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Thanks for the clarification.

The reason for LNUM slowing modern x86 is maybe just that integer calculations (s.a. simple increment) need to be range checked to find out potential falling to FP realm. For a FP, any operation can just be done, without checks. I'll look for a neato way to bypass this, so x86 double+int32 users won't be hit by the patch (if it gets in some day).


On Thu, 27 Mar 2008 10:34:54 +0100
 David Kastrup <> wrote:
Asko Kauppi <> writes:

In my view, Mike's results are in line with the Core Duo results I had

What cannot be done is treat x86 as a single optimization target. It
is not.

Then again, modern x86's are utterly fast on FP, which they calculate
as fast as integers.

No, they don't. Integer arithmetic can be parallelized much more thoroughly. But when we are working with a byte-code interpreter, the parallelization will speed up the byte code interpreter itself, but hardly the arithmetic fed into it: the interpreter will not issue
arithmetic fast enough to make a difference.

David Kastrup