diff --git a/benchmarks/Benchmark_dwf.cc b/benchmarks/Benchmark_dwf.cc
index 290bf1df..9ce8f0db 100644
--- a/benchmarks/Benchmark_dwf.cc
+++ b/benchmarks/Benchmark_dwf.cc
@@ -25,7 +25,7 @@ int main (int argc, char ** argv)
 
   std::vector<int> latt4 = GridDefaultLatt();
   const int Ls=8;
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/benchmarks/Benchmark_wilson.cc b/benchmarks/Benchmark_wilson.cc
index 7d1bd8df..aa34ccf4 100644
--- a/benchmarks/Benchmark_wilson.cc
+++ b/benchmarks/Benchmark_wilson.cc
@@ -22,13 +22,16 @@ int main (int argc, char ** argv)
 
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
   GridCartesian               Grid(latt_size,simd_layout,mpi_layout);
   GridRedBlackCartesian     RBGrid(latt_size,simd_layout,mpi_layout);
 
   int threads = GridThread::GetThreads();
   std::cout << "Grid is setup to use "<<threads<<" threads"<<std::endl;
+  std::cout << "Grid floating point word size is REALF"<< sizeof(RealF)<<std::endl;
+  std::cout << "Grid floating point word size is REALD"<< sizeof(RealD)<<std::endl;
+  std::cout << "Grid floating point word size is REAL"<< sizeof(Real)<<std::endl;
 
   std::vector<int> seeds({1,2,3,4});
   GridParallelRNG          pRNG(&Grid);
diff --git a/configure b/configure
index 07b99339..06ca42d5 100755
--- a/configure
+++ b/configure
@@ -751,6 +751,7 @@ enable_silent_rules
 enable_dependency_tracking
 enable_openmp
 enable_simd
+enable_precision
 enable_comms
 enable_doxygen
 enable_dot
@@ -1398,6 +1399,8 @@ Optional Features:
   --enable-simd=SSE4|AVX|AVX2|AVX512|MIC
                           Select instructions to be SSE4.0, AVX 1.0, AVX
                           2.0+FMA, AVX 512, MIC
+  --enable-precision=single|double
+                          Select default word size of Real
   --enable-comms=none|mpi Select communications
   --enable-doxygen        enable documentation generation with doxygen (auto)
   --enable-dot            use 'dot' to generate graphs in doxygen (auto)
@@ -6728,6 +6731,27 @@ $as_echo "#define EMPTY_SIMD 1" >>confdefs.h
      ;;
 esac
 
+# Check whether --enable-precision was given.
+if test "${enable_precision+set}" = set; then :
+  enableval=$enable_precision; ac_PRECISION=${enable_precision}
+else
+  ac_PRECISION=single
+fi
+
+case ${ac_PRECISION} in
+     single)
+       echo default precision is single
+
+$as_echo "#define GRID_DEFAULT_PRECISION_SINGLE 1" >>confdefs.h
+
+     ;;
+     double)
+       echo default precision is double
+
+$as_echo "#define GRID_DEFAULT_PRECISION_DOUBLE 1" >>confdefs.h
+
+     ;;
+esac
 
 # Check whether --enable-comms was given.
 if test "${enable_comms+set}" = set; then :
diff --git a/configure.ac b/configure.ac
index cf0da9eb..5ef6fa8d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -120,6 +120,17 @@ case ${ac_SIMD} in
      ;;
 esac
 
+AC_ARG_ENABLE([precision],[AC_HELP_STRING([--enable-precision=single|double],[Select default word size of Real])],[ac_PRECISION=${enable_precision}],[ac_PRECISION=single])
+case ${ac_PRECISION} in
+     single)
+       echo default precision is single
+       AC_DEFINE([GRID_DEFAULT_PRECISION_SINGLE],[1],[GRID_DEFAULT_PRECISION is SINGLE] )
+     ;;
+     double)
+       echo default precision is double
+       AC_DEFINE([GRID_DEFAULT_PRECISION_DOUBLE],[1],[GRID_DEFAULT_PRECISION is DOUBLE] )
+     ;;
+esac
 
 AC_ARG_ENABLE([comms],[AC_HELP_STRING([--enable-comms=none|mpi],[Select communications])],[ac_COMMS=${enable_comms}],[ac_COMMS=none])
 
diff --git a/lib/GridConfig.h.in b/lib/GridConfig.h.in
index 8ff77f3d..1ec0ecf5 100644
--- a/lib/GridConfig.h.in
+++ b/lib/GridConfig.h.in
@@ -18,6 +18,12 @@
 /* GRID_COMMS_NONE */
 #undef GRID_COMMS_NONE
 
+/* GRID_DEFAULT_PRECISION is DOUBLE */
+#undef GRID_DEFAULT_PRECISION_DOUBLE
+
+/* GRID_DEFAULT_PRECISION is SINGLE */
+#undef GRID_DEFAULT_PRECISION_SINGLE
+
 /* Support Altivec instructions */
 #undef HAVE_ALTIVEC
 
diff --git a/lib/Simd.h b/lib/Simd.h
index 474e5dd3..7da0d7ad 100644
--- a/lib/Simd.h
+++ b/lib/Simd.h
@@ -17,7 +17,6 @@ namespace Grid {
 
   typedef  float  RealF;
   typedef  double RealD;
-#define GRID_DEFAULT_PRECISION_DOUBLE
 #ifdef GRID_DEFAULT_PRECISION_DOUBLE
   typedef RealD   Real;
 #else
diff --git a/tests/Test_GaugeAction.cc b/tests/Test_GaugeAction.cc
index 1ce8306e..612eb693 100644
--- a/tests/Test_GaugeAction.cc
+++ b/tests/Test_GaugeAction.cc
@@ -33,7 +33,7 @@ int main (int argc, char ** argv)
   Grid_init(&argc,&argv);
 
 
-  std::vector<int> simd_layout = GridDefaultSimd(4,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(4,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
   std::vector<int> latt_size  ({16,16,16,32});
   std::vector<int> clatt_size  ({4,4,4,8});
diff --git a/tests/Test_cayley_cg.cc b/tests/Test_cayley_cg.cc
index 32174035..23004be9 100644
--- a/tests/Test_cayley_cg.cc
+++ b/tests/Test_cayley_cg.cc
@@ -55,7 +55,7 @@ int main (int argc, char ** argv)
   std::cout << "Grid is setup to use "<<threads<<" threads"<<std::endl;
 
   const int Ls=8;
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_cayley_coarsen_support.cc b/tests/Test_cayley_coarsen_support.cc
index 72536942..473fa10a 100644
--- a/tests/Test_cayley_coarsen_support.cc
+++ b/tests/Test_cayley_coarsen_support.cc
@@ -23,7 +23,7 @@ int main (int argc, char ** argv)
 
   const int Ls=8;
 
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
 
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
@@ -34,7 +34,7 @@ int main (int argc, char ** argv)
   for(int d=0;d<clatt.size();d++){
     clatt[d] = clatt[d]/2;
   }
-  GridCartesian *Coarse4d =  SpaceTimeGrid::makeFourDimGrid(clatt, GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());;
+  GridCartesian *Coarse4d =  SpaceTimeGrid::makeFourDimGrid(clatt, GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());;
   GridCartesian *Coarse5d =  SpaceTimeGrid::makeFiveDimGrid(1,Coarse4d);
 
   std::vector<int> seeds4({1,2,3,4});
diff --git a/tests/Test_cayley_even_odd.cc b/tests/Test_cayley_even_odd.cc
index 4b5630f7..21c828db 100644
--- a/tests/Test_cayley_even_odd.cc
+++ b/tests/Test_cayley_even_odd.cc
@@ -32,7 +32,7 @@ int main (int argc, char ** argv)
   std::cout << "Grid is setup to use "<<threads<<" threads"<<std::endl;
 
   const int Ls=8;
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_cayley_ldop_cr.cc b/tests/Test_cayley_ldop_cr.cc
index 8926c19c..2e67df26 100644
--- a/tests/Test_cayley_ldop_cr.cc
+++ b/tests/Test_cayley_ldop_cr.cc
@@ -10,7 +10,7 @@ int main (int argc, char ** argv)
 
   const int Ls=8;
 
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
 
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
@@ -23,7 +23,7 @@ int main (int argc, char ** argv)
   for(int d=0;d<clatt.size();d++){
     clatt[d] = clatt[d]/2;
   }
-  GridCartesian *Coarse4d =  SpaceTimeGrid::makeFourDimGrid(clatt, GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());;
+  GridCartesian *Coarse4d =  SpaceTimeGrid::makeFourDimGrid(clatt, GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());;
   GridCartesian *Coarse5d =  SpaceTimeGrid::makeFiveDimGrid(1,Coarse4d);
 
   std::vector<int> seeds4({1,2,3,4});
diff --git a/tests/Test_cf_coarsen_support.cc b/tests/Test_cf_coarsen_support.cc
index 4a4cf3e9..959f5a9b 100644
--- a/tests/Test_cf_coarsen_support.cc
+++ b/tests/Test_cf_coarsen_support.cc
@@ -22,7 +22,7 @@ int main (int argc, char ** argv)
 
   const int Ls=9;
 
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_cf_cr_unprec.cc b/tests/Test_cf_cr_unprec.cc
index e74fc85e..90acb503 100644
--- a/tests/Test_cf_cr_unprec.cc
+++ b/tests/Test_cf_cr_unprec.cc
@@ -22,7 +22,7 @@ int main (int argc, char ** argv)
 
   const int Ls=9;
 
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_contfrac_cg.cc b/tests/Test_contfrac_cg.cc
index 5851f5e6..1b937cef 100644
--- a/tests/Test_contfrac_cg.cc
+++ b/tests/Test_contfrac_cg.cc
@@ -56,7 +56,7 @@ int main (int argc, char ** argv)
   std::cout << "Grid is setup to use "<<threads<<" threads"<<std::endl;
 
   const int Ls=9;
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_contfrac_even_odd.cc b/tests/Test_contfrac_even_odd.cc
index a246b904..5d39b7df 100644
--- a/tests/Test_contfrac_even_odd.cc
+++ b/tests/Test_contfrac_even_odd.cc
@@ -32,7 +32,7 @@ int main (int argc, char ** argv)
   std::cout << "Grid is setup to use "<<threads<<" threads"<<std::endl;
 
   const int Ls=9;
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_cshift.cc b/tests/Test_cshift.cc
index e571a338..cd85439c 100644
--- a/tests/Test_cshift.cc
+++ b/tests/Test_cshift.cc
@@ -8,7 +8,7 @@ int main (int argc, char ** argv)
   Grid_init(&argc,&argv);
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(4,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(4,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
 
   GridCartesian        Fine(latt_size,simd_layout,mpi_layout);
diff --git a/tests/Test_cshift_red_black.cc b/tests/Test_cshift_red_black.cc
index 5cafd04f..79ebcfc5 100644
--- a/tests/Test_cshift_red_black.cc
+++ b/tests/Test_cshift_red_black.cc
@@ -9,7 +9,7 @@ int main (int argc, char ** argv)
 
   std::vector<int> latt_size   = GridDefaultLatt();
   int Nd = latt_size.size();
-  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
 
   std::vector<int> mask(Nd,1);
diff --git a/tests/Test_dwf_cg_prec.cc b/tests/Test_dwf_cg_prec.cc
index 28848ff9..d429ee92 100644
--- a/tests/Test_dwf_cg_prec.cc
+++ b/tests/Test_dwf_cg_prec.cc
@@ -22,7 +22,7 @@ int main (int argc, char ** argv)
 
   const int Ls=8;
 
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_dwf_cg_schur.cc b/tests/Test_dwf_cg_schur.cc
index 8415c489..ac3989d9 100644
--- a/tests/Test_dwf_cg_schur.cc
+++ b/tests/Test_dwf_cg_schur.cc
@@ -22,7 +22,7 @@ int main (int argc, char ** argv)
 
   const int Ls=8;
 
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_dwf_cg_unprec.cc b/tests/Test_dwf_cg_unprec.cc
index f4f63c50..055e1bef 100644
--- a/tests/Test_dwf_cg_unprec.cc
+++ b/tests/Test_dwf_cg_unprec.cc
@@ -22,7 +22,7 @@ int main (int argc, char ** argv)
 
   const int Ls=8;
 
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_dwf_cr_unprec.cc b/tests/Test_dwf_cr_unprec.cc
index 2cf7065c..c2b75853 100644
--- a/tests/Test_dwf_cr_unprec.cc
+++ b/tests/Test_dwf_cr_unprec.cc
@@ -25,7 +25,7 @@ int main (int argc, char ** argv)
 
   const int Ls=8;
 
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_dwf_even_odd.cc b/tests/Test_dwf_even_odd.cc
index 5ec73212..3ad01076 100644
--- a/tests/Test_dwf_even_odd.cc
+++ b/tests/Test_dwf_even_odd.cc
@@ -26,7 +26,7 @@ int main (int argc, char ** argv)
 
 
   const int Ls=8;
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_dwf_fpgcr.cc b/tests/Test_dwf_fpgcr.cc
index a0d6ee96..969377a0 100644
--- a/tests/Test_dwf_fpgcr.cc
+++ b/tests/Test_dwf_fpgcr.cc
@@ -25,7 +25,7 @@ int main (int argc, char ** argv)
 
   const int Ls=8;
 
-  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplexF::Nsimd()),GridDefaultMpi());
+  GridCartesian         * UGrid   = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
   GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
   GridCartesian         * FGrid   = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
   GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
diff --git a/tests/Test_gamma.cc b/tests/Test_gamma.cc
index f4f507a7..1f9cb491 100644
--- a/tests/Test_gamma.cc
+++ b/tests/Test_gamma.cc
@@ -14,7 +14,7 @@ int main (int argc, char ** argv)
   Grid_init(&argc,&argv);
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(4,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(4,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
      
   GridCartesian     Grid(latt_size,simd_layout,mpi_layout);
diff --git a/tests/Test_lie_generators.cc b/tests/Test_lie_generators.cc
index d36e463e..588baeda 100644
--- a/tests/Test_lie_generators.cc
+++ b/tests/Test_lie_generators.cc
@@ -15,7 +15,7 @@ int main (int argc, char ** argv)
 
   std::vector<int> latt({4,4,4,8});
   GridCartesian * grid = SpaceTimeGrid::makeFourDimGrid(latt, 
-							GridDefaultSimd(Nd,vComplexF::Nsimd()),
+							GridDefaultSimd(Nd,vComplex::Nsimd()),
 							GridDefaultMpi());
   
   GridRedBlackCartesian * rbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(grid);
diff --git a/tests/Test_main.cc b/tests/Test_main.cc
index 85450047..295b1981 100644
--- a/tests/Test_main.cc
+++ b/tests/Test_main.cc
@@ -27,7 +27,7 @@ int main (int argc, char ** argv)
   Grid_init(&argc,&argv);
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(4,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(4,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
 
   latt_size.resize(4);
diff --git a/tests/Test_multishift_sqrt.cc b/tests/Test_multishift_sqrt.cc
index 1ecc1fde..3d69fdf1 100644
--- a/tests/Test_multishift_sqrt.cc
+++ b/tests/Test_multishift_sqrt.cc
@@ -56,7 +56,7 @@ int main (int argc, char ** argv)
   Grid_init(&argc,&argv);
 
   GridCartesian *grid = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), 
-						       GridDefaultSimd(Nd,vComplexF::Nsimd()),
+						       GridDefaultSimd(Nd,vComplex::Nsimd()),
 						       GridDefaultMpi());
 
   double     lo=0.001;
diff --git a/tests/Test_quenched_update.cc b/tests/Test_quenched_update.cc
index cb58144b..e419d002 100644
--- a/tests/Test_quenched_update.cc
+++ b/tests/Test_quenched_update.cc
@@ -14,7 +14,7 @@ int main (int argc, char ** argv)
 
   std::vector<int> latt({8,8,8,8});
   GridCartesian * grid = SpaceTimeGrid::makeFourDimGrid(latt, 
-							GridDefaultSimd(Nd,vComplexF::Nsimd()),
+							GridDefaultSimd(Nd,vComplex::Nsimd()),
 							GridDefaultMpi());
   
   GridRedBlackCartesian * rbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(grid);
diff --git a/tests/Test_rng.cc b/tests/Test_rng.cc
index 1731b740..9cd05a22 100644
--- a/tests/Test_rng.cc
+++ b/tests/Test_rng.cc
@@ -9,7 +9,7 @@ int main (int argc, char ** argv)
   Grid_init(&argc,&argv);
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(4,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(4,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
      
   GridCartesian     Grid(latt_size,simd_layout,mpi_layout);
diff --git a/tests/Test_rng_fixed.cc b/tests/Test_rng_fixed.cc
index c836c93f..a4171401 100644
--- a/tests/Test_rng_fixed.cc
+++ b/tests/Test_rng_fixed.cc
@@ -9,7 +9,7 @@ int main (int argc, char ** argv)
   Grid_init(&argc,&argv);
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(4,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(4,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
      
   GridCartesian     Grid(latt_size,simd_layout,mpi_layout);
diff --git a/tests/Test_simd.cc b/tests/Test_simd.cc
index f4858d06..800001be 100644
--- a/tests/Test_simd.cc
+++ b/tests/Test_simd.cc
@@ -185,7 +185,7 @@ int main (int argc, char ** argv)
   Grid_init(&argc,&argv);
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(4,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(4,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
     
   GridCartesian     Grid(latt_size,simd_layout,mpi_layout);
diff --git a/tests/Test_stencil.cc b/tests/Test_stencil.cc
index 9770ed7c..3f6bb4fe 100644
--- a/tests/Test_stencil.cc
+++ b/tests/Test_stencil.cc
@@ -10,7 +10,7 @@ int main (int argc, char ** argv)
 
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
 
   double volume = latt_size[0]*latt_size[1]*latt_size[2]*latt_size[3];
diff --git a/tests/Test_wilson_cg_prec.cc b/tests/Test_wilson_cg_prec.cc
index 6365ee32..c59699e4 100644
--- a/tests/Test_wilson_cg_prec.cc
+++ b/tests/Test_wilson_cg_prec.cc
@@ -22,7 +22,7 @@ int main (int argc, char ** argv)
 
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
   GridCartesian               Grid(latt_size,simd_layout,mpi_layout);
   GridRedBlackCartesian     RBGrid(latt_size,simd_layout,mpi_layout);
diff --git a/tests/Test_wilson_cg_schur.cc b/tests/Test_wilson_cg_schur.cc
index 56abcd4a..1484a6a8 100644
--- a/tests/Test_wilson_cg_schur.cc
+++ b/tests/Test_wilson_cg_schur.cc
@@ -22,7 +22,7 @@ int main (int argc, char ** argv)
 
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
   GridCartesian               Grid(latt_size,simd_layout,mpi_layout);
   GridRedBlackCartesian     RBGrid(latt_size,simd_layout,mpi_layout);
diff --git a/tests/Test_wilson_cg_unprec.cc b/tests/Test_wilson_cg_unprec.cc
index 4e42af42..5984cac9 100644
--- a/tests/Test_wilson_cg_unprec.cc
+++ b/tests/Test_wilson_cg_unprec.cc
@@ -21,7 +21,7 @@ int main (int argc, char ** argv)
   Grid_init(&argc,&argv);
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
   GridCartesian               Grid(latt_size,simd_layout,mpi_layout);
   GridRedBlackCartesian     RBGrid(latt_size,simd_layout,mpi_layout);
diff --git a/tests/Test_wilson_cr_unprec.cc b/tests/Test_wilson_cr_unprec.cc
index 1aa04632..468f0d5a 100644
--- a/tests/Test_wilson_cr_unprec.cc
+++ b/tests/Test_wilson_cr_unprec.cc
@@ -22,7 +22,7 @@ int main (int argc, char ** argv)
 
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
   GridCartesian               Grid(latt_size,simd_layout,mpi_layout);
   GridRedBlackCartesian     RBGrid(latt_size,simd_layout,mpi_layout);
diff --git a/tests/Test_wilson_even_odd.cc b/tests/Test_wilson_even_odd.cc
index 91fbb90f..90d15e99 100644
--- a/tests/Test_wilson_even_odd.cc
+++ b/tests/Test_wilson_even_odd.cc
@@ -21,7 +21,7 @@ int main (int argc, char ** argv)
   Grid_init(&argc,&argv);
 
   std::vector<int> latt_size   = GridDefaultLatt();
-  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplexF::Nsimd());
+  std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
   std::vector<int> mpi_layout  = GridDefaultMpi();
   GridCartesian               Grid(latt_size,simd_layout,mpi_layout);
   GridRedBlackCartesian     RBGrid(latt_size,simd_layout,mpi_layout);
@@ -55,7 +55,9 @@ int main (int argc, char ** argv)
   Umu=zero;
   for(int nn=0;nn<Nd;nn++){
     random(pRNG,U[nn]);
+    std::cout<<"U[nn]"<<norm2(U[nn])<<std::endl;
     PokeIndex<LorentzIndex>(Umu,U[nn],nn);
+    std::cout<<"Umu"<<norm2(Umu)<<std::endl;
   }
 
   RealD mass=0.1;