Revert of Reland "Integrate SIMD optimisations for zlib"

third_party/zlib/fill_window_sse.c

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");
-}