ((next_fld_type & LEGACY_PREFIX) == LEGACY_PREFIX ) begin
check_legacy_prefix(offs2,next_fld_type,offs);
end
offs3=offs2;
if ((next_fld_type & REX_PREFIX) == REX_PREFIX ) begin
check_rex_prefix(offs3,next_fld_type,offs2);
end
offs4=offs3;
if ((next_fld_type & OPCODE) == OPCODE ) begin
check_opcode(offs4,next_fld_type,offs3);
end
offs5=offs4;
if ((next_fld_type & MOD_RM) == MOD_RM ) begin
check_modrm(offs5,next_fld_type,offs4);
end
offs6=offs5;
if ((next_fld_type & SIB) == SIB ) begin
check_sib(offs7,next_fld_type,offs6);
end
offs7=offs6;
if ((next_fld_type & DISPLACEMENT) == DISPLACEMENT) begin
check_disp(offs8,next_fld_type,offs7);
end
offs8=offs7;
increment_by = offs8;
byte_incr = increment_by;
if (num_inst_bytes == 2'b01)
decode_instr();
else
decode_instr2();
if (mnemonic_stream == 0);
if (opcode_stream[191:0] == 0);
end
endtask
task toascii;
output logic[15:0] O;
input logic[7:0] V;
logic[7:0] N1;
logic[7:0] N2;
begin
case ({4'b0,V[7:4]})