one manual patch from upstream Eigen that has not been ported to 3.3.x

Author: yixuan

inst/include/Eigen/src/Core/util/DisableStupidWarnings.h

@@ -4,7 +4,6 @@
 #ifdef _MSC_VER
   // 4100 - unreferenced formal parameter (occurred e.g. in aligned_allocator::destroy(pointer p))
   // 4101 - unreferenced local variable
-  // 4127 - conditional expression is constant
   // 4181 - qualifier applied to reference type ignored
   // 4211 - nonstandard extension used : redefined extern to static
   // 4244 - 'argument' : conversion from 'type1' to 'type2', possible loss of data
@@ -20,7 +19,7 @@
   #ifndef EIGEN_PERMANENTLY_DISABLE_STUPID_WARNINGS
     #pragma warning( push )
   #endif
-  #pragma warning( disable : 4100 4101 4127 4181 4211 4244 4273 4324 4503 4512 4522 4700 4714 4717 4800)
+  #pragma warning( disable : 4100 4101 4181 4211 4244 4273 4324 4503 4512 4522 4700 4714 4717 4800)
 
 #elif defined __INTEL_COMPILER
   // 2196 - routine is both "inline" and "noinline" ("noinline" assumed)
@@ -42,6 +41,9 @@
     #pragma clang diagnostic push
   #endif
   #pragma clang diagnostic ignored "-Wconstant-logical-operand"
+  #if __clang_major__ >= 3 && __clang_minor__ >= 5
+    #pragma clang diagnostic ignored "-Wabsolute-value"
+  #endif
 
 #elif defined __GNUC__ && __GNUC__>=6
 
@@ -53,6 +55,7 @@
 #endif
 
 #if defined __NVCC__
+  #pragma diag_suppress boolean_controlling_expr_is_constant
   // Disable the "statement is unreachable" message
   #pragma diag_suppress code_is_unreachable
   // Disable the "dynamic initialization in unreachable code" message
@@ -70,6 +73,7 @@
   #pragma diag_suppress 2671
   #pragma diag_suppress 2735
   #pragma diag_suppress 2737
+  #pragma diag_suppress 2739
 #endif
 
 #endif // not EIGEN_WARNINGS_DISABLED