Author: Slater Wold
Date: 13:15:47 03/30/04
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On March 30, 2004 at 13:43:38, Gerd Isenberg wrote: >On March 30, 2004 at 02:34:21, Slater Wold wrote: > >>Arasan 7.4 32-bit: >> >>D12 00:18 @ 729.047 N/sec (starting position) >> >>Arasan 7.4 64-bit: >> >>D12 00:17 @ 771,932 N/sec (starting position) >> >> >>64-bit Arasan compiled with: -O2 -Ot -Og -Oi -Gr -GX -Oy -Ob2 -GL >>32-bit Arasan would NOT compile on my machine under W2003, so the binary used is >>from the Arasan home page. > >Hi Slater, > >may you supply a small table with all engines you tested so far? >Speedup factor would nice and whether an engine is bitboard based or not ;-) Will do, when I get home. >As i saw so far, the 64-bit speedup is not as good as expected. >I can't imagine that the signed index issue is that expensive. >With similar optimization abilities the 64-bit code should be much faster, >simply due to the eight additional registers and (per default? fastcall instead >of cdecl or pascal parameter passing). Alignment and Load/Store forewarding >stalls are important issues too, but even true for 32-bit code. Please keep in mind, two HUGE points. 1. The MS compiler works. It is NOT fine tuned. VC .NET, ICC, all have years of testing and optimizing, when the 64-bit compiler I have has not been. Eugene tells me that it is much better now. Public beta in June; I guess we'll see. 2. The programs I am compiling have also not been changed or modified in anyway; EXCEPT Crafty. Eugene has done work on Crafty, and remember it gets at LEAST 25% from going 64-bit. And of course, no other program gets close to the speedup of Crafty (no doubt, thanks to Eugene's work). >My guess is, that the 64-bit ms-compiler you use is yet too safe or paranoid >with aliasing issues and tends to write locals inside registers to memory >permanently. However, it would be interesing to have a look at the generated >assembly for some middle sized (20-30 lines c-code) functions with some locals, >for 32-bit and 64-bit each. Eugene will do it, and if I have time, I will too tonite. >Thanks, >Gerd
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