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


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.


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