From 55574053d07b56a342e34e1592d771352e533604 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Tue, 17 May 2011 21:30:12 +0200
Subject: [PATCH] fix bug #267: alloca is not aligned on arm (transplanted from
 179d42bb2b03199d8731a83f24b115d22c16ce20 )

---
 Eigen/src/Core/util/Memory.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Eigen/src/Core/util/Memory.h b/Eigen/src/Core/util/Memory.h
index d00d3aad1..e84c664a9 100644
--- a/Eigen/src/Core/util/Memory.h
+++ b/Eigen/src/Core/util/Memory.h
@@ -529,10 +529,16 @@ template<typename T> class aligned_stack_memory_handler
   */
 #ifdef EIGEN_ALLOCA
 
+  #ifdef __arm__
+    #define EIGEN_ALIGNED_ALLOCA(SIZE) reinterpret_cast<void*>((reinterpret_cast<size_t>(EIGEN_ALLOCA(SIZE+16)) & ~(size_t(15))) + 16)
+  #else
+    #define EIGEN_ALIGNED_ALLOCA EIGEN_ALLOCA
+  #endif
+
   #define ei_declare_aligned_stack_constructed_variable(TYPE,NAME,SIZE,BUFFER) \
     TYPE* NAME = (BUFFER)!=0 ? (BUFFER) \
                : reinterpret_cast<TYPE*>( \
-                      (sizeof(TYPE)*SIZE<=EIGEN_STACK_ALLOCATION_LIMIT) ? EIGEN_ALLOCA(sizeof(TYPE)*SIZE) \
+                      (sizeof(TYPE)*SIZE<=EIGEN_STACK_ALLOCATION_LIMIT) ? EIGEN_ALIGNED_ALLOCA(sizeof(TYPE)*SIZE) \
                     : Eigen::internal::aligned_malloc(sizeof(TYPE)*SIZE) );  \
     Eigen::internal::aligned_stack_memory_handler<TYPE> EIGEN_CAT(NAME,_stack_memory_destructor)((BUFFER)==0 ? NAME : 0,SIZE,sizeof(TYPE)*SIZE>EIGEN_STACK_ALLOCATION_LIMIT)