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author | yann.collet.73@gmail.com <yann.collet.73@gmail.com@650e7d94-2a16-8b24-b05c-7c0b3f6821cd> | 2012-07-24 17:12:23 (GMT) |
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committer | yann.collet.73@gmail.com <yann.collet.73@gmail.com@650e7d94-2a16-8b24-b05c-7c0b3f6821cd> | 2012-07-24 17:12:23 (GMT) |
commit | cfbace25d7bb8bbc25ab29e0c308e61a529dfc70 (patch) | |
tree | c66fbb2d2680bad5f874d9981f321dec3ec50f67 | |
parent | d9ef5117f6d2a0e19a60a957b206a3719b879406 (diff) | |
download | lz4-cfbace25d7bb8bbc25ab29e0c308e61a529dfc70.zip lz4-cfbace25d7bb8bbc25ab29e0c308e61a529dfc70.tar.gz lz4-cfbace25d7bb8bbc25ab29e0c308e61a529dfc70.tar.bz2 |
lz4.c : changed a tuning parameter name to MEMORY_USAGE, to better reflect its impact
Makefile : default produces native binary, all produce native & 32-bits binaries
git-svn-id: https://lz4.googlecode.com/svn/trunk@70 650e7d94-2a16-8b24-b05c-7c0b3f6821cd
-rw-r--r-- | Makefile | 4 | ||||
-rw-r--r-- | lz4.c | 18 |
2 files changed, 12 insertions, 10 deletions
@@ -8,7 +8,9 @@ else OUTPUT = LZ4Demo.exe endif -all: lz4demo +default: lz4demo + +all: lz4demo lz4demo32 lz4demo: lz4.c lz4.h lz4hc.c lz4hc.h bench.c lz4demo.c gcc -O3 -I. -std=c99 -Wall -W -Wundef -Wno-implicit-function-declaration lz4hc.c lz4.c bench.c lz4demo.c -o $(OUTPUT) @@ -34,12 +34,12 @@ //**************************************
// Tuning parameters
//**************************************
-// COMPRESSIONLEVEL :
-// Increasing this value improves compression ratio
-// Lowering this value reduces memory usage
-// Reduced memory usage typically improves speed, due to cache effect (ex : L1 32KB for Intel, L1 64KB for AMD)
-// Memory usage formula : N->2^(N+2) Bytes (examples : 12 -> 16KB ; 17 -> 512KB)
-#define COMPRESSIONLEVEL 12
+// MEMORY_USAGE :
+// Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
+// Increasing memory usage improves compression ratio
+// Reduced memory usage can improve speed, due to cache effect
+// Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
+#define MEMORY_USAGE 14
// NOTCOMPRESSIBLE_CONFIRMATION :
// Decreasing this value will make the algorithm skip faster data segments considered "incompressible"
@@ -57,8 +57,8 @@ #define LZ4_COMPRESSMIN 0
// BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE :
-// This will provide a boost to performance for big endian cpu, but the resulting compressed stream will be incompatible with little-endian CPU.
-// You can set this option to 1 in situations where data will stay within closed environment
+// This will provide a small boost to performance for big endian cpu, but the resulting compressed stream will be incompatible with little-endian CPU.
+// You can set this option to 1 in situations where data will remain within closed environment
// This option is useless on Little_Endian CPU (such as x86)
//#define BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE 1
@@ -181,7 +181,7 @@ typedef struct _U64_S { U64 v; } U64_S; //**************************************
#define MINMATCH 4
-#define HASH_LOG COMPRESSIONLEVEL
+#define HASH_LOG (MEMORY_USAGE-2)
#define HASHTABLESIZE (1 << HASH_LOG)
#define HASH_MASK (HASHTABLESIZE - 1)
|