These macros are standard in src's cairoint.h and test's cairo-test.h
internal header files, so for consistency do the same thing with perf's
cairo-perf.h.
Reviewed-by: Uli Schlachter <psychon@znc.in>
Use "mild outliers" method to remove exceptional speed-ups and slow-downs
from the graph, so that the majority of information is not lost by the
scaling. Add the timing labels to the bars so that the true factor is
always presented.
cairo-perf-chart takes multiple runs (currently it is limited to
prefiltered data sets) and pretty-prints a chart showing performace
improvements/regressions (in either ASCII or HTML) along with a
cairo-perf-chart.png
