1 files changed, 21 insertions, 5 deletions
diff --git a/deps/v8/third_party/zlib/contrib/optimizations/inffast_chunk.h b/deps/v8/third_party/zlib/contrib/optimizations/inffast_chunk.h
index 39c771b863..cc861bd09d 100644
--- a/deps/v8/third_party/zlib/contrib/optimizations/inffast_chunk.h
+++ b/deps/v8/third_party/zlib/contrib/optimizations/inffast_chunk.h
@@ -1,6 +1,7 @@
 /* inffast_chunk.h -- header to use inffast_chunk.c
  * Copyright (C) 1995-2003, 2010 Mark Adler
  * Copyright (C) 2017 ARM, Inc.
+ * Copyright 2023 The Chromium Authors
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -11,16 +12,31 @@
 
 #include "inffast.h"
 
-/* INFLATE_FAST_MIN_INPUT: the minimum number of input bytes needed so that
-   we can safely call inflate_fast() with only one up-front bounds check. One
+/* INFLATE_FAST_MIN_INPUT:
+   The minimum number of input bytes needed so that we can safely call
+   inflate_fast() with only one up-front bounds check. One
    length/distance code pair (15 bits for the length code, 5 bits for length
    extra, 15 bits for the distance code, 13 bits for distance extra) requires
-   reading up to 48 input bits (6 bytes). The wide input data reading option
-   requires a little endian machine, and reads 64 input bits (8 bytes).
+   reading up to 48 input bits. Additionally, in the same iteraction, we may
+   decode two literals from the root-table (requiring MIN_OUTPUT = 258 + 2).
+
+   Each root-table entry is up to 10 bits, for a total of 68 input bits each
+   iteraction.
+
+   The refill variant reads 8 bytes from the buffer at a time, and advances
+   the input pointer by up to 7 bytes, ensuring there are at least 56-bits
+   available in the bit-buffer. The technique was documented by Fabian Giesen
+   on his blog as variant 4 in the article 'Reading bits in far too many ways':
+   https://fgiesen.wordpress.com/2018/02/20/
+
+   In the worst case, we may refill twice in the same iteraction, requiring
+   MIN_INPUT = 8 + 7.
 */
 #ifdef INFLATE_CHUNK_READ_64LE
 #undef INFLATE_FAST_MIN_INPUT
-#define INFLATE_FAST_MIN_INPUT 8
+#define INFLATE_FAST_MIN_INPUT 15
+#undef INFLATE_FAST_MIN_OUTPUT
+#define INFLATE_FAST_MIN_OUTPUT 260
 #endif
 
 void ZLIB_INTERNAL inflate_fast_chunk_ OF((z_streamp strm, unsigned start));