By: someone (someone.delete@this.somewhere.com), November 19, 2010 8:22 am
Room: Moderated Discussions
anonymous (no@spam.com) on 11/19/10 wrote:
---------------------------
>>I guess you are ignorant of the fact that IA64 includes
>>means for the compiler to associate hints about the
>>spacial and temporal locality of the data associated
>>with each load and store instruction as well as specify
>>the degree of ordering strictness required between sets
>>of memory transfers. These features, AFAIK unique to
>>IA64, allow conflict and capacity misses to be reduced
>>as well as avoiding stalls from hardware enforcement
>>of unnecessary memory ordering.
>
>The compiler can only annotate loads and stores for
>which it managed to tell or predict locality. And hey,
>in real life loads and stores do depend on input data
>which simply is not available at compile time, period.
Streaming vs non-streaming data is mostly a function
of program structure and associated alogorithms, rather
than specific values of data involved from run to run.
>
>Also, a compiler that manages to gain locality insight
>can issue prefetches for desired addresses and cache
>levels, use non-temporals, etc. on e.g. x86 -- IA64 is
>certainly not the only ISA which lets you do this stuff.
IA64 also has unique features for prefetch such as
advanced loads etc; that is a separate issue.
>
>>It is funny how negative opinion of IA64 is so highly
>>correlated with degree of sheer ignorance about it. ;^)
>
>Maybe ignorance about IA64 correlates with its success?
Change "success" to "ubiquity" and I'll agree with
you. Given the average IPF system is a ~$90K Unix
server in a secure computer room in a corporate tower
or government bunker the overwhelming majority of
people in enthusiast forums will never have direct and
conscious interaction with IA64 hardware let alone be
in the same room. OTOH, the vast majority will see
and use x86 systems every day. Maybe PowerPC too
(Xbox, PS3, or WII).
However most of those people will indirectly use IPF
systems every day even though they aren't aware, like
using an ATM or making a call on their cell phone etc.
Not to mention things they expect to always work even
if they never have to use them, like the 911 system.
---------------------------
>>I guess you are ignorant of the fact that IA64 includes
>>means for the compiler to associate hints about the
>>spacial and temporal locality of the data associated
>>with each load and store instruction as well as specify
>>the degree of ordering strictness required between sets
>>of memory transfers. These features, AFAIK unique to
>>IA64, allow conflict and capacity misses to be reduced
>>as well as avoiding stalls from hardware enforcement
>>of unnecessary memory ordering.
>
>The compiler can only annotate loads and stores for
>which it managed to tell or predict locality. And hey,
>in real life loads and stores do depend on input data
>which simply is not available at compile time, period.
Streaming vs non-streaming data is mostly a function
of program structure and associated alogorithms, rather
than specific values of data involved from run to run.
>
>Also, a compiler that manages to gain locality insight
>can issue prefetches for desired addresses and cache
>levels, use non-temporals, etc. on e.g. x86 -- IA64 is
>certainly not the only ISA which lets you do this stuff.
IA64 also has unique features for prefetch such as
advanced loads etc; that is a separate issue.
>
>>It is funny how negative opinion of IA64 is so highly
>>correlated with degree of sheer ignorance about it. ;^)
>
>Maybe ignorance about IA64 correlates with its success?
Change "success" to "ubiquity" and I'll agree with
you. Given the average IPF system is a ~$90K Unix
server in a secure computer room in a corporate tower
or government bunker the overwhelming majority of
people in enthusiast forums will never have direct and
conscious interaction with IA64 hardware let alone be
in the same room. OTOH, the vast majority will see
and use x86 systems every day. Maybe PowerPC too
(Xbox, PS3, or WII).
However most of those people will indirectly use IPF
systems every day even though they aren't aware, like
using an ATM or making a call on their cell phone etc.
Not to mention things they expect to always work even
if they never have to use them, like the 911 system.