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Fix Neg16 to work on “unsigned” values that sneak in
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Ideally, we won’t see any unsigned 16-bit values in the simulator, but just in case one does, use a test that works either way in Neg16.
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@mossprescott
mossprescott committed Apr 22, 2024
1 parent 8d4a79c commit 7d86b61
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2 changes: 1 addition & 1 deletion nand/codegen.py
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Original file line number Diff line number Diff line change
Expand Up @@ -282,7 +282,7 @@ def component_expr(comp):
elif comp.label == 'Eq16':
return binary16(comp, "({a} & 0xffff) == ({b} & 0xffff)")
elif comp.label == 'Neg16':
return unary16(comp, "{} < 0")
return unary16(comp, "({} & 0x8000) != 0")
elif comp.label == 'Inc16':
return None
elif comp.label == 'Dec16':
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127 changes: 21 additions & 106 deletions nand/test_codegen.py
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Original file line number Diff line number Diff line change
Expand Up @@ -56,126 +56,41 @@ def test_and3():
assert and3.out == (a and b and c)


def test_alu():
alu = run(project_02.ALU.constr())

# HACK: copied verbatim from test_02

alu.x = 0
alu.y = -1

alu.zx = 1; alu.nx = 0; alu.zy = 1; alu.ny = 0; alu.f = 1; alu.no = 0 # 0
assert alu.out == 0 and alu.zr == 1 and alu.ng == 0

alu.zx = 1; alu.nx = 1; alu.zy = 1; alu.ny = 1; alu.f = 1; alu.no = 1 # 1
assert alu.out == 1 and alu.zr == 0 and alu.ng == 0

alu.zx = 1; alu.nx = 1; alu.zy = 1; alu.ny = 0; alu.f = 1; alu.no = 0 # -1
assert alu.out == -1 and alu.zr == 0 and alu.ng == 1

alu.zx = 0; alu.nx = 0; alu.zy = 1; alu.ny = 1; alu.f = 0; alu.no = 0 # X
assert alu.out == 0 and alu.zr == 1 and alu.ng == 0

alu.zx = 1; alu.nx = 1; alu.zy = 0; alu.ny = 0; alu.f = 0; alu.no = 0 # Y
assert alu.out == -1 and alu.zr == 0 and alu.ng == 1

alu.zx = 0; alu.nx = 0; alu.zy = 1; alu.ny = 1; alu.f = 0; alu.no = 1 # !X
assert alu.out == -1 and alu.zr == 0 and alu.ng == 1

alu.zx = 1; alu.nx = 1; alu.zy = 0; alu.ny = 0; alu.f = 0; alu.no = 1 # !Y
assert alu.out == 0 and alu.zr == 1 and alu.ng == 0

alu.zx = 0; alu.nx = 0; alu.zy = 1; alu.ny = 1; alu.f = 1; alu.no = 1 # -X
assert alu.out == 0 and alu.zr == 1 and alu.ng == 0

alu.zx = 1; alu.nx = 1; alu.zy = 0; alu.ny = 0; alu.f = 1; alu.no = 1 # -Y
assert alu.out == 1 and alu.zr == 0 and alu.ng == 0

alu.zx = 0; alu.nx = 1; alu.zy = 1; alu.ny = 1; alu.f = 1; alu.no = 1 # X + 1
assert alu.out == 1 and alu.zr == 0 and alu.ng == 0

alu.zx = 1; alu.nx = 1; alu.zy = 0; alu.ny = 1; alu.f = 1; alu.no = 1 # Y + 1
assert alu.out == 0 and alu.zr == 1 and alu.ng == 0
# Repeat the ALU tests:

alu.zx = 0; alu.nx = 0; alu.zy = 1; alu.ny = 1; alu.f = 1; alu.no = 0 # X - 1
assert alu.out == -1 and alu.zr == 0 and alu.ng == 1
import test_02

alu.zx = 1; alu.nx = 1; alu.zy = 0; alu.ny = 0; alu.f = 1; alu.no = 0 # Y - 1
assert alu.out == -2 and alu.zr == 0 and alu.ng == 1

alu.zx = 0; alu.nx = 0; alu.zy = 0; alu.ny = 0; alu.f = 1; alu.no = 0 # X + Y
assert alu.out == -1 and alu.zr == 0 and alu.ng == 1
# Note: not running the same tests on "compiled" because of the extra dependency
run_codegen = test_02.run(simulator="codegen")

alu.zx = 0; alu.nx = 1; alu.zy = 0; alu.ny = 0; alu.f = 1; alu.no = 1 # X - Y
assert alu.out == 1 and alu.zr == 0 and alu.ng == 0

alu.zx = 0; alu.nx = 0; alu.zy = 0; alu.ny = 1; alu.f = 1; alu.no = 1 # Y - X
assert alu.out == -1 and alu.zr == 0 and alu.ng == 1
def test_halfAdder():
test_02.test_halfAdder(run_codegen)

alu.zx = 0; alu.nx = 0; alu.zy = 0; alu.ny = 0; alu.f = 0; alu.no = 0 # X & Y
assert alu.out == 0 and alu.zr == 1 and alu.ng == 0
def test_fullAdder():
test_02.test_fullAdder(run_codegen)

alu.zx = 0; alu.nx = 1; alu.zy = 0; alu.ny = 1; alu.f = 0; alu.no = 1 # X | Y
assert alu.out == -1 and alu.zr == 0 and alu.ng == 1
def test_inc16():
test_02.test_inc16(run_codegen)

def test_add16():
test_02.test_add16(run_codegen)

alu.x = 17
alu.y = 3
def test_zero16():
test_02.test_zero16(run_codegen)

alu.zx = 1; alu.nx = 0; alu.zy = 1; alu.ny = 0; alu.f = 1; alu.no = 0 # 0
assert alu.out == 0 and alu.zr == 1 and alu.ng == 0
def test_neg16():
test_02.test_neg16(run_codegen)

alu.zx = 1; alu.nx = 1; alu.zy = 1; alu.ny = 1; alu.f = 1; alu.no = 1 # 1
assert alu.out == 1 and alu.zr == 0 and alu.ng == 0
def test_alu_nostat():
test_02.test_alu_nostat(run_codegen)

alu.zx = 1; alu.nx = 1; alu.zy = 1; alu.ny = 0; alu.f = 1; alu.no = 0 # -1
assert alu.out == -1 and alu.zr == 0 and alu.ng == 1

alu.zx = 0; alu.nx = 0; alu.zy = 1; alu.ny = 1; alu.f = 0; alu.no = 0 # X
assert alu.out == 17 and alu.zr == 0 and alu.ng == 0

alu.zx = 1; alu.nx = 1; alu.zy = 0; alu.ny = 0; alu.f = 0; alu.no = 0 # Y
assert alu.out == 3 and alu.zr == 0 and alu.ng == 0

alu.zx = 0; alu.nx = 0; alu.zy = 1; alu.ny = 1; alu.f = 0; alu.no = 1 # !X
assert alu.out == -18 and alu.zr == 0 and alu.ng == 1

alu.zx = 1; alu.nx = 1; alu.zy = 0; alu.ny = 0; alu.f = 0; alu.no = 1 # !Y
assert alu.out == -4 and alu.zr == 0 and alu.ng == 1

alu.zx = 0; alu.nx = 0; alu.zy = 1; alu.ny = 1; alu.f = 1; alu.no = 1 # -X
assert alu.out == -17 and alu.zr == 0 and alu.ng == 1

alu.zx = 1; alu.nx = 1; alu.zy = 0; alu.ny = 0; alu.f = 1; alu.no = 1 # -Y
assert alu.out == -3 and alu.zr == 0 and alu.ng == 1

alu.zx = 0; alu.nx = 1; alu.zy = 1; alu.ny = 1; alu.f = 1; alu.no = 1 # X + 1
assert alu.out == 18 and alu.zr == 0 and alu.ng == 0

alu.zx = 1; alu.nx = 1; alu.zy = 0; alu.ny = 1; alu.f = 1; alu.no = 1 # Y + 1
assert alu.out == 4 and alu.zr == 0 and alu.ng == 0

alu.zx = 0; alu.nx = 0; alu.zy = 1; alu.ny = 1; alu.f = 1; alu.no = 0 # X - 1
assert alu.out == 16 and alu.zr == 0 and alu.ng == 0

alu.zx = 1; alu.nx = 1; alu.zy = 0; alu.ny = 0; alu.f = 1; alu.no = 0 # Y - 1
assert alu.out == 2 and alu.zr == 0 and alu.ng == 0

alu.zx = 0; alu.nx = 0; alu.zy = 0; alu.ny = 0; alu.f = 1; alu.no = 0 # X + Y
assert alu.out == 20 and alu.zr == 0 and alu.ng == 0

alu.zx = 0; alu.nx = 1; alu.zy = 0; alu.ny = 0; alu.f = 1; alu.no = 1 # X - Y
assert alu.out == 14 and alu.zr == 0 and alu.ng == 0

alu.zx = 0; alu.nx = 0; alu.zy = 0; alu.ny = 1; alu.f = 1; alu.no = 1 # Y - X
assert alu.out == -14 and alu.zr == 0 and alu.ng == 1

alu.zx = 0; alu.nx = 0; alu.zy = 0; alu.ny = 0; alu.f = 0; alu.no = 0 # X & Y
assert alu.out == 1 and alu.zr == 0 and alu.ng == 0
def test_alu():
test_02.test_alu(run=run_codegen)

alu.zx = 0; alu.nx = 1; alu.zy = 0; alu.ny = 1; alu.f = 0; alu.no = 1 # X | Y
assert alu.out == 19 and alu.zr == 0 and alu.ng == 0

# Repeat the CPU tests:

def test_pc():
pc = run(project_03.PC.constr())
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