X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fgeneric%2Fearly-objdef.lisp;h=eb6927509bbb286d175cbaa4b3ef4e7c1c410c53;hb=19319c931fc1636835dbef71808cc10e252bcf45;hp=18596f410b91a03476e22ec22a8a1cfea1f3b56e;hpb=0c7ffa8fb85a94482814835c9f28abfd0400ab99;p=sbcl.git diff --git a/src/compiler/generic/early-objdef.lisp b/src/compiler/generic/early-objdef.lisp index 18596f4..eb69275 100644 --- a/src/compiler/generic/early-objdef.lisp +++ b/src/compiler/generic/early-objdef.lisp @@ -11,93 +11,243 @@ (in-package "SB!VM") -;;; FIXME: It's clever using :SUFFIX -TYPE for these things, but it's -;;; a pain for people just learning to find their way around the code -;;; who want to use lexical search to figure out where things like -;;; EVEN-FIXNUM-LOWTAG are defined. Remove the :SUFFIXes and just expand -;;; out the full names. Or even define them in DEF EVEN-FIXNUM-LOWTAG -;;; style so searches like 'def.*even-fixnum-lowtag' can find them. - -;;; tags for the main low-level types, to be stored in the low three -;;; bits to identify the type of a machine word +;;; Tags for the main low-level types are stored in the low n (usually three) +;;; bits to identify the type of a machine word. Certain constraints +;;; apply: +;;; * EVEN-FIXNUM-LOWTAG and ODD-FIXNUM-LOWTAG must be 0 and 4: code +;;; which shifts left two places to convert raw integers to tagged +;;; fixnums is ubiquitous. +;;; * LIST-POINTER-LOWTAG + N-WORD-BYTES = OTHER-POINTER-LOWTAG: NIL +;;; is both a cons and a symbol (at the same address) and depends on this. +;;; See the definition of SYMBOL in objdef.lisp +;;; * OTHER-POINTER-LOWTAG > 4: Some code in the SPARC backend, +;;; which uses bit 2 of the ALLOC register to indicate that +;;; PSEUDO-ATOMIC is on, doesn't strip the low bits of reg_ALLOC +;;; before ORing in OTHER-POINTER-LOWTAG within a PSEUDO-ATOMIC +;;; section. +;;; * OTHER-IMMEDIATE-0-LOWTAG are spaced 4 apart: various code wants to +;;; iterate through these +;;; * Allocation code on Alpha wants lowtags for heap-allocated +;;; objects to be odd. +;;; (These are just the ones we know about as of sbcl-0.7.1.22. There +;;; might easily be more, since these values have stayed highly +;;; constrained for more than a decade, an inviting target for +;;; inventive abstraction-phobic maintainers.:-) +;;; +;;; Another way to look at lowtags is that there is no one lowtag +;;; length. On 32-bit platforms, fixnums and other-immediates have a +;;; lowtag length of two bits, and pointers have a lowtag length of +;;; three bits. On 64-bit platforms, fixnums and pointers gain an +;;; extra bit, and six "pad" lowtags waste the extra encoding space so +;;; obtained. +;;; +;;; x00 -- fixnum +;;; x10 -- other-immediate +;;; 001 -- instance-pointer +;;; 011 -- list-pointer +;;; 101 -- fun-pointer +;;; 111 -- other-pointer +;;; +;;; If you change the tag layout, check the various functions in +;;; src/runtime/runtime.h to see if they need to be updated, along +;;; with print_obj() in src/runtime/print.c, possibly gc_init_tables() +;;; in src/runtime/gc-common-c and possibly the code in src/code/room. (eval-when (:compile-toplevel :load-toplevel :execute) ;; The EVAL-WHEN is necessary (at least for Lispworks), because the ;; second DEFENUM uses the value of OTHER-IMMEDIATE-0-LOWTAG, which is ;; defined in the first DEFENUM. -- AL 20000216 - (defenum (:suffix -lowtag) - even-fixnum - ;; Note: CMU CL, and SBCL < 0.pre7.39, had FUN-POINTER-LOWTAG - ;; here. We swapped FUN-POINTER-LOWTAG and - ;; INSTANCE-POINTER-LOWTAG in sbcl-0.pre7.39 in order to help with a - ;; low-level pun in the function call sequence on the PPC port. - ;; For more information, see the PPC port code. -- WHN 2001-10-03 - instance-pointer - other-immediate-0 - list-pointer - odd-fixnum - fun-pointer - other-immediate-1 - other-pointer)) + #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or)) + (defenum () + even-fixnum-lowtag + other-immediate-0-lowtag + pad0-lowtag + instance-pointer-lowtag + pad1-lowtag + other-immediate-1-lowtag + pad2-lowtag + list-pointer-lowtag + odd-fixnum-lowtag + other-immediate-2-lowtag + pad3-lowtag + fun-pointer-lowtag + pad4-lowtag + other-immediate-3-lowtag + pad5-lowtag + other-pointer-lowtag) + #!+#.(cl:if (cl:= 32 sb!vm:n-word-bits) '(and) '(or)) + (defenum () + even-fixnum-lowtag + instance-pointer-lowtag + other-immediate-0-lowtag + list-pointer-lowtag + odd-fixnum-lowtag + fun-pointer-lowtag + other-immediate-1-lowtag + other-pointer-lowtag)) + +(def!constant nil-value + (+ static-space-start n-word-bytes other-pointer-lowtag)) + +(defconstant-eqx fixnum-lowtags + #.(let ((fixtags nil)) + (do-external-symbols (sym "SB!VM") + (let* ((name (symbol-name sym)) + (len (length name))) + (when (and (boundp sym) + (integerp (symbol-value sym)) + (> len 7) + (string= name "-LOWTAG" :start1 (- len 7)) + (zerop (logand (symbol-value sym) fixnum-tag-mask))) + (push sym fixtags)))) + `',(sort fixtags #'string< :key #'symbol-name)) + #'equal) ;;; the heap types, stored in 8 bits of the header of an object on the ;;; heap, to identify the type of the heap object (which'll be at ;;; least two machine words, often more) -(defenum (:suffix -widetag - :start (+ (ash 1 n-lowtag-bits) other-immediate-0-lowtag) - :step (ash 1 (1- n-lowtag-bits))) - bignum - ratio - single-float - double-float - #!+long-float long-float - complex - complex-single-float - complex-double-float - #!+long-float complex-long-float +;;; +;;; Note: the order specified here is not critical for correctness, +;;; but (FIXME) with %TEST-HEADERS as currently defined, BIGNUM must +;;; be first, and COMPLEX-ARRAY must be last. +;;; +;;; However, for efficiency, we prefer contiguous sets of widetags for +;;; "similar" objects, so that type checking can be done with a range +;;; check, rather than several individual checks. +;;; +;;; * BIGNUM + RATIO (+ FIXNUM) = RATIONAL +;;; +;;; * SINGLE-FLOAT + DOUBLE-FLOAT + LONG-FLOAT = FLOAT +;;; +;;; * RATIONAL + FLOAT = REAL +;;; +;;; * (FIXME: COMPLEX example, which needs fixing anyway -- see +;;; UPGRADED-COMPLEX-PART-TYPE) +;;; +;;; * SIMPLE-ARRAY-* = (SIMPLE-ARRAY * (*)) +;;; +;;; * SIMPLE-ARRAY-NIL + SIMPLE-BASE-STRING = SIMPLE-STRING +;;; +;;; * SIMPLE-ARRAY + COMPLEX-ARRAYOID = (SATISFIES ARRAY-HEADER-P) +;;; +;;; In addition, with +;;; sufficient care we can cause extra combinations to appear with +;;; differences in only one bit, permitting a more efficient type +;;; test. As an example, if SIMPLE-BASE-STRING = 0xA6 and +;;; COMPLEX-BASE-STRING = 0xE6, then the type test for BASE-STRING is +;;; +;;; AND tag, ~0x40, tag +;;; ANDcc tag, 0xA6, tag +;;; JNE tag, label +;;; +;;; rather than two separate tests and jumps +(defenum (;; The first widetag must be greater than SB!VM:LOWTAG-LIMIT + ;; otherwise code in generic/early-type-vops will suffer + ;; a long, horrible death. --njf, 2004-08-09 + :start (+ (ash 1 n-lowtag-bits) other-immediate-0-lowtag) + :step 4) + ;; NOTE: the binary numbers off to the side are only valid for 32-bit + ;; ports; add #b1000 if you want to know the values for 64-bit ports. + ;; And note that the numbers get a little scrambled further down. + ;; --njf, 2004-08-09 + bignum-widetag ; 00001010 + ratio-widetag ; 00001110 + single-float-widetag ; 00010010 + double-float-widetag ; 00010110 + complex-widetag ; 00011010 + complex-single-float-widetag ; 00011110 + complex-double-float-widetag ; 00100010 + + code-header-widetag ; 00100110 + + simple-fun-header-widetag ; 00101010 + closure-header-widetag ; 00101110 + funcallable-instance-header-widetag ; 00110010 + + return-pc-header-widetag ; 00110110 + value-cell-header-widetag ; 00111010 + symbol-header-widetag ; 00111110 + character-widetag ; 01000010 + sap-widetag ; 01000110 + unbound-marker-widetag ; 01001010 + weak-pointer-widetag ; 01001110 + instance-header-widetag ; 01010010 + fdefn-widetag ; 01010110 + + no-tls-value-marker-widetag ; 01011010 + #!-sb-simd-pack + unused01-widetag + #!+sb-simd-pack + simd-pack-widetag ; 01011110 + unused02-widetag ; 01100010 + unused03-widetag ; 01100110 + unused04-widetag ; 01101010 + unused05-widetag ; 01101110 + unused06-widetag ; 01110010 + unused07-widetag ; 01110110 + #!+#.(cl:if (cl:= 32 sb!vm:n-word-bits) '(and) '(or)) + unused08-widetag ; 01111010 + #!+#.(cl:if (cl:= 32 sb!vm:n-word-bits) '(and) '(or)) + unused09-widetag ; 01111110 - simple-array - simple-string - simple-bit-vector - simple-vector - simple-array-unsigned-byte-2 - simple-array-unsigned-byte-4 - simple-array-unsigned-byte-8 - simple-array-unsigned-byte-16 - simple-array-unsigned-byte-32 - simple-array-signed-byte-8 - simple-array-signed-byte-16 - simple-array-signed-byte-30 - simple-array-signed-byte-32 - simple-array-single-float - simple-array-double-float - #!+long-float simple-array-long-float - simple-array-complex-single-float - simple-array-complex-double-float - #!+long-float simple-array-complex-long-float - complex-string - complex-bit-vector - complex-vector - complex-array + #!+#.(cl:if (cl:= 32 sb!vm:n-word-bits) '(and) '(or)) + unused10-widetag ; 10000010 + #!+#.(cl:if (cl:= 32 sb!vm:n-word-bits) '(and) '(or)) + unused11-widetag ; 10000110 - code-header - simple-fun-header - closure-header - funcallable-instance-header - closure-fun-header + simple-array-unsigned-byte-2-widetag ; 10001010 + simple-array-unsigned-byte-4-widetag ; 10001110 + simple-array-unsigned-byte-7-widetag ; 10010010 + simple-array-unsigned-byte-8-widetag ; 10010110 + simple-array-unsigned-byte-15-widetag ; 10011010 + simple-array-unsigned-byte-16-widetag ; 10011110 + simple-array-nil-widetag ; 10100010 + simple-base-string-widetag ; 10100110 + #!+sb-unicode simple-character-string-widetag + simple-bit-vector-widetag ; 10101010 + simple-vector-widetag ; 10101110 + #!+#.(cl:if (cl:= 32 sb!vm:n-word-bits) '(and) '(or)) + simple-array-unsigned-fixnum-widetag ; 10110010 + simple-array-unsigned-byte-31-widetag ; 10110110 + simple-array-unsigned-byte-32-widetag ; 10111010 + #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or)) + simple-array-unsigned-fixnum-widetag + #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or)) + simple-array-unsigned-byte-63-widetag + #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or)) + simple-array-unsigned-byte-64-widetag + simple-array-signed-byte-8-widetag ; 10111110 + simple-array-signed-byte-16-widetag ; 11000010 + #!+#.(cl:if (cl:= 32 sb!vm:n-word-bits) '(and) '(or)) + simple-array-fixnum-widetag ; 11000110 + simple-array-signed-byte-32-widetag ; 11001010 + #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or)) + simple-array-fixnum-widetag + #!+#.(cl:if (cl:= 64 sb!vm:n-word-bits) '(and) '(or)) + simple-array-signed-byte-64-widetag + simple-array-single-float-widetag ; 11001110 + simple-array-double-float-widetag ; 11010010 + simple-array-complex-single-float-widetag ; 11010110 + simple-array-complex-double-float-widetag ; 11011010 + simple-array-widetag ; 11011110 + complex-vector-nil-widetag ; 11100010 + complex-base-string-widetag ; 11100110 + #!+sb-unicode complex-character-string-widetag + complex-bit-vector-widetag ; 11101010 + complex-vector-widetag ; 11101110 + complex-array-widetag ; 11110010 - return-pc-header - value-cell-header - symbol-header - base-char - sap - unbound-marker - weak-pointer - instance-header - fdefn) + #!+#.(cl:if (cl:= 32 sb!vm:n-word-bits) '(and) '(or)) + unused12-widetag ; 11110110 + #!+(and #.(cl:if (cl:= 32 sb!vm:n-word-bits) '(and) '(or)) + (not sb-unicode)) + unused13-widetag ; 11111010 + #!+(and #.(cl:if (cl:= 32 sb!vm:n-word-bits) '(and) '(or)) + (not sb-unicode)) + unused14-widetag ; 11111110 +) ;;; the different vector subtypes -(defenum (:prefix vector- :suffix -subtype) - normal - unused - valid-hashing - must-rehash) +(defenum () + vector-normal-subtype + vector-unused-subtype + vector-valid-hashing-subtype)