AstroBWT: add AVX2 Salsa20 implementation

+4.5% speedup on Ryzen 5 5600X

src/crypto/astrobwt/xmm6int/salsa20_xmm6int-avx2.c

@@ -0,0 +1,105 @@
+/*
+ * ISC License
+ *
+ * Copyright (c) 2013-2021
+ * Frank Denis <j at pureftpd dot org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef __GNUC__
+#pragma GCC target("sse2")
+#pragma GCC target("ssse3")
+#pragma GCC target("sse4.1")
+#pragma GCC target("avx2")
+#endif
+
+#include <emmintrin.h>
+#include <immintrin.h>
+#include <smmintrin.h>
+#include <tmmintrin.h>
+
+#define ROUNDS 20
+
+typedef struct salsa_ctx {
+    uint32_t input[16];
+} salsa_ctx;
+
+static const int TR[16] = {
+    0, 5, 10, 15, 12, 1, 6, 11, 8, 13, 2, 7, 4, 9, 14, 3
+};
+
+#define LOAD32_LE(p) *((uint32_t*)(p))
+#define STORE32_LE(dst, src) memcpy((dst), &(src), sizeof(uint32_t))
+
+static void
+salsa_keysetup(salsa_ctx *ctx, const uint8_t *k)
+{
+    ctx->input[TR[1]]  = LOAD32_LE(k + 0);
+    ctx->input[TR[2]]  = LOAD32_LE(k + 4);
+    ctx->input[TR[3]]  = LOAD32_LE(k + 8);
+    ctx->input[TR[4]]  = LOAD32_LE(k + 12);
+    ctx->input[TR[11]] = LOAD32_LE(k + 16);
+    ctx->input[TR[12]] = LOAD32_LE(k + 20);
+    ctx->input[TR[13]] = LOAD32_LE(k + 24);
+    ctx->input[TR[14]] = LOAD32_LE(k + 28);
+    ctx->input[TR[0]]  = 0x61707865;
+    ctx->input[TR[5]]  = 0x3320646e;
+    ctx->input[TR[10]] = 0x79622d32;
+    ctx->input[TR[15]] = 0x6b206574;
+}
+
+static void
+salsa_ivsetup(salsa_ctx *ctx, const uint8_t *iv, const uint8_t *counter)
+{
+    ctx->input[TR[6]] = LOAD32_LE(iv + 0);
+    ctx->input[TR[7]] = LOAD32_LE(iv + 4);
+    ctx->input[TR[8]] = counter == NULL ? 0 : LOAD32_LE(counter + 0);
+    ctx->input[TR[9]] = counter == NULL ? 0 : LOAD32_LE(counter + 4);
+}
+
+static void
+salsa20_encrypt_bytes(salsa_ctx *ctx, const uint8_t *m, uint8_t *c,
+                      unsigned long long bytes)
+{
+    uint32_t * const x = &ctx->input[0];
+
+    if (!bytes) {
+        return; /* LCOV_EXCL_LINE */
+    }
+
+#include "u8.h"
+#include "u4.h"
+#include "u1.h"
+#include "u0.h"
+}
+
+int salsa20_stream_avx2(void* c, uint64_t clen, const void* iv, const void* key)
+{
+	struct salsa_ctx ctx;
+
+	if (!clen) {
+		return 0;
+	}
+
+	salsa_keysetup(&ctx, (const uint8_t*)key);
+	salsa_ivsetup(&ctx, (const uint8_t*)iv, NULL);
+	memset(c, 0, clen);
+	salsa20_encrypt_bytes(&ctx, (const uint8_t*)c, (uint8_t*)c, clen);
+
+	return 0;
+}