2013/6/13 Terry Guo <flameroc@xxxxxxxxx>:
> Hi there,
>
> For the below simple case, I think poly1[i] should be hoisted to
> outermost loop to avoid loading from innermost loop at each iteration.
> But for arm-none-eabi target like cortex-m4, gcc fails to do so. Is
> this a normal case or a missing optimization? Please advise.
>
> void
> PolyMul (float *poly1, unsigned int n1,
> float *poly2, unsigned int n2,
> float *polymul, unsigned int *nmul)
> {
> unsigned int i, j;
>
> for (i = 0; i <= n1; i++)
> for (j = 0; j <= n2; j++)
> polymul[i+j] += poly1[i] * poly2[j];
> }
>
> Thanks.
>
> BR,
> Terry
Unless you use 'restrict' qualifier to the pointer type,
I don't think compiler can do such optimization due to aliasing issue.
Best regards,
jasonwucj
