On 2019-08-19 3:35 a.m., John Darrington wrote:
On Fri, Aug 16, 2019 at 10:50:13AM -0400, Vladimir Makarov wrote:
No I meant something like that
(define_special_memory_constraint "a" ...)
(define_predicate "my_special_predicate" ...
{
if (lra_in_progress_p)
return REG_P (op) && REGNO (op) >= FIRST_PSEUDO_REGISTER &&
reg_renumber[REGNO(op)] < 0;
return true if memory with sp addressing;
})
I think LRA spills pseudo-register and it will be memory addressed by sp
at the end of LRA.
What I've done is this:
(define_predicate "my_special_predicate"
(match_operand 0 "memory_operand")
{
debug_rtx (op);
gcc_assert (MEM_P (op));
op = XEXP (op, 0);
if (GET_CODE (op) == PLUS)
op = XEXP (op, 0);
if (lra_in_progress)
{
fprintf (stderr, "%s:%d\n", __FILE__, __LINE__);
return REG_P (op) && REGNO (op) >= FIRST_PSEUDO_REGISTER &&
reg_renumber[REGNO(op)] < 0;
}
if (REG_P (op))
{
int regno = REGNO (op);
return (regno == 10); // register is the stack pointer
}
return true;
})
(and many variations) Unfortunately, any moderately complicated input
still results in a (mem (reg) ) insn repeatedly entering the
lra_in_progress case and returning false, and eventually terminating with
"internal compiler error: maximum number of generated reload insns per insn achieved (90)"
Any other ideas?
As I remember there were a few other ideas from Richard Biener and
Segher Boessenkool. I also proposed to add a new address register which
will be always a fixed stack memory slot at the end. Unfortunately I am
not familiar with the target and the port to say in details how to do
it. But I think it is worth to try.
