Deal with unknown or mixed endian architectures properly. If known little

or big endian, for large loads always memcpy, then go back and swap as
needed. Otherwise (unknown or mixed endian) just load one at a time as
usual.

1 files changed, 18 insertions, 22 deletions

diff --git a/src/utils/loadstor.h b/src/utils/loadstor.h
index 77a6e846c..256a6f849 100644
--- a/src/utils/loadstor.h
+++ b/src/utils/loadstor.h
@@ -202,24 +202,22 @@ inline void load_le(T out[],
                     const byte in[],
                     u32bit count)
    {
-#if defined(BOTAN_TARGET_CPU_IS_LITTLE_ENDIAN)
+#if defined(BOTAN_TARGET_CPU_HAS_KNOWN_ENDIANNESS)
    std::memcpy(out, in, sizeof(T)*count);
-#else
+
+#if defined(BOTAN_TARGET_CPU_IS_BIG_ENDIAN)
    const u32bit blocks = count - (count % 4);
    const u32bit left = count - blocks;
 
    for(u32bit i = 0; i != blocks; i += 4)
-      {
-      out[0] = load_le<T>(in, 0);
-      out[1] = load_le<T>(in, 1);
-      out[2] = load_le<T>(in, 2);
-      out[3] = load_le<T>(in, 3);
-
-      out += 4;
-      in  += 4*sizeof(T);
-      }
+      bswap_4(out + i);
 
    for(u32bit i = 0; i != left; ++i)
+      out[blocks+i] = reverse_bytes(out[blocks+i]);
+#endif
+
+#else
+   for(u32bit i = 0; i != count; ++i)
       out[i] = load_le<T>(in, i);
 #endif
    }
@@ -261,24 +259,22 @@ inline void load_be(T out[],
                     const byte in[],
                     u32bit count)
    {
-#if defined(BOTAN_TARGET_CPU_IS_BIG_ENDIAN)
+#if defined(BOTAN_TARGET_CPU_HAS_KNOWN_ENDIANNESS)
    std::memcpy(out, in, sizeof(T)*count);
-#else
+
+#if defined(BOTAN_TARGET_CPU_IS_LITTLE_ENDIAN)
    const u32bit blocks = count - (count % 4);
    const u32bit left = count - blocks;
 
    for(u32bit i = 0; i != blocks; i += 4)
-      {
-      out[0] = load_be<T>(in, 0);
-      out[1] = load_be<T>(in, 1);
-      out[2] = load_be<T>(in, 2);
-      out[3] = load_be<T>(in, 3);
-
-      out += 4;
-      in  += 4*sizeof(T);
-      }
+      bswap_4(out + i);
 
    for(u32bit i = 0; i != left; ++i)
+      out[blocks+i] = reverse_bytes(out[blocks+i]);
+#endif
+
+#else
+   for(u32bit i = 0; i != count; ++i)
       out[i] = load_be<T>(in, i);
 #endif
    }