Gull

[outAtime]

Having a look at Gull and noticed some strange mobility code for bishops..

Code: Select all

score += choose_popcnt<HPopCnt>((~Board->bb&#91;White&#93;) & att & BishopMajorWhite&#41; * BishopMobMajor 

where BishopMajorWhite is:

Code: Select all

#define BishopMajorWhite Convert(0x7EFFFF7E3C000000,uint64)

Can anyone explain what is being counted here?

[Gerd Isenberg]

Having a look at Gull and noticed some strange mobility code for bishops..

Code: Select all

score += choose_popcnt<HPopCnt>((~Board->bb&#91;White&#93;) & att & BishopMajorWhite&#41; * BishopMobMajor 

where BishopMajorWhite is:

Code: Select all

#define BishopMajorWhite Convert(0x7EFFFF7E3C000000,uint64)

Can anyone explain what is being counted here?

It seems to count the number of squares attacked by white bishop(s), not occupied by own pieces and restricted to this area of 32 squares for forward mobility:

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0x7EFFFF7E3C000000

 . 1 1 1 1 1 1 .
 1 1 1 1 1 1 1 1
 1 1 1 1 1 1 1 1
 . 1 1 1 1 1 1 .
 . . 1 1 1 1 . .
 . . . . . . . .
 . . . . . . . .
 . . . . . . . .

[Dann Corbit]

Having a look at Gull and noticed some strange mobility code for bishops..

Code: Select all

score += choose_popcnt<HPopCnt>((~Board->bb&#91;White&#93;) & att & BishopMajorWhite&#41; * BishopMobMajor 

where BishopMajorWhite is:

Code: Select all

#define BishopMajorWhite Convert(0x7EFFFF7E3C000000,uint64)

Can anyone explain what is being counted here?

Here is BishopMajorWhite :

Code: Select all

01111110
11111111
11111111
01111110
00111100
00000000
00000000
00000000