* [Bug target/39949] [4.5 regression] Revision 146874 breaks %z on x87 insns
2009-04-28 16:34 [Bug target/39949] New: [4.5 regression] Revision 146874 breaks %z on x87 insns hjl dot tools at gmail dot com
@ 2009-04-28 16:40 ` ubizjak at gmail dot com
2009-04-28 16:45 ` hjl dot tools at gmail dot com
` (9 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: ubizjak at gmail dot com @ 2009-04-28 16:40 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from ubizjak at gmail dot com 2009-04-28 16:39 -------
Wontfix, the code uses undocumented operand modifier.
--
ubizjak at gmail dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |WONTFIX
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39949
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug target/39949] [4.5 regression] Revision 146874 breaks %z on x87 insns
2009-04-28 16:34 [Bug target/39949] New: [4.5 regression] Revision 146874 breaks %z on x87 insns hjl dot tools at gmail dot com
2009-04-28 16:40 ` [Bug target/39949] " ubizjak at gmail dot com
@ 2009-04-28 16:45 ` hjl dot tools at gmail dot com
2009-04-28 18:12 ` bonzini at gnu dot org
` (8 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: hjl dot tools at gmail dot com @ 2009-04-28 16:45 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from hjl dot tools at gmail dot com 2009-04-28 16:45 -------
None of x86 insn modifiers are documented and %z comments in gcc
source codes on 4.3/4.4 branches are simply incorrect. %z has been
working on x87 insns since day 1 on gcc.gnu.org back to 1992. Why
do we have to break existing user codes with few benefits to anyone?
--
hjl dot tools at gmail dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|WONTFIX |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39949
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug target/39949] [4.5 regression] Revision 146874 breaks %z on x87 insns
2009-04-28 16:34 [Bug target/39949] New: [4.5 regression] Revision 146874 breaks %z on x87 insns hjl dot tools at gmail dot com
2009-04-28 16:40 ` [Bug target/39949] " ubizjak at gmail dot com
2009-04-28 16:45 ` hjl dot tools at gmail dot com
@ 2009-04-28 18:12 ` bonzini at gnu dot org
2009-04-28 18:13 ` bonzini at gnu dot org
` (7 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: bonzini at gnu dot org @ 2009-04-28 18:12 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from bonzini at gnu dot org 2009-04-28 18:12 -------
H.J., please do not make up testcases and tell us who was actually using %z for
x87 as of March 31st, 2009.
Otherwise, this bug has the same level of seriousness as the one I'm closing it
as duplicate of.
*** This bug has been marked as a duplicate of 5 ***
--
bonzini at gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |bonzini at gnu dot org
Status|UNCONFIRMED |RESOLVED
Resolution| |DUPLICATE
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39949
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug target/39949] [4.5 regression] Revision 146874 breaks %z on x87 insns
2009-04-28 16:34 [Bug target/39949] New: [4.5 regression] Revision 146874 breaks %z on x87 insns hjl dot tools at gmail dot com
` (2 preceding siblings ...)
2009-04-28 18:12 ` bonzini at gnu dot org
@ 2009-04-28 18:13 ` bonzini at gnu dot org
2009-04-28 18:14 ` bonzini at gnu dot org
` (6 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: bonzini at gnu dot org @ 2009-04-28 18:13 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from bonzini at gnu dot org 2009-04-28 18:13 -------
reopening...
--
bonzini at gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|DUPLICATE |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39949
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug target/39949] [4.5 regression] Revision 146874 breaks %z on x87 insns
2009-04-28 16:34 [Bug target/39949] New: [4.5 regression] Revision 146874 breaks %z on x87 insns hjl dot tools at gmail dot com
` (3 preceding siblings ...)
2009-04-28 18:13 ` bonzini at gnu dot org
@ 2009-04-28 18:14 ` bonzini at gnu dot org
2009-04-28 18:22 ` hjl dot tools at gmail dot com
` (5 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: bonzini at gnu dot org @ 2009-04-28 18:14 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from bonzini at gnu dot org 2009-04-28 18:14 -------
... to mark as waiting.
--
bonzini at gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |WAITING
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39949
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug target/39949] [4.5 regression] Revision 146874 breaks %z on x87 insns
2009-04-28 16:34 [Bug target/39949] New: [4.5 regression] Revision 146874 breaks %z on x87 insns hjl dot tools at gmail dot com
` (4 preceding siblings ...)
2009-04-28 18:14 ` bonzini at gnu dot org
@ 2009-04-28 18:22 ` hjl dot tools at gmail dot com
2009-04-28 18:23 ` pinskia at gcc dot gnu dot org
` (4 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: hjl dot tools at gmail dot com @ 2009-04-28 18:22 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from hjl dot tools at gmail dot com 2009-04-28 18:22 -------
(In reply to comment #3)
> H.J., please do not make up testcases and tell us who was actually using %z for
> x87 as of March 31st, 2009.
>
If I had told you that we had had several internal applications
which use %z on x87 since 1998, would it make a difference?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39949
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug target/39949] [4.5 regression] Revision 146874 breaks %z on x87 insns
2009-04-28 16:34 [Bug target/39949] New: [4.5 regression] Revision 146874 breaks %z on x87 insns hjl dot tools at gmail dot com
` (5 preceding siblings ...)
2009-04-28 18:22 ` hjl dot tools at gmail dot com
@ 2009-04-28 18:23 ` pinskia at gcc dot gnu dot org
2009-04-28 19:33 ` bonzini at gnu dot org
` (3 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2009-04-28 18:23 UTC (permalink / raw)
To: gcc-bugs
------- Comment #7 from pinskia at gcc dot gnu dot org 2009-04-28 18:23 -------
Considering this is all undocumened no.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |RESOLVED
Resolution| |WONTFIX
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39949
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug target/39949] [4.5 regression] Revision 146874 breaks %z on x87 insns
2009-04-28 16:34 [Bug target/39949] New: [4.5 regression] Revision 146874 breaks %z on x87 insns hjl dot tools at gmail dot com
` (6 preceding siblings ...)
2009-04-28 18:23 ` pinskia at gcc dot gnu dot org
@ 2009-04-28 19:33 ` bonzini at gnu dot org
2009-04-28 20:47 ` rguenth at gcc dot gnu dot org
` (2 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: bonzini at gnu dot org @ 2009-04-28 19:33 UTC (permalink / raw)
To: gcc-bugs
------- Comment #8 from bonzini at gnu dot org 2009-04-28 19:33 -------
Subject: Re: [4.5 regression] Revision 146874 breaks %z on
x87 insns
> If I had told you that we had had several internal applications
> which use %z on x87 since 1998, would it make a difference?
Maybe no, but it wouldn't sound so kafkian.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39949
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug target/39949] [4.5 regression] Revision 146874 breaks %z on x87 insns
2009-04-28 16:34 [Bug target/39949] New: [4.5 regression] Revision 146874 breaks %z on x87 insns hjl dot tools at gmail dot com
` (7 preceding siblings ...)
2009-04-28 19:33 ` bonzini at gnu dot org
@ 2009-04-28 20:47 ` rguenth at gcc dot gnu dot org
2009-04-28 23:51 ` jakub at gcc dot gnu dot org
2009-04-29 5:10 ` bonzini at gnu dot org
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2009-04-28 20:47 UTC (permalink / raw)
To: gcc-bugs
------- Comment #9 from rguenth at gcc dot gnu dot org 2009-04-28 20:47 -------
FWIW I agree. Relying on undocumented behavior is as invalid as any other
invalid asm that happened to work in the past.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39949
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug target/39949] [4.5 regression] Revision 146874 breaks %z on x87 insns
2009-04-28 16:34 [Bug target/39949] New: [4.5 regression] Revision 146874 breaks %z on x87 insns hjl dot tools at gmail dot com
` (8 preceding siblings ...)
2009-04-28 20:47 ` rguenth at gcc dot gnu dot org
@ 2009-04-28 23:51 ` jakub at gcc dot gnu dot org
2009-04-29 5:10 ` bonzini at gnu dot org
10 siblings, 0 replies; 12+ messages in thread
From: jakub at gcc dot gnu dot org @ 2009-04-28 23:51 UTC (permalink / raw)
To: gcc-bugs
------- Comment #10 from jakub at gcc dot gnu dot org 2009-04-28 23:51 -------
I disagree, while the modifiers are perhaps undocumented, there is tons of
software in the wild that uses them heavily (I don't know about %z, but many
other modifiers) and breaking that all would be a terrible idea.
Look at longlong.h for examples, glibc, Linux kernel just to name a few. Just
do
find . -name \*.[ch] | xargs grep '[^%]%[a-zA-Z][0-9]'
and you'll see lots of those (of course with some false positives, but those
are
easily recognizable), on many different targets.
The right thing is just to document them.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39949
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug target/39949] [4.5 regression] Revision 146874 breaks %z on x87 insns
2009-04-28 16:34 [Bug target/39949] New: [4.5 regression] Revision 146874 breaks %z on x87 insns hjl dot tools at gmail dot com
` (9 preceding siblings ...)
2009-04-28 23:51 ` jakub at gcc dot gnu dot org
@ 2009-04-29 5:10 ` bonzini at gnu dot org
10 siblings, 0 replies; 12+ messages in thread
From: bonzini at gnu dot org @ 2009-04-29 5:10 UTC (permalink / raw)
To: gcc-bugs
------- Comment #11 from bonzini at gnu dot org 2009-04-29 05:09 -------
Subject: Re: [4.5 regression] Revision 146874 breaks %z on
x87 insns
> The right thing is just to document them.
Agreed. But the question is whether to break %z and all but one
person reckon it would be actually *fixing* it.
Paolo
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39949
^ permalink raw reply [flat|nested] 12+ messages in thread