This patch optimizes 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. No speed test has been performed in u-boot.
Size increase on ppc: 484 bytes
Signed-off-by: Joakim Tjernlund Joakim.Tjernlund@transmode.se ---
I have the same optimization queued for linux. Figured it would be useful for u-boot too.
Testing and feedback welcome.
lib_generic/zlib.c | 56 ++++++++++++++++++++++++++++++++++++++++----------- 1 files changed, 44 insertions(+), 12 deletions(-)
diff --git a/lib_generic/zlib.c b/lib_generic/zlib.c index 8fe3bd0..5721968 100644 --- a/lib_generic/zlib.c +++ b/lib_generic/zlib.c @@ -26,8 +26,10 @@ #define ZUTIL_H #define ZLIB_INTERNAL
-#include "u-boot/zlib.h" #include <common.h> +#include <compiler.h> +#include <asm/unaligned.h> +#include "u-boot/zlib.h" /* To avoid a build time warning */ #ifdef STDC #include <malloc.h> @@ -400,6 +402,7 @@ void inflate_fast OF((z_streamp strm, unsigned start)); */ #define OFF 1 #define PUP(a) *++(a) +#define UP_UNALIGNED(a) get_unaligned(++(a))
/* Decode literal, length, and distance codes and write out the resulting @@ -616,18 +619,47 @@ unsigned start; /* inflate()'s starting value for strm->avail_out */ } } 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 */