[Bug target/97269] [11 Regression] ICE in change_address_1, at emit-rtl.c:2275 since r11-3427-ge94797250b403d66cb3624a594e41faf0dd76617

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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97269

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Sandiford <rsandifo@gcc.gnu.org>:

https://gcc.gnu.org/g:e8beba1cfc761cc35762283b3b44a355ef05e25b

commit r11-6461-ge8beba1cfc761cc35762283b3b44a355ef05e25b
Author: Richard Sandiford <richard.sandiford@arm.com>
Date:   Tue Jan 5 11:29:10 2021 +0000

    explow, aarch64: Fix force-Pmode-to-mem for ILP32 [PR97269]

    This patch fixes a mode/rtx mismatch for ILP32 targets in:

              mem = force_const_mem (ptr_mode, imm);

    where imm can be Pmode rather than ptr_mode.

    The patch uses convert_memory_address to convert the Pmode address
    to ptr_mode before the call.  However, immediate addresses can in
    general contain unspecs, and convert_memory_address wasn't set up
    to handle those.

    The patch therefore adds some generic unspec handling to
    convert_memory_address_addr_space_1.  As the comment says, we can add
    a target hook if this behaviour turns out to be wrong for some targets.
    But I think what the patch does is a strict improvement over the status
    quo: without it, we would try to force the unspec into a register,
    but nevertheless wrap the result in a (const ...).  That in turn
    would be invalid rtl and seems bound to generate an ICE later.

    I tested the explow.c part using -fstack-protector with local hacks
    to force SYMBOL_FORCE_TO_MEM for UNSPEC_SALT_ADDR.

    Fixes c-c++-common/torture/pr57945.c and various other tests.

    gcc/
            PR target/97269
            * explow.c (convert_memory_address_addr_space_1): Handle UNSPECs
            nested in CONSTs.
            * config/aarch64/aarch64.c (aarch64_expand_mov_immediate): Use
            convert_memory_address to convert symbolic immediates to ptr_mode
            before forcing them to memory.