From 7feee8f380a8d811a6a343682fa1d2baa121a6d9 Mon Sep 17 00:00:00 2001
From: Duncan Sands <baldrick@free.fr>
Date: Mon, 10 Dec 2007 17:43:13 +0000
Subject: Fix PR1836: in the interpreter, read and write apints using the
 minimum possible number of bytes.  For little endian targets run on little
 endian machines, apints are stored in memory from LSB to MSB as before.  For
 big endian targets on big endian machines they are stored from MSB to LSB
 which wasn't always the case before (if the target and host endianness
 doesn't match values are stored according to the host's endianness).  Doing
 this requires knowing the endianness of the host, which is determined when
 configuring - thanks go to Anton for this.  Only having access to little
 endian machines I was unable to properly test the big endian part, which is
 also the most complicated...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44796 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Config/config.h.in  |  6 ++++++
 include/llvm/Target/TargetData.h | 11 +++++++++++
 2 files changed, 17 insertions(+)

(limited to 'include/llvm')

diff --git a/include/llvm/Config/config.h.in b/include/llvm/Config/config.h.in
index 32e154a..64858f2 100644
--- a/include/llvm/Config/config.h.in
+++ b/include/llvm/Config/config.h.in
@@ -494,6 +494,9 @@
 /* Installation prefix directory */
 #undef LLVM_PREFIX
 
+/* Define if this target is little endian */
+#undef LSB_FIRST
+
 /* Define if the OS needs help to load dependent libraries for dlopen(). */
 #undef LTDL_DLOPEN_DEPLIBS
 
@@ -511,6 +514,9 @@
 /* Define to the system default library search path. */
 #undef LTDL_SYSSEARCHPATH
 
+/* Define if this target is big endian */
+#undef MSB_FIRST
+
 /* Define if /dev/zero should be used when mapping RWX memory, or undefine if
    its not necessary */
 #undef NEED_DEV_ZERO_FOR_MMAP
diff --git a/include/llvm/Target/TargetData.h b/include/llvm/Target/TargetData.h
index 3136a38..fd52ef3 100644
--- a/include/llvm/Target/TargetData.h
+++ b/include/llvm/Target/TargetData.h
@@ -23,6 +23,7 @@
 #include "llvm/Pass.h"
 #include "llvm/Support/DataTypes.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/Config/config.h"
 #include <string>
 
 namespace llvm {
@@ -142,6 +143,16 @@ public:
   bool          isLittleEndian()       const { return     LittleEndian; }
   bool          isBigEndian()          const { return    !LittleEndian; }
 
+  /// Host endianness...
+  bool hostIsLittleEndian() const {
+#ifdef LSB_FIRST
+    return true;
+#else
+    return false;
+#endif
+  }
+  bool hostIsBigEndian() const { return !hostIsLittleEndian(); }
+
   /// getStringRepresentation - Return the string representation of the
   /// TargetData.  This representation is in the same format accepted by the
   /// string constructor above.
-- 
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