https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95775
Bug ID: 95775
Summary: Command line argument for target_clones?
Product: gcc
Version: 10.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: yyc1992 at gmail dot com
Target Milestone: ---
Would it make sense to add a command line argument that is roughly equivalent
to to adding `target_clones` to all functions?
In terms of usefulness, I believe it will be a very cheap way for many
libraries to turn on the support with minimal code change. It certainly won't
be as optimized as best possible but neither is target_clones attribute itself
compared to hand wrote different implementations using compiler
intrinsics/assembly...
In terms of implementation, I believe most of the issues I've hit when adding
such attribute to functions has been fixed so I have little issue using it now.
It'll also be a new feature so it shouldn't really break any existing code.
And for further improvement, the compiler should have fair knowledge of what
instruction can be/has been used and can omit some of the cloning in order to
reduce code size. I don't think this needs to be included in the first version
though...
And IIUC this is something that icc does automatically? (If that can serve as a
argument for this feature...)
