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Unified Diff: third_party/zlib/fill_window_sse.c

Issue 665203006: Revert of Reland "Integrate SIMD optimisations for zlib" (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Created 6 years, 2 months ago
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Index: third_party/zlib/fill_window_sse.c
diff --git a/third_party/zlib/fill_window_sse.c b/third_party/zlib/fill_window_sse.c
deleted file mode 100644
index 949ccce1ba9ccc83ceb07922428b22b6c8eb6ca1..0000000000000000000000000000000000000000
--- a/third_party/zlib/fill_window_sse.c
+++ /dev/null
@@ -1,175 +0,0 @@
-/*
- * Fill Window with SSE2-optimized hash shifting
- *
- * Copyright (C) 2013 Intel Corporation
- * Authors:
- * Arjan van de Ven <arjan@linux.intel.com>
- * Jim Kukunas <james.t.kukunas@linux.intel.com>
- *
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
-
-#include <immintrin.h>
-#include "deflate.h"
-
-#define UPDATE_HASH(s,h,i) \
- {\
- if (s->level < 6) { \
- h = (3483 * (s->window[i]) +\
- 23081* (s->window[i+1]) +\
- 6954 * (s->window[i+2]) +\
- 20947* (s->window[i+3])) & s->hash_mask;\
- } else {\
- h = (25881* (s->window[i]) +\
- 24674* (s->window[i+1]) +\
- 25811* (s->window[i+2])) & s->hash_mask;\
- }\
- }\
-
-extern int read_buf OF((z_streamp strm, Bytef *buf, unsigned size));
-
-void fill_window_sse(deflate_state *s)
-{
- const __m128i xmm_wsize = _mm_set1_epi16(s->w_size);
-
- register unsigned n;
- register Posf *p;
- unsigned more; /* Amount of free space at the end of the window. */
- uInt wsize = s->w_size;
-
- Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
-
- do {
- more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
-
- /* Deal with !@#$% 64K limit: */
- if (sizeof(int) <= 2) {
- if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
- more = wsize;
-
- } else if (more == (unsigned)(-1)) {
- /* Very unlikely, but possible on 16 bit machine if
- * strstart == 0 && lookahead == 1 (input done a byte at time)
- */
- more--;
- }
- }
-
- /* If the window is almost full and there is insufficient lookahead,
- * move the upper half to the lower one to make room in the upper half.
- */
- if (s->strstart >= wsize+MAX_DIST(s)) {
-
- zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
- s->match_start -= wsize;
- s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
- s->block_start -= (long) wsize;
-
- /* Slide the hash table (could be avoided with 32 bit values
- at the expense of memory usage). We slide even when level == 0
- to keep the hash table consistent if we switch back to level > 0
- later. (Using level 0 permanently is not an optimal usage of
- zlib, so we don't care about this pathological case.)
- */
- n = s->hash_size;
- p = &s->head[n];
- p -= 8;
- do {
- __m128i value, result;
-
- value = _mm_loadu_si128((__m128i *)p);
- result = _mm_subs_epu16(value, xmm_wsize);
- _mm_storeu_si128((__m128i *)p, result);
-
- p -= 8;
- n -= 8;
- } while (n > 0);
-
- n = wsize;
-#ifndef FASTEST
- p = &s->prev[n];
- p -= 8;
- do {
- __m128i value, result;
-
- value = _mm_loadu_si128((__m128i *)p);
- result = _mm_subs_epu16(value, xmm_wsize);
- _mm_storeu_si128((__m128i *)p, result);
-
- p -= 8;
- n -= 8;
- } while (n > 0);
-#endif
- more += wsize;
- }
- if (s->strm->avail_in == 0) break;
-
- /* If there was no sliding:
- * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
- * more == window_size - lookahead - strstart
- * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
- * => more >= window_size - 2*WSIZE + 2
- * In the BIG_MEM or MMAP case (not yet supported),
- * window_size == input_size + MIN_LOOKAHEAD &&
- * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
- * Otherwise, window_size == 2*WSIZE so more >= 2.
- * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
- */
- Assert(more >= 2, "more < 2");
-
- n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
- s->lookahead += n;
-
- /* Initialize the hash value now that we have some input: */
- if (s->lookahead >= MIN_MATCH) {
- uInt str = s->strstart;
- s->ins_h = s->window[str];
- if (str >= 1)
- UPDATE_HASH(s, s->ins_h, str + 1 - (MIN_MATCH-1));
-#if MIN_MATCH != 3
- Call UPDATE_HASH() MIN_MATCH-3 more times
-#endif
- }
- /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
- * but this is not important since only literal bytes will be emitted.
- */
-
- } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
-
- /* If the WIN_INIT bytes after the end of the current data have never been
- * written, then zero those bytes in order to avoid memory check reports of
- * the use of uninitialized (or uninitialised as Julian writes) bytes by
- * the longest match routines. Update the high water mark for the next
- * time through here. WIN_INIT is set to MAX_MATCH since the longest match
- * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
- */
- if (s->high_water < s->window_size) {
- ulg curr = s->strstart + (ulg)(s->lookahead);
- ulg init;
-
- if (s->high_water < curr) {
- /* Previous high water mark below current data -- zero WIN_INIT
- * bytes or up to end of window, whichever is less.
- */
- init = s->window_size - curr;
- if (init > WIN_INIT)
- init = WIN_INIT;
- zmemzero(s->window + curr, (unsigned)init);
- s->high_water = curr + init;
- }
- else if (s->high_water < (ulg)curr + WIN_INIT) {
- /* High water mark at or above current data, but below current data
- * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
- * to end of window, whichever is less.
- */
- init = (ulg)curr + WIN_INIT - s->high_water;
- if (init > s->window_size - s->high_water)
- init = s->window_size - s->high_water;
- zmemzero(s->window + s->high_water, (unsigned)init);
- s->high_water += init;
- }
- }
-
- Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
- "not enough room for search");
-}
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