feat: use fast memcpy for net

common/usb_memcpy.h

@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2024, sakumisu
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include <stdint.h>
+#include <stddef.h>
+
+#define ALIGN_UP_DWORD(x) ((uint32_t)(x) & (sizeof(uint32_t) - 1))
+
+static inline void dword2array(char *addr, uint32_t w)
+{
+    addr[0] = w;
+    addr[1] = w >> 8;
+    addr[2] = w >> 16;
+    addr[3] = w >> 24;
+}
+
+static inline void *usb_memcpy(void *s1, const void *s2, size_t n)
+{
+    char *b1 = s1;
+    const char *b2 = s2;
+    uint32_t *w1;
+    const uint32_t *w2;
+
+    if (ALIGN_UP_DWORD(b1) == ALIGN_UP_DWORD(b2)) {
+        while (ALIGN_UP_DWORD(b1) != 0 && n > 0) {
+            *b1++ = *b2++;
+            --n;
+        }
+
+        w1 = (uint32_t *)b1;
+        w2 = (const uint32_t *)b2;
+
+        while (n >= 4 * sizeof(uint32_t)) {
+            *w1++ = *w2++;
+            *w1++ = *w2++;
+            *w1++ = *w2++;
+            *w1++ = *w2++;
+            n -= 4 * sizeof(uint32_t);
+        }
+
+        while (n >= sizeof(uint32_t)) {
+            *w1++ = *w2++;
+            n -= sizeof(uint32_t);
+        }
+
+        b1 = (char *)w1;
+        b2 = (const char *)w2;
+
+        while (n--) {
+            *b1++ = *b2++;
+        }
+    } else {
+        while (n > 0 && ALIGN_UP_DWORD(b2) != 0) {
+            *b1++ = *b2++;
+            --n;
+        }
+
+        w2 = (const uint32_t *)b2;
+
+        while (n >= 4 * sizeof(uint32_t)) {
+         dword2array(b1, *w2++);
+            b1 += sizeof(uint32_t);
+         dword2array(b1, *w2++);
+            b1 += sizeof(uint32_t);
+         dword2array(b1, *w2++);
+            b1 += sizeof(uint32_t);
+         dword2array(b1, *w2++);
+            b1 += sizeof(uint32_t);
+            n -= 4 * sizeof(uint32_t);
+        }
+
+        while (n >= sizeof(uint32_t)) {
+         dword2array(b1, *w2++);
+            b1 += sizeof(uint32_t);
+            n -= sizeof(uint32_t);
+        }
+
+        b2 = (const char *)w2;
+
+        while (n--) {
+            *b1++ = *b2++;
+        }
+    }
+    return s1;
+}