Subject: [PATCH 0/3] Add __ioread32_copy() and use it

From: [email-masked] (Andi Kleen)
Date: Wed, 16 Sep 2015 04:55:46 +0200

> Under what circumstances will the compiler (or linker?) do this? 

Compiler.

> LTO enabled?

Yes it's for LTO.  The optimization allows the compiler to drop unused
functions, which is very popular with users (a lot use it to get smaller
kernel images)

-Andi

-- 
ak at linux.intel.com -- Speaking for myself only.