[gcc/devel/sh-lra] LRA: Take scratch as implicit unused output reloads

[Oleg Endo via Gcc-cvs]

https://gcc.gnu.org/g:dbd192caf14916d0869c7123e03ad21ef7bfd65f

commit dbd192caf14916d0869c7123e03ad21ef7bfd65f
Author: Alexandre Oliva <ol...@gnu.org>
Date:   Fri Sep 20 18:22:12 2024 +0900

    LRA: Take scratch as implicit unused output reloads
    
    gcc/ChangeLog:
            * lra-constraints.cc (match_reload, process_alt_operands,
            curr_insn_transform): Take scratch as implicit unused
            output reloads.

Diff:
---
 gcc/lra-constraints.cc | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/gcc/lra-constraints.cc b/gcc/lra-constraints.cc
index fdcc07764a2e..4bc40ef532ba 100644
--- a/gcc/lra-constraints.cc
+++ b/gcc/lra-constraints.cc
@@ -1213,7 +1213,9 @@ 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 ();
@@ -2946,7 +2948,8 @@ 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)
+                  && ! ira_former_scratch_p (REGNO (operand_reg[nop])))
                  || (curr_static_id->operand[nop].type != OP_OUT
                      && no_input_reloads_p && ! const_to_mem)
                  || (this_alternative_matches >= 0
@@ -2956,7 +2959,9 @@ 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])
+                             && ! (ira_former_scratch_p
+                                   (REGNO (operand_reg[nop])))))))
                {
                  if (lra_dump_file != NULL)
                    fprintf
@@ -4744,7 +4749,8 @@ 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);