forked from M-Labs/artiq
d6eb2b023a
This reverts 425cd7851, which broke the use of casts to define
integer width.
Instead of it, two steps are taken:
* First, literals are monomorphized, leading to predictable result.
* Second, casts are monomorphized, in a top-bottom way. I.e.
consider the expression `int64(round(x))`. If round() was visited
first, the intermediate precision would be 32-bit, which is
clearly undesirable. Therefore, contextual rules should take
priority over non-contextual ones.
Fixes #1252.
48 lines
1.9 KiB
Python
48 lines
1.9 KiB
Python
"""
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:class:`CastMonomorphizer` uses explicit casts to monomorphize
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expressions of undetermined integer type to either 32 or 64 bits.
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"""
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from pythonparser import algorithm, diagnostic
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from .. import types, builtins, asttyped
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class CastMonomorphizer(algorithm.Visitor):
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def __init__(self, engine):
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self.engine = engine
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def visit_CallT(self, node):
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if (types.is_builtin(node.func.type, "int") or
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types.is_builtin(node.func.type, "int32") or
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types.is_builtin(node.func.type, "int64")):
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typ = node.type.find()
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if (not types.is_var(typ["width"]) and
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len(node.args) == 1 and
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builtins.is_int(node.args[0].type) and
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types.is_var(node.args[0].type.find()["width"])):
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if isinstance(node.args[0], asttyped.BinOpT):
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# Binary operations are a bit special: they can widen, and so their
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# return type is indeterminate until both argument types are fully known.
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# In case we first monomorphize the return type, and then some argument type,
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# and argument type is wider than return type, we'll introduce a conflict.
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return
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node.args[0].type.unify(typ)
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if types.is_builtin(node.func.type, "int") or \
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types.is_builtin(node.func.type, "round"):
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typ = node.type.find()
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if types.is_var(typ["width"]):
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typ["width"].unify(types.TValue(32))
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self.generic_visit(node)
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def visit_CoerceT(self, node):
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if isinstance(node.value, asttyped.NumT) and \
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builtins.is_int(node.type) and \
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builtins.is_int(node.value.type) and \
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not types.is_var(node.type["width"]) and \
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types.is_var(node.value.type["width"]):
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node.value.type.unify(node.type)
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self.generic_visit(node)
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