Faster memcpy

maxdev1 · Feb 11, 2025 · 4af2c4e · 4af2c4e
1 parent 1006a67
commit 4af2c4e
Showing 1 changed file with 22 additions and 5 deletions.
diff --git a/libc/src/string/memcpy.c b/libc/src/string/memcpy.c
@@ -24,13 +24,30 @@
 /**
  *
  */
-void* memcpy(void* dest, const void* src, size_t num) {
+void* memcpy(void* dest, const void* src, size_t num)
+{
 
-	uint8_t* src_8 = (uint8_t*) src;
-	uint8_t* dest_8 = (uint8_t*) dest;
-	while (num--) {
-		*dest_8++ = *src_8++;
+	uint8_t* targetPtr = (uint8_t*) dest;
+	const uint8_t* sourcePtr = (const uint8_t*) src;
+
+	while(num >= 4)
+	{
+		*(uint32_t*) targetPtr = *(const uint32_t*) sourcePtr;
+		targetPtr += 4;
+		sourcePtr += 4;
+		num -= 4;
+	}
+
+	while(num >= 2)
+	{
+		*(uint16_t*) targetPtr = *(const uint16_t*) sourcePtr;
+		targetPtr += 2;
+		sourcePtr += 2;
+		num -= 2;
 	}
 
+	while(num--)
+		*targetPtr++ = *sourcePtr++;
+
 	return dest;
 }