Re: CGEN_DIS_HASH: how to get endianness and/or instruction size?

["Frank Ch. Eigler" <fche@redhat.com>]

Hi -

joern wrote:

> [...]
> The top 5 bits of the first 16 bit word are what is known as major
> opcode field.  [...]
> I reckon that, given a suitably endian-correted input,
> I could make an adequate hash by using a switch based on
> the 5 bit major opcode to decide which bits from the first 16
> bit word to use.

Heck, just use those five bits.

> I had already written the hash function, only to discover that the
> endian check depended on an argument that was not passed to my
> macro/function.

You should use the *value* rather than *buf* input.

> Its easy to change his code into incorrect and/or useless (return 0)
> code that will compile [...]

It is neither incorrect nor useless.  It just means that the hash
table will be degenerate, and a linear search will be required for
each disassembled instruction.  It won't hurt anyone and will only
slightly worsen global warming.

> Unless otherwise expressly stated, this message does not create or vary =
> any contractual relationship between you and ARC International.  [...]

That's a relief!

- FChE