Pawn clean up #2255
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Pawn clean up #2255
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Seems that there's a bit of an overlap between this and the assorted trivial cleanup PR you opened. |
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Indeed, but not a problem. The assorted trivial cleanups are "work in progress" stuff, and have lower priority. They will be rebased a few times before being commited. |
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Merged via 33c3a04, congrats :-) |
mstembera
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Jul 31, 2019
Non functional simplification when we find the passed pawns in pawn.cpp and some code clean up. It also better follows the pattern "flag the pawn" and "score the pawn". ------------------------- The idea behind the third condition for candidate passed pawn is a little bit difficult to visualize. Just for the record, the idea is the following: Consider White e5 d4 against black e6. d4 can (in some endgames) push to d5 and lever e6. Thanks to this sacrifice, or after d5xe6, we consider e5 as "passed". However: - if White e5/d4 against black e6/c6: d4 cannot safely push to d5 since d5 is double attacked; - if White e5/d4 against black e6/d5: d4 cannot safely push to d5 since it is occupied. This is exactly what the following expression does: ``` && (shift<Up>(support) & ~(theirPawns | dblAttackThem))) ``` -------------------------- http://tests.stockfishchess.org/tests/view/5d3325bb0ebc5925cf0e6e91 LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 124666 W: 27586 L: 27669 D: 69411 Closes official-stockfish#2255 No functional change
mstembera
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Aug 1, 2019
Non functional simplification when we find the passed pawns in pawn.cpp and some code clean up. It also better follows the pattern "flag the pawn" and "score the pawn". ------------------------- The idea behind the third condition for candidate passed pawn is a little bit difficult to visualize. Just for the record, the idea is the following: Consider White e5 d4 against black e6. d4 can (in some endgames) push to d5 and lever e6. Thanks to this sacrifice, or after d5xe6, we consider e5 as "passed". However: - if White e5/d4 against black e6/c6: d4 cannot safely push to d5 since d5 is double attacked; - if White e5/d4 against black e6/d5: d4 cannot safely push to d5 since it is occupied. This is exactly what the following expression does: ``` && (shift<Up>(support) & ~(theirPawns | dblAttackThem))) ``` -------------------------- http://tests.stockfishchess.org/tests/view/5d3325bb0ebc5925cf0e6e91 LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 124666 W: 27586 L: 27669 D: 69411 Closes official-stockfish#2255 No functional change
mstembera
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Aug 29, 2019
Non functional simplification when we find the passed pawns in pawn.cpp and some code clean up. It also better follows the pattern "flag the pawn" and "score the pawn". ------------------------- The idea behind the third condition for candidate passed pawn is a little bit difficult to visualize. Just for the record, the idea is the following: Consider White e5 d4 against black e6. d4 can (in some endgames) push to d5 and lever e6. Thanks to this sacrifice, or after d5xe6, we consider e5 as "passed". However: - if White e5/d4 against black e6/c6: d4 cannot safely push to d5 since d5 is double attacked; - if White e5/d4 against black e6/d5: d4 cannot safely push to d5 since it is occupied. This is exactly what the following expression does: ``` && (shift<Up>(support) & ~(theirPawns | dblAttackThem))) ``` -------------------------- http://tests.stockfishchess.org/tests/view/5d3325bb0ebc5925cf0e6e91 LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 124666 W: 27586 L: 27669 D: 69411 Closes official-stockfish#2255 No functional change
pb00068
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Sep 10, 2019
Non functional simplification when we find the passed pawns in pawn.cpp and some code clean up. It also better follows the pattern "flag the pawn" and "score the pawn". ------------------------- The idea behind the third condition for candidate passed pawn is a little bit difficult to visualize. Just for the record, the idea is the following: Consider White e5 d4 against black e6. d4 can (in some endgames) push to d5 and lever e6. Thanks to this sacrifice, or after d5xe6, we consider e5 as "passed". However: - if White e5/d4 against black e6/c6: d4 cannot safely push to d5 since d5 is double attacked; - if White e5/d4 against black e6/d5: d4 cannot safely push to d5 since it is occupied. This is exactly what the following expression does: ``` && (shift<Up>(support) & ~(theirPawns | dblAttackThem))) ``` -------------------------- http://tests.stockfishchess.org/tests/view/5d3325bb0ebc5925cf0e6e91 LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 124666 W: 27586 L: 27669 D: 69411 Closes official-stockfish#2255 No functional change
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Non functional simplification when we find the passed pawns in pawn.cpp and some code clean up
http://tests.stockfishchess.org/tests/view/5d3325bb0ebc5925cf0e6e91
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 124666 W: 27586 L: 27669 D: 69411
bench: 3357457