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Re: Proposal for `info float' layout
- To: hjl at lucon dot org
- Subject: Re: Proposal for `info float' layout
- From: Mark Kettenis <kettenis at wins dot uva dot nl>
- Date: Mon, 1 Nov 1999 19:43:15 +0100 (CET)
- CC: gdb at sourceware dot cygnus dot com, jimb at cygnus dot com, eliz at gnu dot org, jtc at redback dot com, hjl at lucon dot org
- References: <19991101170951.082811B493@ocean.lucon.org>
Date: Mon, 1 Nov 1999 09:09:50 -0800 (PST)
From: hjl@lucon.org (H.J. Lu)
May I suggest we use
R3: Special 0x00000000000000000000 Denormal 0.0024438394034300000
R4: Empty 0x00000000000000000000 Zero 0
R4: Empty 0x00000000000000000000 Normal 1.0
It is more consistent and easy to read.
Thanks for your suggestion. It gives me the opportunity to say a few
things about how I came to my proposal for the new layout.
While your suggested layout may seem more consistent, I don't think it
is easier to read.
Keep in mind that GDB is a debugger. We should try to create the
layout that is most useful for finding bugs. Based on this principle
I made some decisions:
* My code deliberately does not try to interpret the contents of
empty registers. Doing so would needlesly clutter the display with
information that is almost certainly irrelevent, thus making it
harder to find information that is relevant. If you really want
the contents of an empty register as a floating point number, you
can always display the register by using GDB's `print' command.
* My code deliberately prints only a further classification of a
floating point number if it is `Denormal' or `Pseudo-denormal'.
This makes denormals stand out which is important since a denormal
is a clear sign for problematic code. The user's program might
perform poorly since it is losing precision.
I think zeroes stand out enough for themselves, and a normal number
is ... well, a normal number. Nothing special and doesn't require
any additional attention. Only its value is relevant.
Mark