[zlib] Reland Enable LIT_MEM code path

Introduced on zlib 1.3.0.1, this will allow a small compression
speed improvement at cost of using a bit more memory.

Observed average gain was 2.6% (SPR) and 2.3% (M1).

It is interesting that it will have a bigger impact on files with
higher entropy like JPG (+5.3%) and pre-compressed (baddata +7%),
probably because those are cases where more literals are produced
by the encoder since it is harder to find matches in LZ77 for such
inputs.

Bug: 1447443
Change-Id: I88e6514edcab186cf9680534510fb98fe4e71222
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5123674
Commit-Queue: Adenilson Cavalcanti <cavalcantii@chromium.org>
Reviewed-by: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1238747}
NOKEYCHECK=True
GitOrigin-RevId: 0907ce97d55eab9484b17efce416354463cbafeb

1 files changed, 1 insertions, 1 deletions

diff --git a/deflate.h b/deflate.h
index 654d094..eb7f072 100644
--- a/deflate.h
+++ b/deflate.h
@@ -25,7 +25,7 @@
 
 /* define LIT_MEM to slightly increase the speed of deflate (order 1% to 2%) at
    the cost of a larger memory footprint */
-/* #define LIT_MEM */
+#define LIT_MEM
 
 /* ===========================================================================
  * Internal compression state.