[Bug rtl-optimization/88311] [9 Regression] mlongcall indirections are optimised away (for binutils versions that don't support AS_PLTSEQ)

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88311

Iain Sandoe <iains at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amodra at gcc dot gnu.org
            Summary|mlongcall indirections are  |[9 Regression] mlongcall
                   |optimised away              |indirections are optimised
                   |                            |away (for binutils versions
                   |                            |that don't support
                   |                            |AS_PLTSEQ)

--- Comment #5 from Iain Sandoe <iains at gcc dot gnu.org> ---
So the reason that Segher and I were seeing different results is that I was
using the default BINUTILS on the platform (2.27) and Segher was using 2.31.

The salient difference appears to be this (from auto-host.h):
2.27  .... 2.31
/* #undef HAVE_AS_PLTSEQ */         |   #define HAVE_AS_PLTSEQ 1

As a second point - I checked r266557 and that produces correct code with:

GNU assembler version 2.27 (ppc64-redhat-linux) using BFD version version
2.27-28.base.el7_5.1

It's possible that the patch sequence 266599-266610 could have caused this.