On 07/11/2016 01:55 AM, Martin Liška wrote:
Hello.
During investigation of an IVOPTs issue, I noticed that tree-ssa-loop-ivopts.c
uses a hard-coded
constant AVG_LOOP_NITER. Very similar constant can be seen in cfgloopanal.c.
Thus, I've changed
that to a new param.
Apart from that, I would like to change the default value to 10.
As numbers of SPEC CPU2006 show:
Loop count: 18236
avg. # of iter: 11908.46
median # of iter: 10.00
avg. (1% cutoff) # of iter: 1003.87
avg. (5% cutoff) # of iter: 449.78
avg. (10% cutoff) # of iter: 209.46
avg. (20% cutoff) # of iter: 62.24
avg. (30% cutoff) # of iter: 42.69
Even though the average number of loop iteration is quite high, let's start to
increase it
conservatively to 10. Benchmark results are within a noise level (-Ofast runs
faster by 0.47%).
Patch survives regression tests and bootstraps on x86_64-linux-gnu.
Ready for trunk?
Don't you need a corresponding change to invoke.texi?
OK with that change.
jeff
