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Old February 25th 14, 01:35 AM posted to comp.sys.intel,comp.sys.ibm.pc.hardware.chips,alt.windows7.general
Robert Redelmeier
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Posts: 316
Default How many x86 instructions?

In comp.sys.ibm.pc.hardware.chips Jason wrote in part:

On Fri, 21 Feb 2014 14:23:01 +0000 (UTC) "Robert Redelmeier"
wrote in article le7ng5$jfq$

In comp.sys.ibm.pc.hardware.chips Yousuf Khan wrote in part:
But it goes to show why the age of compilers is well and
truly upon us, there's no human way to keep track of these
machine language instructions. Compilers just use a subset,
and just repeat those instructions over and over again.


Hate to break it to you, but you are behind the times. Compilers
are passe' -- "modern" systems use interpreters like JIT Java.

How else you you think Android gets Apps to run on the dogs-breakfast
of ARM processors out there? It is [nearly] all interpreted Java.
So much so that Dell can get 'roid Apps to run on its x86 tablet!
(AFAIK, iOS still runs compiled Apps prob'cuz Apple _hatez_ Oracle)


Compilers are NOT passe'


I feel quoted-out-of-context. I was replying to Mr Khan (restored above)
that compiled languages were in turn being supplanted by interpreted.

The performance penalty for interpreted languages is a large
factor. It's fine in many situations - scripting languages and
the like - and the modern processors are fast enough to make the
performance hit tolerable. Large-scale applications are still
compiled and heavily optimized. Time is money.


I am well aware of the perfomance penalty of interpreted languages
(I once programmed in APL/360) and that compiling has been
preferable for HPC. However, the differences between compilers
are reducing to the quality of their libraries, especially SIMD and
multi-threading. The flexibility of interpreters might have value.


-- Robert