The PowerPC Processor Element (PPE) complies with version
2.0.2 of the PowerPC architecture, with only minor exceptions.
The following optional
user-mode instructions
are implemented:
- fsqrt(.) – Floating-point square root
- fsqrts(.) – Floating-point square root single
- fres(.) – Floating-point reciprocal estimate single, A-form
- frsqrte(.) – Floating-point reciprocal square root estimate, A-form
- fsel(.) – Floating-point select
- mtocrf – Move to one condition register field, XFX-form
- mfocrf – Move from one condition register field, XFX-form
The following optional instructions that are defined in the PowerPC
Book I are
not implemented. Use of these instructions will cause an
illegal-instruction interrupt:
- mcrxr – Move to condition register from XER
- bccbr – Branch condition to CBR
The following instructions that are not defined in the PowerPC Architecture
are implemented.
Since these instructions are not part of the architecture, they should be
considered highly implementation-specific.
- ldbrx – Load doubleword byte reverse indexed, X-form
- sdbrx – Store doubleword byte reverse indexed, X-form
In addition, the little endian option for data ordering is not available.
A complete list of differences can be found in the Cell Broadband Engine,
Programming Handbook.