🚀 go-pugleaf

In article <4i5lev$fd3@agate.berkeley.edu>,
Nick Kralevich <nickkral@america.CS.Berkeley.EDU> wrote:
 >In article <4lFXuqq00aw=M=iUNp@andrew.cmu.edu>,
 >Nicholas P Konidaris  <npk+@andrew.cmu.edu> wrote:
 >>Ok, these are two totally unrelated questions/comments..  I was coding
 >>around on my box, and wanted to see the speed difference (my CS prof
 >>told me that x++ is faster than x = x + 1)  So, I write code that looks
 >>like:

The ``CS'' prof obviously doesn't understand the construction of programming
languages. The computation, and data flow is identical in either case.
In the intermediate representation generated by the compiler's syntactic
and semantic analysis, you may not recognize the difference between x++
and x = x + 1, or x += 1 anymore. If a three-operand abstract code is used, all
three may look like:

	t3 := t3 + 1

Where t3 is some sequentially generated temporary value (which will be
subject to register allocation later). When machine-specific optimization is
done, an addition of 1 may be converted into some quick form (such as ADDQ
on a 680x0 which can add a three-bit value 8,1-7, stored inside the opcode,
to an operand) or an increment instruction.

The x++ idiom is faster all right. Faster to type...
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