tools/generate-ten-powers.scm - Issue 973001: Version 2.1.4.1...

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Issue 973001: Version 2.1.4.1... (Closed) Base URL: http://v8.googlecode.com/svn/trunk/

Patch Set: Created 10 years, 9 months ago

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Index: tools/generate-ten-powers.scm

===================================================================

--- tools/generate-ten-powers.scm (revision 4127)

+++ tools/generate-ten-powers.scm (working copy)

@@ -1,286 +0,0 @@

-;; Redistribution and use in source and binary forms, with or without

-;; modification, are permitted provided that the following conditions are

-;; met:

-;;

-;; * Redistributions of source code must retain the above copyright

-;; notice, this list of conditions and the following disclaimer.

-;; * Redistributions in binary form must reproduce the above

-;; copyright notice, this list of conditions and the following

-;; disclaimer in the documentation and/or other materials provided

-;; with the distribution.

-;; * Neither the name of Google Inc. nor the names of its

-;; contributors may be used to endorse or promote products derived

-;; from this software without specific prior written permission.

-;;

-;; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

-;; "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

-;; LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

-;; A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

-;; OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

-;; SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

-;; LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

-;; DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

-;; THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

-;; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

-;; OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

-;; This is a Scheme script for the Bigloo compiler. Bigloo must be compiled with

-;; support for bignums. The compilation of the script can be done as follows:

-;; bigloo -static-bigloo -o generate-ten-powers generate-ten-powers.scm

-;;

-;; Generate approximations of 10^k.

-(module gen-ten-powers

- (static (class Cached-Fast

- v::bignum

- e::bint

- exact?::bool))

- (main my-main))

-;;----------------bignum shifts -----------------------------------------------

-(define (bit-lshbx::bignum x::bignum by::bint)

- (if (<fx by 0)

- #z0

- (*bx x (exptbx #z2 (fixnum->bignum by)))))

-(define (bit-rshbx::bignum x::bignum by::bint)

- (if (<fx by 0)

- #z0

- (/bx x (exptbx #z2 (fixnum->bignum by)))))

-;;----------------the actual power generation -------------------------------

-;; e should be an indication. it might be too small.

-(define (round-n-cut n e nb-bits)

- (define max-container (- (bit-lshbx #z1 nb-bits) 1))

- (define (round n)

- (case *round*

- ((down) n)

- ((up)

- (+bx n

- ;; with the -1 it will only round up if the cut off part is

- ;; non-zero

- (-bx (bit-lshbx #z1

- (-fx (+fx e nb-bits) 1))

- #z1)))

- ((round)

- (+bx n

- (bit-lshbx #z1

- (-fx (+fx e nb-bits) 2))))))

- (let* ((shift (-fx (+fx e nb-bits) 1))

- (cut (bit-rshbx (round n) shift))

- (exact? (=bx n (bit-lshbx cut shift))))

- (if (<=bx cut max-container)

- (values cut e exact?)

- (round-n-cut n (+fx e 1) nb-bits))))

-(define (rounded-/bx x y)

- (case *round*

- ((down) (/bx x y))

- ((up) (+bx (/bx x y) #z1))

- ((round) (let ((tmp (/bx (*bx #z2 x) y)))

- (if (zerobx? (remainderbx tmp #z2))

- (/bx tmp #z2)

- (+bx (/bx tmp #z2) #z1))))))

-(define (generate-powers from to mantissa-size)

- (let* ((nb-bits mantissa-size)

- (offset (- from))

- (nb-elements (+ (- from) to 1))

- (vec (make-vector nb-elements))

- (max-container (- (bit-lshbx #z1 nb-bits) 1)))

- ;; the negative ones. 10^-1, 10^-2, etc.

- ;; We already know, that we can't be exact, so exact? will always be #f.

- ;; Basically we will have a ten^i that we will *10 at each iteration. We

- ;; want to create the matissa of 1/ten^i. However the mantissa must be

- ;; normalized (start with a 1). -> we have to shift the number.

- ;; We shift by multiplying with two^e. -> We encode two^e*(1/ten^i) ==

- ;; two^e/ten^i.

- (let loop ((i 1)

- (ten^i #z10)

- (two^e #z1)

- (e 0))

- (unless (< (- i) from)

- (if (>bx (/bx (*bx #z2 two^e) ten^i) max-container)

- ;; another shift would make the number too big. We are

- ;; hence normalized now.

- (begin

- (vector-set! vec (-fx offset i)

- (instantiate::Cached-Fast

- (v (rounded-/bx two^e ten^i))

- (e (negfx e))

- (exact? #f)))

- (loop (+fx i 1) (*bx ten^i #z10) two^e e))

- (loop i ten^i (bit-lshbx two^e 1) (+fx e 1)))))

- ;; the positive ones 10^0, 10^1, etc.

- ;; start with 1.0. mantissa: 10...0 (1 followed by nb-bits-1 bits)

- ;; -> e = -(nb-bits-1)

- ;; exact? is true when the container can still hold the complete 10^i

- (let loop ((i 0)

- (n (bit-lshbx #z1 (-fx nb-bits 1)))

- (e (-fx 1 nb-bits)))

- (when (<= i to)

- (receive (cut e exact?)

- (round-n-cut n e nb-bits)

- (vector-set! vec (+fx i offset)

- (instantiate::Cached-Fast

- (v cut)

- (e e)

- (exact? exact?)))

- (loop (+fx i 1) (*bx n #z10) e))))

- vec))

-(define (print-c powers from to struct-type

- cache-name max-distance-name offset-name macro64)

- (define (display-power power k)

- (with-access::Cached-Fast power (v e exact?)

- (let ((tmp-p (open-output-string)))

- ;; really hackish way of getting the digits

- (display (format "~x" v) tmp-p)

- (let ((str (close-output-port tmp-p)))

- (printf " {~a(0x~a, ~a), ~a, ~a},\n"

- macro64

- (substring str 0 8)

- (substring str 8 16)

- e

- k)))))

- (define (print-powers-reduced n)

- (print "static const " struct-type " " cache-name

- "(" n ")"

- "[] = {")

- (let loop ((i 0)

- (nb-elements 0)

- (last-e 0)

- (max-distance 0))

- (cond

- ((>= i (vector-length powers))

- (print " };")

- (print "static const int " max-distance-name "(" n ") = "

- max-distance ";")

- (print "// nb elements (" n "): " nb-elements))

- (else

- (let* ((power (vector-ref powers i))

- (e (Cached-Fast-e power)))

- (display-power power (+ i from))

- (loop (+ i n)

- (+ nb-elements 1)

- e

- (cond

- ((=fx i 0) max-distance)

- ((> (- e last-e) max-distance) (- e last-e))

- (else max-distance))))))))

- (print "// ------------ GENERATED FILE ----------------")

- (print "// command used:")

- (print "// "

- (apply string-append (map (lambda (str)

- (string-append " " str))

- *main-args*))

- " // NOLINT")

- (print)

- (print

- "// This file is intended to be included inside another .h or .cc files\n"

- "// with the following defines set:\n"

- "// GRISU_CACHE_STRUCT: should expand to the name of a struct that will\n"

- "// hold the cached powers of ten. Each entry will hold a 64-bit\n"

- "// significand, a 16-bit signed binary exponent, and a 16-bit\n"

- "// signed decimal exponent. Each entry will be constructed as follows:\n"

- "// { significand, binary_exponent, decimal_exponent }.\n"

- "// GRISU_CACHE_NAME(i): generates the name for the different caches.\n"

- "// The parameter i will be a number in the range 1-20. A cache will\n"

- "// hold every i'th element of a full cache. GRISU_CACHE_NAME(1) will\n"

- "// thus hold all elements. The higher i the fewer elements it has.\n"

- "// Ideally the user should only reference one cache and let the\n"

- "// compiler remove the unused ones.\n"

- "// GRISU_CACHE_MAX_DISTANCE(i): generates the name for the maximum\n"

- "// binary exponent distance between all elements of a given cache.\n"

- "// GRISU_CACHE_OFFSET: is used as variable name for the decimal\n"

- "// exponent offset. It is equal to -cache[0].decimal_exponent.\n"

- "// GRISU_UINT64_C: used to construct 64-bit values in a platform\n"

- "// independent way. In order to encode 0x123456789ABCDEF0 the macro\n"

- "// will be invoked as follows: GRISU_UINT64_C(0x12345678,9ABCDEF0).\n")

- (print)

- (print-powers-reduced 1)

- (print-powers-reduced 2)

- (print-powers-reduced 3)

- (print-powers-reduced 4)

- (print-powers-reduced 5)

- (print-powers-reduced 6)

- (print-powers-reduced 7)

- (print-powers-reduced 8)

- (print-powers-reduced 9)

- (print-powers-reduced 10)

- (print-powers-reduced 11)

- (print-powers-reduced 12)

- (print-powers-reduced 13)

- (print-powers-reduced 14)

- (print-powers-reduced 15)

- (print-powers-reduced 16)

- (print-powers-reduced 17)

- (print-powers-reduced 18)

- (print-powers-reduced 19)

- (print-powers-reduced 20)

- (print "static const int GRISU_CACHE_OFFSET = " (- from) ";"))

-;;----------------main --------------------------------------------------------

-(define *main-args* #f)

-(define *mantissa-size* #f)

-(define *dest* #f)

-(define *round* #f)

-(define *from* #f)

-(define *to* #f)

-(define (my-main args)

- (set! *main-args* args)

- (args-parse (cdr args)

- (section "Help")

- (("?") (args-parse-usage #f))

- ((("-h" "--help") (help "?, -h, --help" "This help message"))

- (args-parse-usage #f))

- (section "Misc")

- (("-o" ?file (help "The output file"))

- (set! *dest* file))

- (("--mantissa-size" ?size (help "Container-size in bits"))

- (set! *mantissa-size* (string->number size)))

- (("--round" ?direction (help "Round bignums (down, round or up)"))

- (set! *round* (string->symbol direction)))

- (("--from" ?from (help "start at 10^from"))

- (set! *from* (string->number from)))

- (("--to" ?to (help "go up to 10^to"))

- (set! *to* (string->number to)))

- (else

- (print "Illegal argument `" else "'. Usage:")

- (args-parse-usage #f)))

- (when (not *from*)

- (error "generate-ten-powers"

- "Missing from"

- #f))

- (when (not *to*)

- (error "generate-ten-powers"

- "Missing to"

- #f))

- (when (not *mantissa-size*)

- (error "generate-ten-powers"

- "Missing mantissa size"

- #f))

- (when (not (memv *round* '(up down round)))

- (error "generate-ten-powers"

- "Missing round-method"

- *round*))

- (let ((dividers (generate-powers *from* *to* *mantissa-size*))

- (p (if (not *dest*)

- (current-output-port)

- (open-output-file *dest*))))

- (unwind-protect

- (with-output-to-port p

- (lambda ()

- (print-c dividers *from* *to*

- "GRISU_CACHE_STRUCT" "GRISU_CACHE_NAME"

- "GRISU_CACHE_MAX_DISTANCE" "GRISU_CACHE_OFFSET"

- "GRISU_UINT64_C"

- )))

- (if *dest*

- (close-output-port p)))))

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