Outdated comment in real.c (was: constant folding)

Outdated comment in real.c (was: constant folding)

[Vincent Lefevre]

[Cc to the gcc mailing-list]

On 2009-09-25 02:18:55 +0200, Vincent Lefevre wrote:
> Also, as EXP_BITS is the full (biased) exponent size, it seems that
> the real.c comment is buggy (27 -> 26).

Looking at the history:

Index: real.h
===================================================================
--- real.h      (revision 107860)
+++ real.h      (revision 107861)
@@ -35,7 +35,7 @@
 };
 
 #define SIGNIFICAND_BITS       (128 + HOST_BITS_PER_LONG)
-#define EXP_BITS               (32 - 5)
+#define EXP_BITS               (32 - 6)
 #define MAX_EXP                        ((1 << (EXP_BITS - 1)) - 1)
[...]

but real.c wasn't updated: it still has

   denormal number fits in 17 exponent bits; we store 27.

that comes from r83133.

-- 
Vincent Lefèvre <vincent@vinc17.org> - Web: <http://www.vinc17.org/>
100% accessible validated (X)HTML - Blog: <http://www.vinc17.org/blog/>
Work: CR INRIA - computer arithmetic / Arénaire project (LIP, ENS-Lyon)

Re: Outdated comment in real.c (was: constant folding)

[Kaveh R. GHAZI]

On Fri, 25 Sep 2009, Vincent Lefevre wrote:

> [Cc to the gcc mailing-list]
>
> On 2009-09-25 02:18:55 +0200, Vincent Lefevre wrote:
> > Also, as EXP_BITS is the full (biased) exponent size, it seems that
> > the real.c comment is buggy (27 -> 26).
>
> Looking at the history:
>
> -#define EXP_BITS               (32 - 5)
> +#define EXP_BITS               (32 - 6)

The following change fixes the comment.  Tested with "make" on
x86_64-unknown-linux-gnu.  I'll install this as "obvious" tomorrow if
nobody comments on the patch.

		--Kaveh



2009-09-28  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>

	* real.c: Fix comment to reflect actual exponent size.

diff -rup orig/egcc-SVN20090928/gcc/real.c egcc-SVN20090928/gcc/real.c
--- orig/egcc-SVN20090928/gcc/real.c	2009-09-18 02:00:54.000000000 +0200
+++ egcc-SVN20090928/gcc/real.c	2009-09-28 18:06:06.000000000 +0200
@@ -57,7 +57,7 @@

    Both of these requirements are easily satisfied.  The largest target
    significand is 113 bits; we store at least 160.  The smallest
-   denormal number fits in 17 exponent bits; we store 27.
+   denormal number fits in 17 exponent bits; we store 26.

    Note that the decimal string conversion routines are sensitive to
    rounding errors.  Since the raw arithmetic routines do not themselves