[kaffe] JamVM on ARM (XScale)

S. Meslin-Weber steph at tangency.co.uk
Tue Oct 12 01:57:02 PDT 2004

Hi Rob,

On Mon, Oct 11, 2004 at 12:46:02PM +0100, Robert Lougher wrote:
> The problems that could arise are that I assume floating-point
> emulation is enabled in the kernel (affects calling-convention).  I

Ah, this could cause issues with some linux distributions for ARM
(familiar and OpenZaurus) which are switching to soft-float and not
relying on the kernel to do floating point handling. Note that hybrid
systems with both types requires a set of core libraries for each
*-float so on embedded platforms only one should really be there.

The rationale for this is convincing: 1000% benchmarked improvement in
float speed. I've had this explained to me (in simple terms):

  "with hard float, a kernel exception gets launched ... which needs
  saving status registers and changing privilege rings ... then jump
  into kernel ... then handle that ... then jump out of kernel ...
  that's slooooooooooow"

It'd be nice to be able to use JamVM (and other jvms) on these embedded
distributions too :)

I've verified that SableVM works fine using soft-float too :)



Stephane Meslin-Weber         Email: steph at tangency.co.uk
Software Engineer             Web: http://odonata.tangency.co.uk
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
Url : http://kaffe.org/pipermail/kaffe/attachments/20041012/c43b4443/attachment-0002.pgp 

More information about the kaffe mailing list