https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78468
--- Comment #24 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
The root cause of this mess is actually init_emit:
REGNO_POINTER_ALIGN (VIRTUAL_INCOMING_ARGS_REGNUM) = STACK_BOUNDARY;
REGNO_POINTER_ALIGN (VIRTUAL_STACK_VARS_REGNUM) = STACK_BOUNDARY;
REGNO_POINTER_ALIGN (VIRTUAL_STACK_DYNAMIC_REGNUM) = STACK_BOUNDARY;
REGNO_POINTER_ALIGN (VIRTUAL_OUTGOING_ARGS_REGNUM) = STACK_BOUNDARY;
3 out of 4 are wrong for 32-bit SPARC. VIRTUAL_STACK_DYNAMIC_REGNUM is fixable
but not VIRTUAL_INCOMING_ARGS_REGNUM & VIRTUAL_OUTGOING_ARGS_REGNUM, whose
offset is defined by the ABI.
The code in init_emit looks wrong to me, as STACK_BOUNDARY is documented as:
-- Macro: STACK_BOUNDARY
Define this macro to the minimum alignment enforced by hardware
for the stack pointer on this machine. The definition is a C
expression for the desired alignment (measured in bits). This
value is used as a default if `PREFERRED_STACK_BOUNDARY' is not
defined. On most machines, this should be the same as
`PARM_BOUNDARY'.
but it goes back to 1995; I guess nobody cared about it until Dominik's patch.
