[gcc r16-787] genemit: Avoid using gen_exp in output_add_clobbers

[Richard Sandiford via Gcc-cvs]

https://gcc.gnu.org/g:aca0cf1150d6f6be9ee451b5f91f505aef911f8e

commit r16-787-gaca0cf1150d6f6be9ee451b5f91f505aef911f8e
Author: Richard Sandiford <richard.sandif...@arm.com>
Date:   Wed May 21 10:01:31 2025 +0100

    genemit: Avoid using gen_exp in output_add_clobbers
    
    output_add_clobbers emits code to add:
    
      (clobber (scratch:M))
    
    and/or:
    
      (clobber (reg:M R))
    
    expressions to the end of a PARALLEL.  At the moment, it does this
    using the general gen_exp function.  That makes sense with the code
    in its current form, but with later patches it's more convenient to
    handle the two cases directly.
    
    This also avoids having to pass an md_rtx_info that is unrelated
    to the clobber expressions.
    
    gcc/
            * genemit.cc (clobber_pat::code): Delete.
            (maybe_queue_insn): Don't set clobber_pat::code.
            (output_add_clobbers): Remove info argument and output the two
            REG and SCRATCH cases directly.
            (main): Update call accordingly.

Diff:
---
 gcc/genemit.cc | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/gcc/genemit.cc b/gcc/genemit.cc
index ba64290af53e..21eb0f2df7d2 100644
--- a/gcc/genemit.cc
+++ b/gcc/genemit.cc
@@ -39,7 +39,6 @@ struct clobber_pat
   int first_clobber;
   struct clobber_pat *next;
   int has_hard_reg;
-  rtx_code code;
 } *clobber_list;
 
 /* Records one insn that uses the clobber list.  */
@@ -435,7 +434,6 @@ maybe_queue_insn (const md_rtx_info &info)
              p->first_clobber = i + 1;
              p->next = clobber_list;
              p->has_hard_reg = has_hard_reg;
-             p->code = GET_CODE (insn);
              clobber_list = p;
            }
 
@@ -691,7 +689,7 @@ gen_split (const md_rtx_info &info, FILE *file)
    the end of the vector.  */
 
 static void
-output_add_clobbers (const md_rtx_info &info, FILE *file)
+output_add_clobbers (FILE *file)
 {
   struct clobber_pat *clobber;
   struct clobber_ent *ent;
@@ -709,12 +707,16 @@ output_add_clobbers (const md_rtx_info &info, FILE *file)
 
       for (i = clobber->first_clobber; i < GET_NUM_ELEM (clobber->pattern); 
i++)
        {
-         fprintf (file, "      XVECEXP (pattern, 0, %d) = ", i);
-         rtx clobbered_value = RTVEC_ELT (clobber->pattern, i);
-         /* Pass null for USED since there are no operands.  */
-         generator (clobber->code, NULL, info, file)
-           .gen_exp (clobbered_value);
-         fprintf (file, ";\n");
+         fprintf (file, "    XVECEXP (pattern, 0, %d) ="
+                  " gen_rtx_CLOBBER (VOIDmode, ", i);
+         rtx x = XEXP (RTVEC_ELT (clobber->pattern, i), 0);
+         if (REG_P (x))
+           fprintf (file, "gen_rtx_REG (%smode, %d)",
+                    GET_MODE_NAME (GET_MODE (x)), REGNO (x));
+         else
+           fprintf (file, "gen_rtx_SCRATCH (%smode)",
+                    GET_MODE_NAME (GET_MODE (x)));
+         fprintf (file, ");\n");
        }
 
       fprintf (file, "      break;\n\n");
@@ -1034,7 +1036,7 @@ main (int argc, const char **argv)
 
   /* Write out the routines to add CLOBBERs to a pattern and say whether they
      clobber a hard reg.  */
-  output_add_clobbers (info, file);
+  output_add_clobbers (file);
   output_added_clobbers_hard_reg_p (file);
 
   for (overloaded_name *oname = rtx_reader_ptr->get_overloads ();