[Info-vax] VSI OpenVMS Alpha V8.4-2L1 Layered Product Subset Available

[Stephen Hoffman]

On 2017-07-10 21:52:29 +0000, John Reagan said:

> On Monday, July 10, 2017 at 4:02:39 PM UTC-4, Stephen Hoffman wrote:
>> On 2017-07-10 19:22:38 +0000, John Reagan said:
>>> Not to nitpick, but to avoid confusion.  The standard build is NOT 
>>> unoptimized.  The build uses the default of /OPT=LEVEL=4 for all 
>>> compiles.  However, the default /ARCH value is EV4 (which also sets the 
>>> default for /OPT=TUNE).  We added /ARCH=EV6 to the compilations.  We 
>>> did not add/remove/change any /OPT qualifiers.
>> 
>> This approach interspersed duplicated architecture-specific instruction 
>> streams throughout the objects and executables, and the compilers added 
>>  conditional gates to select the appropriate code.
> 
> Uh, that isn't what you get.  /ARCH=EV6 gets pure EV6 only code.

I was referring to the existing approach used in all OpenVMS Alpha 
releases prior to 2L2.   To the default /ARCH setting.

Pondering whether the underpinnings built for EV6 and later matter to 
the application code, other than around performance differences and 
image sizes.   If not (and I don't immediately see how), then there's 
seemingly no need to identify the build to the application code.   This 
particularly assuming that all future builds will be EV6 or later, as 
I'm guessing there's not going to be a whole lot of interest in 
supporting parallel releases.   (I mention this new-features 
differentiation as HPE shipped a few new features in patch kits for 
V8.4, with no way to differentiate those at run-time.  That 
undifferentiated packaging used by HPE doesn't seem to line up with 
this build-oriented difference, though; that this isn't a new feature, 
but an optimization and the effective end of support for earlier Alpha 
processors.)

All good fodder for VTJ or VU or a VSI blog entry somewhere, too.




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