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; Attributes.

; Copyright (C) 2000, 2003, 2005, 2009 Red Hat, Inc.

; This file is part of CGEN.

; See file COPYING.CGEN for details.

; attributes are really enum attributes with two possible values, but they

; occur frequently enough that they are special cased.

;

; All objects that use attributes must have two methods:

; - 'get-atlist - returns the object's attr-list

; - 'set-atlist! - set the object's attr-list

;

; In .cpu files, attribute lists are associative lists of (NAME VALUE).

; Boolean attributes are specified as (NAME #t) or (NAME #f),

; but for convenience ATTR and !ATTR are also supported.

; integer/enum attrs are specified as (ATTR value).

; string attrs are specified as (ATTR value).

; Bitset attrs are specified as (ATTR val1,val2,val3).

; In all cases the value needn't be constant, and can be an expression,

; though expressions are currently only supported for META-attributes

; (attributes that don't appear in any generated code).

;

; Example:

; (FOO1 !FOO2 (BAR 3) (FOO3 X) (MACH sparc,sparclite))

;

; ??? Implementation of expressions is being postponed as long

; as possible, avoiding adding complications for complication's sake, and

; because I'm not completely sure how I want to do them.

; The syntax for an expression value is (ATTR (rtx-func ...)).

;

; ??? May wish to allow a bitset attribute like (ATTR val1,!val2), where `!'

; means to turn off that particular bit (or bits if val2 refers to several).

;

; ??? May wish to allow specifying enum attributes by only having to

; specify the value (move names into "enum space" or some such).

; An attr-list (or "atlist") is a collection of attributes.

; There is possible confusion between "alist" (associative-list) and

; "atlist" (attribute-list) but in practice I haven't had a problem.

; ??? May wish to change this to a list of objects, as the alist doesn't carry

; enough info.  However the alist is simple and fast.

; An empty attribute-list.

""; The attribute baseclass.

; [meaning attributes themselves can have attributes].

; An odd notion that is of some use.  It's current raison d'etre is to

; support sanitization of attributes [which is implemented with the

; List of object types this attribute is for.

; attr, enum, cpu, mach, model, ifield, hardware, operand,

; A value of #f means the attribute is for everything.

; A class for each type of attribute.

; `values' exists for boolean-attribute to simplify the code, it's ignored.

; Ditto for `default'.  The default for boolean-attribute is always #f.

; VALUES is ignored for string-attribute.

; For bitset attributes VALUES is a list of

; (symbol bit-number-or-#f attr-list comment-or-#f),

; one for each bit.

; Int's are used to record the bitset in the generated code so there's a limit

; of 32 elements, though there's nothing inherent in the description language

; that precludes removing the limit.

; NOTE: While one might want to record each element as an object, there's

; currently no need for the added complexity.

; For integer attributes VALUES is a list of (int),

; one for each possible value,

; or the empty list of all values are permissible.

; Note that each element is itself a list.  This is for consistency.

; For enum attributes VALUES is a list of

; (symbol enum-value-or-#f attr-list comment-or-#f),

; one for each possible.

; If enum-value is #f (unspecified) cgen will apply the standard rule for

; NOTE: While one might want to record each element as an object, there's

; Return a boolean indicating if X is a <boolean-attribute> object.

; Return a symbol indicating the kind of attribute ATTR is.

"attr-kind: internal error, not an attribute class"; Accessors.

; Create an attribute.

; rather than an object containing the value, so we only have to cons

; NAME and VALUE rather than building some object.  This is for simplicity

; and speed.  We try to incrementally complicate things, only as necessary.

; VALUE must be #f or #t.

; VALUES must be a comma separated list of symbols

; (e.g. val1,val2 not (val1 val2)).

; VALUE must be a number (or maybe a symbol).

;;; Return a procedure to parse an attribute.

;;; RIGHT-TYPE? is a procedure that verifies the value is the right type.

;;; MESSAGE is printed if there is an error.

; A boolean attribute's value is either #t or #f.

"boolean attribute not one of #f/#t""invalid argument to string attribute"; A bitset attribute's value is a comma separated list of elements.

; We don't validate the values.  In the case of the MACH attribute,

; been read in.

; ??? Need to decide whether all define-mach's must appear before any

; define-insn's.  It would be nice to be able to spread an architecture's

; description over several .cpu files.

; ??? On the other hand, all machs are specified in define-arch.

; Perhaps creation of builtins could be defered until then.

"improper bitset attribute"; An integer attribute's value is a number

; (or maybe a symbol representing that value).

"improper integer attribute"; An enum attribute's value is a symbol representing that value.

"boolean value list must be (#f #t)"; Ignore values for strings.  We can't do any error checking since

; the default value is (#f #t).

; Parse a bitset attribute's value definition.

; FIXME: treated as enum?

""; Parse an integer attribute's value definition.

; VALUES may be #f which means any value is ok.

; See parse-enum-vals for more info.

""; Make an attribute list object from a list of name/value pairs.

; Parse an attribute definition.

; This is the main routine for building an attribute object from a

; All arguments are in raw (non-evaluated) form.

; TYPE-CLASS is the class of the object to create.

; i.e. one of <{boolean,bitset,integer,enum,string}-attribute>.

; If DEFAULT is #f, use the first value.

; ??? Allowable values for integer attributes is wip.

"Processing attribute "" ...\n";; Pick out name first to augment the error context.

"invalid default""""invalid default""invalid default""invalid default"; Read an attribute description

; This is the main routine for analyzing attributes in the .cpu file.

; CONTEXT is a <context> object for error messages.

; ARG-LIST is an associative list of field name and field value.

; -attr-parse is invoked to create the attribute object.

; attribute type

""; assume for everything

; #f indicates "not set"

; Loop over each element in ARG-LIST, recording what's found.

"invalid attribute type""invalid attribute arg"; Must have type now.

"type not specified"; Establish proper defaults now that we know the type.

; really a nop, but for consistency

;; FIXME

; really a nop, but for consistency

"enum-attribute default not specified""bitset-attribute values not specified"; Now that we've identified the elements, build the object.

"define-attr"; Query routines.

; The result is the object or #f if not found.

; attribute alist ALIST.

; Note that if the attribute isn't present, it is defined to be #f.

; attribute alist ALIST.

; Expand attribute value ATVAL, which is an rtx expression.

; OWNER is the containing object or #f if there is none.

; OWNER is needed if an attribute is defined in terms of other attributes.

; If it's #f obviously ATVAL can't be defined in terms of others.

"-attr-eval: internal error, unsupported result:"; Return value of ATTR in attribute alist ALIST.

; If not present, return the default value.

; OWNER is the containing object or #f if there is none.

; pair? -> cheap non-null-list?

; Return the value of ATTR in ATLIST.

; Same as atlist-attr-value but return nil if attribute not present.

; Return the default for attribute A.

; If A isn't a non-boolean attribute, we assume it's a boolean one, and

; OWNER is the containing object or #f if there is none.

; pair? -> cheap non-null-list?

; If no default was provided, use the first value.

; Return a boolean indicating if X is present in BITSET.

; Bitset values are recorded as val1,val2,....

; Get/set attributes of OBJ.

; As a speed up, we allow objects to specify an empty attribute list

; ??? There is atlist-empty now which should be used directly.

; Add attribute ATTR to OBJ.

; The attribute is prepended to the front so it overrides any existing

; Add attribute list ATLIST to OBJ.

; Must have same prefix.

; OBJ is any object that supports attributes.

; Return a boolean indicating if attribute ATTR is present in OBJ.

; If the attribute isn't present, the default is returned.

; Return boolean of whether OBJ has attribute ATTR value VALUE or not.

; OBJ is any object that supports attributes.

; NOTE: The default value of the attribute IS considered.

; or not.

; OBJ is any object that supports attributes.

; NOTE: The default value of the attribute IS NOT considered.

; Utilities.

; Convert a bitset value "a,b,c" into a list (a b c).

; Generate a list representing a bit mask of the indices of 'values'

; within 'all-values'. Each element in the resulting list represents a byte.

; Both bits and bytes are indexed from left to right starting at 0

"charmask-bytes for "" ""\n""indices: ""\n""result: ""\n"; Convert a bitset value into a bit string based on the

"{ "", \"""\\x""\" }"; Return the enum of ATTR-NAME for type TYPE.

; TYPE is one of 'ifld, 'hw, 'operand, 'insn.

"CGEN_""_"; Return a list of enum value definitions for gen-enum-decl.

; Attributes numbers are organized as follows: booleans are numbered 0-31.

; are left unused.  Non-booleans are numbered starting at 32.

; An alternative is start numbering the booleans at 32.  The generated code

; is simpler with the current way (the "- 32" to get back the bit number or

;

; Three special values are created:

; END-BOOLS - mark end of boolean attributes

; END-NBOOLS - mark end of non-boolean attributes

; START-NBOOLS - marks the start of the non-boolean attributes

; (needed in case first non-bool is sanytized out).

;

; ATTR-OBJ-LIST is a list of <attribute> objects (always subclassed of course).

; Sort an alist of attributes so non-boolean attributes are at the front.

; This is required by the C support code (cgen.h:CGEN_ATTR_VALUE).

; Boolean attributes appear as (NAME . #t/#f), non-boolean ones appear as

; (NAME . VALUE).  Attributes of the same type are sorted by name.

;(display (list a b "\n"))

; we know b is non-bool here

; Sort ATTR-LIST into two lists: bools and non-bools.

; The car of the result is the bools, the cdr is the non-bools.

; and used for the few special attributes that are refered to by

; architecture independent code.

; For each of non-bools and bools, put attributes with the INDEX attribute

; first.  This is used to sort a list of attributes for output (e.g. define

; the attr enum).

; FIXME: Record index number with the INDEX attribute and sort on it.

; Return number of non-bools in attributes ATLIST.

; Given an alist of attributes, return the non-bools.

; Given an alist of attributes, return the bools.

; Parse an attribute spec.

; CONTEXT is a <context> object or #f if there is none.

; The result is the attribute alist.

"unknown attribute""unknown attribute""improper attribute"; Parse an object attribute spec.

; ATTRS is a list of attribute specs (e.g. (FOO !BAR (BAZ 3))).

; The result is an <attr-list> object.

; Return the source form of an atlist's values.

; Externally attributes are ((name1 value1) (name2 value2) ...).

; Internally they are ((name1 . value1) (name2 . value2) ...).

; Cons an attribute to an attribute list to create a new attribute list.

; signify an empty attribute list, in which case we make the prefix of the

; result "").

; The prefix for the new atlist is taken from the first one.

; Remove meta-attributes from ALIST.

; "meta" may be the wrong adjective to use here.

; The attributes in question are not intended to appear in generated files.

; FIXME: Why not use find?

; Remove meta-attributes from ATTR-LIST.

; The attributes in question are not intended to appear in generated files.

; They started out being attributes of attributes, hence the name "meta".

; FIXME: Why not use find?

; Remove duplicates from ATTRS, a list of attributes.

; Attribute lists are typically small so we use a simple O^2 algorithm.

; defined to pick the first entry of each attribute.

; Return a list of all attrs in TABLE-LIST, a list of lists of arbitrary

; attributes where the insns and macro-insns are on separate lists and

; appending them into one list would be unnecessarily expensive.

; ACCESSOR is a function to access the attrs field from TABLE-LIST.

; Duplicates are eliminated and the list is sorted so non-boolean attributes

; are at the front (required by the C code that fetches attribute values).

; STD-ATTRS is an `attr-list' object of attrs that are always available.

; The actual values returned are random (e.g. #t vs #f).  We could

; canonicalize them.

; The result is an alist of all the attributes that are used in TABLE-LIST.

; ??? The cdr of each element is some random value.  Perhaps it should be

; the default value or perhaps we should just return a list of names.

; ??? No longer used.

; Return lists of attributes for particular object types.

; Current behaviour puts the non-bools at the front.

; Methods to emit the C value of an attribute.

; independent part of CGEN), but there isn't a better place for them

; (maybe utils-cgen.scm?) and there's only a few of them.

"0""1";(string-upcase (string-append (obj:str-name self) "_" value)))

"isa""|(1<<""_"")""{ ""isa""{ ""|(1<<""_"")"", 0 }"" }""{ { "", 0 } }""_""{ { "", 0 } }";; Doesn't handle escape sequences.

"\"""\""; Called before loading a .cpu file to initialize.

Define an attribute, name/value pair list version.

; One thing this does is define all attributes requiring a fixed index,

; ??? Perhaps it would make sense to define all predefined attributes here.

"virtual object"; The meta attribute is used for attributes that aren't to appear in

; generated output (need a better name).

; Objects to keep local to a generated file.

; Attributes requiring fixed indices.

; ALIAS is used for instructions that are aliases of more general insns.

; ALIAS insns are ignored by the simulator.

"insn is an alias of another"; Called after loading a .cpu file to perform any post-processing required.