emit-rtl.c (gen_lowpart_common): Disable optimization of initialized float-int…

emit-rtl.c (gen_lowpart_common): Disable optimization of initialized float-int union if the value is a NaN.

        * emit-rtl.c (gen_lowpart_common): Disable optimization of
        initialized float-int union if the value is a NaN.

From-SVN: r22371

gcc/ChangeLog

+Wed Sep  9 23:31:36 1998  (Stephen L Moshier) <moshier@world.std.com>
+
+	* emit-rtl.c (gen_lowpart_common): Disable optimization of
+	initialized float-int union if the value is a NaN.
+
 Wed Sep  9 23:00:48 1998  Nathan Sidwell  <nathan@acm.org>
 
 	* c-lex.c (real_yylex): Don't warn about long long constants if 

gcc/emit-rtl.c

@@ -774,6 +774,9 @@ gen_lowpart_common (mode, x)
 
       i = INTVAL (x);
       r = REAL_VALUE_FROM_TARGET_SINGLE (i);
+      /* Avoid changing the bit pattern of a NaN.  */
+      if (REAL_VALUE_ISNAN (r))
+	return 0;
       return CONST_DOUBLE_FROM_REAL_VALUE (r, mode);
     }
 #else
@@ -812,6 +815,8 @@ gen_lowpart_common (mode, x)
 	i[0] = low, i[1] = high;
 
       r = REAL_VALUE_FROM_TARGET_DOUBLE (i);
+      if (REAL_VALUE_ISNAN (r))
+	return 0;
       return CONST_DOUBLE_FROM_REAL_VALUE (r, mode);
     }
 #else