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

[Dinar Temirbulatov 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;
+      }
+    }
+  }
+
+  void assert_equal(const Memory &Other) {
+    for (unsigned I = 0; I < N; I++) {
+      assert(ptr[I] == Other.ptr[I]);
+    }
+  }
+
+  void assert_equal(std::initializer_list<uint8_t> S) {
+    assert(S.size() == N);
+    auto It = S.begin();
+    for (unsigned I = 0; I < N; I++) {
+      assert(ptr[I] == *It++);
+    }
+  }
+
+  void assert_elemt_equal_at(unsigned I, uint8_t elem) {
+    assert(ptr[I] == elem);
+  }
+};
+
+int main() {
+
+  // Testing memcpy from Src to Dst.
+  {
+    Memory<8> Src(1);
+    Memory<8> Dst;
+    if (!__arm_sc_memcpy(Dst.ptr, Src.ptr, 8))
+      abort();
+    Dst.assert_equal(Src);
+    Dst.assert_equal({0, 1, 2, 3, 4, 5, 6, 7});
+  }
+
+  // Testing memcpy from Src to Dst with pointer offset.
+  {
+    Memory<8> Src(1);
+    Memory<8> Dst(1);
+    if (!__arm_sc_memcpy(Dst.ptr + 1, Src.ptr, 6))
+      abort();
+    Dst.assert_equal({0, 0, 1, 2, 3, 4, 5, 7});
+  }
+
+  // Testing memchr.
+  {
+    Memory<8> Src(4);
+    for (unsigned I = 0; I < 8; I++) {
+      uint8_t E = Src.ptr[I];
+      uint8_t *Elem = (uint8_t *)memchr(Src.ptr, E, 8);
+      if (!Elem)
+        abort();
+      Src.assert_elemt_equal_at(Elem - Src.ptr, *Elem);
+      assert(__arm_sc_memchr(Src.ptr, E, 8) == memchr(Src.ptr, E, 8));
+    }
+  }
+
+  // Testing memset.
+  {
+    Memory<8> Array;
+    if (!__arm_sc_memset(Array.ptr, 2, 8))
+      abort();
+    Array.assert_equal({2, 2, 2, 2, 2, 2, 2, 2});
+  }
+
+  // Testing memset with pointer offset.
+  {
+    Memory<8> Array(1);
+    if (!__arm_sc_memset(Array.ptr + 1, 2, 6))
+      abort();
+    Array.assert_equal({0, 2, 2, 2, 2, 2, 2, 7});
+  }
+
+  // Testing memset with different pointer offset.
+  {
+    for (unsigned I = 0; I < 16; I++) {
+      Memory<16> Array(2);
+      if (!__arm_sc_memset(Array.ptr + I, I, 16 - I))
+        abort();
+
+      uint8_t OrigElem = 0;
+      for (unsigned J = 0; J < 16; J++) {
+        if (I == 0) {
+          Array.assert_elemt_equal_at(J, 0);
+        } else if (J < I) {
+          Array.assert_elemt_equal_at(J, OrigElem);
+        } else {
+          Array.assert_elemt_equal_at(J, (uint8_t)I);
+        }
+        OrigElem += 2;
+      }
+    }
+  }
+
----------------
dtemirbulatov wrote:

Done.

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