On 03/09/2018 06:51 AM, Richard Biener wrote:
On Fri, Mar 9, 2018 at 11:32 AM, Richard Biener <richard.guent...@gmail.com> wrote:
callgrind shows that propagate_binfo_offsets recursing to self very many times is likely the issue. Your templates build a very deep inheritance chain and it seems that the binfo offset propagation ends up being exponential here. I would have expected that any bases have already correct offsets so we don't need the recursion to bases of bases? Ah, so in this case we have offset of 1 because sizeof is always nonzero. So the issue might just be that BINFO_OFFSET is not relative to the parent?
Correct, it's relative to the complete object.
doens't improve things. We call this functions millions of times creating millions of INTEGER_CSTs. Can BINFO_OFFSET be non-constant?
No. (if it's a vbase, it shows the offset in the complete object, IIRC, and there's other data to let code generation know some vtable inspection is needed when the dynamic type is unknown).
nathan -- Nathan Sidwell
