Hello Dave,
thank you for your answers.
Yes, the reason for "my" confusion was twofold:
first, the documentation of IBM, which states that the remaining components
of partially initialized automatic structures are not initialized, which
is not
conforming to the ANSI standard and is not what t
>I would kindly ask IBM to change the description in a way to be
>compatible to the ANSI standard and to that what the compilers,
>in fact, do.
You need to send your doc change request as an RCF. Send an eMail
with your comments to mhvr...@us.ibm.com
I have made good experience, although it may
> -Original Message-
> From: IBM Mainframe Discussion List
> [mailto:ibm-m...@bama.ua.edu] On Behalf Of Thomas David Rivers
> Sent: Wednesday, May 19, 2010 8:40 AM
> To: IBM-MAIN@bama.ua.edu
> Subject: Re: partially initialized structures in C
>
> Bernd,
&
Bernd Oppolzer wrote:
Hello David,
which version of the compiler did generate the MVC instructions?
was this with or without the INITAUTO option?
We use the z/OS v1.6 version, and this version only generates the MVI,
not the MVCs.
We will not use INITAUTO due to serious performance degradation
Hi Again Bernd,
That psuedo-assembler appears to be initializing
a 5-bytes of storage. Are you sure the 'scp1215ein'
data type is 24 bytes? Can you show the
typedef for 'scp1215ein'?
Does there happen to be any packing going on?
Bitfields, etc...
- Dave Rivers -
Bernd Oppolzer w
Bernd,
That sounds like a compiler bug, but more detail would
be needed to be sure.
The ANSI C standard basically works like this:
A structure initialized a file scope (static or not) will be
initialized to all zeros.
If the structure is being initialized within a function
(at a
Hello David and all others,
I have to apologize.
The MVC instructions which initialize the rest of the structure come
very late,
some 40 instructions later, after the function prologue, so I didn't
realize them.
But in fact, you are right, David, they are there, and the structure is
initializ
Hi Bernd
We had several PMR's about the C++ compiler and the compiler team
reacted always
very fast and competently (maybe as they are in Canada ;-) )
On 5/19/2010 9:21 AM, Bernd Oppolzer wrote:
Hello David,
which version of the compiler did generate the MVC instructions?
was this with o
Bernd,
I'm using z/OS V1.10 without INITAUTO. We've compiled our code all the
way back to OS/390 2.8 and I can't recall ever seeing
this problem. I'm sure it's a codegen bug, otherwise what is the point
of the MVI?
I wouldn't accept anything other than a fix from IBM. Although your
compiler
Hello David,
which version of the compiler did generate the MVC instructions?
was this with or without the INITAUTO option?
We use the z/OS v1.6 version, and this version only generates the MVI,
not the MVCs.
We will not use INITAUTO due to serious performance degradation.
At the moment, manag
To David:
no, there is no MVC. This is the z/OS V1.6 C-Compiler.
I will try and examine the newer versions. Maybe the error is only in this
version. But the description in the language reference also tells that the
remaining components remain uninitialized, which is very strange.
We, too, do thi
To: IBM-MAIN@bama.ua.edu
Subject: partially initialized structures in C (3)
Sorry for the missing line feeds.
C statement:
*scp1215ein in1215 = { 0 };
Pseudo ASSEMBLER (structure starts at 272(r13)):
STr6,(,r13,272)
MVI (r13,276),0
C statement:
*scp1215aus out
Are you sure there isn't an MVC after the MVI?
I rely on that kind of initialization all the time and have never had a
problem. A quick test program shows the correct behavior.
If this is not working as the ANSI standard I suggest you open a PMR. To
circumvent the problem compile with INITAUTO(
Yes, with respect to the IBM description, it works correct.
But the IBM description is wrong with respect to the ANSI C definition.
I also checked the language references of some other compilers,
that is, SGI or Microsoft. In all other cases, the remaining structure
components
are initialized wi
> -Original Message-
> From: IBM Mainframe Discussion List
> [mailto:ibm-m...@bama.ua.edu] On Behalf Of Bernd Oppolzer
> Sent: Tuesday, May 18, 2010 2:27 PM
> To: IBM-MAIN@bama.ua.edu
> Subject: Re: partially initialized structures in C
>
> Yes. I personally use
ay 18, 2010 2:14 PM
To: IBM-MAIN@bama.ua.edu
Subject: partially initialized structures in C (3)
Sorry for the missing line feeds.
C statement:
*scp1215ein in1215 = { 0 };
Pseudo ASSEMBLER (structure starts at 272(r13)):
STr6,(,r13,272)
MVI (r13,276),0
C statement:
*scp12
> -Original Message-
> From: IBM Mainframe Discussion List
> [mailto:ibm-m...@bama.ua.edu] On Behalf Of Bernd Oppolzer
> Sent: Tuesday, May 18, 2010 2:14 PM
> To: IBM-MAIN@bama.ua.edu
> Subject: partially initialized structures in C (3)
>
> Sorry for the mi
Sorry for the missing line feeds.
C statement:
*scp1215ein in1215 = { 0 };
Pseudo ASSEMBLER (structure starts at 272(r13)):
STr6,(,r13,272)
MVI (r13,276),0
C statement:
*scp1215aus out1215= { 0 };
Pseudo ASSEMBLER (structure starts at 296(r13)):
STr6
To make it clear:
*scp1215ein in1215 = { 0 };
STr6,(,r13,272)
MVI (r13,276),0
*scp1215aus out1215= { 0 };
STr6,(,r13,296)
MVI (r13,300)
Hello all,
sorry for asking this question on IBM-Main, but the C370 list is so silent
that I doubt that anyone is actually listening.
We observed a sort of problem today which showed up as a 0C4 abend
due to a not proper initialized pointer component of a C structure.
Further examination showed
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