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52 lines
1.9 KiB
Plaintext
52 lines
1.9 KiB
Plaintext
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HLDS: The "High Level Data Structure". See hlds.m.
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moduleinfo: Another name for the HLDS.
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LLDS: The "Low Level Data Structure". See llds.m.
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inst: instantiatedness. An inst holds three different sorts of
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information. It indicates whether a variable is free, partially
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bound, or ground. If a variable is bound, it may indicate
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which functor(s) the variable can be bound to. Also,
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an inst records whether a value is unique, or whether
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it may be aliased.
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liveness: this term is used to mean two quite different things!
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(1) There's a notion of liveness used in mode analysis:
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a variable is live if either it or an alias might be
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used later on in the computation.
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(2) There's a different notion of liveness used for code generation:
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a variable becomes live (is "born") when the register or stack
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slot holding the variable first acquires a value, and dies when
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that value will definitely not be needed again within this procedure.
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This notion is low-level because it could depend on the low-level
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representation details (in particular, `no_tag' representations
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ought to affect liveness).
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mode: this has two meanings:
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(1) a mapping from one instantiatedness to another
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(the mode of a single variable)
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(2) a mapping from an initial instantiatedness of a predicate's
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arguments to their final instantiatedness
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(the mode of a predicate)
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proc (procedure): a particular mode of a predicate.
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procinfo: the structure in HLDS which contains
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information about a procedure.
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predinfo: the structure in HLDS which contains information about
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a predicate.
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codeinfo: a structure used by codegen.m
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switch: a disjunction which does a case analysis on the toplevel
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functor of some variable.
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super-homogenous form (SHF): a simplified, flattened form of goals, where
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each unification is split into its component pieces; in particular,
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the arguments of each predicate call and functor must be distinct
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variables.
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