[gcc r11-4923] Fix PRE NEW_SETS guarding

[Richard Biener]

https://gcc.gnu.org/g:2e8b368c3d33fd8ddafdd37f8e1b2ba45d1a122e

commit r11-4923-g2e8b368c3d33fd8ddafdd37f8e1b2ba45d1a122e
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Nov 11 18:15:57 2020 +0100

    Fix PRE NEW_SETS guarding
    
    Accesses to NEW_SETS should be properly guarded.  Committed
    as obvious.
    
    2020-11-11  Richard Biener  <rguenther@suse.de>
    
            PR tree-optimization/97623
            * tree-ssa-pre.c (create_expression_by_pieces): Guard
            NEW_SETS access.
            (insert_into_preds_of_block): Likewise.

Diff:
---
 gcc/tree-ssa-pre.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index 6dea8c28a1a..10d223bd365 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -3064,7 +3064,8 @@ create_expression_by_pieces (basic_block block, pre_expr expr,
 	      vn_info->value_id = get_next_value_id ();
 	      nameexpr = get_or_alloc_expr_for_name (forcedname);
 	      add_to_value (vn_info->value_id, nameexpr);
-	      bitmap_value_replace_in_set (NEW_SETS (block), nameexpr);
+	      if (NEW_SETS (block))
+		bitmap_value_replace_in_set (NEW_SETS (block), nameexpr);
 	      bitmap_value_replace_in_set (AVAIL_OUT (block), nameexpr);
 	    }
 
@@ -3231,8 +3232,8 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum,
   bitmap_insert_into_set (PHI_GEN (block), newphi);
   bitmap_value_replace_in_set (AVAIL_OUT (block),
 			       newphi);
-  bitmap_insert_into_set (NEW_SETS (block),
-			  newphi);
+  if (NEW_SETS (block))
+    bitmap_insert_into_set (NEW_SETS (block), newphi);
 
   /* If we insert a PHI node for a conversion of another PHI node
      in the same basic-block try to preserve range information.