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feat: move arm instr decoding to module

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This commit is contained in:
Rekai Nyangadzayi Musuka
2022-07-27 13:23:29 -03:00
parent 9d037fdc3e
commit c397b7069d
10 changed files with 106 additions and 104 deletions
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192
src/core/cpu.zig
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@@ -10,22 +10,105 @@ const FilePaths = @import("util.zig").FilePaths;
const Allocator = std.mem.Allocator;
const File = std.fs.File;
// ARM Instruction Groups
const dataProcessing = @import("cpu/arm/data_processing.zig").dataProcessing;
const psrTransfer = @import("cpu/arm/psr_transfer.zig").psrTransfer;
const singleDataTransfer = @import("cpu/arm/single_data_transfer.zig").singleDataTransfer;
const halfAndSignedDataTransfer = @import("cpu/arm/half_signed_data_transfer.zig").halfAndSignedDataTransfer;
const blockDataTransfer = @import("cpu/arm/block_data_transfer.zig").blockDataTransfer;
const armBranch = @import("cpu/arm/branch.zig").branch;
const branchAndExchange = @import("cpu/arm/branch.zig").branchAndExchange;
const armSoftwareInterrupt = @import("cpu/arm/software_interrupt.zig").armSoftwareInterrupt;
const singleDataSwap = @import("cpu/arm/single_data_swap.zig").singleDataSwap;
// ARM Instructions
pub const arm = struct {
pub const InstrFn = fn (*Arm7tdmi, *Bus, u32) void;
const lut: [0x1000]InstrFn = populate();
const multiply = @import("cpu/arm/multiply.zig").multiply;
const multiplyLong = @import("cpu/arm/multiply.zig").multiplyLong;
const processing = @import("cpu/arm/data_processing.zig").dataProcessing;
const psrTransfer = @import("cpu/arm/psr_transfer.zig").psrTransfer;
const transfer = @import("cpu/arm/single_data_transfer.zig").singleDataTransfer;
const halfSignedTransfer = @import("cpu/arm/half_signed_data_transfer.zig").halfAndSignedDataTransfer;
const blockTransfer = @import("cpu/arm/block_data_transfer.zig").blockDataTransfer;
const branch = @import("cpu/arm/branch.zig").branch;
const branchExchange = @import("cpu/arm/branch.zig").branchAndExchange;
const swi = @import("cpu/arm/software_interrupt.zig").armSoftwareInterrupt;
const swap = @import("cpu/arm/single_data_swap.zig").singleDataSwap;
// THUMB Instruction Groups
const multiply = @import("cpu/arm/multiply.zig").multiply;
const multiplyLong = @import("cpu/arm/multiply.zig").multiplyLong;
// Undefined ARM Instruction handler
fn und(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void {
const id = armIdx(opcode);
cpu.panic("[CPU/Decode] ID: 0x{X:0>3} 0x{X:0>8} is an illegal opcode", .{ id, opcode });
}
fn populate() [0x1000]InstrFn {
return comptime {
@setEvalBranchQuota(0xE000);
var ret = [_]InstrFn{und} ** 0x1000;
var i: usize = 0;
while (i < ret.len) : (i += 1) {
ret[i] = switch (@as(u2, i >> 10)) {
0b00 => if (i == 0x121) blk: {
break :blk branchExchange;
} else if (i & 0xFCF == 0x009) blk: {
const A = i >> 5 & 1 == 1;
const S = i >> 4 & 1 == 1;
break :blk multiply(A, S);
} else if (i & 0xFBF == 0x109) blk: {
const B = i >> 6 & 1 == 1;
break :blk swap(B);
} else if (i & 0xF8F == 0x089) blk: {
const U = i >> 6 & 1 == 1;
const A = i >> 5 & 1 == 1;
const S = i >> 4 & 1 == 1;
break :blk multiplyLong(U, A, S);
} else if (i & 0xE49 == 0x009 or i & 0xE49 == 0x049) blk: {
const P = i >> 8 & 1 == 1;
const U = i >> 7 & 1 == 1;
const I = i >> 6 & 1 == 1;
const W = i >> 5 & 1 == 1;
const L = i >> 4 & 1 == 1;
break :blk halfSignedTransfer(P, U, I, W, L);
} else if (i & 0xD90 == 0x100) blk: {
const I = i >> 9 & 1 == 1;
const R = i >> 6 & 1 == 1;
const kind = i >> 4 & 0x3;
break :blk psrTransfer(I, R, kind);
} else blk: {
const I = i >> 9 & 1 == 1;
const S = i >> 4 & 1 == 1;
const instrKind = i >> 5 & 0xF;
break :blk processing(I, S, instrKind);
},
0b01 => if (i >> 9 & 1 == 1 and i & 1 == 1) und else blk: {
const I = i >> 9 & 1 == 1;
const P = i >> 8 & 1 == 1;
const U = i >> 7 & 1 == 1;
const B = i >> 6 & 1 == 1;
const W = i >> 5 & 1 == 1;
const L = i >> 4 & 1 == 1;
break :blk transfer(I, P, U, B, W, L);
},
else => switch (@as(u2, i >> 9 & 0x3)) {
// MSB is guaranteed to be 1
0b00 => blk: {
const P = i >> 8 & 1 == 1;
const U = i >> 7 & 1 == 1;
const S = i >> 6 & 1 == 1;
const W = i >> 5 & 1 == 1;
const L = i >> 4 & 1 == 1;
break :blk blockTransfer(P, U, S, W, L);
},
0b01 => blk: {
const L = i >> 8 & 1 == 1;
break :blk branch(L);
},
0b10 => und, // COP Data Transfer
0b11 => if (i >> 8 & 1 == 1) swi() else und, // COP Data Operation + Register Transfer
},
};
}
return ret;
};
}
};
// THUMB Instructions
pub const thumb = struct {
pub const InstrFn = fn (*Arm7tdmi, *Bus, u16) void;
const lut: [0x400]InstrFn = populate();
@@ -143,9 +226,6 @@ pub const thumb = struct {
}
};
pub const ArmInstrFn = fn (*Arm7tdmi, *Bus, u32) void;
const arm_lut: [0x1000]ArmInstrFn = armPopulate();
const enable_logging = false;
const log = std.log.scoped(.Arm7Tdmi);
@@ -359,7 +439,7 @@ pub const Arm7tdmi = struct {
if (enable_logging) if (self.log_file) |file| self.debug_log(file, opcode);
if (checkCond(self.cpsr, @truncate(u4, opcode >> 28))) {
arm_lut[armIdx(opcode)](self, &self.bus, opcode);
arm.lut[armIdx(opcode)](self, &self.bus, opcode);
}
}
}
@@ -590,79 +670,6 @@ pub fn checkCond(cpsr: PSR, cond: u4) bool {
};
}
fn armPopulate() [0x1000]ArmInstrFn {
return comptime {
@setEvalBranchQuota(0xE000);
var lut = [_]ArmInstrFn{armUndefined} ** 0x1000;
var i: usize = 0;
while (i < lut.len) : (i += 1) {
lut[i] = switch (@as(u2, i >> 10)) {
0b00 => if (i == 0x121) blk: {
break :blk branchAndExchange;
} else if (i & 0xFCF == 0x009) blk: {
const A = i >> 5 & 1 == 1;
const S = i >> 4 & 1 == 1;
break :blk multiply(A, S);
} else if (i & 0xFBF == 0x109) blk: {
const B = i >> 6 & 1 == 1;
break :blk singleDataSwap(B);
} else if (i & 0xF8F == 0x089) blk: {
const U = i >> 6 & 1 == 1;
const A = i >> 5 & 1 == 1;
const S = i >> 4 & 1 == 1;
break :blk multiplyLong(U, A, S);
} else if (i & 0xE49 == 0x009 or i & 0xE49 == 0x049) blk: {
const P = i >> 8 & 1 == 1;
const U = i >> 7 & 1 == 1;
const I = i >> 6 & 1 == 1;
const W = i >> 5 & 1 == 1;
const L = i >> 4 & 1 == 1;
break :blk halfAndSignedDataTransfer(P, U, I, W, L);
} else if (i & 0xD90 == 0x100) blk: {
const I = i >> 9 & 1 == 1;
const R = i >> 6 & 1 == 1;
const kind = i >> 4 & 0x3;
break :blk psrTransfer(I, R, kind);
} else blk: {
const I = i >> 9 & 1 == 1;
const S = i >> 4 & 1 == 1;
const instrKind = i >> 5 & 0xF;
break :blk dataProcessing(I, S, instrKind);
},
0b01 => if (i >> 9 & 1 == 1 and i & 1 == 1) armUndefined else blk: {
const I = i >> 9 & 1 == 1;
const P = i >> 8 & 1 == 1;
const U = i >> 7 & 1 == 1;
const B = i >> 6 & 1 == 1;
const W = i >> 5 & 1 == 1;
const L = i >> 4 & 1 == 1;
break :blk singleDataTransfer(I, P, U, B, W, L);
},
else => switch (@as(u2, i >> 9 & 0x3)) {
// MSB is guaranteed to be 1
0b00 => blk: {
const P = i >> 8 & 1 == 1;
const U = i >> 7 & 1 == 1;
const S = i >> 6 & 1 == 1;
const W = i >> 5 & 1 == 1;
const L = i >> 4 & 1 == 1;
break :blk blockDataTransfer(P, U, S, W, L);
},
0b01 => blk: {
const L = i >> 8 & 1 == 1;
break :blk armBranch(L);
},
0b10 => armUndefined, // COP Data Transfer
0b11 => if (i >> 8 & 1 == 1) armSoftwareInterrupt() else armUndefined, // COP Data Operation + Register Transfer
},
};
}
return lut;
};
}
pub const PSR = extern union {
mode: Bitfield(u32, 0, 5),
t: Bit(u32, 5),
@@ -697,8 +704,3 @@ fn getMode(bits: u5) ?Mode {
fn getModeChecked(cpu: *const Arm7tdmi, bits: u5) Mode {
return getMode(bits) orelse cpu.panic("[CPU/CPSR] 0b{b:0>5} is an invalid CPU mode", .{bits});
}
fn armUndefined(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void {
const id = armIdx(opcode);
cpu.panic("[CPU/Decode] ID: 0x{X:0>3} 0x{X:0>8} is an illegal opcode", .{ id, opcode });
}

2
src/core/cpu/arm/block_data_transfer.zig
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@@ -1,6 +1,6 @@
const Bus = @import("../../Bus.zig");
const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
const InstrFn = @import("../../cpu.zig").ArmInstrFn;
const InstrFn = @import("../../cpu.zig").arm.InstrFn;
pub fn blockDataTransfer(comptime P: bool, comptime U: bool, comptime S: bool, comptime W: bool, comptime L: bool) InstrFn {
return struct {

2
src/core/cpu/arm/branch.zig
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@@ -2,7 +2,7 @@ const std = @import("std");
const Bus = @import("../../Bus.zig");
const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
const InstrFn = @import("../../cpu.zig").ArmInstrFn;
const InstrFn = @import("../../cpu.zig").arm.InstrFn;
const sext = @import("../../util.zig").sext;

2
src/core/cpu/arm/data_processing.zig
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@@ -1,6 +1,6 @@
const Bus = @import("../../Bus.zig");
const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
const InstrFn = @import("../../cpu.zig").ArmInstrFn;
const InstrFn = @import("../../cpu.zig").arm.InstrFn;
const rotateRight = @import("../barrel_shifter.zig").rotateRight;
const execute = @import("../barrel_shifter.zig").execute;

2
src/core/cpu/arm/half_signed_data_transfer.zig
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@@ -2,7 +2,7 @@ const std = @import("std");
const Bus = @import("../../Bus.zig");
const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
const InstrFn = @import("../../cpu.zig").ArmInstrFn;
const InstrFn = @import("../../cpu.zig").arm.InstrFn;
const sext = @import("../../util.zig").sext;
const rotr = @import("../../util.zig").rotr;

2
src/core/cpu/arm/multiply.zig
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@@ -1,6 +1,6 @@
const Bus = @import("../../Bus.zig");
const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
const InstrFn = @import("../../cpu.zig").ArmInstrFn;
const InstrFn = @import("../../cpu.zig").arm.InstrFn;
pub fn multiply(comptime A: bool, comptime S: bool) InstrFn {
return struct {

2
src/core/cpu/arm/psr_transfer.zig
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@@ -2,7 +2,7 @@ const std = @import("std");
const Bus = @import("../../Bus.zig");
const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
const InstrFn = @import("../../cpu.zig").ArmInstrFn;
const InstrFn = @import("../../cpu.zig").arm.InstrFn;
const PSR = @import("../../cpu.zig").PSR;
const log = std.log.scoped(.PsrTransfer);

2
src/core/cpu/arm/single_data_swap.zig
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@@ -2,7 +2,7 @@ const std = @import("std");
const Bus = @import("../../Bus.zig");
const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
const InstrFn = @import("../../cpu.zig").ArmInstrFn;
const InstrFn = @import("../../cpu.zig").arm.InstrFn;
const rotr = @import("../../util.zig").rotr;

2
src/core/cpu/arm/single_data_transfer.zig
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@@ -4,7 +4,7 @@ const util = @import("../../util.zig");
const shifter = @import("../barrel_shifter.zig");
const Bus = @import("../../Bus.zig");
const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
const InstrFn = @import("../../cpu.zig").ArmInstrFn;
const InstrFn = @import("../../cpu.zig").arm.InstrFn;
const rotr = @import("../../util.zig").rotr;

2
src/core/cpu/arm/software_interrupt.zig
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@@ -1,6 +1,6 @@
const Bus = @import("../../Bus.zig");
const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
const InstrFn = @import("../../cpu.zig").ArmInstrFn;
const InstrFn = @import("../../cpu.zig").arm.InstrFn;
pub fn armSoftwareInterrupt() InstrFn {
return struct {