This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: Speed up _cpp_clean_line and _cpp_skip_block_comment
Zack Weinberg wrote:-
> >> before after change %
> >> _cpp_clean_line
> >> instructions 2 210 404 682 1 801 726 448 -399 678 234 18
> >> memory reads 516 097 743 240 090 189 -276 007 554 53
> >> memory writes 161 268 766 25 054 442 -136 214 334 84
> >>
> >> _cpp_skip_block_comment
> >> instructions 758 363 288 589 357 957 -169 005 331 22
> >> memory reads 107 773 080 107 773 080 0 0
> >> memory writes 105 088 372 19 690 732 - 85 397 640 81
> >
> > What do these numbers mean? I can guess the first column only.
>
> The numbers are the various counts gathered before and after the
> patch. That is, I applied the same test case to two cc1 executables,
> identical except that one didn't have the patch applied and the other
> did. Then the third column is 2 - 1 and the fourth is the change as a
> percentage of the 'before' count.
>
> Is that what you wanted to know? I am not sure I understand your
> question.
I see. It looked like 3 sets of 3 columns; Mike made clear that the
spaces were spurious.
Neil.