Re: Porting HP C from Alpha to Itanium - __DIVG_C

Hi John,

Note that floating isn't the only place where you might have to change
code. Code that use the LIB$ calling standard routines (which have both
hardware and calling standard implications) require some changes between
Alpha and I64.

Can you please provide a brief description of the changes reqd and the
profile of code that will require them? (or a pointer to specific docs)

As far as not wanting to SYS$IEEE_SET_FP_xxx for each subroutine (stack
unwinding issues, ASTs etc etc) can you please describe what was done to
control the user mode altering of big/little-endian in similar
circumstances?

Cheers Richard Maher

"John Reagan" <john.reagan@xxxxxx> wrote in message
news:f4188t$p23$1@xxxxxxxxxxxxxxxxxxxxxx
David J Dachtera wrote:



...which, of course, goes well beyond the highly touted "re-compile and
re-link"
source-code compatibility (other than privileged code, that is).


I'll freely admit that the differences in floating point between Alpha
and Itanium may require some applications to change. There is a white
paper that we provided early on for the port to Itanium that tried to
document all the issues. Go to www.hp.com/go/openvms, click on
Whitepapers, look for one titled "OpenVMS Floating Point whitepaper".
It was published in 2003. However, it was not updated to describe the
various new system services and how/why/where to use them. I agree with
Fred that perhaps some additional documentation might be required.
Where to put that?

Note that floating isn't the only place where you might have to change
code. Code that use the LIB$ calling standard routines (which have both
hardware and calling standard implications) require some changes between
Alpha and I64.

Re-compile, re-link, and re-test is a goal. I think it happens most of
the time.

--
John Reagan
OpenVMS Pascal/Macro-32/COBOL Project Leader
Hewlett-Packard Company


.

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