Paul Zimmermann <paul.zimmerm...@inria.fr> writes:
> I suggest taking fixed non-rational ratios, for example sqrt(2), sqrt(3),
> sqrt(5), and comparing the old and new code over the range of sizes where
> this code is used.
Would it make sense to hack speed mpn_mul.r to do that? Currently,
specifying an r > 0 gives a fix size of the second operand, and r < 0
implies a fix product size of |r|.
If we change the latter to instead imply a fixed ratio, e.g., use |r| /
100, by this change of line 1126 is speed.h:
- if (size1 < 0) size1 = -size1 - s->size; \
+ if (size1 < 0) size1 = -size1 * s->size / 100; \
we could specify a 3/5 = 60% ratio like
tune$ ./speed -p 1000000 -c -s 10-200 -f1.1 mpn_mul.-60
overhead 5.00 cycles, precision 1000000 units of 9.94e-10 secs, CPU freq
1006.24 MHz
mpn_mul.-60
10 135.27
11 148.22
12 180.78
13 192.64
14 230.74
15 272.04
16 296.78
17 340.74
18 349.28
19 432.63
20 481.87
22 548.86
24 650.80
26 724.24
28 861.18
30 1022.95
33 1184.50
36 1405.78
39 1652.40
42 1908.10
46 2280.28
50 2580.60
55 3136.99
60 3493.01
66 4095.82
72 4807.55
79 5422.07
86 6186.81
94 7193.20
103 8372.21
113 9886.82
124 11556.88
136 13422.05
149 16084.65
163 17925.33
179 20106.22
196 23446.72
Does that make sense? Or can you suggest some other interface to specify
a fixed ratio?
Regards,
/Niels
--
Niels Möller. PGP key CB4962D070D77D7FCB8BA36271D8F1FF368C6677.
Internet email is subject to wholesale government surveillance.
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