-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On
Behalf Of Peter Bishop
Sent: Sunday, January 19, 2020 4:20 PM
To: [email protected]
Subject: Re: Metal C using Z/OS macros in C macros
Hi David,
Thanks for sharing this snippet.
I'm not a C person, so I have a dumb question: how does the value of microSecs
not
equal zero? From my naive view it would seem to be the difference between two
things that are the same, with period having been equated to secs in the
previous
statement. I am guessing it may have something to do with microSecs and period
being doubles where secs is an integer, but it may have nothing to do with that.
Probably time for RTFM, which begs the question of which FM to R.
Thanks again in advance for any elaboration while I try to find the answer,
Peter
On Sun, 19 Jan 2020 18:50:17 +0800, David Crayford <[email protected]>
wrote:
The XLC compiler supports named operands in __asm blocks which are much
easier to understand.
/** Constant for TOD clock unit for a second */
static const uint64_t TOD_TIME_SEC = 0xF4240000LLU;
int nanoSleep(double period) {
int rc;
int secs = period;
double microSecs = period - secs;
uint64_t timerUnits = (secs * TOD_TIME_SEC) + (microSecs * TOD_TIME_SEC);
__asm (" STIMER WAIT,MICVL=%[micvl]\n"
" ST 15,%[rc]"
: [rc]"=m"(rc)
: [micvl]"m"(timerUnits)
: "r15");
return rc;
}
On 2020-01-18 12:31 AM, Farley, Peter x23353 wrote:
The %0 and %1 are parameters to the __asm function, it will do the substitution
of
the 2nd and 3rd parameter in the __asm(...) invocation into the %0 and %1 spots
in
the 1st parameter.
And I concur with your description - the *invocation* of the "SETUP(...)" macro
will specify the variables to be used and *those* variables are the ones that
need to be
defined, "xx" and "yy" in your example.
If the OP (Mr. Reichman) codes the *invocation* of the SETUP macro as follows:
SETUP(supstate,key)
Then both "supstate" and "key" must be defined C variables.
The __asm function does not *define* variables, it just *uses* them. The
variables
mentioned in an __asm invocation must already be defined in the C code.
Peter
-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On
Behalf Of retired mainframer
Sent: Friday, January 17, 2020 11:06 AM
To: [email protected]
Subject: Re: Metal C using Z/OS macros in C macros
In you C code, when you "invoke" the macro, you would provide the values of the
two macro parameters. Something like
SETSUP(xx,yy)
It is the xx and yy that would show up inside the two parenthetical expressions
in
the generated code. Keep in mind that a C macro performs simple text
substitution
long before the actual compilation starts.
Based on the generated code you show, you would not terminate the above
invocation with a semicolon.
I've never used __asm but is
__asm ( " MODESET KEY=%0,MODE=%1 \n" : "=s"(xx), "=s"(yy) ) what you
want the compiler to see?
Are you using %0 and %1 to mean the macro parameters? That is not the way C
macros work.
It looks like there should be a line continuation back slash following the left
brace.
I don't think you want the one that follows the right brace since there is no
following
line.
-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On
Behalf Of Joseph Reichman
Sent: Friday, January 17, 2020 5:22 AM
To: [email protected]
Subject: Metal C using Z/OS macros in C macros
Just wondering if I can do something like this
#define SETSUP(supstate,key) \
{
__asm ( " MODESET KEY=%0,MODE=%1 \n" : "=s"(supstate), "=s"(key) ) \
} \
Seems like the variables have to be defined
----------------------------------------------------------------------
This message and any attachments are intended only for the use of the addressee
and may contain information that is privileged and confidential. If the reader
of the
message is not the intended recipient or an authorized representative of the
intended
recipient, you are hereby notified that any dissemination of this communication
is
strictly prohibited. If you have received this communication in error, please
notify us
immediately by e-mail and delete the message and any attachments from your
system.
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [email protected] with the message: INFO IBM-MAIN
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [email protected] with the message: INFO IBM-MAIN
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [email protected] with the message: INFO IBM-MAIN
