[PATCH 2/3] gimple-fold: Return early for GIMPLE_COND with true/false

[Andrew Pinski]

To speed up things slightly so not needing to call all the way through
to match and simplify, we should return early for true/false on GIMPLE_COND.

gcc/ChangeLog:

        * gimple-fold.cc (fold_stmt_1): For GIMPLE_COND return early
        for true/false.

Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
---
 gcc/gimple-fold.cc | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc
index 94d5a1ebbd7..2381a82d2b1 100644
--- a/gcc/gimple-fold.cc
+++ b/gcc/gimple-fold.cc
@@ -6646,12 +6646,19 @@ fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace, 
tree (*valueize) (tree),
       break;
     case GIMPLE_COND:
       {
+       gcond *gc = as_a <gcond *> (stmt);
+       /* If the cond is already true/false, just return false.  */
+       if (gimple_cond_true_p (gc)
+           || gimple_cond_false_p (gc))
+         {
+           fold_undefer_overflow_warnings (false, stmt, 0);
+           return false;
+         }
        /* Canonicalize operand order.  */
-       tree lhs = gimple_cond_lhs (stmt);
-       tree rhs = gimple_cond_rhs (stmt);
+       tree lhs = gimple_cond_lhs (gc);
+       tree rhs = gimple_cond_rhs (gc);
        if (tree_swap_operands_p (lhs, rhs))
          {
-           gcond *gc = as_a <gcond *> (stmt);
            gimple_cond_set_lhs (gc, rhs);
            gimple_cond_set_rhs (gc, lhs);
            gimple_cond_set_code (gc,
-- 
2.43.0