Implement a better workaround for GCC's bug #87544

1 files changed, 10 insertions, 9 deletions

diff --git a/Eigen/src/Core/util/Memory.h b/Eigen/src/Core/util/Memory.h
index 46a0dbc69..6664770f3 100644
--- a/Eigen/src/Core/util/Memory.h
+++ b/Eigen/src/Core/util/Memory.h
@@ -884,18 +884,19 @@ public:
 
   ~aligned_allocator() {}
 
+  #if EIGEN_COMP_GNUC_STRICT && EIGEN_GNUC_AT_LEAST(7,0)
+  // In gcc std::allocator::max_size() is bugged making gcc triggers a warning:
+  // eigen/Eigen/src/Core/util/Memory.h:189:12: warning: argument 1 value '18446744073709551612' exceeds maximum object size 9223372036854775807
+  // See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87544
+  size_type max_size() const {
+    return (std::numeric_limits<std::ptrdiff_t>::max)()/sizeof(T);
+  }
+  #endif
+
   pointer allocate(size_type num, const void* /*hint*/ = 0)
   {
     internal::check_size_for_overflow<T>(num);
-    size_type size = num * sizeof(T);
-#if EIGEN_COMP_GNUC_STRICT && EIGEN_GNUC_AT_LEAST(7,0)
-    // workaround gcc bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87544
-    // It triggered eigen/Eigen/src/Core/util/Memory.h:189:12: warning: argument 1 value '18446744073709551612' exceeds maximum object size 9223372036854775807
-    if(size>=std::size_t((std::numeric_limits<std::ptrdiff_t>::max)()))
-      return 0;
-    else
-#endif
-      return static_cast<pointer>( internal::aligned_malloc(size) );
+    return static_cast<pointer>( internal::aligned_malloc(num * sizeof(T)) );
   }
 
   void deallocate(pointer p, size_type /*num*/)