[Bug target/70113] New: [AArch64] -mpc-relative-literal-loads conflicts with fix-cortex-a53-843419

["clyon at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70113

            Bug ID: 70113
           Summary: [AArch64] -mpc-relative-literal-loads conflicts with
                    fix-cortex-a53-843419
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: clyon at gcc dot gnu.org
  Target Milestone: ---

This is a follow-up to PR 633304.

When the Linux kernel is configured with CONFIG_ARM64_ERRATUM_843419, the
support for relocations R_AARCH64_ADR_PREL_PG_HI21 and
R_AARCH64_ADR_PREL_PG_HI21_NC is removed from the kernel to avoid loading
objects with possibly offending sequences. In this case the kernel is built
with
-mcmodel=large.

However, since -mpc-relative-literal-loads is now disabled by default, GCC may
still emit such relocations.

This PR is a proposal to change GCC's -mfix-cortex-a53-843419 to change the
default for -mpc-relative-literal-loads.

I proposed a patch:

https://gcc.gnu.org/ml/gcc-patches/2016-01/msg01986.html