Hi,
On Mon, Aug 15, 2011 at 10:52 AM, Arnaud Lacombe <lacombar@xxxxxxxxx> wrote:
> [...]
> I'd be interested to also know the cost of all those new symbols on
> build time...
>
here it is; on the parsing itself:
After 1000 iteration of:
% /usr/libexec/gcc/x86_64-redhat-linux/4.5.1/cc1 -E -quiet -v -include
include/generated/autoconf.h /dev/null -o /dev/null -mtune=generic
-march=x86-64 2>/dev/null
x include.before
+ include.after
+--------------------------------------------------------------------------+
| x x x x x x + + + + + + + + +|
||MA_| |_A_| |
+--------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 1000 0.016 0.021 0.016 0.01637 0.00077310911
+ 1000 0.034 0.043 0.035 0.035227 0.00076161083
Difference at 95.0% confidence
0.018857 +/- 6.7264e-05
115.192% +/- 0.410898%
(Student's t, pooled s = 0.000767382)
After 1000 successive build of `init/main.o' (directly calling gcc):
x include.before
+ include.after
+--------------------------------------------------------------------------+
| xxxxx**++++++ + + |
| xxxxx***+++++ x ++ x + + |
| xxxxx***++*+++ +x+ x x x++ x + x+ ++* x x * |
| xxxxx****+*++**+**+*+*x x*xx*++*x++*+**x+ *+* +x *++x* x*++ + +|
||____|_A___M_A|_____| |
+--------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 1000 0.628 0.835 0.631 0.636217 0.024724466
+ 1000 0.648 0.873 0.651 0.657341 0.026185882
Difference at 95.0% confidence
0.021124 +/- 0.00223216
3.32025% +/- 0.350849%
(Student's t, pooled s = 0.0254657)
Now, an `allyesconfig' take about 5h30 hours to complete on my Core2
T5670 (capped at 1.2GHz), so this patch would cost an extra 10min.
Still significant, but not too much :-)
- Arnaud
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