Re: [CFT, v4] Vectorized _cpp_clean_line

[Luis Machado <luisgpm at linux dot vnet dot ibm dot com>]

On Wed, 2010-08-18 at 14:49 -0700, Richard Henderson wrote:
> On 08/18/2010 12:51 PM, Richard Henderson wrote:
> > Before:
> > 
> >   %   cumulative   self              self     total           
> >  time   seconds   seconds    calls  ms/call  ms/call  name    
> >  29.41      0.05     0.05   168709     0.00     0.00  ._cpp_clean_line
> >  17.65      0.08     0.03   606267     0.00     0.00  ._cpp_lex_direct
> >  11.76      0.10     0.02   168081     0.00     0.00  .linemap_line_start
> >  11.76      0.12     0.02                             .variably_modified_type_p
> >   5.88      0.13     0.01   503900     0.00     0.00  ._cpp_lex_token
> > 
> > After:
> > 
> >   %   cumulative   self              self     total           
> >  time   seconds   seconds    calls  ms/call  ms/call  name    
> >  20.83      0.05     0.05   606267     0.00     0.00  ._cpp_lex_direct
> >  20.83      0.10     0.05   228345     0.00     0.00  .ht_lookup_with_hash
> >  16.67      0.14     0.04                             .variably_modified_type_p
> >   4.17      0.15     0.01   503900     0.00     0.00  ._cpp_lex_token
> >   4.17      0.16     0.01   304199     0.00     0.00  ._cpp_lex_identifier
> >   4.17      0.17     0.01   304199     0.00     0.00  .cpp_token_as_text
> >   4.17      0.18     0.01   168709     0.00     0.00  ._cpp_clean_line
> > 
> > Note that ._cpp_clean_line is about 5 times faster.
> > 
> > Is the cpu you're testing on (power7 or what?) just that much
> > better with the original integer code?
> 
> Not to overload you too much, but here's an incremental patch
> to test as well.
> 
> You do have to add "-maltivec" to {BOOT,STAGE}_CFLAGS at the moment,
> since the ppc backend does not yet support the kind of target mixing
> and matching that i386 port does.  On that same G5 I get:
> 
>   %   cumulative   self              self     total           
>  time   seconds   seconds    calls  ms/call  ms/call  name    
>  37.50      0.06     0.06   606267     0.00     0.00  ._cpp_lex_direct
>  12.50      0.08     0.02   504424     0.00     0.00  .cpp_get_token_with_location
>  12.50      0.10     0.02   503900     0.00     0.00  ._cpp_lex_token
>  12.50      0.12     0.02                             .variably_modified_type_p
>   6.25      0.13     0.01   457580     0.00     0.00  .cpp_output_token
>   6.25      0.14     0.01   217473     0.00     0.00  .init_pp_output
>   6.25      0.15     0.01    40842     0.00     0.00  ._cpp_test_assertion
>   6.25      0.16     0.01        1    10.00   140.00  .preprocess_file
>   0.00      0.16     0.00   633800     0.00     0.00  .cpp_get_token
>   0.00      0.16     0.00   505969     0.00     0.00  .linemap_lookup
>   0.00      0.16     0.00   304199     0.00     0.00  ._cpp_lex_identifier
>   0.00      0.16     0.00   304199     0.00     0.00  .cpp_token_as_text
>   0.00      0.16     0.00   228345     0.00     0.00  .ht_lookup_with_hash
>   0.00      0.16     0.00   180752     0.00     0.00  ._cpp_get_fresh_line
>   0.00      0.16     0.00   173870     0.00     0.00  ._cpp_init_tokenrun
>   0.00      0.16     0.00   168709     0.00     0.00  ._cpp_clean_line
> 
> I.e. _cpp_clean_line has essentially vanished off the radar.  It
> seems likely that oprofile across an entire bootstrap stage would
> be more likely to be able to pick out how much time it really takes.
> 
> 
> r~

I'll get it tested.

Luis