ArmPkg/CompilerIntrinsicsLib: Add memcmp, memmove intrinsics for MSFT

We could have reused memmove.asm for ARM, but we would still need to add
an implemention for ARM64, so we use the same source for both archs.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Pete Batard <pete@akeo.ie>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf

@@ -26,6 +26,8 @@
 
   memcpy_ms.c          | MSFT
   memset_ms.c          | MSFT
+  memcmp_ms.c          | MSFT
+  memmove_ms.c         | MSFT
 
 [Sources.ARM]
   Arm/mullu.asm        | RVCT

ArmPkg/Library/CompilerIntrinsicsLib/memcmp_ms.c

@@ -0,0 +1,31 @@
+//------------------------------------------------------------------------------
+//
+// Copyright (c) 2019, Pete Batard. All rights reserved.
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+//------------------------------------------------------------------------------
+
+#if defined(_M_ARM64)
+typedef unsigned __int64  size_t;
+#else
+typedef unsigned __int32  size_t;
+#endif
+
+int memcmp(void *, void *, size_t);
+#pragma intrinsic(memcmp)
+#pragma function(memcmp)
+int memcmp(const void *s1, const void *s2, size_t n)
+{
+  unsigned char const *t1 = s1;
+  unsigned char const *t2 = s2;
+
+  while (n--) {
+    if (*t1 != *t2)
+      return (int)*t1 - (int)*t2;
+    t1++;
+    t2++;
+  }
+
+  return 0;
+}

ArmPkg/Library/CompilerIntrinsicsLib/memmove_ms.c

@@ -0,0 +1,34 @@
+//------------------------------------------------------------------------------
+//
+// Copyright (c) 2019, Pete Batard. All rights reserved.
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+//------------------------------------------------------------------------------
+
+#if defined(_M_ARM64)
+typedef unsigned __int64  size_t;
+#else
+typedef unsigned __int32  size_t;
+#endif
+
+void* memmove(void *, const void *, size_t);
+#pragma intrinsic(memmove)
+#pragma function(memmove)
+void* memmove(void *dest, const void *src, size_t n)
+{
+  unsigned char *d = dest;
+  unsigned char const *s = src;
+
+  if (d < s) {
+    while (n--)
+      *d++ = *s++;
+  } else {
+    d += n;
+    s += n;
+    while (n--)
+      *--d = *--s;
+  }
+
+  return dest;
+}