initial commit, 4.5 stable

thirdparty/sdl/stdlib/SDL_memmove.c

@@ -0,0 +1,73 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+
+#ifdef SDL_memmove
+#undef SDL_memmove
+#endif
+#if SDL_DYNAMIC_API
+#define SDL_memmove SDL_memmove_REAL
+#endif
+void *SDL_memmove(SDL_OUT_BYTECAP(len) void *dst, SDL_IN_BYTECAP(len) const void *src, size_t len)
+{
+#if defined(__GNUC__) && (defined(HAVE_LIBC) && HAVE_LIBC)
+    // Presumably this is well tuned for speed.
+    return __builtin_memmove(dst, src, len);
+#elif defined(HAVE_MEMMOVE)
+    return memmove(dst, src, len);
+#else
+    char *srcp = (char *)src;
+    char *dstp = (char *)dst;
+
+    if (src < dst) {
+        srcp += len - 1;
+        dstp += len - 1;
+        while (len--) {
+            *dstp-- = *srcp--;
+        }
+    } else {
+        while (len--) {
+            *dstp++ = *srcp++;
+        }
+    }
+    return dst;
+#endif // HAVE_MEMMOVE
+}
+
+
+#ifndef HAVE_LIBC
+// NOLINTNEXTLINE(readability-redundant-declaration)
+extern void *memmove(void *dst, const void *src, size_t len);
+#if defined(_MSC_VER) && !defined(__INTEL_LLVM_COMPILER)
+#pragma intrinsic(memmove)
+#endif
+
+#if defined(_MSC_VER) && !defined(__clang__)
+#pragma function(memmove)
+#endif
+// NOLINTNEXTLINE(readability-inconsistent-declaration-parameter-name)
+void *memmove(void *dst, const void *src, size_t len)
+{
+    return SDL_memmove(dst, src, len);
+}
+#endif // !HAVE_LIBC
+