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-rw-r--r--neozip/arch/power/crc32_power8.c593
1 files changed, 593 insertions, 0 deletions
diff --git a/neozip/arch/power/crc32_power8.c b/neozip/arch/power/crc32_power8.c
new file mode 100644
index 0000000000..a7a2fb7435
--- /dev/null
+++ b/neozip/arch/power/crc32_power8.c
@@ -0,0 +1,593 @@
+/* crc32 for POWER8 using VSX instructions
+ * Copyright (C) 2021 IBM Corporation
+ *
+ * Author: Rogerio Alves <rogealve@br.ibm.com>
+ *
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Calculate the checksum of data that is 16 byte aligned and a multiple of
+ * 16 bytes.
+ *
+ * The first step is to reduce it to 1024 bits. We do this in 8 parallel
+ * chunks in order to mask the latency of the vpmsum instructions. If we
+ * have more than 32 kB of data to checksum we repeat this step multiple
+ * times, passing in the previous 1024 bits.
+ *
+ * The next step is to reduce the 1024 bits to 64 bits. This step adds
+ * 32 bits of 0s to the end - this matches what a CRC does. We just
+ * calculate constants that land the data in this 32 bits.
+ *
+ * We then use fixed point Barrett reduction to compute a mod n over GF(2)
+ * for n = CRC using POWER8 instructions. We use x = 32.
+ *
+ * http://en.wikipedia.org/wiki/Barrett_reduction
+ *
+ * This code uses gcc vector builtins instead using assembly directly.
+ */
+
+#ifdef POWER8_VSX_CRC32
+
+#include "zbuild.h"
+#include "zendian.h"
+
+#include "crc32_constants.h"
+#include "crc32_braid_tbl.h"
+
+#include "power_intrins.h"
+
+#define MAX_SIZE 32768
+#define VMX_ALIGN 16
+#define VMX_ALIGN_MASK (VMX_ALIGN-1)
+
+static unsigned int crc32_align(unsigned int crc, const unsigned char *p, unsigned long len) {
+ while (len--)
+ crc = crc_table[(crc ^ *p++) & 0xff] ^ (crc >> 8);
+ return crc;
+}
+
+static unsigned int ALIGNED_(32) __crc32_vpmsum(unsigned int crc, const void* p, unsigned long len);
+
+Z_INTERNAL uint32_t crc32_power8(uint32_t crc, const unsigned char *p, size_t _len) {
+ unsigned int prealign;
+ unsigned int tail;
+
+ unsigned long len = (unsigned long) _len;
+
+ crc ^= 0xffffffff;
+
+ if (len < VMX_ALIGN + VMX_ALIGN_MASK) {
+ crc = crc32_align(crc, p, len);
+ goto out;
+ }
+
+ if ((unsigned long)p & VMX_ALIGN_MASK) {
+ prealign = (unsigned int)ALIGN_DIFF(p, VMX_ALIGN);
+ crc = crc32_align(crc, p, prealign);
+ len -= prealign;
+ p += prealign;
+ }
+
+ crc = __crc32_vpmsum(crc, p, ALIGN_DOWN(len, VMX_ALIGN));
+
+ tail = len & VMX_ALIGN_MASK;
+ if (tail) {
+ p += ALIGN_DOWN(len, VMX_ALIGN);
+ crc = crc32_align(crc, p, tail);
+ }
+
+out:
+ crc ^= 0xffffffff;
+
+ return crc;
+}
+
+Z_INTERNAL uint32_t crc32_copy_power8(uint32_t crc, uint8_t *dst, const uint8_t *src, size_t len) {
+ crc = crc32_power8(crc, src, len);
+ memcpy(dst, src, len);
+ return crc;
+}
+
+/* When we have a load-store in a single-dispatch group and address overlap
+ * such that forward is not allowed (load-hit-store) the group must be flushed.
+ * A group ending NOP prevents the flush.
+ */
+#define GROUP_ENDING_NOP __asm__("ori 2,2,0" ::: "memory")
+
+#if BYTE_ORDER == BIG_ENDIAN
+#define BYTESWAP_DATA
+#endif
+
+#ifdef BYTESWAP_DATA
+#define VEC_PERM(vr, va, vb, vc) vr = vec_perm(va, vb, (__vector unsigned char) vc)
+#if BYTE_ORDER == LITTLE_ENDIAN
+/* Byte reverse permute constant LE. */
+static const __vector unsigned long long vperm_const ALIGNED_(16) = { 0x08090A0B0C0D0E0FUL, 0x0001020304050607UL };
+#else
+static const __vector unsigned long long vperm_const ALIGNED_(16) = { 0x0F0E0D0C0B0A0908UL, 0X0706050403020100UL };
+#endif
+#else
+#define VEC_PERM(vr, va, vb, vc)
+#endif
+
+static unsigned int ALIGNED_(32) __crc32_vpmsum(unsigned int crc, const void* p, unsigned long len) {
+
+ const __vector unsigned long long vzero = {0,0};
+ const __vector unsigned long long vones = {0xffffffffffffffffUL, 0xffffffffffffffffUL};
+
+ const __vector unsigned long long vmask_32bit =
+ (__vector unsigned long long)vec_sld((__vector unsigned char)vzero, (__vector unsigned char)vones, 4);
+
+ const __vector unsigned long long vmask_64bit =
+ (__vector unsigned long long)vec_sld((__vector unsigned char)vzero, (__vector unsigned char)vones, 8);
+
+ __vector unsigned long long vcrc;
+
+ __vector unsigned long long vconst1, vconst2;
+
+ /* vdata0-vdata7 will contain our data (p). */
+ __vector unsigned long long vdata0, vdata1, vdata2, vdata3, vdata4, vdata5, vdata6, vdata7;
+
+ /* v0-v7 will contain our checksums */
+ __vector unsigned long long v0 = {0,0};
+ __vector unsigned long long v1 = {0,0};
+ __vector unsigned long long v2 = {0,0};
+ __vector unsigned long long v3 = {0,0};
+ __vector unsigned long long v4 = {0,0};
+ __vector unsigned long long v5 = {0,0};
+ __vector unsigned long long v6 = {0,0};
+ __vector unsigned long long v7 = {0,0};
+
+
+ /* Vector auxiliary variables. */
+ __vector unsigned long long va0, va1, va2, va3, va4, va5, va6, va7;
+
+ unsigned int offset; /* Constant table offset. */
+
+ unsigned long i; /* Counter. */
+ unsigned long chunks;
+
+ unsigned long block_size;
+ int next_block = 0;
+
+ /* Align by 128 bits. The last 128 bit block will be processed at end. */
+ unsigned long length = len & 0xFFFFFFFFFFFFFF80UL;
+
+ vcrc = (__vector unsigned long long)__builtin_pack_vector_int128(0UL, crc);
+
+ /* Short version. */
+ if (len < 256) {
+ /* Calculate where in the constant table we need to start. */
+ offset = 256 - len;
+
+ vconst1 = vec_ld(offset, vcrc_short_const);
+ vdata0 = vec_ld(0, (__vector unsigned long long*) p);
+ VEC_PERM(vdata0, vdata0, vconst1, vperm_const);
+
+ /* xor initial value */
+ vdata0 = vec_xor(vdata0, vcrc);
+
+ vdata0 = (__vector unsigned long long) __builtin_crypto_vpmsumw(
+ (__vector unsigned int)vdata0, (__vector unsigned int)vconst1);
+ v0 = vec_xor(v0, vdata0);
+
+ for (i = 16; i < len; i += 16) {
+ vconst1 = vec_ld(offset + i, vcrc_short_const);
+ vdata0 = vec_ld(i, (__vector unsigned long long*) p);
+ VEC_PERM(vdata0, vdata0, vconst1, vperm_const);
+ vdata0 = (__vector unsigned long long) __builtin_crypto_vpmsumw(
+ (__vector unsigned int)vdata0, (__vector unsigned int)vconst1);
+ v0 = vec_xor(v0, vdata0);
+ }
+ } else {
+
+ /* Load initial values. */
+ vdata0 = vec_ld(0, (__vector unsigned long long*) p);
+ vdata1 = vec_ld(16, (__vector unsigned long long*) p);
+
+ VEC_PERM(vdata0, vdata0, vdata0, vperm_const);
+ VEC_PERM(vdata1, vdata1, vdata1, vperm_const);
+
+ vdata2 = vec_ld(32, (__vector unsigned long long*) p);
+ vdata3 = vec_ld(48, (__vector unsigned long long*) p);
+
+ VEC_PERM(vdata2, vdata2, vdata2, vperm_const);
+ VEC_PERM(vdata3, vdata3, vdata3, vperm_const);
+
+ vdata4 = vec_ld(64, (__vector unsigned long long*) p);
+ vdata5 = vec_ld(80, (__vector unsigned long long*) p);
+
+ VEC_PERM(vdata4, vdata4, vdata4, vperm_const);
+ VEC_PERM(vdata5, vdata5, vdata5, vperm_const);
+
+ vdata6 = vec_ld(96, (__vector unsigned long long*) p);
+ vdata7 = vec_ld(112, (__vector unsigned long long*) p);
+
+ VEC_PERM(vdata6, vdata6, vdata6, vperm_const);
+ VEC_PERM(vdata7, vdata7, vdata7, vperm_const);
+
+ /* xor in initial value */
+ vdata0 = vec_xor(vdata0, vcrc);
+
+ p = (char *)p + 128;
+
+ do {
+ /* Checksum in blocks of MAX_SIZE. */
+ block_size = length;
+ if (block_size > MAX_SIZE) {
+ block_size = MAX_SIZE;
+ }
+
+ length = length - block_size;
+
+ /*
+ * Work out the offset into the constants table to start at. Each
+ * constant is 16 bytes, and it is used against 128 bytes of input
+ * data - 128 / 16 = 8
+ */
+ offset = (MAX_SIZE/8) - (block_size/8);
+ /* We reduce our final 128 bytes in a separate step */
+ chunks = (block_size/128)-1;
+
+ vconst1 = vec_ld(offset, vcrc_const);
+
+ va0 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata0,
+ (__vector unsigned long long)vconst1);
+ va1 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata1,
+ (__vector unsigned long long)vconst1);
+ va2 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata2,
+ (__vector unsigned long long)vconst1);
+ va3 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata3,
+ (__vector unsigned long long)vconst1);
+ va4 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata4,
+ (__vector unsigned long long)vconst1);
+ va5 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata5,
+ (__vector unsigned long long)vconst1);
+ va6 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata6,
+ (__vector unsigned long long)vconst1);
+ va7 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata7,
+ (__vector unsigned long long)vconst1);
+
+ if (chunks > 1) {
+ offset += 16;
+ vconst2 = vec_ld(offset, vcrc_const);
+ GROUP_ENDING_NOP;
+
+ vdata0 = vec_ld(0, (__vector unsigned long long*) p);
+ VEC_PERM(vdata0, vdata0, vdata0, vperm_const);
+
+ vdata1 = vec_ld(16, (__vector unsigned long long*) p);
+ VEC_PERM(vdata1, vdata1, vdata1, vperm_const);
+
+ vdata2 = vec_ld(32, (__vector unsigned long long*) p);
+ VEC_PERM(vdata2, vdata2, vdata2, vperm_const);
+
+ vdata3 = vec_ld(48, (__vector unsigned long long*) p);
+ VEC_PERM(vdata3, vdata3, vdata3, vperm_const);
+
+ vdata4 = vec_ld(64, (__vector unsigned long long*) p);
+ VEC_PERM(vdata4, vdata4, vdata4, vperm_const);
+
+ vdata5 = vec_ld(80, (__vector unsigned long long*) p);
+ VEC_PERM(vdata5, vdata5, vdata5, vperm_const);
+
+ vdata6 = vec_ld(96, (__vector unsigned long long*) p);
+ VEC_PERM(vdata6, vdata6, vdata6, vperm_const);
+
+ vdata7 = vec_ld(112, (__vector unsigned long long*) p);
+ VEC_PERM(vdata7, vdata7, vdata7, vperm_const);
+
+ p = (char *)p + 128;
+
+ /*
+ * main loop. Each iteration calculates the CRC for a 128-byte
+ * block.
+ */
+ for (i = 0; i < chunks-2; i++) {
+ vconst1 = vec_ld(offset, vcrc_const);
+ offset += 16;
+ GROUP_ENDING_NOP;
+
+ v0 = vec_xor(v0, va0);
+ va0 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata0,
+ (__vector unsigned long long)vconst2);
+ vdata0 = vec_ld(0, (__vector unsigned long long*) p);
+ VEC_PERM(vdata0, vdata0, vdata0, vperm_const);
+ GROUP_ENDING_NOP;
+
+ v1 = vec_xor(v1, va1);
+ va1 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata1,
+ (__vector unsigned long long)vconst2);
+ vdata1 = vec_ld(16, (__vector unsigned long long*) p);
+ VEC_PERM(vdata1, vdata1, vdata1, vperm_const);
+ GROUP_ENDING_NOP;
+
+ v2 = vec_xor(v2, va2);
+ va2 = __builtin_crypto_vpmsumd((__vector unsigned long long)
+ vdata2, (__vector unsigned long long)vconst2);
+ vdata2 = vec_ld(32, (__vector unsigned long long*) p);
+ VEC_PERM(vdata2, vdata2, vdata2, vperm_const);
+ GROUP_ENDING_NOP;
+
+ v3 = vec_xor(v3, va3);
+ va3 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata3,
+ (__vector unsigned long long)vconst2);
+ vdata3 = vec_ld(48, (__vector unsigned long long*) p);
+ VEC_PERM(vdata3, vdata3, vdata3, vperm_const);
+
+ vconst2 = vec_ld(offset, vcrc_const);
+ GROUP_ENDING_NOP;
+
+ v4 = vec_xor(v4, va4);
+ va4 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata4,
+ (__vector unsigned long long)vconst1);
+ vdata4 = vec_ld(64, (__vector unsigned long long*) p);
+ VEC_PERM(vdata4, vdata4, vdata4, vperm_const);
+ GROUP_ENDING_NOP;
+
+ v5 = vec_xor(v5, va5);
+ va5 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata5,
+ (__vector unsigned long long)vconst1);
+ vdata5 = vec_ld(80, (__vector unsigned long long*) p);
+ VEC_PERM(vdata5, vdata5, vdata5, vperm_const);
+ GROUP_ENDING_NOP;
+
+ v6 = vec_xor(v6, va6);
+ va6 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata6,
+ (__vector unsigned long long)vconst1);
+ vdata6 = vec_ld(96, (__vector unsigned long long*) p);
+ VEC_PERM(vdata6, vdata6, vdata6, vperm_const);
+ GROUP_ENDING_NOP;
+
+ v7 = vec_xor(v7, va7);
+ va7 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata7,
+ (__vector unsigned long long)vconst1);
+ vdata7 = vec_ld(112, (__vector unsigned long long*) p);
+ VEC_PERM(vdata7, vdata7, vdata7, vperm_const);
+
+ p = (char *)p + 128;
+ }
+
+ /* First cool down */
+ vconst1 = vec_ld(offset, vcrc_const);
+ offset += 16;
+
+ v0 = vec_xor(v0, va0);
+ va0 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata0,
+ (__vector unsigned long long)vconst1);
+ GROUP_ENDING_NOP;
+
+ v1 = vec_xor(v1, va1);
+ va1 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata1,
+ (__vector unsigned long long)vconst1);
+ GROUP_ENDING_NOP;
+
+ v2 = vec_xor(v2, va2);
+ va2 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata2,
+ (__vector unsigned long long)vconst1);
+ GROUP_ENDING_NOP;
+
+ v3 = vec_xor(v3, va3);
+ va3 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata3,
+ (__vector unsigned long long)vconst1);
+ GROUP_ENDING_NOP;
+
+ v4 = vec_xor(v4, va4);
+ va4 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata4,
+ (__vector unsigned long long)vconst1);
+ GROUP_ENDING_NOP;
+
+ v5 = vec_xor(v5, va5);
+ va5 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata5,
+ (__vector unsigned long long)vconst1);
+ GROUP_ENDING_NOP;
+
+ v6 = vec_xor(v6, va6);
+ va6 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata6,
+ (__vector unsigned long long)vconst1);
+ GROUP_ENDING_NOP;
+
+ v7 = vec_xor(v7, va7);
+ va7 = __builtin_crypto_vpmsumd((__vector unsigned long long)vdata7,
+ (__vector unsigned long long)vconst1);
+ }/* else */
+
+ /* Second cool down. */
+ v0 = vec_xor(v0, va0);
+ v1 = vec_xor(v1, va1);
+ v2 = vec_xor(v2, va2);
+ v3 = vec_xor(v3, va3);
+ v4 = vec_xor(v4, va4);
+ v5 = vec_xor(v5, va5);
+ v6 = vec_xor(v6, va6);
+ v7 = vec_xor(v7, va7);
+
+ /*
+ * vpmsumd produces a 96 bit result in the least significant bits
+ * of the register. Since we are bit reflected we have to shift it
+ * left 32 bits so it occupies the least significant bits in the
+ * bit reflected domain.
+ */
+ v0 = (__vector unsigned long long)vec_sld((__vector unsigned char)v0,
+ (__vector unsigned char)vzero, 4);
+ v1 = (__vector unsigned long long)vec_sld((__vector unsigned char)v1,
+ (__vector unsigned char)vzero, 4);
+ v2 = (__vector unsigned long long)vec_sld((__vector unsigned char)v2,
+ (__vector unsigned char)vzero, 4);
+ v3 = (__vector unsigned long long)vec_sld((__vector unsigned char)v3,
+ (__vector unsigned char)vzero, 4);
+ v4 = (__vector unsigned long long)vec_sld((__vector unsigned char)v4,
+ (__vector unsigned char)vzero, 4);
+ v5 = (__vector unsigned long long)vec_sld((__vector unsigned char)v5,
+ (__vector unsigned char)vzero, 4);
+ v6 = (__vector unsigned long long)vec_sld((__vector unsigned char)v6,
+ (__vector unsigned char)vzero, 4);
+ v7 = (__vector unsigned long long)vec_sld((__vector unsigned char)v7,
+ (__vector unsigned char)vzero, 4);
+
+ /* xor with the last 1024 bits. */
+ va0 = vec_ld(0, (__vector unsigned long long*) p);
+ VEC_PERM(va0, va0, va0, vperm_const);
+
+ va1 = vec_ld(16, (__vector unsigned long long*) p);
+ VEC_PERM(va1, va1, va1, vperm_const);
+
+ va2 = vec_ld(32, (__vector unsigned long long*) p);
+ VEC_PERM(va2, va2, va2, vperm_const);
+
+ va3 = vec_ld(48, (__vector unsigned long long*) p);
+ VEC_PERM(va3, va3, va3, vperm_const);
+
+ va4 = vec_ld(64, (__vector unsigned long long*) p);
+ VEC_PERM(va4, va4, va4, vperm_const);
+
+ va5 = vec_ld(80, (__vector unsigned long long*) p);
+ VEC_PERM(va5, va5, va5, vperm_const);
+
+ va6 = vec_ld(96, (__vector unsigned long long*) p);
+ VEC_PERM(va6, va6, va6, vperm_const);
+
+ va7 = vec_ld(112, (__vector unsigned long long*) p);
+ VEC_PERM(va7, va7, va7, vperm_const);
+
+ p = (char *)p + 128;
+
+ vdata0 = vec_xor(v0, va0);
+ vdata1 = vec_xor(v1, va1);
+ vdata2 = vec_xor(v2, va2);
+ vdata3 = vec_xor(v3, va3);
+ vdata4 = vec_xor(v4, va4);
+ vdata5 = vec_xor(v5, va5);
+ vdata6 = vec_xor(v6, va6);
+ vdata7 = vec_xor(v7, va7);
+
+ /* Check if we have more blocks to process */
+ next_block = 0;
+ if (length != 0) {
+ next_block = 1;
+
+ /* zero v0-v7 */
+ v0 = vec_xor(v0, v0);
+ v1 = vec_xor(v1, v1);
+ v2 = vec_xor(v2, v2);
+ v3 = vec_xor(v3, v3);
+ v4 = vec_xor(v4, v4);
+ v5 = vec_xor(v5, v5);
+ v6 = vec_xor(v6, v6);
+ v7 = vec_xor(v7, v7);
+ }
+ length = length + 128;
+
+ } while (next_block);
+
+ /* Calculate how many bytes we have left. */
+ length = (len & 127);
+
+ /* Calculate where in (short) constant table we need to start. */
+ offset = 128 - length;
+
+ v0 = vec_ld(offset, vcrc_short_const);
+ v1 = vec_ld(offset + 16, vcrc_short_const);
+ v2 = vec_ld(offset + 32, vcrc_short_const);
+ v3 = vec_ld(offset + 48, vcrc_short_const);
+ v4 = vec_ld(offset + 64, vcrc_short_const);
+ v5 = vec_ld(offset + 80, vcrc_short_const);
+ v6 = vec_ld(offset + 96, vcrc_short_const);
+ v7 = vec_ld(offset + 112, vcrc_short_const);
+
+ offset += 128;
+
+ v0 = (__vector unsigned long long)__builtin_crypto_vpmsumw(
+ (__vector unsigned int)vdata0, (__vector unsigned int)v0);
+ v1 = (__vector unsigned long long)__builtin_crypto_vpmsumw(
+ (__vector unsigned int)vdata1, (__vector unsigned int)v1);
+ v2 = (__vector unsigned long long)__builtin_crypto_vpmsumw(
+ (__vector unsigned int)vdata2, (__vector unsigned int)v2);
+ v3 = (__vector unsigned long long)__builtin_crypto_vpmsumw(
+ (__vector unsigned int)vdata3, (__vector unsigned int)v3);
+ v4 = (__vector unsigned long long)__builtin_crypto_vpmsumw(
+ (__vector unsigned int)vdata4, (__vector unsigned int)v4);
+ v5 = (__vector unsigned long long)__builtin_crypto_vpmsumw(
+ (__vector unsigned int)vdata5, (__vector unsigned int)v5);
+ v6 = (__vector unsigned long long)__builtin_crypto_vpmsumw(
+ (__vector unsigned int)vdata6, (__vector unsigned int)v6);
+ v7 = (__vector unsigned long long)__builtin_crypto_vpmsumw(
+ (__vector unsigned int)vdata7, (__vector unsigned int)v7);
+
+ /* Now reduce the tail (0-112 bytes). */
+ for (i = 0; i < length; i+=16) {
+ vdata0 = vec_ld(i,(__vector unsigned long long*)p);
+ VEC_PERM(vdata0, vdata0, vdata0, vperm_const);
+ va0 = vec_ld(offset + i,vcrc_short_const);
+ va0 = (__vector unsigned long long)__builtin_crypto_vpmsumw(
+ (__vector unsigned int)vdata0, (__vector unsigned int)va0);
+ v0 = vec_xor(v0, va0);
+ }
+
+ /* xor all parallel chunks together. */
+ v0 = vec_xor(v0, v1);
+ v2 = vec_xor(v2, v3);
+ v4 = vec_xor(v4, v5);
+ v6 = vec_xor(v6, v7);
+
+ v0 = vec_xor(v0, v2);
+ v4 = vec_xor(v4, v6);
+
+ v0 = vec_xor(v0, v4);
+ }
+
+ /* Barrett Reduction */
+ vconst1 = vec_ld(0, v_Barrett_const);
+ vconst2 = vec_ld(16, v_Barrett_const);
+
+ v1 = (__vector unsigned long long)vec_sld((__vector unsigned char)v0,
+ (__vector unsigned char)v0, 8);
+ v0 = vec_xor(v1,v0);
+
+ /* shift left one bit */
+ __vector unsigned char vsht_splat = vec_splat_u8 (1);
+ v0 = (__vector unsigned long long)vec_sll((__vector unsigned char)v0, vsht_splat);
+
+ v0 = vec_and(v0, vmask_64bit);
+
+ /*
+ * The reflected version of Barrett reduction. Instead of bit
+ * reflecting our data (which is expensive to do), we bit reflect our
+ * constants and our algorithm, which means the intermediate data in
+ * our vector registers goes from 0-63 instead of 63-0. We can reflect
+ * the algorithm because we don't carry in mod 2 arithmetic.
+ */
+
+ /* bottom 32 bits of a */
+ v1 = vec_and(v0, vmask_32bit);
+
+ /* ma */
+ v1 = __builtin_crypto_vpmsumd((__vector unsigned long long)v1,
+ (__vector unsigned long long)vconst1);
+
+ /* bottom 32bits of ma */
+ v1 = vec_and(v1, vmask_32bit);
+ /* qn */
+ v1 = __builtin_crypto_vpmsumd((__vector unsigned long long)v1,
+ (__vector unsigned long long)vconst2);
+ /* a - qn, subtraction is xor in GF(2) */
+ v0 = vec_xor (v0, v1);
+
+ /*
+ * Since we are bit reflected, the result (ie the low 32 bits) is in
+ * the high 32 bits. We just need to shift it left 4 bytes
+ * V0 [ 0 1 X 3 ]
+ * V0 [ 0 X 2 3 ]
+ */
+
+ /* shift result into top 64 bits of */
+ v0 = (__vector unsigned long long)vec_sld((__vector unsigned char)v0,
+ (__vector unsigned char)vzero, 4);
+
+#if BYTE_ORDER == BIG_ENDIAN
+ return v0[0];
+#else
+ return v0[1];
+#endif
+}
+
+#endif
generated by cgit 0.0.5-2-1-g0f52 (git 2.46.0) at 2026-04-05 16:20:46 +0000