flate

commit d374cb0ffda5de8dbdf8d084f37d3118e582a282
parent 64ad43df7e9e67bde4f4008a233578ec63ef60cf
Author: nsz <nszabolcs@gmail.com>
Date:   Tue, 18 Aug 2009 14:58:57 +0200

+LzEnd, -accidental p4 opt
Diffstat:
Makefile
 | 
2
+-
deflate.c
 | 
3
++-

2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
@@ -1,5 +1,5 @@
 #CFLAGS=-g -Wall -ansi -pedantic
-CFLAGS=-O3 -march=pentium4 -Wall -ansi -pedantic
+CFLAGS=-O3 -Wall -ansi -pedantic
 LDFLAGS=
 SRC=inflate.c inflate_example.c inflate_simple.c \
     deflate.c deflate_example.c
diff --git a/deflate.c b/deflate.c
@@ -24,6 +24,7 @@ enum {
 	HistSize    = 2*WinSize, /* history buffer size (64K, indexed with ushort) */
 	DstSize     = WinSize + MaxMatch + 6, /* worst case compressed block size */
 	LzSize      = 1 << 13, /* lz buffer size */
+	LzEnd       = LzSize - 2, /* guard that lzbuf does not overflow in the next iteration */
 	LzLitFlag   = 1 << 15  /* marks literal run length in lz buffer */
 };
 
@@ -539,7 +540,7 @@ static void startblock(State *s) {
 static int endblock(State *s) {
 	int n;
 
-	if (s->pos >= EndPos || s->lz - s->lzbuf > LzSize - 3 || (s->eof && s->avail == 0)) {
+	if (s->pos >= EndPos || s->lz - s->lzbuf >= LzEnd || (s->eof && s->avail == 0)) {
 		/* deflate block */
 		flushlit(s);
 		if (s->prevm.len)