commit 0a70fa595953ff1e6e46266d7f86bc6d7e3400a4
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Sep 16 17:36:44 2016 +0100

    Replace modulus with mask operation in over-aligned new
    
    2016-09-16  Jonathan Wakely  <jwakely@redhat.com>
    	    Marc Glisse  <marc.glisse@inria.fr>
    
    	* libsupc++/new_opa.cc [_GLIBCXX_HAVE_ALIGNED_ALLOC]
    	(operator new(size_t, align_val_t)): Replace modulus operator with
    	mask.

diff --git a/libstdc++-v3/libsupc++/new_opa.cc b/libstdc++-v3/libsupc++/new_opa.cc
index 9c859c1..91e53a8 100644
--- a/libstdc++-v3/libsupc++/new_opa.cc
+++ b/libstdc++-v3/libsupc++/new_opa.cc
@@ -69,7 +69,7 @@ operator new (std::size_t sz, std::align_val_t al)
 
 #if _GLIBCXX_HAVE_ALIGNED_ALLOC
   /* C11: the value of size shall be an integral multiple of alignment.  */
-  if (std::size_t rem = sz % align)
+  if (std::size_t rem = sz & (align - 1))
     sz += align - rem;
 #endif