zlib: properly split patches

This package had two patches (with two headers etc.) in one file,
which would have quilt merging them during a refresh.

Separate these patches into two files, as the original intent seems
to be having them separate.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

package/libs/zlib/patches/002-arm-specific-optimisations-for-inflate.patch

@@ -1907,505 +1907,3 @@ index 00000000..ac333e8c
 +    state = (struct inflate_state FAR *)strm->state;
 +    return (unsigned long)(state->next - state->codes);
 +}
-
-From 247147654fe5cd11cf15d8dff91440405ea57040 Mon Sep 17 00:00:00 2001
-From: Simon Hosie <simon.hosie@arm.com>
-Date: Wed, 12 Apr 2017 15:44:21 -0700
-Subject: [PATCH 2/2] Inflate using wider loads and stores
-
-In inflate_fast() the output pointer always has plenty of room to write. This
-means that so long as the target is capable, wide un-aligned loads and stores
-can be used to transfer several bytes at once. When the reference distance is
-too short simply unroll the data a little to increase the distance.
-
-Change-Id: I59854eb25d2b1e43561c8a2afaf9175bf10cf674
----
- contrib/arm/chunkcopy.h | 279 ++++++++++++++++++++++++++++++++++++++++++++++++
- contrib/arm/inffast.c   |  96 +++++++----------
- contrib/arm/inflate.c   |  22 ++--
- 3 files changed, 335 insertions(+), 62 deletions(-)
- create mode 100644 contrib/arm/chunkcopy.h
-
-diff --git a/contrib/arm/chunkcopy.h b/contrib/arm/chunkcopy.h
-new file mode 100644
-index 00000000..2d6fd6f9
---- /dev/null
-+++ b/contrib/arm/chunkcopy.h
-@@ -0,0 +1,279 @@
-+/* chunkcopy.h -- fast copies and sets
-+ * Copyright (C) 2017 ARM, Inc.
-+ * For conditions of distribution and use, see copyright notice in zlib.h
-+ */
-+
-+#ifndef CHUNKCOPY_H
-+#define CHUNKCOPY_H
-+
-+#include "zutil.h"
-+#include <arm_neon.h>
-+
-+#if __STDC_VERSION__ >= 199901L
-+#define Z_RESTRICT restrict
-+#else
-+#define Z_RESTRICT
-+#endif
-+
-+typedef uint8x16_t chunkcopy_chunk_t;
-+#define CHUNKCOPY_CHUNK_SIZE sizeof(chunkcopy_chunk_t)
-+
-+/*
-+   Ask the compiler to perform a wide, unaligned load with an machine
-+   instruction appropriate for the chunkcopy_chunk_t type.
-+ */
-+static inline chunkcopy_chunk_t loadchunk(const unsigned char FAR *s) {
-+    chunkcopy_chunk_t c;
-+    __builtin_memcpy(&c, s, sizeof(c));
-+    return c;
-+}
-+
-+/*
-+   Ask the compiler to perform a wide, unaligned store with an machine
-+   instruction appropriate for the chunkcopy_chunk_t type.
-+ */
-+static inline void storechunk(unsigned char FAR *d, chunkcopy_chunk_t c) {
-+    __builtin_memcpy(d, &c, sizeof(c));
-+}
-+
-+/*
-+   Perform a memcpy-like operation, but assume that length is non-zero and that
-+   it's OK to overwrite at least CHUNKCOPY_CHUNK_SIZE bytes of output even if
-+   the length is shorter than this.
-+
-+   It also guarantees that it will properly unroll the data if the distance
-+   between `out` and `from` is at least CHUNKCOPY_CHUNK_SIZE, which we rely on
-+   in chunkcopy_relaxed().
-+
-+   Aside from better memory bus utilisation, this means that short copies
-+   (CHUNKCOPY_CHUNK_SIZE bytes or fewer) will fall straight through the loop
-+   without iteration, which will hopefully make the branch prediction more
-+   reliable.
-+ */
-+static inline unsigned char FAR *chunkcopy_core(unsigned char FAR *out,
-+                                                const unsigned char FAR *from,
-+                                                unsigned len) {
-+    int bump = (--len % CHUNKCOPY_CHUNK_SIZE) + 1;
-+    storechunk(out, loadchunk(from));
-+    out += bump;
-+    from += bump;
-+    len /= CHUNKCOPY_CHUNK_SIZE;
-+    while (len-- > 0) {
-+        storechunk(out, loadchunk(from));
-+        out += CHUNKCOPY_CHUNK_SIZE;
-+        from += CHUNKCOPY_CHUNK_SIZE;
-+    }
-+    return out;
-+}
-+
-+/*
-+   Like chunkcopy_core, but avoid writing beyond of legal output.
-+
-+   Accepts an additional pointer to the end of safe output.  A generic safe
-+   copy would use (out + len), but it's normally the case that the end of the
-+   output buffer is beyond the end of the current copy, and this can still be
-+   exploited.
-+ */
-+static inline unsigned char FAR *chunkcopy_core_safe(unsigned char FAR *out,
-+                                                     const unsigned char FAR * from,
-+                                                     unsigned len,
-+                                                     unsigned char FAR *limit) {
-+    Assert(out + len <= limit, "chunk copy exceeds safety limit");
-+    if (limit - out < CHUNKCOPY_CHUNK_SIZE) {
-+        const unsigned char FAR * Z_RESTRICT rfrom = from;
-+        if (len & 8) { __builtin_memcpy(out, rfrom, 8); out += 8; rfrom += 8; }
-+        if (len & 4) { __builtin_memcpy(out, rfrom, 4); out += 4; rfrom += 4; }
-+        if (len & 2) { __builtin_memcpy(out, rfrom, 2); out += 2; rfrom += 2; }
-+        if (len & 1) { *out++ = *rfrom++; }
-+        return out;
-+    }
-+    return chunkcopy_core(out, from, len);
-+}
-+
-+/*
-+   Perform short copies until distance can be rewritten as being at least
-+   CHUNKCOPY_CHUNK_SIZE.
-+
-+   This assumes that it's OK to overwrite at least the first
-+   2*CHUNKCOPY_CHUNK_SIZE bytes of output even if the copy is shorter than
-+   this.  This assumption holds within inflate_fast() which starts every
-+   iteration with at least 258 bytes of output space available (258 being the
-+   maximum length output from a single token; see inffast.c).
-+ */
-+static inline unsigned char FAR *chunkunroll_relaxed(unsigned char FAR *out,
-+                                                     unsigned FAR *dist,
-+                                                     unsigned FAR *len) {
-+    const unsigned char FAR *from = out - *dist;
-+    while (*dist < *len && *dist < CHUNKCOPY_CHUNK_SIZE) {
-+        storechunk(out, loadchunk(from));
-+        out += *dist;
-+        *len -= *dist;
-+        *dist += *dist;
-+    }
-+    return out;
-+}
-+
-+
-+static inline uint8x16_t chunkset_vld1q_dup_u8x8(const unsigned char FAR * Z_RESTRICT from) {
-+#if defined(__clang__) || defined(__aarch64__)
-+    return vreinterpretq_u8_u64(vld1q_dup_u64((void *)from));
-+#else
-+    /* 32-bit GCC uses an alignment hint for vld1q_dup_u64, even when given a
-+     * void pointer, so here's an alternate implementation.
-+     */
-+    uint8x8_t h = vld1_u8(from);
-+    return vcombine_u8(h, h);
-+#endif
-+}
-+
-+/*
-+   Perform an overlapping copy which behaves as a memset() operation, but
-+   supporting periods other than one, and assume that length is non-zero and
-+   that it's OK to overwrite at least CHUNKCOPY_CHUNK_SIZE*3 bytes of output
-+   even if the length is shorter than this.
-+ */
-+static inline unsigned char FAR *chunkset_core(unsigned char FAR *out,
-+                                               unsigned period,
-+                                               unsigned len) {
-+    uint8x16_t f;
-+    int bump = ((len - 1) % sizeof(f)) + 1;
-+
-+    switch (period) {
-+    case 1:
-+        f = vld1q_dup_u8(out - 1);
-+        vst1q_u8(out, f);
-+        out += bump;
-+        len -= bump;
-+        while (len > 0) {
-+            vst1q_u8(out, f);
-+            out += sizeof(f);
-+            len -= sizeof(f);
-+        }
-+        return out;
-+    case 2:
-+        f = vreinterpretq_u8_u16(vld1q_dup_u16((void *)(out - 2)));
-+        vst1q_u8(out, f);
-+        out += bump;
-+        len -= bump;
-+        if (len > 0) {
-+            f = vreinterpretq_u8_u16(vld1q_dup_u16((void *)(out - 2)));
-+            do {
-+                vst1q_u8(out, f);
-+                out += sizeof(f);
-+                len -= sizeof(f);
-+            } while (len > 0);
-+        }
-+        return out;
-+    case 4:
-+        f = vreinterpretq_u8_u32(vld1q_dup_u32((void *)(out - 4)));
-+        vst1q_u8(out, f);
-+        out += bump;
-+        len -= bump;
-+        if (len > 0) {
-+            f = vreinterpretq_u8_u32(vld1q_dup_u32((void *)(out - 4)));
-+            do {
-+                vst1q_u8(out, f);
-+                out += sizeof(f);
-+                len -= sizeof(f);
-+            } while (len > 0);
-+        }
-+        return out;
-+    case 8:
-+        f = chunkset_vld1q_dup_u8x8(out - 8);
-+        vst1q_u8(out, f);
-+        out += bump;
-+        len -= bump;
-+        if (len > 0) {
-+            f = chunkset_vld1q_dup_u8x8(out - 8);
-+            do {
-+                vst1q_u8(out, f);
-+                out += sizeof(f);
-+                len -= sizeof(f);
-+            } while (len > 0);
-+        }
-+        return out;
-+    }
-+    out = chunkunroll_relaxed(out, &period, &len);
-+    return chunkcopy_core(out, out - period, len);
-+}
-+
-+/*
-+   Perform a memcpy-like operation, but assume that length is non-zero and that
-+   it's OK to overwrite at least CHUNKCOPY_CHUNK_SIZE bytes of output even if
-+   the length is shorter than this.
-+
-+   Unlike chunkcopy_core() above, no guarantee is made regarding the behaviour
-+   of overlapping buffers, regardless of the distance between the pointers.
-+   This is reflected in the `restrict`-qualified pointers, allowing the
-+   compiler to reorder loads and stores.
-+ */
-+static inline unsigned char FAR *chunkcopy_relaxed(unsigned char FAR * Z_RESTRICT out,
-+                                                   const unsigned char FAR * Z_RESTRICT from,
-+                                                   unsigned len) {
-+    return chunkcopy_core(out, from, len);
-+}
-+
-+/*
-+   Like chunkcopy_relaxed, but avoid writing beyond of legal output.
-+
-+   Unlike chunkcopy_core_safe() above, no guarantee is made regarding the
-+   behaviour of overlapping buffers, regardless of the distance between the
-+   pointers.  This is reflected in the `restrict`-qualified pointers, allowing
-+   the compiler to reorder loads and stores.
-+
-+   Accepts an additional pointer to the end of safe output.  A generic safe
-+   copy would use (out + len), but it's normally the case that the end of the
-+   output buffer is beyond the end of the current copy, and this can still be
-+   exploited.
-+ */
-+static inline unsigned char FAR *chunkcopy_safe(unsigned char FAR *out,
-+                                                const unsigned char FAR * Z_RESTRICT from,
-+                                                unsigned len,
-+                                                unsigned char FAR *limit) {
-+    Assert(out + len <= limit, "chunk copy exceeds safety limit");
-+    return chunkcopy_core_safe(out, from, len, limit);
-+}
-+
-+/*
-+   Perform chunky copy within the same buffer, where the source and destination
-+   may potentially overlap.
-+
-+   Assumes that len > 0 on entry, and that it's safe to write at least
-+   CHUNKCOPY_CHUNK_SIZE*3 bytes to the output.
-+ */
-+static inline unsigned char FAR *chunkcopy_lapped_relaxed(unsigned char FAR *out,
-+                                                          unsigned dist,
-+                                                          unsigned len) {
-+    if (dist < len && dist < CHUNKCOPY_CHUNK_SIZE) {
-+        return chunkset_core(out, dist, len);
-+    }
-+    return chunkcopy_core(out, out - dist, len);
-+}
-+
-+/*
-+   Behave like chunkcopy_lapped_relaxed, but avoid writing beyond of legal output.
-+
-+   Accepts an additional pointer to the end of safe output.  A generic safe
-+   copy would use (out + len), but it's normally the case that the end of the
-+   output buffer is beyond the end of the current copy, and this can still be
-+   exploited.
-+ */
-+static inline unsigned char FAR *chunkcopy_lapped_safe(unsigned char FAR *out,
-+                                                       unsigned dist,
-+                                                       unsigned len,
-+                                                       unsigned char FAR *limit) {
-+    Assert(out + len <= limit, "chunk copy exceeds safety limit");
-+    if (limit - out < CHUNKCOPY_CHUNK_SIZE * 3) {
-+        /* TODO: try harder to optimise this */
-+        while (len-- > 0) {
-+            *out = *(out - dist);
-+            out++;
-+        }
-+        return out;
-+    }
-+    return chunkcopy_lapped_relaxed(out, dist, len);
-+}
-+
-+#undef Z_RESTRICT
-+
-+#endif /* CHUNKCOPY_H */
-diff --git a/contrib/arm/inffast.c b/contrib/arm/inffast.c
-index 0dbd1dbc..f7f50071 100644
---- a/contrib/arm/inffast.c
-+++ b/contrib/arm/inffast.c
-@@ -7,6 +7,7 @@
- #include "inftrees.h"
- #include "inflate.h"
- #include "inffast.h"
-+#include "chunkcopy.h"
- 
- #ifdef ASMINF
- #  pragma message("Assembler code may have bugs -- use at your own risk")
-@@ -57,6 +58,7 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
-     unsigned char FAR *out;     /* local strm->next_out */
-     unsigned char FAR *beg;     /* inflate()'s initial strm->next_out */
-     unsigned char FAR *end;     /* while out < end, enough space available */
-+    unsigned char FAR *limit;   /* safety limit for chunky copies */
- #ifdef INFLATE_STRICT
-     unsigned dmax;              /* maximum distance from zlib header */
- #endif
-@@ -84,12 +86,13 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
-     out = strm->next_out;
-     beg = out - (start - strm->avail_out);
-     end = out + (strm->avail_out - 257);
-+    limit = out + strm->avail_out;
- #ifdef INFLATE_STRICT
-     dmax = state->dmax;
- #endif
-     wsize = state->wsize;
-     whave = state->whave;
--    wnext = state->wnext;
-+    wnext = (state->wnext == 0 && whave >= wsize) ? wsize : state->wnext;
-     window = state->window;
-     hold = state->hold;
-     bits = state->bits;
-@@ -197,70 +200,51 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
- #endif
-                     }
-                     from = window;
--                    if (wnext == 0) {           /* very common case */
--                        from += wsize - op;
--                        if (op < len) {         /* some from window */
--                            len -= op;
--                            do {
--                                *out++ = *from++;
--                            } while (--op);
--                            from = out - dist;  /* rest from output */
--                        }
-+                    if (wnext >= op) {          /* contiguous in window */
-+                        from += wnext - op;
-                     }
--                    else if (wnext < op) {      /* wrap around window */
--                        from += wsize + wnext - op;
-+                    else {                      /* wrap around window */
-                         op -= wnext;
-+                        from += wsize - op;
-                         if (op < len) {         /* some from end of window */
-                             len -= op;
--                            do {
--                                *out++ = *from++;
--                            } while (--op);
--                            from = window;
--                            if (wnext < len) {  /* some from start of window */
--                                op = wnext;
--                                len -= op;
--                                do {
--                                    *out++ = *from++;
--                                } while (--op);
--                                from = out - dist;      /* rest from output */
--                            }
-+                            out = chunkcopy_safe(out, from, op, limit);
-+                            from = window;      /* more from start of window */
-+                            op = wnext;
-+                            /* This (rare) case can create a situation where
-+                               the first chunkcopy below must be checked.
-+                             */
-                         }
-                     }
--                    else {                      /* contiguous in window */
--                        from += wnext - op;
--                        if (op < len) {         /* some from window */
--                            len -= op;
--                            do {
--                                *out++ = *from++;
--                            } while (--op);
--                            from = out - dist;  /* rest from output */
--                        }
--                    }
--                    while (len > 2) {
--                        *out++ = *from++;
--                        *out++ = *from++;
--                        *out++ = *from++;
--                        len -= 3;
--                    }
--                    if (len) {
--                        *out++ = *from++;
--                        if (len > 1)
--                            *out++ = *from++;
-+                    if (op < len) {             /* still need some from output */
-+                        out = chunkcopy_safe(out, from, op, limit);
-+                        len -= op;
-+                        /* When dist is small the amount of data that can be
-+                           copied from the window is also small, and progress
-+                           towards the dangerous end of the output buffer is
-+                           also small.  This means that for trivial memsets and
-+                           for chunkunroll_relaxed() a safety check is
-+                           unnecessary.  However, these conditions may not be
-+                           entered at all, and in that case it's possible that
-+                           the main copy is near the end.
-+                          */
-+                        out = chunkunroll_relaxed(out, &dist, &len);
-+                        out = chunkcopy_safe(out, out - dist, len, limit);
-+                    } else {
-+                        /* from points to window, so there is no risk of
-+                           overlapping pointers requiring memset-like behaviour
-+                         */
-+                        out = chunkcopy_safe(out, from, len, limit);
-                     }
-                 }
-                 else {
--                    from = out - dist;          /* copy direct from output */
--                    do {                        /* minimum length is three */
--                        *out++ = *from++;
--                        *out++ = *from++;
--                        *out++ = *from++;
--                        len -= 3;
--                    } while (len > 2);
--                    if (len) {
--                        *out++ = *from++;
--                        if (len > 1)
--                            *out++ = *from++;
--                    }
-+                    /* Whole reference is in range of current output.  No
-+                       range checks are necessary because we start with room
-+                       for at least 258 bytes of output, so unroll and roundoff
-+                       operations can write beyond `out+len` so long as they
-+                       stay within 258 bytes of `out`.
-+                     */
-+                    out = chunkcopy_lapped_relaxed(out, dist, len);
-                 }
-             }
-             else if ((op & 64) == 0) {          /* 2nd level distance code */
-diff --git a/contrib/arm/inflate.c b/contrib/arm/inflate.c
-index ac333e8c..e40322c3 100644
---- a/contrib/arm/inflate.c
-+++ b/contrib/arm/inflate.c
-@@ -84,6 +84,7 @@
- #include "inftrees.h"
- #include "inflate.h"
- #include "inffast.h"
-+#include "contrib/arm/chunkcopy.h"
- 
- #ifdef MAKEFIXED
- #  ifndef BUILDFIXED
-@@ -405,10 +406,20 @@ unsigned copy;
- 
-     /* if it hasn't been done already, allocate space for the window */
-     if (state->window == Z_NULL) {
-+        unsigned wsize = 1U << state->wbits;
-         state->window = (unsigned char FAR *)
--                        ZALLOC(strm, 1U << state->wbits,
-+                        ZALLOC(strm, wsize + CHUNKCOPY_CHUNK_SIZE,
-                                sizeof(unsigned char));
-         if (state->window == Z_NULL) return 1;
-+#ifdef INFLATE_CLEAR_UNUSED_UNDEFINED
-+        /* Copies from the overflow portion of this buffer are undefined and
-+           may cause analysis tools to raise a warning if we don't initialize
-+           it.  However, this undefined data overwrites other undefined data
-+           and is subsequently either overwritten or left deliberately
-+           undefined at the end of decode; so there's really no point.
-+         */
-+        memset(state->window + wsize, 0, CHUNKCOPY_CHUNK_SIZE);
-+#endif
-     }
- 
-     /* if window not in use yet, initialize */
-@@ -1175,17 +1186,16 @@ int flush;
-                 else
-                     from = state->window + (state->wnext - copy);
-                 if (copy > state->length) copy = state->length;
-+                if (copy > left) copy = left;
-+                put = chunkcopy_safe(put, from, copy, put + left);
-             }
-             else {                              /* copy from output */
--                from = put - state->offset;
-                 copy = state->length;
-+                if (copy > left) copy = left;
-+                put = chunkcopy_lapped_safe(put, state->offset, copy, put + left);
-             }
--            if (copy > left) copy = left;
-             left -= copy;
-             state->length -= copy;
--            do {
--                *put++ = *from++;
--            } while (--copy);
-             if (state->length == 0) state->mode = LEN;
-             break;
-         case LIT: