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Sorry this is probably a very basic question, as I don't have a strong knowledge in the field, but here is my question.

I use Shark to optimize some of my code (so far, ~3-4 fold increase, after ~ half a dozen hot spots were fixed). However, I found in many places the comment 'Invariant load', typically when looping over an array and using the loop variable as the index (this particular code is not worth any optimization, it is just the simplest example I could find in my code):

/* int i ; double *dsdrate,*dsdr */
for (i=0;i<countSpecies;i++)	/* Invariant load, Early exit */
	dsdrate[i]=dsdr[i];	/* Invariant load, Unroll, Unaligned loop start */

So what exactly is causing these 'Invariant load' warnings from Shark? It seems it disappears when I increment a pointer inside the loop instead, like so (I did not test that particular code in Shark, though):
double *p1=dsdrate;
double *p2=dsdr;
for (i=0;i<countSpecies;i++) {
	*p1=*p2;
	p1++;
	p2++;
}

There are maybe a couple of places where I could do some optimization on those 'Invariant load' warnings. Thanks for your input!

charles

-- 
Charles Parnot
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