Comparison of GCC-4.9 and LLVM-3.4 performance on SPECInt2000 for x86-64 and ARM

[Vladimir Makarov]

On 2014-06-25, 10:37 AM, Marc Glisse wrote:
> On Wed, 25 Jun 2014, Vladimir Makarov wrote:
>
>> Maybe.  But in this case LLVM did a right thing.  The variable
>> addressing was through a restrict pointer.
>
> Ah, gcc implements (on purpose?) a weak version of restrict, where it
> only considers that 2 restrict pointers don't alias, whereas all other
> compilers assume that restrict pointers don't alias other non-derived
> pointers (see several PRs in bugzilla). I believe Richard recently added
> code that would make implementing the strong version of restrict easier.
> Maybe that's what is missing here?
>

May be. At least I saw 3 different restrict pointers in this code.