I guess they are trying to use a vm primitive that does not convert the encoding, such as the bitblt. Is there not another primitive to do this? Alexandre
Le 18 mars 2015 à 10:55, Guillermo Polito <guillermopolito@gmail.com> a écrit :
Hi!
We are here with Stef looking at the calcEndianess method which introduces a dependency to Form and BitBlt from SmalltalkImage.
bytes := #[0 0 0 0]. "(1 2 3 4) or (4 3 2 1)" word := WordArray with: 16r01020304. blt := (BitBlt toForm: (Form new hackBits: bytes)) sourceForm: (Form new hackBits: word). blt combinationRule: Form over. "store" blt sourceY: 0; destY: 0; height: 1; width: 4. blt sourceX: 0; destX: 0. blt copyBits. "paste the word into the bytes" bytes first = 1 ifTrue: [^ #big]. bytes first = 4 ifTrue: [^ #little]. self error: 'Ted is confused'.
Is that code really useful? I mean, usually all machines are little endian now, aren't they?
And in case big endianess comes back, shouldn't be easier and cheaper to do it with just a primitive? It will be much less code than using BitBlt and Form and some calculations, and simpler, and it looks like the responsibility of the VM to know that...
Guille