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chore: move arm/thumb lut idx functions

This commit is contained in:
Rekai Nyangadzayi Musuka 2022-09-06 23:58:24 -03:00
parent f3c05b6fe6
commit fa862f095a
1 changed files with 16 additions and 14 deletions
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30
src/core/cpu.zig
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@ -28,9 +28,14 @@ pub const arm = struct {
const multiply = @import("cpu/arm/multiply.zig").multiply;
const multiplyLong = @import("cpu/arm/multiply.zig").multiplyLong;
/// Determine index into ARM InstrFn LUT
fn idx(opcode: u32) u12 {
return @truncate(u12, opcode >> 20 & 0xFF) << 4 | @truncate(u12, opcode >> 4 & 0xF);
}
// Undefined ARM Instruction handler
fn und(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void {
const id = armIdx(opcode);
const id = idx(opcode);
cpu.panic("[CPU/Decode] ID: 0x{X:0>3} 0x{X:0>8} is an illegal opcode", .{ id, opcode });
}
@ -120,9 +125,14 @@ pub const thumb = struct {
const swi = @import("cpu/thumb/software_interrupt.zig").fmt17;
const branch = @import("cpu/thumb/branch.zig");
/// Determine index into THUMB InstrFn LUT
fn idx(opcode: u16) u10 {
return @truncate(u10, opcode >> 6);
}
/// Undefined THUMB Instruction Handler
fn und(cpu: *Arm7tdmi, _: *Bus, opcode: u16) void {
const id = thumbIdx(opcode);
const id = idx(opcode);
cpu.panic("[CPU/Decode] ID: 0b{b:0>10} 0x{X:0>2} is an illegal opcode", .{ id, opcode });
}
@ -420,13 +430,13 @@ pub const Arm7tdmi = struct {
const opcode = self.fetch(u16);
if (cpu_logging) self.logger.?.mgbaLog(self, opcode);
thumb.lut[thumbIdx(opcode)](self, self.bus, opcode);
thumb.lut[thumb.idx(opcode)](self, self.bus, opcode);
} else {
const opcode = self.fetch(u32);
if (cpu_logging) self.logger.?.mgbaLog(self, opcode);
if (checkCond(self.cpsr, @truncate(u4, opcode >> 28))) {
arm.lut[armIdx(opcode)](self, self.bus, opcode);
arm.lut[arm.idx(opcode)](self, self.bus, opcode);
}
}
}
@ -517,11 +527,11 @@ pub const Arm7tdmi = struct {
if (self.cpsr.t.read()) {
const opcode = self.bus.dbgRead(u16, self.r[15] - 4);
const id = thumbIdx(opcode);
const id = thumb.idx(opcode);
std.debug.print("opcode: ID: 0x{b:0>10} 0x{X:0>4}\n", .{ id, opcode });
} else {
const opcode = self.bus.dbgRead(u32, self.r[15] - 4);
const id = armIdx(opcode);
const id = arm.idx(opcode);
std.debug.print("opcode: ID: 0x{X:0>3} 0x{X:0>8}\n", .{ id, opcode });
}
@ -601,14 +611,6 @@ pub const Arm7tdmi = struct {
}
};
inline fn armIdx(opcode: u32) u12 {
return @truncate(u12, opcode >> 20 & 0xFF) << 4 | @truncate(u12, opcode >> 4 & 0xF);
}
inline fn thumbIdx(opcode: u16) u10 {
return @truncate(u10, opcode >> 6);
}
pub fn checkCond(cpsr: PSR, cond: u4) bool {
return switch (cond) {
0x0 => cpsr.z.read(), // EQ - Equal