On Tue, 2024-04-30 at 21:15 +0200, Richard Biener via Gcc wrote: > > > > Am 30.04.2024 um 21:11 schrieb Jason Merrill via Gcc > > <gcc@gcc.gnu.org>: > > > > On Fri, Apr 26, 2024 at 5:44 AM Aldy Hernandez via Gcc > > <gcc@gcc.gnu.org> wrote: > > > > > > In implementing prange (pointer ranges), I have found a 1.74% > > > slowdown > > > in VRP, even without any code path actually using the code. I > > > have > > > tracked this down to irange::get_bitmask() being compiled > > > differently > > > with and without the bare bones patch. With the patch, > > > irange::get_bitmask() has a lot of code inlined into it, > > > particularly > > > get_bitmask_from_range() and consequently the wide_int_storage > > > code. > > ... > > > +static irange_bitmask > > > +get_bitmask_from_range (tree type, > > > + const wide_int &min, const wide_int &max) > > ... > > > -irange_bitmask > > > -irange::get_bitmask_from_range () const > > > > My guess is that this is the relevant change: the old function has > > external linkage, and is therefore interposable, which inhibits > > inlining. The new function has internal linkage, which allows > > inlining. > > > > Relatedly, I wonder if we want to build GCC with -fno-semantic- > > interposition? > > I guess that’s a good idea, though it’s already implied when doing > LTO bootstrap and building cc1 and friends? (But not for libgccjit?)
[CCing jit mailing list] FWIW I've no idea if any libgccjit users are using semantic interposition; I suspect the answer is "no one is using it". Antoyo, Andrea [also CCed]: are either of you using semantic interposition of symbols within libgccjit? If not, we *might* get a slightly faster libgccjit by building it with -fno-semantic-interposition. Or maybe not... Dave > > Richard > > > > > Jason > > >
