https://gcc.gnu.org/g:15f8ce096527c8ac55bb4a9c2954d2db80aa4efc
commit 15f8ce096527c8ac55bb4a9c2954d2db80aa4efc Author: Alexandre Oliva <[email protected]> Date: Mon Aug 5 14:16:37 2024 -0300 [lra] take scratch as implicit unused output reloads [PR55212] When trying to convert the SH port to use LRA, the first issue I hit was the need for dealing with former scratch registers at places we didn't need to on other ports, treating them like unused output reloads instead of rejecting them. for gcc/ChangeLog PR target/55212 * lra-constraints.cc (match_reload): Treat former scratch regs as implicit unused output reloads. (process_alt_operands): Likewise. (curr_insn_transform): Likewise. Diff: --- gcc/lra-constraints.cc | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/gcc/lra-constraints.cc b/gcc/lra-constraints.cc index 66a300bf268b..910f3fba8f47 100644 --- a/gcc/lra-constraints.cc +++ b/gcc/lra-constraints.cc @@ -1243,7 +1243,9 @@ match_reload (signed char out, signed char *ins, signed char *outs, return; /* See a comment for the input operand above. */ narrow_reload_pseudo_class (out_rtx, goal_class); - if (find_reg_note (curr_insn, REG_UNUSED, out_rtx) == NULL_RTX) + if (find_reg_note (curr_insn, REG_UNUSED, out_rtx) == NULL_RTX + && !ira_former_scratch_p (REGNO (SUBREG_P (out_rtx) + ? SUBREG_REG (out_rtx) : out_rtx))) { reg = SUBREG_P (out_rtx) ? SUBREG_REG (out_rtx) : out_rtx; start_sequence (); @@ -3002,7 +3004,8 @@ process_alt_operands (int only_alternative) objects with a REG_UNUSED note. */ if ((curr_static_id->operand[nop].type != OP_IN && no_output_reloads_p - && ! find_reg_note (curr_insn, REG_UNUSED, op)) + && ! find_reg_note (curr_insn, REG_UNUSED, op) + && ! scratch_p) || (curr_static_id->operand[nop].type != OP_OUT && no_input_reloads_p && ! const_to_mem) || (this_alternative_matches >= 0 @@ -3012,7 +3015,8 @@ process_alt_operands (int only_alternative) [this_alternative_matches].type != OP_IN) && ! find_reg_note (curr_insn, REG_UNUSED, no_subreg_reg_operand - [this_alternative_matches]))))) + [this_alternative_matches]) + && ! scratch_p)))) { if (lra_dump_file != NULL) fprintf @@ -4856,7 +4860,8 @@ curr_insn_transform (bool check_only_p) if (type != OP_IN && find_reg_note (curr_insn, REG_UNUSED, old) == NULL_RTX /* OLD can be an equivalent constant here. */ - && !CONSTANT_P (old)) + && !CONSTANT_P (old) + && !ira_former_scratch_p (REGNO (old))) { start_sequence (); lra_emit_move (type == OP_INOUT ? copy_rtx (old) : old, new_reg);
