[gcc/trunk] Use auto_vec in ssa_equiv_stack.

[Aldy Hernandez <aldyh@gcc.gnu.org>]

https://gcc.gnu.org/g:04a040d907a83af54e0a98bdba5bfabc0ef4f700

commit 04a040d907a83af54e0a98bdba5bfabc0ef4f700
Author: Aldy Hernandez <aldyh@redhat.com>
Date:   Thu Jun 10 09:20:30 2021 +0200

    Use auto_vec in ssa_equiv_stack.
    
    There is a mismatch between the new and the delete for the
    ssa_equiv_stack class.  The correct idiom should have been delete[].
    It has been pointed out that perhaps a better alternative is to use
    an auto_vec which does everything automatically.  Plus, it is more
    consistent with m_stack which is already an auto_vec.
    
    This patch fixes the issue in PR100984.
    
    Tested on x86-64 Linux.
    
    gcc/ChangeLog:
    
            PR tree-optimization/100984
            * gimple-ssa-evrp.c  (ssa_equiv_stack): Use auto_vec for
            replacements table.
            (ssa_equiv_stack::~ssa_equiv_stack): Remove.

Diff:
---
 gcc/gimple-ssa-evrp.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/gcc/gimple-ssa-evrp.c b/gcc/gimple-ssa-evrp.c
index 7e1cf51239a..eb8320ae9d8 100644
--- a/gcc/gimple-ssa-evrp.c
+++ b/gcc/gimple-ssa-evrp.c
@@ -53,7 +53,6 @@ class ssa_equiv_stack
 {
 public:
   ssa_equiv_stack ();
-  ~ssa_equiv_stack ();
   void enter (basic_block);
   void leave (basic_block);
   void push_replacement (tree name, tree replacement);
@@ -61,19 +60,13 @@ public:
 
 private:
   auto_vec<std::pair <tree, tree>> m_stack;
-  tree *m_replacements;
+  auto_vec<tree> m_replacements;
   const std::pair <tree, tree> m_marker = std::make_pair (NULL, NULL);
 };
 
 ssa_equiv_stack::ssa_equiv_stack ()
 {
-  m_replacements = new tree[num_ssa_names] ();
-}
-
-ssa_equiv_stack::~ssa_equiv_stack ()
-{
-  m_stack.release ();
-  delete m_replacements;
+  m_replacements.safe_grow_cleared (num_ssa_names);
 }
 
 // Pushes a marker at the given point.