search for: check_if_x_is_speci

...ns me about __builtin_assume_aligned and this > scheme is the control dependencies. In gcc, it is the return value of the > intrinsic that carries the alignment guarantee, and I think that this makes > a lot of sense. Consider something like this: > > void foo(double *x) { > if (check_if_x_is_special(&global_state)) { > y = __builtin_assume_aligned(x, 16); > do_something(y); > } else > do_something_else(x); > } > > with this scheme, there is never a danger that the alignment assumption > can be lifted and incorrectly applied to x in an inlined > do...

...? The thing that most concerns me about __builtin_assume_aligned and this scheme is the control dependencies. In gcc, it is the return value of the intrinsic that carries the alignment guarantee, and I think that this makes a lot of sense. Consider something like this: void foo(double *x) { if (check_if_x_is_special(&global_state)) { y = __builtin_assume_aligned(x, 16); do_something(y); } else do_something_else(x); } with this scheme, there is never a danger that the alignment assumption can be lifted and incorrectly applied to x in an inlined do_something_else(x). If we simply have the in...

On Sep 7, 2013, at 7:41 AM, Hal Finkel <hfinkel at anl.gov> wrote: >> On Feb 7, 2013, at 10:58 PM, Hal Finkel < hfinkel at anl.gov > wrote: >> >> >> >> >> As long as this is brainstorming time, I actually like the idea of >> an >> llvm.invariant intrinsic that the optimizers know to ignore. I >> like >> it for other

----- Original Message ----- > > > > On Aug 19, 2013, at 8:06 PM, Hal Finkel < hfinkel at anl.gov > wrote: > > > > ----- Original Message ----- > > > > On Feb 22, 2013, at 6:28 AM, Hal Finkel < hfinkel at anl.gov > wrote: > > > > ----- Original Message ----- > > > From: "Andrew Trick" < atrick at