On Sun, Feb 21, 2016 at 07:40:22AM +0000, commits at source.squeak.org wrote:
> Eliot Miranda uploaded a new version of System to project The Trunk:
> http://source.squeak.org/trunk/System-eem.801.mcz
> 
> ==================== Summary ====================
> 
> Name: System-eem.801
> Author: eem
> Time: 20 February 2016, 11:40:02.089874 pm
> UUID: cb00963a-1c90-40c0-9539-04c88c0afa5f
> Ancestors: System-mt.800
> 
> In Spur calcEndianness can be a lot simpler.
> 

This works in Spur because ByteArray can now adopt an instance of WordArray,
is that right?

Does the test work on big endian 64-bit? I think that it will, but if there
is any doubt it might be safer to use a two element WordArray:

    WordArray with: 16r01020304 with: 16r01020304

The method comment describes the old String implementation, so it would be
good to update that.

Dave



> =============== Diff against System-mt.800 ===============
> 
> Item was changed:
>   ----- Method: SmalltalkImage>>calcEndianness (in category 'system attributes') -----
>   calcEndianness
> - 	| bytes word blt |
>   	"What endian-ness is the current hardware?  The String '1234' will be stored into a machine word.  On BigEndian machines (the Mac), $1 will be the high byte if the word.  On LittleEndian machines (the PC), $4 will be the high byte."
>   	"Smalltalk endianness"
> + 	| wordThenBytes |
> + 	wordThenBytes := WordArray with: 16r01020304.
> + 	ByteArray adoptInstance: wordThenBytes.
> + 	wordThenBytes first = 1 ifTrue: [^#big].
> + 	wordThenBytes first = 4 ifTrue: [^#little].
> + 	self error: 'The author is confused'!
> - 
> - 	bytes := ByteArray withAll: #(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'.!
>