Re: [MIT-Scheme-devel] Is it still a PORT?

[Joe Marshall]

Just pushed a few more changes.  I wrote a simple benchmark which just
involved reading 97800 symbols from a file.  (The symbols were already
interned).  Before these latest changes, the median speed was 13872
symbols per second.  These last changes put us at 14662 symbols per
second.  (For comparison, the C version can only read 2000 symbols
per second)

I think there's only another 5% improvement that would be easy to get, but
it's not worth it.

On Tue, Nov 24, 2009 at 10:40 AM, Joe Marshall <address@hidden> wrote:
> On Tue, Nov 24, 2009 at 10:21 AM, Taylor R Campbell <address@hidden> wrote:
>>   Date: Tue, 24 Nov 2009 09:37:39 -0800
>>   From: Joe Marshall <address@hidden>
>>
>>   It turns out that when you read a source code file that the
>>   inner loop of the parser does a lot of superfluous checking
>>   of PORT?  Although PORT? is an inexpensive operation,
>>   it still involves an out-of-line call, and it gets called eleven times
>>   for each character of input.
>>
>> Hmm...  How about caching the values of (port/operation/read-char
>> port) and (port/operation port 'DISCRETIONARY-WRITE-CHAR) in the db,
>> which should also avoid some ASSQ calls?
>
> Here's what I've got so far:
> (View in fixed-width.  Left column is original, right column is changes so 
> far.)
>
> read-unquoted                                         read-unquoted
> #[unnamed-procedure]
> #[unnamed-procedure]
> peek-char                                             %peek-char
> #[let-procedure]                                      #[let-procedure]
> #[internal-lambda]
> #[internal-lambda]
> loop                                                  loop
> input-port/peek-char
> port/operation/peek-char
> port/type
> port?                         ***
> #[unnamed-procedure]
> #[unnamed-procedure]
> generic-io/peek-char
> generic-io/peek-char
> generic-io/read-char
> generic-io/read-char
> port/state                                            port/state
> port?                         ***                     port?
> reset-prev-char                                       reset-prev-char
> #[let-procedure]                                      #[let-procedure]
> #[internal-lambda]
> #[internal-lambda]
> loop                                                  loop
> read-next-char                                        read-next-char
> #[unnamed-procedure]
> #[unnamed-procedure]
> decode-char                                           decode-char
> #[unnamed-procedure]
> #[unnamed-procedure]
> port/state                                            port/state
> port?                         ***                     port?
> transcribe-input-char
> transcribe-input-char
> transcribe-char                                       transcribe-char
> eof-object?                                           eof-object?
> char-set-member?                                      char-set-member?
> char-set?                                             char-set?
> %char-set-member?
> %char-set-member?
> guarantee-constituent
> guarantee-constituent
> char-set-member?                                      char-set-member?
> char-set?                                             char-set?
> %char-set-member?
> %char-set-member?
> #[unnamed-procedure]
> #[unnamed-procedure]
> read-char                                             %read-char
> port/operation
> port-type/%operation
> port/type
> port?                        ***
> port-type/operation
> guarantee-port-type
> port-type?
> assq                                                  assq
> #[let-procedure]                                      #[let-procedure]
> #[internal-lambda]
> #[internal-lambda]
> loop                                                  loop
> loop                                                  loop
> loop                                                  loop
> #[let-procedure]                                      #[let-procedure]
> #[internal-lambda]
> #[internal-lambda]
> loop                                                  loop
> input-port/read-char
> port/operation/read-char
> port/type
> port?                        ***
> #[unnamed-procedure]
> #[unnamed-procedure]
> operation/read-char
> operation/read-char
> generic-io/read-char
> generic-io/read-char
> port/state                                            port/state
> port?                        ***                      port?
> reset-prev-char                                       reset-prev-char
> #[let-procedure]                                      #[let-procedure]
> #[internal-lambda]
> #[internal-lambda]
> loop                                                  loop
> read-next-char                                        read-next-char
> #[unnamed-procedure]
> #[unnamed-procedure]
> decode-char                                           decode-char
> #[unnamed-procedure]
> #[unnamed-procedure]
> eof-object?                                           eof-object?
> transcribe-input-char
> transcribe-input-char
> #[let-procedure]                                      #[let-procedure]
> operation/discretionary-write-char
> operation/discretionary-write-char
> #[unnamed-procedure]
> #[unnamed-procedure]
> port/state                                            port/state
> port?                        ***                      port?
> char-downcase                                         char-downcase
> %char-downcase                                        %char-downcase
> optional-output-port
> guarantee-output-port
> output-port?
> port?                        ***
> output-port/write-char                                %write-char
> port/operation/write-char
> port/type
> port?                        ***
> #[unnamed-procedure]
> #[unnamed-procedure]
> narrow-out/write-char
> narrow-out/write-char
> port/state                                            port/state
> port?                        ***                      port?
> maybe-grow-buffer
> maybe-grow-buffer
> #[let-procedure]                                      #[let-procedure]
> wide-string?                                          wide-string?
> new-column                                            new-column
> transcribe-char                                       transcribe-char
> output-port/discretionary-flush
> port/operation/discretionary-flush-output
> port/type
> port?                        ***
> #[unnamed-procedure]
> #[unnamed-procedure]
> no-flush                                              no-flush
> discretionary-flush-transcript
> discretionary-flush-transcript
>
> I'll get to the ASSQ call when it is a larger proportion of the calls.
> I have to fix port/state first.
>
> --
> ~jrm
>



-- 
~jrm