[gcc(refs/users/meissner/heads/work068)] Avoid NaN and denormal values in XXSPLTIDP.

[gcc(refs/users/meissner/heads/work068)] Avoid NaN and denormal values in XXSPLTIDP.

[Michael Meissner]

https://gcc.gnu.org/g:39dfb439be18b0b820f02dbe2c51999721ff58fc

commit 39dfb439be18b0b820f02dbe2c51999721ff58fc
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Tue Sep 14 10:29:25 2021 -0400

    Avoid NaN and denormal values in XXSPLTIDP.
    
    2021-09-14  Michael Meissner  <meissner@linux.ibm.com>
    
    gcc/
    
            * config/rs6000/predicates.md (easy_fp_constant_float_to_v2df):
            Avoid integer values that look like NaN or denormal values in
            XXSPLTIDP.

Diff:
---
 gcc/config/rs6000/predicates.md | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/gcc/config/rs6000/predicates.md b/gcc/config/rs6000/predicates.md
index c8f7d975b7c..635a08ec8d6 100644
--- a/gcc/config/rs6000/predicates.md
+++ b/gcc/config/rs6000/predicates.md
@@ -666,6 +666,11 @@
       HOST_WIDE_INT df_value = INTVAL (element);
       long df_words[2];
 
+      /* Stay away from NaNs and denormal values.  */
+      int exponent = (df_value >> 52) & 0x7ff;
+      if (exponent == 0 || exponent == 0x7ff)
+	return false;
+
       df_words[0] = (df_value >> 32) & 0xffffffff;
       df_words[1] = df_value & 0xffffffff;