zba/src/cpu/branch.zig

20 lines
479 B
Zig

const arm = @import("../cpu.zig");
const util = @import("../util.zig");
const Bus = @import("../bus.zig").Bus;
const Arm7tdmi = arm.Arm7tdmi;
const InstrFn = arm.InstrFn;
pub fn branch(comptime L: bool) InstrFn {
return struct {
fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void {
if (L) {
cpu.r[14] = cpu.r[15] - 4;
}
cpu.r[15] = cpu.fakePC() +% util.u32SignExtend(24, opcode << 2);
}
}.inner;
}