[LLVMdev] Helping the optimizer along (__assume)

Paul Biggar paul.biggar at gmail.com
Thu Oct 23 13:21:35 PDT 2008

Hi Danny,

On Thu, Oct 23, 2008 at 8:16 PM, Daniel Berlin <dberlin at dberlin.org> wrote:
> Doesn't llvm-gcc support GCC's builtin_expect?
> Or does it transform it into nothing?

This isnt the same as GCC's builtin-expect, to my knowledge.
Builtin_expect will leave branch prediction hints, but won't remove
the branch. This would remove the branch. There was a discussion of
adding this to GCC a long time ago
(http://gcc.gnu.org/ml/gcc/2003-11/msg00324.html), but it looks like
nothing came of it, though you probably know better than me.


Paul Biggar
paul.biggar at gmail.com

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