https://gcc.gnu.org/g:d2e3635aa1820346050b85009df82a60cdd8206f
commit r15-6851-gd2e3635aa1820346050b85009df82a60cdd8206f
Author: Eric Botcazou <ebotca...@adacore.com>
Date: Mon Jan 6 09:09:49 2025 +0100
ada: Add more commentary to System.Val_Real.Large_Powfive
gcc/ada/ChangeLog:
* libgnat/s-valrea.adb (Large_Powfive) [2 parameters]: Add a couple
of additional comments.
Diff:
---
gcc/ada/libgnat/s-valrea.adb | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/gcc/ada/libgnat/s-valrea.adb b/gcc/ada/libgnat/s-valrea.adb
index ed22366840f7..aff694dd7219 100644
--- a/gcc/ada/libgnat/s-valrea.adb
+++ b/gcc/ada/libgnat/s-valrea.adb
@@ -396,6 +396,9 @@ package body System.Val_Real is
begin
pragma Assert (Exp > Maxexp);
+ -- This routine supports any type but it is not necessary to invoke it
+ -- for large types because the above one is sufficient for them.
+
pragma Warnings (Off, "-gnatw.a");
pragma Assert (not Is_Large_Type);
pragma Warnings (On, "-gnatw.a");
@@ -407,6 +410,8 @@ package body System.Val_Real is
-- its final value does not overflow but, if it's too large, then do not
-- bother doing it since overflow is just fine. The scaling factor is -3
-- for every power of 5 above the maximum, in other words division by 8.
+ -- Note that Maxpow is an upper bound of the span of exponents for which
+ -- scaling is needed, but it's OK to apply it even if it is not needed.
if Exp - Maxexp <= Maxpow then
S := 3 * (Exp - Maxexp);
