Hello,
I'm curious what's need to be done in order to have by-four version of
CRC32 enabled by default let's say at least on amd64? Attached patch
is quite aggressive as I put an option into generic GENERIC, but still
I hope it may be usable as a starting point. Performance of CRC32 went
up from 360 MB/s to 970 MB/s on my e3-1220v3 with this compiled in.
Thanks! Karel
diff --git a/sys/conf/GENERIC b/sys/conf/GENERIC
index 4aefba1..7ab41d1 100644
--- a/sys/conf/GENERIC
+++ b/sys/conf/GENERIC
@@ -43,6 +43,7 @@ option MSDOSFS # MS-DOS file system
option FIFO # FIFOs; RECOMMENDED
option TMPFS # efficient memory file system
option FUSE # FUSE
+option BYFOUR # faster CRC32 implementation
option SOCKET_SPLICE # Socket Splicing for TCP and UDP
option TCP_SACK # Selective Acknowledgements for TCP
diff --git a/sys/lib/libz/Makefile b/sys/lib/libz/Makefile
index 93f04fe..81dc850 100644
--- a/sys/lib/libz/Makefile
+++ b/sys/lib/libz/Makefile
@@ -5,8 +5,6 @@ LIB= z
NOPIC=
NOPROFILE=
-# Tweak knobs to generate small libz code
-CPPFLAGS+= -DSLOW -DSMALL -DNOBYFOUR -DNO_GZIP -DDYNAMIC_CRC_TABLE
CPPFLAGS+= -I. ${ZCPPFLAGS}
# files to be copied down from libz.
diff --git a/sys/lib/libz/crc32.c b/sys/lib/libz/crc32.c
index eac7d74..67f7775 100644
--- a/sys/lib/libz/crc32.c
+++ b/sys/lib/libz/crc32.c
@@ -29,12 +29,15 @@
#define local static
-#ifndef _KERNEL
/* Find a four-byte integer type for crc32_little() and crc32_big(). */
#ifndef NOBYFOUR
# ifdef STDC /* need ANSI C limits.h to determine sizes */
+#ifndef _KERNEL
# include <limits.h>
# define BYFOUR
+#else
+# include <sys/limits.h>
+#endif
# if (UINT_MAX == 0xffffffffUL)
typedef unsigned int u4;
# else
@@ -50,10 +53,12 @@
# endif
# endif /* STDC */
#endif /* !NOBYFOUR */
-#endif
/* Definitions for doing the crc four data bytes at a time. */
#ifdef BYFOUR
+#ifdef _KERNEL
+#include <sys/stdint.h>
+#endif
# define REV(w) (((w)>>24)+(((w)>>8)&0xff00)+ \
(((w)&0xff00)<<8)+(((w)&0xff)<<24))
local unsigned long crc32_little OF((unsigned long,
