On 03/02/2015 06:56 PM, Matt Turner wrote:
On Mon, Mar 2, 2015 at 4:37 PM, Brian Paul <bri...@vmware.com> wrote:
On 03/02/2015 04:03 PM, Eric Anholt wrote:
Kenneth Graunke <kenn...@whitecape.org> writes:
Generated by the following Coccinelle semantic patch:
@@
expression E;
@@
if (
-E
+unlikely(E)
)
{ ... _mesa_error(...) ... }
Improves performance in OglBatch7 (a CPU-bound microbenchmark) on
an i7 4750HQ (Haswell) by 1.08546% +/- 0.519734% (n=292).
Signed-off-by: Kenneth Graunke <kenn...@whitecape.org>
Neat!
I think you're supposed to be able to get the same result by marking
_mesa_error as attribute cold. Then nobody can forget to mark their
conditions as unlikely in the future.
I suspect unlikely() would be supported by more compilers than 'cold'.
FWIW, this link [0] says MSVC doesn't implement hot/cold nor unlikely.
Thanks for checking on that. I was thinking that MSVC had something
like unlikely/expect but I guess I was misremembering.
MSVC is the compiler I had in mind in my reply to Eric's message.
Other than MSVC... there's really gcc and clang. I'd opt for the ~10
line patch :)
Sounds good then.
-Brian
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/mesa-dev
