[Bug rtl-optimization/112476] New: [14 Regression] unrecognizable insn with -O2 -march=la464 on loongarch64

[xen0n at gentoo dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112476

            Bug ID: 112476
           Summary: [14 Regression] unrecognizable insn with -O2
                    -march=la464 on loongarch64
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: xen0n at gentoo dot org
  Target Milestone: ---
            Target: loongarch64-linux-gnu

Created attachment 56551
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56551&action=edit
Minimized reproducer

The attached code minified from Skia, ICEs with "unrecognizable insn" when
compiled with SIMD apparently active and the backend wanting to do something
with it.

According to my preliminary debugging: the bug disappears when the extra layer
of wrapping function is removed, when the two "&a" arguments get changed, and
when the memcpy is rewritten to a simple pointer dereference.