genmatch.c (struct capture_info): Add same_as field.

2015-07-24  Richard Biener  <rguenther@suse.de>

	* genmatch.c (struct capture_info): Add same_as field.
	(capture_info::capture_info): Initialize same_as.
	(capture_info::walk_match): Compute same_as.
	(capture_info::walk_result): Compute stuff for the leader.
	(capture_info::walk_c_expr): Likewise.
	(dt_simplify::gen_1): Only look at leaders when deciding
	to force no side-effects or emit side-effects of omitted operands.

From-SVN: r226152

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b613180edaf6251893b738b1b8c67489e3edfb6a..6f8ae02f199dc9f82066ece848fb0300edaadc86 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2015-07-24  Richard Biener  <rguenther@suse.de>
+
+       * genmatch.c (struct capture_info): Add same_as field.
+       (capture_info::capture_info): Initialize same_as.
+       (capture_info::walk_match): Compute same_as.
+       (capture_info::walk_result): Compute stuff for the leader.
+       (capture_info::walk_c_expr): Likewise.
+       (dt_simplify::gen_1): Only look at leaders when deciding
+       to force no side-effects or emit side-effects of omitted operands.
+
 2015-07-24  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
 
        * config/s390/s390.c (s390_save_gprs_to_fprs): Add CFA_REGISTER

diff --git a/gcc/genmatch.c b/gcc/genmatch.c
index cb2377095fe91a5d10f8a1542cc4f08306b7c6d7..83e66c6acc56e2cde3a684e819654f06c5768572 100644 (file)
--- a/gcc/genmatch.c
+++ b/gcc/genmatch.c
@@ -1582,6 +1582,7 @@ struct capture_info
       bool cond_expr_cond_p;
       unsigned long toplevel_msk;
       int result_use_count;
+      unsigned same_as;
     };
 
   auto_vec<cinfo> info;
@@ -1601,6 +1602,9 @@ capture_info::capture_info (simplify *s, operand *result)
 
   force_no_side_effects = 0;
   info.safe_grow_cleared (s->capture_max + 1);
+  for (int i = 0; i <= s->capture_max; ++i)
+    info[i].same_as = i;
+
   e = as_a <expr *> (s->match);
   for (unsigned i = 0; i < e->ops.length (); ++i)
     walk_match (e->ops[i], i,
@@ -1634,9 +1638,16 @@ capture_info::walk_match (operand *o, unsigned toplevel_arg,
        walk_match (c->what, toplevel_arg, conditional_p, false);
       /* We need to look past multiple captures to find a captured
         expression as with conditional converts two captures
-        can be collapsed onto the same expression.  */
+        can be collapsed onto the same expression.  Also collect
+        what captures capture the same thing.  */
       while (c->what && is_a <capture *> (c->what))
-       c = as_a <capture *> (c->what);
+       {
+         c = as_a <capture *> (c->what);
+         if (info[c->where].same_as != c->where
+             && info[c->where].same_as != info[where].same_as)
+           fatal_at (c->location, "cannot handle this collapsed capture");
+         info[c->where].same_as = info[where].same_as;
+       }
       /* Mark expr (non-leaf) captures and forced single-use exprs.  */
       expr *e;
       if (c->what
@@ -1682,19 +1693,20 @@ capture_info::walk_result (operand *o, bool conditional_p, operand *result)
 {
   if (capture *c = dyn_cast <capture *> (o))
     {
-      info[c->where].result_use_count++;
+      unsigned where = info[c->where].same_as;
+      info[where].result_use_count++;
       /* If we substitute an expression capture we don't know
          which captures this will end up using (well, we don't
         compute that).  Force the uses to be side-effect free
         which means forcing the toplevels that reach the
         expression side-effect free.  */
-      if (info[c->where].expr_p)
-       force_no_side_effects |= info[c->where].toplevel_msk;
+      if (info[where].expr_p)
+       force_no_side_effects |= info[where].toplevel_msk;
       /* Mark CSE capture uses as forced to have no side-effects. */
       if (c->what
          && is_a <expr *> (c->what))
        {
-         info[c->where].cse_p = true;
+         info[where].cse_p = true;
          walk_result (c->what, true, result);
        }
     }
@@ -1783,7 +1795,8 @@ capture_info::walk_c_expr (c_expr *e)
            id = (const char *)n->val.str.text;
          else
            id = (const char *)CPP_HASHNODE (n->val.node.node)->ident.str;
-         info[*e->capture_ids->get(id)].force_no_side_effects_p = true;
+         unsigned where = *e->capture_ids->get(id);
+         info[info[where].same_as].force_no_side_effects_p = true;
        }
     }
 }
@@ -2767,6 +2780,8 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
          if (!is_predicate)
            for (int i = 0; i < s->capture_max + 1; ++i)
              {
+               if (cinfo.info[i].same_as != (unsigned)i)
+                 continue;
                if (!cinfo.info[i].force_no_side_effects_p
                    && cinfo.info[i].result_use_count > 1)
                  {
@@ -2842,6 +2857,8 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
             on TREE_SIDE_EFFECTS emit omit_one_operand.  */
          for (int i = 0; i < s->capture_max + 1; ++i)
            {
+             if (cinfo.info[i].same_as != (unsigned)i)
+               continue;
              if (!cinfo.info[i].force_no_side_effects_p
                  && !cinfo.info[i].expr_p
                  && cinfo.info[i].result_use_count == 0)