Re: Itanium support is back in GCC 15

gcalliet <gerard.calliet@pia-sofer.fr> wrote:

 
On my side I have always thought the failure of Itanium - they said
Itanic - have been just the bad meeting between the conservatism of
geeks and the inchoate laws of the market. Our hatred of Itanium
contributed to the long life of the very archaic x86 to which the very
wise Intel returned, for its greater good.

Failure of Itanic was extensively disscussed in comp.arch.  There
were fundamental issues, EPIC concept required compiler arrange
code in clever way to gain good performance.  Hand coding small
examples suggested that it is possible to write fast code for
EPIC, but both when Itanic project started and now nobody knows
how to do this in a compiler.  There is related issue, when
Itanic started is was not known how to get good instruction
paralellism on conventional architectures.  But then branch predictors
happened and Intel and AMD were able to get good ILP from x86
(the same could be done with many other architectures, but is
incompatible with Itanic principles).

Beside fundamental problems there were several specific blunders.

Anyway, Itanic was late, expensive and had unimpressive performance.
Some people were waiting for it, but what was promised (top
performance) never appeared.

--
                              Waldek Hebisch