Commit e69eae65 authored by Joakim Tjernlund's avatar Joakim Tjernlund Committed by Linus Torvalds
Browse files

zlib: make new optimized inflate endian independent 



Commit 6846ee5c ("zlib: Fix build of
powerpc boot wrapper") made the new optimized inflate only available on
arch's that define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS.

This patch will again enable the optimization for all arch's by defining
our own endian independent version of unaligned access.  As an added
bonus, arch's that define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS do a
plain load instead.

Signed-off-by: default avatarJoakim Tjernlund <Joakim.Tjernlund@transmode.se>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5ceaa2f3

lib/zlib_inflate/inffast.c

+30 −40
Original line number Diff line number Diff line
@@ -8,21 +8,6 @@ 
#include "inflate.h"

#include "inffast.h"



/* Only do the unaligned "Faster" variant when

 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is set

 *

 * On powerpc, it won't be as we don't include autoconf.h

 * automatically for the boot wrapper, which is intended as

 * we run in an environment where we may not be able to deal

 * with (even rare) alignment faults. In addition, we do not

 * define __KERNEL__ for arch/powerpc/boot unlike x86

 */



#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS

#include <asm/unaligned.h>

#include <asm/byteorder.h>

#endif



#ifndef ASMINF



/* Allow machine dependent optimization for post-increment or pre-increment.
@@ -36,14 +21,31 @@ 
   - Pentium III (Anderson)

   - M68060 (Nikl)

 */

union uu {

	unsigned short us;

	unsigned char b[2];

};



/* Endian independed version */

static inline unsigned short

get_unaligned16(const unsigned short *p)

{

	union uu  mm;

	unsigned char *b = (unsigned char *)p;



	mm.b[0] = b[0];

	mm.b[1] = b[1];

	return mm.us;

}



#ifdef POSTINC

#  define OFF 0

#  define PUP(a) *(a)++

#  define UP_UNALIGNED(a) get_unaligned((a)++)

#  define UP_UNALIGNED(a) get_unaligned16((a)++)

#else

#  define OFF 1

#  define PUP(a) *++(a)

#  define UP_UNALIGNED(a) get_unaligned(++(a))

#  define UP_UNALIGNED(a) get_unaligned16(++(a))

#endif



/*
@@ -256,7 +258,6 @@ void inflate_fast(z_streamp strm, unsigned start) 
                    }

                }

                else {

#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS

		    unsigned short *sout;

		    unsigned long loops;
@@ -274,7 +275,11 @@ void inflate_fast(z_streamp strm, unsigned start) 
			sfrom = (unsigned short *)(from - OFF);

			loops = len >> 1;

			do

#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS

			    PUP(sout) = PUP(sfrom);

#else

			    PUP(sout) = UP_UNALIGNED(sfrom);

#endif

			while (--loops);

			out = (unsigned char *)sout + OFF;

			from = (unsigned char *)sfrom + OFF;
@@ -282,14 +287,13 @@ void inflate_fast(z_streamp strm, unsigned start) 
			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

			if (dist == 1) {

				union uu mm;

				/* copy one char pattern to both bytes */

				mm.us = pat16;

				mm.b[0] = mm.b[1];

				pat16 = mm.us;

			}

			loops = len >> 1;

			do

			    PUP(sout) = pat16;
@@ -298,20 +302,6 @@ void inflate_fast(z_streamp strm, unsigned start) 
		    }

		    if (len & 1)

			PUP(out) = PUP(from);

#else /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */

                    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);

                    }

#endif /* !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */

                }

            }

            else if ((op & 64) == 0) {          /* 2nd level distance code */

CRA Git | Maintained and supported by SUSTech CRA and CCSE