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-rw-r--r--zlib/contrib/asm686/README.68617
-rw-r--r--zlib/contrib/asm686/match.S40
2 files changed, 51 insertions, 6 deletions
diff --git a/zlib/contrib/asm686/README.686 b/zlib/contrib/asm686/README.686
index a593f23af..a0bf3bea4 100644
--- a/zlib/contrib/asm686/README.686
+++ b/zlib/contrib/asm686/README.686
@@ -32,3 +32,20 @@ then do:
CFLAGS="-O3 -DASMV" ./configure
make OBJA=match.o
+
+
+Update:
+
+I've been ignoring these assembly routines for years, believing that
+gcc's generated code had caught up with it sometime around gcc 2.95
+and the major rearchitecting of the Pentium 4. However, I recently
+learned that, despite what I believed, this code still has some life
+in it. On the Pentium 4 and AMD64 chips, it continues to run about 8%
+faster than the code produced by gcc 4.1.
+
+In acknowledgement of its continuing usefulness, I've altered the
+license to match that of the rest of zlib. Share and Enjoy!
+
+Brian Raiter
+breadbox@muppetlabs.com
+April, 2007
diff --git a/zlib/contrib/asm686/match.S b/zlib/contrib/asm686/match.S
index 5c3e9ee36..fa4210927 100644
--- a/zlib/contrib/asm686/match.S
+++ b/zlib/contrib/asm686/match.S
@@ -1,9 +1,23 @@
-/* match.s -- Pentium-Pro-optimized version of longest_match()
- * Written for zlib 1.1.2
- * Copyright (C) 1998 Brian Raiter <breadbox@muppetlabs.com>
+/* match.S -- x86 assembly version of the zlib longest_match() function.
+ * Optimized for the Intel 686 chips (PPro and later).
*
- * This is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License.
+ * Copyright (C) 1998, 2007 Brian Raiter <breadbox@muppetlabs.com>
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event will the author be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ * claim that you wrote the original software. If you use this software
+ * in a product, an acknowledgment in the product documentation would be
+ * appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ * misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
*/
#ifndef NO_UNDERLINE
@@ -69,17 +83,25 @@
.text
/* uInt longest_match(deflate_state *deflatestate, IPos curmatch) */
+.cfi_sections .debug_frame
longest_match:
+.cfi_startproc
/* Save registers that the compiler may be using, and adjust %esp to */
/* make room for our stack frame. */
pushl %ebp
+ .cfi_def_cfa_offset 8
+ .cfi_offset ebp, -8
pushl %edi
+ .cfi_def_cfa_offset 12
pushl %esi
+ .cfi_def_cfa_offset 16
pushl %ebx
+ .cfi_def_cfa_offset 20
subl $LocalVarsSize, %esp
+ .cfi_def_cfa_offset LocalVarsSize+20
/* Retrieve the function arguments. %ecx will hold cur_match */
/* throughout the entire function. %edx will hold the pointer to the */
@@ -94,7 +116,7 @@ longest_match:
/* if (s->prev_length >= s->good_match) { */
/* chain_length >>= 2; */
/* } */
-
+
movl dsPrevLen(%edx), %eax
movl dsGoodMatch(%edx), %ebx
cmpl %ebx, %eax
@@ -322,8 +344,14 @@ LookaheadRet:
/* Restore the stack and return from whence we came. */
addl $LocalVarsSize, %esp
+ .cfi_def_cfa_offset 20
popl %ebx
+ .cfi_def_cfa_offset 16
popl %esi
+ .cfi_def_cfa_offset 12
popl %edi
+ .cfi_def_cfa_offset 8
popl %ebp
+ .cfi_def_cfa_offset 4
+.cfi_endproc
match_init: ret