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Get and set top of range of a location. Make AND do this to A reg.

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This commit is contained in:
Chris Pressey 2018-02-14 15:13:35 +00:00
parent 93e2dada16
commit 2897a04718
1 changed files with 21 additions and 1 deletions
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22
src/sixtypical/analyzer.py
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@ -164,6 +164,18 @@ class Context(object):
for ref in refs:
self._range[ref] = ref.max_range()
def set_top_of_range(self, ref, top):
self.assert_meaningful(ref)
(bottom, _) = self._range[ref]
self._range[ref] = (bottom, top)
def get_top_of_range(self, ref):
if isinstance(ref, ConstantRef):
return ref.value
self.assert_meaningful(ref)
(_, top) = self._range[ref]
return top
def set_unmeaningful(self, *refs):
for ref in refs:
if ref in self._range:
@ -351,7 +363,15 @@ class Analyzer(object):
self.assert_type(TYPE_BYTE, src, dest)
context.assert_meaningful(src, dest)
context.set_written(FLAG_Z, FLAG_N, FLAG_C)
elif opcode in ('and', 'or', 'xor'):
elif opcode == 'and':
self.assert_type(TYPE_BYTE, src, dest)
context.assert_meaningful(src, dest)
context.set_written(dest, FLAG_Z, FLAG_N)
# If you AND the A register with a value V, the resulting value of A
# cannot exceed the value of V; i.e. the maximum value of A becomes
# the maximum value of V.
context.set_top_of_range(dest, context.get_top_of_range(src))
elif opcode in ('or', 'xor'):
self.assert_type(TYPE_BYTE, src, dest)
context.assert_meaningful(src, dest)
context.set_written(dest, FLAG_Z, FLAG_N)