17 lines
605 B
Zig
17 lines
605 B
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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pub fn format12(comptime isSP: bool, comptime rd: 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 left = if (isSP) cpu.r[13] else cpu.r[15] + 2 & 0xFFFF_FFFD; // fetch (+2)
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const right = @truncate(u10, opcode & 0xFF) << 2;
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const result = left + right; // TODO: What about overflows?
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cpu.r[rd] = result;
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}
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}.inner;
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}
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