34 lines
1.1 KiB
Zig
34 lines
1.1 KiB
Zig
const std = @import("std");
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const Bus = @import("../../Bus.zig");
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const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
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const InstrFn = @import("../../cpu.zig").ThumbInstrFn;
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const add = @import("../arm/data_processing.zig").add;
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const sub = @import("../arm/data_processing.zig").sub;
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pub fn format2(comptime I: bool, is_sub: bool, rn: u3) InstrFn {
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return struct {
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fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u16) void {
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const rs = opcode >> 3 & 0x7;
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const rd = @truncate(u3, opcode);
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if (is_sub) {
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// SUB
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cpu.r[rd] = if (I) blk: {
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break :blk sub(true, cpu, cpu.r[rs], @as(u32, rn));
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} else blk: {
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break :blk sub(true, cpu, cpu.r[rs], cpu.r[rn]);
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};
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} else {
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// ADD
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cpu.r[rd] = if (I) blk: {
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break :blk add(true, cpu, cpu.r[rs], @as(u32, rn));
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} else blk: {
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break :blk add(true, cpu, cpu.r[rs], cpu.r[rn]);
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};
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}
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}
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}.inner;
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}
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