https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104117
--- Comment #26 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by Iain D Sandoe <ia...@gcc.gnu.org>: https://gcc.gnu.org/g:53254184bda6305ac38e6e37480303b9f167b5ae commit r11-9879-g53254184bda6305ac38e6e37480303b9f167b5ae Author: Iain Sandoe <i...@sandoe.co.uk> Date: Mon Feb 7 15:36:35 2022 +0000 Darwin, rs6000: Amend lo_sum use for forced constants [PR104117]. Two issues resulted in this PR, which manifests when we force a constant into memory in LRA (in PIC code on Darwin). The presence of such forced constants is quite dependent on other RTL optimisations, and it is easy for the issue to become latent for a specific case. First, in the Darwin-specific rs6000 backend code, we were not being careful enough in rejecting invalid symbolic addresses. Specifically, when generating PIC code, we require a SYMBOL_REF to be wrapped in an UNSPEC_MACHOPIC_OFFSET. We now split the Darwin high/low selectors into two: 1. One that handles non-PIC addresses (kernel mode, mdynamic-no-pic). 2. One that handles PIC addresses and rejects SYMBOL_REFs unless they are suitably wrapped in the MACHOPIC_OFFSET unspec. The second case is handled by providing a new predicate (macho_pic_address) that checks the requirements. Backported from 4c3792d448964f7bd99e7eac2c29c9eb7c2bfb84 and f1b3e3853329b58fb2e50c17487df2ecbc4a5608 Signed-off-by: Iain Sandoe <i...@sandoe.co.uk> Co-authored-by: Vladimir Makarov <vmaka...@redhat.com> PR target/104117 gcc/ChangeLog: * config/rs6000/rs6000.c (darwin_rs6000_legitimate_lo_sum_const_p): Check for UNSPEC_MACHOPIC_OFFSET wrappers on symbolic addresses when emitting PIC code. (legitimate_lo_sum_address_p): Likewise. (rs6000_legitimize_address): Do not apply the TLS processing to Darwin. * config/rs6000/darwin.md (@machopic_high_<mode>): New. (@machopic_low_<mode>): New. * config/rs6000/predicates.md (macho_pic_address): New.
