Compiler options for PowerPC

[Jakob Lechner]

Hi,

Segher Boessenkool <segher@kernel.crashing.org> wrote:

>> This "clrlwi" instruction belongs to some extended mnemonics of the 
>> PowerPC ISA and it seems that the simulator I'm using doesn't support
>> these instructions.
>
> Extended mnemonics compile to the same opcodes as some basic
> mnemonic does.

Thank you, I didn't know that.

> If your simulator doesn't support the actual instruction, rlwinm
> in this case, you better get it fixed.

The rlwinm instruction of course is supported. I accidentally thought
the clrlwi instruction was the problem but it turned out that in fact
the simulator aborts when executing the dcbt instruction.
This instruction is a cache prefetch instruction.

Is there a compiler option for disabling the dcbt instruction and 
similar cache control instructions?

Best regards
Jakob