in message <EGEGIJHKDKJGAJMGIDPNCEHJCCAA.jwalden@...> you wrote:
> Thanks for the clarification!
You are welcome.
> I am used to the x86 world, and when I disassemble something, I
> am used to seeing a one for one mapping from instruction to op-code.
This is the same with PowerPC. But there may be several equivalent
mnemonics to encode the same instruction. The green book ("The
Programming Environments") says: "To simplify assembly language
programming, a set of simplified mnemonics (referred to as extended
mnemonics in the architecture specification) and symbols is provided
> It is obvious that I need to become more proficient in PPC assembly,
> how could you tell that the instruction we "equivalent" - did you
> use a tool, or is it that you are simply that familiar with the PPC
> assembly code.
In this case I didn't need a book; but you can actually look it up.
For example your first statement:
> addi r4,r0,0x0000
The green book lists for "addi":
and the simplified mnemonics:
li rD,value equivalent to addi rD,0,value
la rD,disp(rA) equivalent to addi rD,rA,disp
subi rD,rA,value equivalent to addi rD,rA,-value
The listing you got from the disassembler:
> fff80100: 38 80 00 00 li r4,0
obviously matches rule 1 (well, it's only obvious if you now about
the special role or R0 in such cases :-).
Software Engineering: Embedded and Realtime Systems, Embedded Linux
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