nbody: eliminate redundant xmmintrin.h include for CPU_SSE_openmp

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
nbody: GPU_AOS_tiled_const should be conditional on __CUDA_ARCH__ >= 300

This makes it match Shuffle, et. al.

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
whitespace: clean up trailing whitespace, convert tabs to spaces

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
nbody: add vim modelines

Tired of whitespace damage.

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
nbody: when built without CUDA, invoke NVCC substitute the same as CXX

Also by default make NVCC=CXX, rather than g++.

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
Revert "drop USE_OPENMP flag, use _OPENMP instead, since it indicates compiler support"

This reverts commit 40ce6e8a977aeb185116419910e2c1fce17c450f.

Since 'nvcc' is the compiler for nbody.cu, it doesn't see the _OPENMP define
which was present in the source compilation of the OpenMP implementation. We
can't depend on the _OPENMP macro's existence to determine how the non-CUDA
portions were compiled.

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
nbody: make template function ComputeGravitation_AOS_tiled static

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
nbody: simplify ComputeGravitation_AOS_tiled inner non-diagonal loop

It did an extra iteration where it wasn't necessary, since we specifically
exclude that iteration from running.

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
nbody_CPU_AOS_tiled: bump tile size to 128x128

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
nbody: parallelize CPU_AOS_tiled with OpenMP

Signed-off-by: Steven Noonan <steven@uplinklabs.net>