[gmx-developers] Simplified and updated OpenCL compilation

[Vedran Miletić]

Hi,

new simplified OpenCL looks nice, aside from one rather minor complaint 
regarding error reporting. With a broken version of Mesa I get

-------------------------------------------------------
Program:     gmx mdrun, version 2016-beta2-dev-20160531-2142182-unknown
Source file: src/gromacs/gpu_utils/ocl_compiler.cpp (line 470)
Function:    _cl_program* gmx::ocl::compileProgram(FILE*, const string&, 
const string&, cl_context, cl_device_id, ocl_vendor_id_t)

Internal error (bug):
Failed to compile NBNXN kernels for GPU #AMD TONGA (DRM 3.1.0 /
4.5.5-300.fc24.x86_64, LLVM 3.9.0)
   Could not build OpenCL program, error was CL_BUILD_PROGRAM_FAILURE

For more information and tips for troubleshooting, please check the GROMACS
website at http://www.gromacs.org/Documentation/Errors
-------------------------------------------------------

Previously I would get some garbage output in place of the 
CL_BUILD_PROGRAM_FAILURE sentence, which is a very nice improvement. 
However, I am missing the content from nbnxn_ocl_kernels.cl.FAILED that 
would contain

Compilation of source file failed!
-- Used build options: -DWARP_SIZE_TEST=64 -D_AMD_SOURCE_ 
-DGMX_OCL_FASTGEN_ADD_TWINCUT -DEL_EWALD_ANA -DEELNAME=_ElecEw 
-DLJ_COMB_GEOM -DVDWNAME=_VdwLJCombGeom -DCENTRAL=22 
-DNBNXN_GPU_NCLUSTER_PER_SUPERCLUSTER=8 -DNBNXN_GPU_CLUSTER_SIZE=8 
-DNBNXN_GPU_JGROUP_SIZE=4 -DNBNXN_AVOID_SING_R2_INC=1.0e-12f 
-DIATYPE_SHMEM -I"/usr/local/gromacs/share/gromacs/opencl"
--------------LOG START---------------
input.cl:59:10: fatal error: 'nbnxn_ocl_kernels_fastgen_add_twincut.clh' 
file not found
input.cl:45:36: note: expanded from macro 'FLAVOR_LEVEL_GENERATOR'
---------------LOG END----------------

These lines are not printed in .log file nor stderr. Can they be printed 
in the log or stderr? I will hopefully need this stuff less and less 
once Mesa is fixed, but it is still nice to know why is your build failing.

Regards,
Vedran

-- 
Vedran Miletić
vedran.miletic.net