Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Fri, 08 Jul 2011 13:55:36 +0200

Till Straumann wrote:

Certainly, both CPUs support the mandatory PPC UISA instruction set.
Hence, if you compile code with -mcpu=powerpc then it should execute
on either of the CPUs.

However, the 604 e.g., implements fsqrt/fsrqts (FP square-root in
hardware) which are enabled when you compile with
-mdouble-float/-msingle-float (or implicitly when you use -mcpu=604)
There may be other optional instructions that the 604 has and the
603 does not and which you may want to use if you have a 604.

Does that mean that sqrt() is slower on a ppc604 when I use

vxWorks-ppc32 because the hardware square root is not used?

Dirk

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System