No, it's just a code segment. If you de-compile the binary you will
find that it's a real loops, not being eliminated .
And in fact, the 1000000 will also be a variable.
On Feb 25, 2:19 am, Daniel Berlin <daniel.ber...@gmail.com> wrote:
> This test is worse than worthless, since the loop will be entirely
> eliminated by any sane C compiler, since you don't actually use the
> variable 's' in a way that side-effects.
>
> dexopt doesn't eliminate empty loops for various reasons.
>
> On Feb 24, 10:59 am, lianwei <lianwei.w...@gmail.com> wrote:
>
> > Below is a simple bench between Navive C and Dalvik Java, which is
> > collected from Android SDK 1.1.
>
> > Dalvik(ms) Native(ms)
> > 1+2+...1000000 500 46
> > 1*2*...1000000 530 49
>
> > Source code of Dalvik Java:
> > startTimeMillis = System.currentTimeMillis();
> > for (i = 1; i <= 1000000; i++){
> > s += i; // or s *= i;
> > }
> > endTimeMillis = System.currentTimeMillis();
>
> > Source code ofnativec
> > clock_gettime(CLOCK_MONOTONIC, &tpstart);
> > for (i = 1; i <= 1000000; i++)
> > {
> > s += i; // or s *= i;
> > }
> > clock_gettime(CLOCK_MONOTONIC, &tpend);
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