[cfe-dev] X86 intrinsics running out of IdentifierInfo Builtin IDs

[Reid Kleckner]

It seems increasingly true that we care less about optimizing for size on
32-bit architectures. On a 64-bit platform, we had 32-bits of padding there
already, so we can probably afford the extra space on 32-bit.

On Wed, Jul 1, 2015 at 6:12 AM, Benyei, Guy <guy.benyei at intel.com> wrote:

>  Hi all,
>
> My team is working on adding some more X86 intrinsics to Clang/LLVM, and
> we are hitting the limit of the number of builtins supported by Clang. The
> “ObjCOrBuiltinID” field in the IdentifierInfo class is 11 bits wide, which
> is not sufficient to represent all the new intrinsics, and we are getting
> the "ID too large for field!" assertion.
>
>
>
> The easiest fix seems to be to increase the size of this “ObjCOrBuiltinID”
> field to 12 bits, but that will make the bitfield in IdentifierInfo 33 bits
> wide, consuming an additional 32 bits in some architectures for each
> instance. A quick check shows, that this fix works without any functional
> regressions, but we have no performance numbers yet.
>
>
>
> Please let me know if anyone is opposed to adding this additional bit, or
> if there are any other concerns/suggestions on this issue.
>
>
>
> Thanks
>
> [image: email_signature_guy_new2]
>
>
>
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