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

[Sander de Smalen via llvm-commits]

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@@ -0,0 +1,108 @@
+// REQUIRES: linux, aarch64-target-arch, aarch64-sme-available
+// RUN: %clangxx_builtins %s %librt -o %t && %run %t
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define N 16
+
+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);
+}
+
+class MemoryArea {
+
+  uint8_t dst[N], src[N];
+
+  int sum_and_reset_dst(uint8_t *dest, int n, int j) {
+    int t = 0;
+    for (int i = 0; i < n; i++) {
+      t += dest[i];
+    }
+    for (int i = 0; i < j; i++) {
+      dst[i] = i + 1;
+    }
+    return t;
+  }
+
+public:
+  MemoryArea() {
+    for (int i = 0; i < N; i++) {
+      src[i] = i * 2;
+      dst[i] = i + 1;
+    }
+  }
+
+  // Test correctness of memcpy
+  void test_memcpy() {
+    for (int i = 0; i < 8; i++) {
+      int t[2];
+      if (!__arm_sc_memcpy(dst, src, i))
+        abort();
+      t[0] = sum_and_reset_dst(dst, N, i);
+      memcpy(dst, src, i);
+      t[1] = sum_and_reset_dst(dst, N, i);
+      if (t[0] != t[1])
+        abort();
+    }
+  }
+
+  // Test correctness of memset
+  void test_memset() {
+    for (int i = 0; i < 8; i++) {
+      int t[2];
+      if (!__arm_sc_memset(dst, src[i], i))
+        abort();
+      t[0] = sum_and_reset_dst(dst, N, i);
+      __arm_sc_memset(dst, src[i], i);
+      t[1] = sum_and_reset_dst(dst, N, i);
+      if (t[0] != t[1])
+        abort();
+    }
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sdesmalen-arm wrote:

We discussed this offline, but please write some more specific tests that target the corner cases of the routines.

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