X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=Readme.txt;h=1a3713985e7cec3e47746503892284cd518f4c64;hp=dc76d74227862c7bde9ddb643ad37775358568b6;hb=7622793080dab91375acc43da56852e28c8306fe;hpb=8097e99c699bdc8a62365a9841fc7cce1c3c15a0

diff --git a/Readme.txt b/Readme.txt
index dc76d742..1a371398 100644
--- a/Readme.txt
+++ b/Readme.txt
@@ -45,7 +45,6 @@ PolyGlot documentation.  The book file can be selected by setting the
 UCI parameter "Book File".
 
 
-
 4. Compiling it yourself
 ------------------------
 
@@ -54,27 +53,18 @@ Stockfish directly from the source code with the included Makefile.
 The exception is computer with big-endian CPUs, like PowerPC
 Macintoshes. Some of the bitboard routines in the current version of
 Stockfish are endianness-sensitive, and won't work on a big-endian CPU.
-Ensuring that the line with #define USE_32BIT_ATTACKS" near the top
-of bitboard.h is commented out should solve this problem.
-Commenting out the line with "#define USE_32BIT_ATTACKS" near the
-
-There is also a problem with compiling Stockfish on certain 64-bit
-systems, regardless of the endianness.  If Stockfish segfaults
-immediately after startup, try to comment out the line with
-"#define USE_FOLDED_BITSCAN" near the beginning of bitboard.h and
-recompile.
-
-Finally, even if Stockfish does work without any changes on your
-computer, it might be possible to improve the performance by changing
-some of the #define directives in bitboard.h.  The default settings
-are optimized for 64-bit CPUs.  On 32-bit CPUs, it is probably better
-to switch on USE_32BIT_ATTACKS, and to use BITCOUNT_SWAR_32 instead of
-BITCOUNT_SWAR_64.  For computers with very little memory (like
-handheld devices), it is possible to conserve memory by defining
-USE_COMPACT_ROOK_ATTACKS.
-
-
-6. Terms of use
+
+Stockfish has POPCNT instruction runtime detection and support. This can
+give an extra speed on Core i7 or similar systems. To enable this feature
+(disabled by default) simply uncomment #define USE_POPCNT in bitcount.h
+before to compile.
+
+On 64 bit Unix-like systems the 'bsfq' assembly instruction will be used
+for bit counting. Detection is automatic at compile time, but in case you
+experience compile problems you can comment out #define USE_BSFQ line in types.h
+
+
+5. Terms of use
 ---------------
 
 Stockfish is free, and distributed under the GNU General Public License
@@ -93,7 +83,7 @@ For full details, read the copy of the GPL found in the file named
 Copying.txt.
 
 
-7. Feedback
+6. Feedback
 -----------
 
 The author's e-mail address is mcostalba@gmail.com