Denis Chertykov <cherty...@gmail.com> writes:
> PR rtl-optimization/117868
> gcc/
> * lra-spills.cc (assign_stack_slot_num_and_sort_pseudos): Reuse slots
> only without allocated memory or only with equal or smaller registers
> with equal or smaller alignment.
> (lra_spill): Print slot size as width.
>
>
> diff --git a/gcc/lra-spills.cc b/gcc/lra-spills.cc
> index db78dcd28a3..93a0c92db9f 100644
> --- a/gcc/lra-spills.cc
> +++ b/gcc/lra-spills.cc
> @@ -386,7 +386,18 @@ assign_stack_slot_num_and_sort_pseudos (int
> *pseudo_regnos, int n)
> && ! (lra_intersected_live_ranges_p
> (slots[j].live_ranges,
> lra_reg_info[regno].live_ranges)))
> - break;
> + {
> + /* A slot without allocated memory can be shared. */
> + if (slots[j].mem == NULL_RTX)
> + break;
> +
> + /* A slot with allocated memory can be shared only with equal
> + or smaller register with equal or smaller alignment. */
> + if (slots[j].align >= spill_slot_alignment (mode)
> + && compare_sizes_for_sort (slots[j].size,
> + GET_MODE_SIZE (mode)) != -1)
Sorry for piping up late, but I think this should be:
known_ge (GET_MODE_SIZE (mode), slots[j].size)
>From the comment above compare_sizes_for_sort:
/* Compare A and B for sorting purposes, returning -1 if A should come
before B, 0 if A and B are identical, and 1 if A should come after B.
This is a lexicographical compare of the coefficients in reverse order.
A consequence of this is that all constant sizes come before all
non-constant ones, regardless of magnitude (since a size is never
negative). This is what most callers want. For example, when laying
data out on the stack, it's better to keep all the constant-sized
data together so that it can be accessed as a constant offset from a
single base. */
For example, compare_sizes_for_sort would return 1 for a slot size
of 2+2X and a mode size of 16, but the slot would be too small for X < 7.
Thanks,
Richard
> + break;
> + }
> }
> if (j >= slots_num)
> {
> @@ -656,8 +667,7 @@ lra_spill (void)
> for (i = 0; i < slots_num; i++)
> {
> fprintf (lra_dump_file, " Slot %d regnos (width = ", i);
> - print_dec (GET_MODE_SIZE (GET_MODE (slots[i].mem)),
> - lra_dump_file, SIGNED);
> + print_dec (slots[i].size, lra_dump_file, SIGNED);
> fprintf (lra_dump_file, "):");
> for (curr_regno = slots[i].regno;;
> curr_regno = pseudo_slots[curr_regno].next - pseudo_slots)
