Add 'neozip/' from commit 'c2712b8a345191f6ed79558c089777df94590087'

git-subtree-dir: neozip
git-subtree-mainline: b1e34e861b5d732afe828d58aad2c638135061fd
git-subtree-split: c2712b8a345191f6ed79558c089777df94590087

1 files changed, 232 insertions, 0 deletions

diff --git a/neozip/arch/s390/crc32-vx.c b/neozip/arch/s390/crc32-vx.c
new file mode 100644
index 0000000000..ba00f9a370
--- /dev/null
+++ b/neozip/arch/s390/crc32-vx.c
@@ -0,0 +1,232 @@
+/*
+ * Hardware-accelerated CRC-32 variants for Linux on z Systems
+ *
+ * Use the z/Architecture Vector Extension Facility to accelerate the
+ * computing of bitreflected CRC-32 checksums.
+ *
+ * This CRC-32 implementation algorithm is bitreflected and processes
+ * the least-significant bit first (Little-Endian).
+ *
+ * This code was originally written by Hendrik Brueckner
+ * <brueckner@linux.vnet.ibm.com> for use in the Linux kernel and has been
+ * relicensed under the zlib license.
+ */
+
+#ifdef S390_CRC32_VX
+
+#include "zbuild.h"
+#include "arch_functions.h"
+
+#include <vecintrin.h>
+
+typedef unsigned char uv16qi __attribute__((vector_size(16)));
+typedef unsigned int uv4si __attribute__((vector_size(16)));
+typedef unsigned long long uv2di __attribute__((vector_size(16)));
+
+static uint32_t crc32_le_vgfm_16(uint32_t crc, const uint8_t *buf, size_t len) {
+    /*
+     * The CRC-32 constant block contains reduction constants to fold and
+     * process particular chunks of the input data stream in parallel.
+     *
+     * For the CRC-32 variants, the constants are precomputed according to
+     * these definitions:
+     *
+     *      R1 = [(x4*128+32 mod P'(x) << 32)]' << 1
+     *      R2 = [(x4*128-32 mod P'(x) << 32)]' << 1
+     *      R3 = [(x128+32 mod P'(x) << 32)]'   << 1
+     *      R4 = [(x128-32 mod P'(x) << 32)]'   << 1
+     *      R5 = [(x64 mod P'(x) << 32)]'       << 1
+     *      R6 = [(x32 mod P'(x) << 32)]'       << 1
+     *
+     *      The bitreflected Barret reduction constant, u', is defined as
+     *      the bit reversal of floor(x**64 / P(x)).
+     *
+     *      where P(x) is the polynomial in the normal domain and the P'(x) is the
+     *      polynomial in the reversed (bitreflected) domain.
+     *
+     * CRC-32 (IEEE 802.3 Ethernet, ...) polynomials:
+     *
+     *      P(x)  = 0x04C11DB7
+     *      P'(x) = 0xEDB88320
+     */
+    const uv16qi perm_le2be = {15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0};  /* BE->LE mask */
+    const uv2di r2r1 = {0x1C6E41596, 0x154442BD4};                                     /* R2, R1 */
+    const uv2di r4r3 = {0x0CCAA009E, 0x1751997D0};                                     /* R4, R3 */
+    const uv2di r5 = {0, 0x163CD6124};                                                 /* R5 */
+    const uv2di ru_poly = {0, 0x1F7011641};                                            /* u' */
+    const uv2di crc_poly = {0, 0x1DB710641};                                           /* P'(x) << 1 */
+
+    /*
+     * Load the initial CRC value.
+     *
+     * The CRC value is loaded into the rightmost word of the
+     * vector register and is later XORed with the LSB portion
+     * of the loaded input data.
+     */
+    uv2di v0 = {0, 0};
+    v0 = (uv2di)vec_insert(crc, (uv4si)v0, 3);
+
+    /* Load a 64-byte data chunk and XOR with CRC */
+    uv2di v1 = vec_perm(((uv2di *)buf)[0], ((uv2di *)buf)[0], perm_le2be);
+    uv2di v2 = vec_perm(((uv2di *)buf)[1], ((uv2di *)buf)[1], perm_le2be);
+    uv2di v3 = vec_perm(((uv2di *)buf)[2], ((uv2di *)buf)[2], perm_le2be);
+    uv2di v4 = vec_perm(((uv2di *)buf)[3], ((uv2di *)buf)[3], perm_le2be);
+
+    v1 ^= v0;
+    buf += 64;
+    len -= 64;
+
+    while (len >= 64) {
+        /* Load the next 64-byte data chunk */
+        uv16qi part1 = vec_perm(((uv16qi *)buf)[0], ((uv16qi *)buf)[0], perm_le2be);
+        uv16qi part2 = vec_perm(((uv16qi *)buf)[1], ((uv16qi *)buf)[1], perm_le2be);
+        uv16qi part3 = vec_perm(((uv16qi *)buf)[2], ((uv16qi *)buf)[2], perm_le2be);
+        uv16qi part4 = vec_perm(((uv16qi *)buf)[3], ((uv16qi *)buf)[3], perm_le2be);
+
+        /*
+         * Perform a GF(2) multiplication of the doublewords in V1 with
+         * the R1 and R2 reduction constants in V0.  The intermediate result
+         * is then folded (accumulated) with the next data chunk in PART1 and
+         * stored in V1. Repeat this step for the register contents
+         * in V2, V3, and V4 respectively.
+         */
+        v1 = (uv2di)vec_gfmsum_accum_128(r2r1, v1, part1);
+        v2 = (uv2di)vec_gfmsum_accum_128(r2r1, v2, part2);
+        v3 = (uv2di)vec_gfmsum_accum_128(r2r1, v3, part3);
+        v4 = (uv2di)vec_gfmsum_accum_128(r2r1, v4, part4);
+
+        buf += 64;
+        len -= 64;
+    }
+
+    /*
+     * Fold V1 to V4 into a single 128-bit value in V1.  Multiply V1 with R3
+     * and R4 and accumulating the next 128-bit chunk until a single 128-bit
+     * value remains.
+     */
+    v1 = (uv2di)vec_gfmsum_accum_128(r4r3, v1, (uv16qi)v2);
+    v1 = (uv2di)vec_gfmsum_accum_128(r4r3, v1, (uv16qi)v3);
+    v1 = (uv2di)vec_gfmsum_accum_128(r4r3, v1, (uv16qi)v4);
+
+    while (len >= 16) {
+        /* Load next data chunk */
+        v2 = vec_perm(*(uv2di *)buf, *(uv2di *)buf, perm_le2be);
+
+        /* Fold next data chunk */
+        v1 = (uv2di)vec_gfmsum_accum_128(r4r3, v1, (uv16qi)v2);
+
+        buf += 16;
+        len -= 16;
+    }
+
+    /*
+     * Set up a vector register for byte shifts.  The shift value must
+     * be loaded in bits 1-4 in byte element 7 of a vector register.
+     * Shift by 8 bytes: 0x40
+     * Shift by 4 bytes: 0x20
+     */
+    uv16qi v9 = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+    v9 = vec_insert((unsigned char)0x40, v9, 7);
+
+    /*
+     * Prepare V0 for the next GF(2) multiplication: shift V0 by 8 bytes
+     * to move R4 into the rightmost doubleword and set the leftmost
+     * doubleword to 0x1.
+     */
+    v0 = vec_srb(r4r3, (uv2di)v9);
+    v0[0] = 1;
+
+    /*
+     * Compute GF(2) product of V1 and V0.  The rightmost doubleword
+     * of V1 is multiplied with R4.  The leftmost doubleword of V1 is
+     * multiplied by 0x1 and is then XORed with rightmost product.
+     * Implicitly, the intermediate leftmost product becomes padded
+     */
+    v1 = (uv2di)vec_gfmsum_128(v0, v1);
+
+    /*
+     * Now do the final 32-bit fold by multiplying the rightmost word
+     * in V1 with R5 and XOR the result with the remaining bits in V1.
+     *
+     * To achieve this by a single VGFMAG, right shift V1 by a word
+     * and store the result in V2 which is then accumulated.  Use the
+     * vector unpack instruction to load the rightmost half of the
+     * doubleword into the rightmost doubleword element of V1; the other
+     * half is loaded in the leftmost doubleword.
+     * The vector register with CONST_R5 contains the R5 constant in the
+     * rightmost doubleword and the leftmost doubleword is zero to ignore
+     * the leftmost product of V1.
+     */
+    v9 = vec_insert((unsigned char)0x20, v9, 7);
+    v2 = vec_srb(v1, (uv2di)v9);
+    v1 = vec_unpackl((uv4si)v1);  /* Split rightmost doubleword */
+    v1 = (uv2di)vec_gfmsum_accum_128(r5, v1, (uv16qi)v2);
+
+    /*
+     * Apply a Barret reduction to compute the final 32-bit CRC value.
+     *
+     * The input values to the Barret reduction are the degree-63 polynomial
+     * in V1 (R(x)), degree-32 generator polynomial, and the reduction
+     * constant u.  The Barret reduction result is the CRC value of R(x) mod
+     * P(x).
+     *
+     * The Barret reduction algorithm is defined as:
+     *
+     *    1. T1(x) = floor( R(x) / x^32 ) GF2MUL u
+     *    2. T2(x) = floor( T1(x) / x^32 ) GF2MUL P(x)
+     *    3. C(x)  = R(x) XOR T2(x) mod x^32
+     *
+     *  Note: The leftmost doubleword of vector register containing
+     *  CONST_RU_POLY is zero and, thus, the intermediate GF(2) product
+     *  is zero and does not contribute to the final result.
+     */
+
+    /* T1(x) = floor( R(x) / x^32 ) GF2MUL u */
+    v2 = vec_unpackl((uv4si)v1);
+    v2 = (uv2di)vec_gfmsum_128(ru_poly, v2);
+
+    /*
+     * Compute the GF(2) product of the CRC polynomial with T1(x) in
+     * V2 and XOR the intermediate result, T2(x), with the value in V1.
+     * The final result is stored in word element 2 of V2.
+     */
+    v2 = vec_unpackl((uv4si)v2);
+    v2 = (uv2di)vec_gfmsum_accum_128(crc_poly, v2, (uv16qi)v1);
+
+    return ((uv4si)v2)[2];
+}
+
+#define VX_MIN_LEN 64
+#define VX_ALIGNMENT 16L
+#define VX_ALIGN_MASK (VX_ALIGNMENT - 1)
+
+uint32_t Z_INTERNAL crc32_s390_vx(uint32_t crc, const unsigned char *buf, size_t len) {
+    size_t prealign, aligned, remaining;
+
+    if (len < VX_MIN_LEN + VX_ALIGN_MASK)
+        return crc32_braid(crc, buf, len);
+
+    if ((uintptr_t)buf & VX_ALIGN_MASK) {
+        prealign = (size_t)ALIGN_DIFF(buf, VX_ALIGNMENT);
+        len -= prealign;
+        crc = crc32_braid(crc, buf, prealign);
+        buf += prealign;
+    }
+    aligned = ALIGN_DOWN(len, VX_ALIGNMENT);
+    remaining = len & VX_ALIGN_MASK;
+
+    crc = ~crc32_le_vgfm_16(~crc, buf, aligned);
+
+    if (remaining)
+        crc = crc32_braid(crc, buf + aligned, remaining);
+
+    return crc;
+}
+
+Z_INTERNAL uint32_t crc32_copy_s390_vx(uint32_t crc, uint8_t *dst, const uint8_t *src, size_t len) {
+    crc = crc32_s390_vx(crc, src, len);
+    memcpy(dst, src, len);
+    return crc;
+}
+
+#endif