[avr,patch,applied] PR120441: Limit f7_exp's expo to 1024 (not to 512).

[Georg-Johann Lay]

f7_exp's exponent was limited to |a| < 512, but exponents to to
1024 * ln2 = 709 may occur.
Applied as obvious.

Johann

--

AVR: target/120441 - Fix f7_exp for |x| ≥ 512.

f7_exp limited exponents to 512, but 1023 * ln2 ≈ 709,
hence 1024 is a correct limit.

libgcc/config/avr/libf7/
        PR target/120441
        * libf7.c (f7_exp): Limit aa->expo to 10 (not to 9).

diff --git a/libgcc/config/avr/libf7/libf7.c 
b/libgcc/config/avr/libf7/libf7.c
index a64554c562f..7d70804a59a 100644
--- a/libgcc/config/avr/libf7/libf7.c
+++ b/libgcc/config/avr/libf7/libf7.c
@@ -1649,10 +1649,10 @@ void f7_exp (f7_t *cc, const f7_t *aa)
     return f7_set_nan (cc);

   /* The maximal exponent of 2 for a double is 1023, hence we may limit
-     to  |A| < 1023 * ln2 ~ 709.  We limit to  1024 ~ 1.99 * 2^9  */
+     to  |A| < 1023 * ln2 ~ 709.  We limit to  1024 = 2^10  */

   if (f7_class_inf (a_class)
-      || (f7_class_nonzero (a_class) && aa->expo >= 9))
+      || (f7_class_nonzero (a_class) && aa->expo >= 10))
     {
       if (f7_class_sign (a_class))
        return f7_clr (cc);