[gcc(refs/users/meissner/heads/work104)] Revert change

[Michael Meissner]

https://gcc.gnu.org/g:93982558e1396fea36ca053ba40dd48a47d6a338

commit 93982558e1396fea36ca053ba40dd48a47d6a338
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Wed Jan 4 01:34:54 2023 -0500

    Revert change

Diff:
---
 gcc/tree.cc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/gcc/tree.cc b/gcc/tree.cc
index 46a3a742592..78b64ee98b3 100644
--- a/gcc/tree.cc
+++ b/gcc/tree.cc
@@ -9474,6 +9474,15 @@ build_common_tree_nodes (bool signed_char)
       if (!targetm.floatn_mode (n, extended).exists (&mode))
 	continue;
       int precision = GET_MODE_PRECISION (mode);
+      /* Work around the rs6000 KFmode having precision 113 not
+	 128.  */
+      const struct real_format *fmt = REAL_MODE_FORMAT (mode);
+      gcc_assert (fmt->b == 2 && fmt->emin + fmt->emax == 3);
+      int min_precision = fmt->p + ceil_log2 (fmt->emax - fmt->emin);
+      if (!extended)
+	gcc_assert (min_precision == n);
+      if (precision < min_precision)
+	precision = min_precision;
       FLOATN_NX_TYPE_NODE (i) = make_node (REAL_TYPE);
       TYPE_PRECISION (FLOATN_NX_TYPE_NODE (i)) = precision;
       layout_type (FLOATN_NX_TYPE_NODE (i));