OpenSubdiv/examples/common/cudaInit.h

//
//     Copyright (C) Pixar. All rights reserved.
//
//     This license governs use of the accompanying software. If you
//     use the software, you accept this license. If you do not accept
//     the license, do not use the software.
//
//     1. Definitions
//     The terms "reproduce," "reproduction," "derivative works," and
//     "distribution" have the same meaning here as under U.S.
//     copyright law.  A "contribution" is the original software, or
//     any additions or changes to the software.
//     A "contributor" is any person or entity that distributes its
//     contribution under this license.
//     "Licensed patents" are a contributor's patent claims that read
//     directly on its contribution.
//
//     2. Grant of Rights
//     (A) Copyright Grant- Subject to the terms of this license,
//     including the license conditions and limitations in section 3,
//     each contributor grants you a non-exclusive, worldwide,
//     royalty-free copyright license to reproduce its contribution,
//     prepare derivative works of its contribution, and distribute
//     its contribution or any derivative works that you create.
//     (B) Patent Grant- Subject to the terms of this license,
//     including the license conditions and limitations in section 3,
//     each contributor grants you a non-exclusive, worldwide,
//     royalty-free license under its licensed patents to make, have
//     made, use, sell, offer for sale, import, and/or otherwise
//     dispose of its contribution in the software or derivative works
//     of the contribution in the software.
//
//     3. Conditions and Limitations
//     (A) No Trademark License- This license does not grant you
//     rights to use any contributor's name, logo, or trademarks.
//     (B) If you bring a patent claim against any contributor over
//     patents that you claim are infringed by the software, your
//     patent license from such contributor to the software ends
//     automatically.
//     (C) If you distribute any portion of the software, you must
//     retain all copyright, patent, trademark, and attribution
//     notices that are present in the software.
//     (D) If you distribute any portion of the software in source
//     code form, you may do so only under this license by including a
//     complete copy of this license with your distribution. If you
//     distribute any portion of the software in compiled or object
//     code form, you may only do so under a license that complies
//     with this license.
//     (E) The software is licensed "as-is." You bear the risk of
//     using it. The contributors give no express warranties,
//     guarantees or conditions. You may have additional consumer
//     rights under your local laws which this license cannot change.
//     To the extent permitted under your local laws, the contributors
//     exclude the implied warranties of merchantability, fitness for
//     a particular purpose and non-infringement.
//
#ifndef OSD_CUDA_INIT_H
#define OSD_CUDA_INIT_H

// From "NVIDIA GPU Computing SDK 4.2/C/common/inc/cutil_inline_runtime.h":

// Beginning of GPU Architecture definitions
inline int _ConvertSMVer2Cores_local(int major, int minor)
{
    // Defines for GPU Architecture types (using the SM version to determine the # of cores per SM
    typedef struct {
        int SM; // 0xMm (hexidecimal notation), M = SM Major version, and m = SM minor version
        int Cores;
    } sSMtoCores;

    sSMtoCores nGpuArchCoresPerSM[] =
    { { 0x10,  8 }, // Tesla Generation (SM 1.0) G80 class
      { 0x11,  8 }, // Tesla Generation (SM 1.1) G8x class
      { 0x12,  8 }, // Tesla Generation (SM 1.2) G9x class
      { 0x13,  8 }, // Tesla Generation (SM 1.3) GT200 class
      { 0x20, 32 }, // Fermi Generation (SM 2.0) GF100 class
      { 0x21, 48 }, // Fermi Generation (SM 2.1) GF10x class
      { 0x30, 192}, // Fermi Generation (SM 3.0) GK10x class
      {   -1, -1 }
    };

    int index = 0;
    while (nGpuArchCoresPerSM[index].SM != -1) {
        if (nGpuArchCoresPerSM[index].SM == ((major << 4) + minor) ) {
            return nGpuArchCoresPerSM[index].Cores;
        }
        index++;
    }
    printf("MapSMtoCores undefined SMversion %d.%d!\n", major, minor);
    return -1;
}
// end of GPU Architecture definitions

// This function returns the best GPU (with maximum GFLOPS)
inline int cutGetMaxGflopsDeviceId()
{
    int current_device   = 0, sm_per_multiproc = 0;
    int max_compute_perf = 0, max_perf_device  = 0;
    int device_count     = 0, best_SM_arch     = 0;
    cudaDeviceProp deviceProp;

    cudaGetDeviceCount( &device_count );
    // Find the best major SM Architecture GPU device
    while ( current_device < device_count ) {
        cudaGetDeviceProperties( &deviceProp, current_device );
        if (deviceProp.major > 0 && deviceProp.major < 9999) {
            best_SM_arch = std::max(best_SM_arch, deviceProp.major);
        }
        current_device++;
    }

    // Find the best CUDA capable GPU device
    current_device = 0;
    while( current_device < device_count ) {
        cudaGetDeviceProperties( &deviceProp, current_device );
        if (deviceProp.major == 9999 && deviceProp.minor == 9999) {
            sm_per_multiproc = 1;
        } else {
            sm_per_multiproc = _ConvertSMVer2Cores_local(deviceProp.major, deviceProp.minor);
        }
        int compute_perf  = deviceProp.multiProcessorCount * sm_per_multiproc * deviceProp.clockRate;
        if( compute_perf  > max_compute_perf ) {
            // If we find GPU with SM major > 2, search only these
            if ( best_SM_arch > 2 ) {
                // If our device==dest_SM_arch, choose this, or else pass
                if (deviceProp.major == best_SM_arch) {
                    max_compute_perf  = compute_perf;
                    max_perf_device   = current_device;
                }
            } else {
                max_compute_perf  = compute_perf;
                max_perf_device   = current_device;
            }
        }
        ++current_device;
    }
    return max_perf_device;
}

#endif //OSD_CUDA_INIT_H