The patch titled
zlib: optimize inffast even more
has been added to the -mm tree. Its filename is
zlib-optimize-inffast-even-more.patch
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------------------------------------------------------
Subject: zlib: optimize inffast even more
From: Joakim Tjernlund <Joakim.Tjernlund@xxxxxxxxxxxx>
This improves zlib: Optimize inffast when copying direct from output and
gives another 3-4% improvement for my MPC8321 target. Does not need
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS, 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.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@xxxxxxxxxxxx>
Cc: Alain Knaff <alain@xxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Richard Purdie <rpurdie@xxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/boot/Makefile | 1
lib/zlib_inflate/inffast.c | 54 +++++++++++++++++------------------
2 files changed, 28 insertions(+), 27 deletions(-)
diff -puN arch/powerpc/boot/Makefile~zlib-optimize-inffast-even-more arch/powerpc/boot/Makefile
--- a/arch/powerpc/boot/Makefile~zlib-optimize-inffast-even-more
+++ a/arch/powerpc/boot/Makefile
@@ -34,6 +34,7 @@ BOOTCFLAGS += -fno-stack-protector
endif
BOOTCFLAGS += -I$(obj) -I$(srctree)/$(obj)
+BOOTCFLAGS += -Iarch/powerpc/include
DTS_FLAGS ?= -p 1024
diff -puN lib/zlib_inflate/inffast.c~zlib-optimize-inffast-even-more lib/zlib_inflate/inffast.c
--- a/lib/zlib_inflate/inffast.c~zlib-optimize-inffast-even-more
+++ a/lib/zlib_inflate/inffast.c
@@ -4,6 +4,7 @@
*/
#include <linux/zutil.h>
+#include <asm/unaligned.h>
#include "inftrees.h"
#include "inflate.h"
#include "inffast.h"
@@ -24,9 +25,11 @@
#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
/*
@@ -240,52 +243,49 @@ void inflate_fast(z_streamp strm, unsign
}
else {
from = out - dist; /* copy direct from output */
-#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
/* minimum length is three */
if (dist > 2 ) {
- unsigned short *sout = (unsigned short *)(out - OFF);
- unsigned short *sfrom = (unsigned short *)(from - OFF);
- unsigned long loops = len >> 1;
+ unsigned short *sout;
+ unsigned short *sfrom;
+ unsigned long loops;
+ /* Align out addr, only sfrom might be unaligned */
+ if (!((long)(out - 1 + OFF)) & 1) {
+ PUP(out) = PUP(from);
+ len--;
+ }
+ sout = (unsigned short *)(out - OFF);
+ sfrom = (unsigned short *)(from - OFF);
+ loops = len >> 1;
do
- PUP(sout) = PUP(sfrom);
+ PUP(sout) = UP_UNALIGNED(sfrom);
while (--loops);
out = (unsigned char *)sout + OFF;
from = (unsigned char *)sfrom + OFF;
if (len & 1)
PUP(out) = PUP(from);
- } else if (dist == 2) {
- unsigned short *sout = (unsigned short *)(out - OFF);
+ } else { /* dist == 1 or dist == 2 */
+ unsigned short *sout;
unsigned short pat16;
- unsigned long loops = len >> 1;
+ unsigned long loops;
+ /* Align out addr */
+ if (!((long)(out - 1 + OFF)) & 1) {
+ PUP(out) = PUP(from);
+ len--;
+ }
+ sout = (unsigned short *)(out - OFF);
pat16 = *(sout-2+2*OFF);
+ if (dist == 1)
+ pat16 = (pat16 & 0xff) | ((pat16 & 0xff ) << 8);
+ loops = len >> 1;
do
PUP(sout) = pat16;
while (--loops);
out = (unsigned char *)sout + OFF;
if (len & 1)
PUP(out) = PUP(from);
- } else {
- unsigned char pat8 = *(out - 1 + OFF);
-
- do {
- PUP(out) = pat8;
- } while (--len);
}
-#else
- 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);
- }
-#endif
}
}
else if ((op & 64) == 0) { /* 2nd level distance code */
_
Patches currently in -mm which might be from Joakim.Tjernlund@xxxxxxxxxxxx are
zlib-optimize-inffast-when-copying-direct-from-output.patch
zlib-optimize-inffast-even-more.patch
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