The patch titled
zlib: optimize inffast when copying direct from output
has been removed from the -mm tree. Its filename was
zlib-optimize-inffast-when-copying-direct-from-output.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: zlib: optimize inffast when copying direct from output
From: Joakim Tjernlund <Joakim.Tjernlund@xxxxxxxxxxxx>
JFFS2 uses lesser compression ratio and inflate always ends up in "copy
direct from output" case.
This patch tries to optimize the direct copy procedure. Uses
get_unaligned() but only in one place.
The copy loop just above this one can also use this optimization, but I
havn't done so as I have not tested if it is a win there too.
On my MPC8321 this is about 17% faster on my JFFS2 root FS than the
original.
[akpm@xxxxxxxxxxxxxxxxxxxx: coding-style fixes]
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@xxxxxxxxxxxx>
Cc: Roel Kluin <roel.kluin@xxxxxxxxx>
Cc: Richard Purdie <rpurdie@xxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/boot/Makefile | 4 +-
lib/zlib_inflate/inffast.c | 55 ++++++++++++++++++++++++++++-------
2 files changed, 47 insertions(+), 12 deletions(-)
diff -puN arch/powerpc/boot/Makefile~zlib-optimize-inffast-when-copying-direct-from-output arch/powerpc/boot/Makefile
--- a/arch/powerpc/boot/Makefile~zlib-optimize-inffast-when-copying-direct-from-output
+++ a/arch/powerpc/boot/Makefile
@@ -20,7 +20,7 @@
all: $(obj)/zImage
BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
- -fno-strict-aliasing -Os -msoft-float -pipe \
+ -fno-strict-aliasing -Os -msoft-float -pipe -D__KERNEL__\
-fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
-isystem $(shell $(CROSS32CC) -print-file-name=include)
BOOTAFLAGS := -D__ASSEMBLY__ $(BOOTCFLAGS) -traditional -nostdinc
@@ -34,6 +34,8 @@ BOOTCFLAGS += -fno-stack-protector
endif
BOOTCFLAGS += -I$(obj) -I$(srctree)/$(obj)
+BOOTCFLAGS += -include include/linux/autoconf.h -Iarch/powerpc/include
+BOOTCFLAGS += -Iinclude
DTS_FLAGS ?= -p 1024
diff -puN lib/zlib_inflate/inffast.c~zlib-optimize-inffast-when-copying-direct-from-output lib/zlib_inflate/inffast.c
--- a/lib/zlib_inflate/inffast.c~zlib-optimize-inffast-when-copying-direct-from-output
+++ a/lib/zlib_inflate/inffast.c
@@ -4,6 +4,8 @@
*/
#include <linux/zutil.h>
+#include <asm/unaligned.h>
+#include <asm/byteorder.h>
#include "inftrees.h"
#include "inflate.h"
#include "inffast.h"
@@ -24,9 +26,11 @@
#ifdef POSTINC
# define OFF 0
# define PUP(a) *(a)++
+# define UP_UNALIGNED(a) get_unaligned((a)++)
#else
# define OFF 1
# define PUP(a) *++(a)
+# define UP_UNALIGNED(a) get_unaligned(++(a))
#endif
/*
@@ -239,18 +243,47 @@ void inflate_fast(z_streamp strm, unsign
}
}
else {
+ unsigned short *sout;
+ unsigned long loops;
+
from = out - dist; /* copy direct from output */
- do { /* minimum length is three */
- PUP(out) = PUP(from);
- PUP(out) = PUP(from);
- PUP(out) = PUP(from);
- len -= 3;
- } while (len > 2);
- if (len) {
- PUP(out) = PUP(from);
- if (len > 1)
- PUP(out) = PUP(from);
- }
+ /* minimum length is three */
+ /* Align out addr */
+ if (!((long)(out - 1 + OFF) & 1)) {
+ PUP(out) = PUP(from);
+ len--;
+ }
+ sout = (unsigned short *)(out - OFF);
+ if (dist > 2) {
+ unsigned short *sfrom;
+
+ sfrom = (unsigned short *)(from - OFF);
+ loops = len >> 1;
+ do
+ PUP(sout) = UP_UNALIGNED(sfrom);
+ while (--loops);
+ out = (unsigned char *)sout + OFF;
+ from = (unsigned char *)sfrom + OFF;
+ } else { /* dist == 1 or dist == 2 */
+ unsigned short pat16;
+
+ pat16 = *(sout-2+2*OFF);
+ if (dist == 1)
+#if defined(__BIG_ENDIAN)
+ pat16 = (pat16 & 0xff) | ((pat16 & 0xff) << 8);
+#elif defined(__LITTLE_ENDIAN)
+ pat16 = (pat16 & 0xff00) | ((pat16 & 0xff00) >> 8);
+#else
+#error __BIG_ENDIAN nor __LITTLE_ENDIAN is defined
+#endif
+ loops = len >> 1;
+ do
+ PUP(sout) = pat16;
+ while (--loops);
+ out = (unsigned char *)sout + OFF;
+ }
+ if (len & 1)
+ PUP(out) = PUP(from);
}
}
else if ((op & 64) == 0) { /* 2nd level distance code */
_
Patches currently in -mm which might be from Joakim.Tjernlund@xxxxxxxxxxxx are
origin.patch
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