Blog "Chess Engines Diary" - needs a new laptop for chess engine tests

♔ We use for testing only 2 old laptops: 1. Acer - Intel Core i3-3217U ( 5 years old),2. Lenovo - Intel Core i7-4710MQ is over 3 years old (He works 24 hours a day)
♕♞ A modern laptop that will be designed only for chess engine tests costs (with software) about $ 1000-1200 (4200-4500 PLN). We will no longer invest private money, and chess engine testing costs are big. That is why we are starting the collection for the purchase of a laptop for testing.
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Sunday, December 11, 2016

Stockfish 16120309 - new version


Stockfish, UCI chess engine

Leader of the ranking list JCER = 3368

🔬 Author: Andrey Neporada 
More:

Timestamp: 1480754227 

Help GCC to optimize msb() to single instruction 

GCC compiles builtin_clzll to “63 ^ BSR”. BSR is processor instruction "Bit Scan Reverse". 
So old msb() function is basically 63 - 63 ^ BSR. 
Unfortunately, GCC fails to simplify this expression. 

Old function compiles to 
bsrq %rdi, %rdi 
movl $63, %eax 
xorq $63, %rdi 
subl %edi, %eax 
ret 

New function compiles to 
bsrq %rdi, %rax 
ret 

BTW, Clang compiles both function to the same (optimal) code. 

No functional change.


Stockfish 16120309 - download



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