From 12e5eca4ea269f90b7cb0792248509967e5e821d Mon Sep 17 00:00:00 2001
From: Vincent Hanquez <vincent@snarc.org>
Date: Fri, 9 Dec 2016 15:01:58 +0000
Subject: [PATCH] add basic framework to tests and query for alignments

---
 cbits/cryptonite_align.h | 51 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 cbits/cryptonite_align.h

diff --git a/cbits/cryptonite_align.h b/cbits/cryptonite_align.h
new file mode 100644
index 0000000..e07058d
--- /dev/null
+++ b/cbits/cryptonite_align.h
@@ -0,0 +1,51 @@
+#ifndef CRYPTONITE_ALIGN_H
+#define CRYPTONITE_ALIGN_H
+
+#include "cryptonite_bitfn.h"
+
+#if (defined(__i386__))
+# define UNALIGNED_ACCESS_OK
+#elif defined(__x86_64__)
+# define UNALIGNED_ACCESS_OK
+#else
+# define UNALIGNED_ACCESS_FAULT
+#endif
+
+/* n need to be power of 2.
+ * IS_ALIGNED(p,8) */
+#define IS_ALIGNED(p,alignment) (((uintptr_t) (p)) & ((alignment)-1))
+
+#ifdef WITH_ASSERT_ALIGNMENT
+#include <stdio.h>
+#include <stdlib.h>
+#include <inttypes.h>
+# define ASSERT_ALIGNMENT(up, alignment) \
+	do { if (IS_ALIGNED(up, alignment)) \
+	{ printf("ALIGNMENT-ASSERT-FAILURE: %s:%d: ptr=%p alignment=%d\n", __FILE__, __LINE__, (void *) up, (alignment)); \
+	  exit(99); \
+	}; } while (0)
+#else
+# define ASSERT_ALIGNMENT(p, n) do {} while (0)
+#endif
+
+#ifdef UNALIGNED_ACCESS_OK
+#define need_alignment(p,n) (0)
+#else
+#define need_alignment(p,n) IS_ALIGNED(p,n)
+#endif
+
+static inline uint32_t load_le32_aligned(const uint8_t *p)
+{
+	return le32_to_cpu(*((uint32_t *) p));		
+}
+
+#ifdef UNALIGNED_ACCESS_OK
+#define load_le32(a) load_le32_aligned(a)
+#else
+static inline uint32_t load_le32(const uint8_t *p)
+{
+	return ((uint32_t)p[0]) | ((uint32_t)p[1] <<  8) | ((uint32_t)p[2] << 16) | ((uint32_t)p[3] << 24);
+}
+#endif
+
+#endif