A cross-platform simulator for the GreenArrays GA144 multi-computer chip.
Implement `if` and `-if` opcodes
+45
-2
+45
-2
src/opcodes.zig
+45
-2
src/opcodes.zig
···
69
69
call,
70
70
unext,
71
71
next,
72
-
nop,
73
-
nop,
72
+
_if,
73
+
minus_if,
74
74
fetchP,
75
75
fetchPlus,
76
76
fetchB,
···
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226
try expectEqual(0x122, computer.return_stack.t);
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227
computer.step();
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228
try expectEqual(0x22, computer.p.address.local);
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+
}
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+
231
+
/// if
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+
///
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/// **If**. If T is nonzero, continues with the next instruction word addressed by P. If T is zero, jumps
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+
pub fn _if(self: *Computer) void {
235
+
if (self.data_stack.t == 0) {
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+
self.p.jump(self.slot, self.i);
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+
}
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+
}
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+
240
+
test _if {
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+
var computer: Computer = .reset;
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+
computer.i = @bitCast(f18.Jump{ .destination = 0x44 });
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+
computer.slot = 1;
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+
computer.data_stack.t = 0;
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+
246
+
_if(&computer);
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+
try expectEqual(0x44, computer.p.address.local);
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+
computer.step();
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+
try expectEqual(0, computer.p.address.local);
250
+
}
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+
252
+
/// -if
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+
///
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+
/// Minus-if. If T is negative (T17 set), continues with the next instruction
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+
/// word addressed by P. If T is positive, jumps
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+
pub fn minus_if(self: *Computer) void {
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+
if (self.data_stack.t >= 0) {
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+
self.p.jump(self.slot, self.i);
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+
}
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+
}
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+
262
+
test minus_if {
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+
var computer: Computer = .reset;
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+
computer.i = @bitCast(f18.Jump{ .destination = 0x44 });
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+
computer.slot = 1;
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+
computer.data_stack.t = 1;
267
+
268
+
minus_if(&computer);
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+
try expectEqual(0x44, computer.p.address.local);
270
+
computer.step();
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+
try expectEqual(0, computer.p.address.local);
229
272
}
230
273
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274
/// @p