Re: [PATCH] genmatch fix (PR tree-optimization/71563)

[Jakub Jelinek]

On Thu, Dec 29, 2016 at 10:18:34PM +0100, Jakub Jelinek wrote:
> On Tue, Dec 20, 2016 at 09:45:03PM +0100, Jakub Jelinek wrote:
> > That is what I tried first, but there is some bug in genmatch.c that
> > prevents it.  The:
> >  (for vec (VECTOR_CST CONSTRUCTOR)
> >   (simplify
> >    (shiftrotate @0 vec@1)
> > results in case SSA_NAME: being added to a switch:
> >     case SSA_NAME:
> >       if (do_valueize (valueize, op1) != NULL_TREE)
> >         {
> >           gimple *def_stmt = SSA_NAME_DEF_STMT (op1);
> >           if (gassign *def = dyn_cast <gassign *> (def_stmt))
> >             switch (gimple_assign_rhs_code (def))
> >               {
> >               case CONSTRUCTOR:
> > and the SSA_NAME@1 in another simplification resulted in another
> >     case SSA_NAME:
> > into the same switch (rather than appending to the case SSA_NAME).
> 
> This patch attempts to deal with that.  The change for the new version of
> the patch with SSA_NAME@1 I'll post right away is (twice).  Two case SSA_NAME:
> in a single switch of course don't work well.

Oops, forgot to add the actual patch, here it is:

2017-01-02  Jakub Jelinek  <ja...@redhat.com>

        * genmatch.c (dt_node::gen_kids_1): If generic_exprs include SSA_NAME
        and exprs_len || fns_len, emit the code for SSA_NAME next to the exprs
        and fns handling, rather than in a separate case SSA_NAME.

--- gcc/genmatch.c.jj   2016-11-09 16:34:58.000000000 +0100
+++ gcc/genmatch.c      2016-12-29 22:11:25.088950033 +0100
@@ -2913,6 +2913,20 @@ dt_node::gen_kids_1 (FILE *f, int indent
 
       indent -= 6;
       fprintf_indent (f, indent, "    }\n");
+      /* See if there is SSA_NAME among generic_exprs and if yes, emit it
+        here rather than in the next loop.  */
+      for (unsigned i = 0; i < generic_exprs.length (); ++i)
+       {
+         expr *e = as_a <expr *>(generic_exprs[i]->op);
+         id_base *op = e->operation;
+         if (*op == SSA_NAME && (exprs_len || fns_len))
+           {
+             fprintf_indent (f, indent + 4, "{\n");
+             generic_exprs[i]->gen (f, indent + 6, gimple);
+             fprintf_indent (f, indent + 4, "}\n");
+           }
+       }
+
       fprintf_indent (f, indent, "  break;\n");
     }
 
@@ -2922,6 +2936,9 @@ dt_node::gen_kids_1 (FILE *f, int indent
       id_base *op = e->operation;
       if (*op == CONVERT_EXPR || *op == NOP_EXPR)
        fprintf_indent (f, indent, "CASE_CONVERT:\n");
+      else if (*op == SSA_NAME && (exprs_len || fns_len))
+       /* Already handled above.  */
+       continue;
       else
        fprintf_indent (f, indent, "case %s:\n", op->id);
       fprintf_indent (f, indent, "  {\n");


        Jakub