https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78468
--- Comment #40 from Wilco <wdijkstr at arm dot com> --- (In reply to Eric Botcazou from comment #39) > > The existing alloca code relies on STACK_BOUNDARY being set correctly. Has > > the value been fixed already for the OS variants mentioned? If stack > > alignment can't be guaranteed by OS/runtime/prolog, STACK_BOUNDARY should be > > 8. > > No, no, no, please read the ??? note I put in emit-rtl.c. STACK_BOUNDARY is > correct, the problem is the declared alignment of the virtual registers. If you cannot guarantee the alignment of the pointers to STACK_BOUNDARY then STACK_BOUNDARY is incorrect. GCC uses the STACK_BOUNDARY guarantee in optimizations so it is essential to get this right if you want correct code generation.
