🚀 go-pugleaf

In article <721864322@sheol.UUCP> throopw@sheol.UUCP (Wayne Throop) writes:

   : From: hrubin@mentor.cc.purdue.edu (Herman Rubin)
   : This is not a change in subject.  It is the question of whether one
   : is allowed to directly use the machine hardware, or whether one must
   : HOPE that the compiler writer considered what you are doing when the
   : compiler was produced.  

   Nonsense.  Even if your notation is a pointer notation, you must HOPE
   that the compiler writer will translate that into the machine
   instructions you think are best for your task.

In fact, more importantly, if you use pointer notation when you mean
array indexing, you are going to get less then optimal performance on
different hardware. Array indexing can be transformed relatively
easily by a compiler into pointer code, but the reverse transformation
is much harder.

This lesson generalizes: if you provide a wide array of high-level
abstractions, the compiler can choose the best implementation for the
given hardware, and if you choose your abstractions well, there need
not be any runtime cost associated with this. On the other hand, if
you program directly in terms of low-level features, you may be able
to optimize your code for one particular architecture (but only if you
know exactly what you are doing), but you will get poor performance on
other architectures.

					Thomas.