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 <rsand...@gcc.gnu.org>: https://gcc.gnu.org/g:e8beba1cfc761cc35762283b3b44a355ef05e25b commit r11-6461-ge8beba1cfc761cc35762283b3b44a355ef05e25b Author: Richard Sandiford <richard.sandif...@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.
