[PATCH] D60583: [AArch64] Implement Vector Funtion ABI name mangling.

Tue Jun 4 14:08:01 PDT 2019

fpetrogalli added a comment.

In D60583#1529878 <https://reviews.llvm.org/D60583#1529878>, @jdoerfert wrote:

> Why/Where did we decide to clobber the attribute list with "non-existent function names"?
>  I don't think an attribute list like this:
>  `attributes #1 = { "_ZGVsM2v_foo" "_ZGVsM32v_foo" "_ZGVsM4v_foo" "_ZGVsM6v_foo" "_ZGVsM8v_foo" "_ZGVsMxv_foo" ... `
>  is helpful in any way, e.g., this would require us to search through all attributes and interpret them one by one.

Agree. This is what was agreed : http://lists.llvm.org/pipermail/cfe-dev/2016-March/047732.html

The new RFC will get rid of this list of string attributes. It will become something like:

  attribute #0 = { declare-variant="comma,separated,list,of,vector,function,ABI,mangled,names" }.

> This seems to me like an ad-hoc implementation of the RFC that is currently discussed but committed before the discussion is finished.

I can assure you that's not the case.

The code in this patch is what it is because it is based on previous (accepted) RFC originally proposed by other people and used by VecClone: https://reviews.llvm.org/D22792

As you can see in the unit tests of the VecClone pass, the variant attribute is added as follows:

  attributes #0 = { nounwind uwtable "vector-variants"="_ZGVbM4_foo1,_ZGVbN4_foo1,_ZGVcM8_foo1,_ZGVcN8_foo1,_ZGVdM8_foo1,_ZGVdN8_foo1,_ZGVeM16_foo1,_ZGVeN16_foo1"  .... }

Nothing in LLVM is using those attributes at the moment, that might be the reason why the string attribute have not yet been moved to a single attribute.

Kind regards,

Francesco

Repository:
  rC Clang

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https://reviews.llvm.org/D60583