From: Marko Kreen <markokr@gmail.com>
Date: Wed, 9 Jul 2014 17:03:55 +0000 (+0300)
Subject: endian: WORDS_UNALIGNED_ACCESS_OK (draft)
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=8f82633a4982943f906588ec741e69089a7d0333;p=libusual.git

endian: WORDS_UNALIGNED_ACCESS_OK (draft)

Seems it might be useful (mainly inside endian.h) for non-gcc/clang
compilers, but needs proof.
---

diff --git a/usual/endian.h b/usual/endian.h
index 58d44e2..8291cde 100644
--- a/usual/endian.h
+++ b/usual/endian.h
@@ -41,6 +41,17 @@
 #include <byteswap.h>
 #endif
 
+/*
+ * Is unaligned access to integers OK?  Does not apply to floats.
+ *
+ * OK: x86, amd64, arm >= v6, ppc
+ */
+#if defined(__amd64__) || defined(__i386__) || defined(__ppc__) || defined(__ppc64__) \
+	|| defined(__ARM_FEATURE_UNALIGNED) \
+	|| defined(_M_IX86) || defined(_M_X64) || defined(_M_PPC) \
+	|| (defined(_M_ARM) && _M_ARM >= 6)
+#define WORDS_UNALIGNED_ACCESS_OK
+#endif
 
 /*
  * Ignore OS defines, as they may define only some subset of functions.