[compiler-rt] [AArch64][compiler-rt] Add memcpy, memset, memmove, memchr simple imp… (PR #77496)

[Sander de Smalen via llvm-commits]

================
@@ -0,0 +1,140 @@
+// REQUIRES: aarch64-target-arch, aarch64-sme-available
+// RUN: %clangxx_builtins %s %librt -o %t && %run %t
+
+#include <cassert>
+#include <initializer_list>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+extern "C" {
+void *__arm_sc_memcpy(void *, const void *, size_t);
+void *__arm_sc_memset(void *, int, size_t);
+void *__arm_sc_memmove(void *, const void *, size_t);
+void *__arm_sc_memchr(const void *, int, size_t);
+}
+
+template <unsigned N> class Memory {
+public:
+  uint8_t ptr[N];
+
+  Memory(int Stride = 0) {
+    if (Stride != 0) {
+      for (unsigned I = 0, Elem = 0; I < N; I++, Elem += Stride) {
+        ptr[I] = Elem;
+      }
+    }
----------------
sdesmalen-arm wrote:

nit:
```suggestion
    if (Stride == 0)
      return;
    for (unsigned I = 0; I < N; ++I)
      ptr[I] = I * Stride;
```


https://github.com/llvm/llvm-project/pull/77496