ocl.c

/*
 * Copyright 2011-2012 Con Kolivas
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 3 of the License, or (at your option)
 * any later version.  See COPYING for more details.
 */

#include "config.h"
#ifdef HAVE_OPENCL

#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <limits.h>
#include <sys/types.h>

#ifdef WIN32
    #include <winsock2.h>
#else
    #include <sys/socket.h>
    #include <netinet/in.h>
    #include <netdb.h>
#endif

#include <time.h>
#include <sys/time.h>
#include <pthread.h>
#include <sys/stat.h>
#include <unistd.h>

#include "findnonce.h"
#include "ocl.h"

int opt_platform_id = -1;

char *file_contents(const char *filename, int *length)
{
    char *fullpath = alloca(PATH_MAX);
    void *buffer;
    FILE *f;

    strcpy(fullpath, opt_kernel_path);
    strcat(fullpath, filename);

    /* Try in the optional kernel path or installed prefix first */
    f = fopen(fullpath, "rb");
    if (!f) {
        /* Then try from the path cgminer was called */
        strcpy(fullpath, cgminer_path);
        strcat(fullpath, filename);
        f = fopen(fullpath, "rb");
    }
    /* Finally try opening it directly */
    if (!f)
        f = fopen(filename, "rb");

    if (!f) {
        applog(LOG_ERR, "Unable to open %s or %s for reading", filename, fullpath);
        return NULL;
    }

    fseek(f, 0, SEEK_END);
    *length = ftell(f);
    fseek(f, 0, SEEK_SET);

    buffer = malloc(*length+1);
    *length = fread(buffer, 1, *length, f);
    fclose(f);
    ((char*)buffer)[*length] = '\0';

    return (char*)buffer;
}

int clDevicesNum(void) {
    cl_int status;
    char pbuff[256];
    cl_uint numDevices;
    cl_uint numPlatforms;
    int most_devices = -1;
    cl_platform_id *platforms;
    cl_platform_id platform = NULL;
    unsigned int i, mdplatform = 0;

    status = clGetPlatformIDs(0, NULL, &numPlatforms);
    /* If this fails, assume no GPUs. */
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: clGetPlatformsIDs failed (no OpenCL SDK installed?)", status);
        return -1;
    }

    if (numPlatforms == 0) {
        applog(LOG_ERR, "clGetPlatformsIDs returned no platforms (no OpenCL SDK installed?)");
        return -1;
    }

    platforms = (cl_platform_id *)alloca(numPlatforms*sizeof(cl_platform_id));
    status = clGetPlatformIDs(numPlatforms, platforms, NULL);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Getting Platform Ids. (clGetPlatformsIDs)", status);
        return -1;
    }

    for (i = 0; i < numPlatforms; i++) {
        if (opt_platform_id >= 0 && (int)i != opt_platform_id)
            continue;

        status = clGetPlatformInfo( platforms[i], CL_PLATFORM_VENDOR, sizeof(pbuff), pbuff, NULL);
        if (status != CL_SUCCESS) {
            applog(LOG_ERR, "Error %d: Getting Platform Info. (clGetPlatformInfo)", status);
            return -1;
        }
        platform = platforms[i];
        applog(LOG_INFO, "CL Platform %d vendor: %s", i, pbuff);
        status = clGetPlatformInfo(platform, CL_PLATFORM_NAME, sizeof(pbuff), pbuff, NULL);
        if (status == CL_SUCCESS)
            applog(LOG_INFO, "CL Platform %d name: %s", i, pbuff);
        status = clGetPlatformInfo(platform, CL_PLATFORM_VERSION, sizeof(pbuff), pbuff, NULL);
        if (status == CL_SUCCESS)
            applog(LOG_INFO, "CL Platform %d version: %s", i, pbuff);
        status = clGetDeviceIDs(platform, CL_DEVICE_TYPE_GPU, 0, NULL, &numDevices);
        if (status != CL_SUCCESS) {
            applog(LOG_INFO, "Error %d: Getting Device IDs (num)", status);
            continue;
        }
        applog(LOG_INFO, "Platform %d devices: %d", i, numDevices);
        if ((int)numDevices > most_devices) {
            most_devices = numDevices;
            mdplatform = i;
        }
        if (numDevices) {
            unsigned int j;
            cl_device_id *devices = (cl_device_id *)malloc(numDevices*sizeof(cl_device_id));

            clGetDeviceIDs(platform, CL_DEVICE_TYPE_GPU, numDevices, devices, NULL);
            for (j = 0; j < numDevices; j++) {
                clGetDeviceInfo(devices[j], CL_DEVICE_NAME, sizeof(pbuff), pbuff, NULL);
                applog(LOG_INFO, "\t%i\t%s", j, pbuff);
            }
            free(devices);
        }
    }

    if (opt_platform_id < 0)
        opt_platform_id = mdplatform;;

    return most_devices;
}

static int advance(char **area, unsigned *remaining, const char *marker)
{
    char *find = memmem(*area, *remaining, marker, strlen(marker));

    if (!find) {
        applog(LOG_DEBUG, "Marker \"%s\" not found", marker);
        return 0;
    }
    *remaining -= find - *area;
    *area = find;
    return 1;
}

#define OP3_INST_BFE_UINT   4ULL
#define OP3_INST_BFE_INT    5ULL
#define OP3_INST_BFI_INT    6ULL
#define OP3_INST_BIT_ALIGN_INT  12ULL
#define OP3_INST_BYTE_ALIGN_INT 13ULL

void patch_opcodes(char *w, unsigned remaining)
{
    uint64_t *opcode = (uint64_t *)w;
    int patched = 0;
    int count_bfe_int = 0;
    int count_bfe_uint = 0;
    int count_byte_align = 0;
    while (42) {
        int clamp = (*opcode >> (32 + 31)) & 0x1;
        int dest_rel = (*opcode >> (32 + 28)) & 0x1;
        int alu_inst = (*opcode >> (32 + 13)) & 0x1f;
        int s2_neg = (*opcode >> (32 + 12)) & 0x1;
        int s2_rel = (*opcode >> (32 + 9)) & 0x1;
        int pred_sel = (*opcode >> 29) & 0x3;
        if (!clamp && !dest_rel && !s2_neg && !s2_rel && !pred_sel) {
            if (alu_inst == OP3_INST_BFE_INT) {
                count_bfe_int++;
            } else if (alu_inst == OP3_INST_BFE_UINT) {
                count_bfe_uint++;
            } else if (alu_inst == OP3_INST_BYTE_ALIGN_INT) {
                count_byte_align++;
                // patch this instruction to BFI_INT
                *opcode &= 0xfffc1fffffffffffULL;
                *opcode |= OP3_INST_BFI_INT << (32 + 13);
                patched++;
            }
        }
        if (remaining <= 8)
            break;
        opcode++;
        remaining -= 8;
    }
    applog(LOG_DEBUG, "Potential OP3 instructions identified: "
        "%i BFE_INT, %i BFE_UINT, %i BYTE_ALIGN",
        count_bfe_int, count_bfe_uint, count_byte_align);
    applog(LOG_DEBUG, "Patched a total of %i BFI_INT instructions", patched);
}

_clState *initCl(unsigned int gpu, char *name, size_t nameSize)
{
    _clState *clState = calloc(1, sizeof(_clState));
    bool patchbfi = false, prog_built = false;
    struct cgpu_info *cgpu = &gpus[gpu];
    cl_platform_id platform = NULL;
    char pbuff[256], vbuff[255];
    cl_platform_id* platforms;
    cl_uint preferred_vwidth;
    cl_device_id *devices;
    cl_uint numPlatforms;
    cl_uint numDevices;
    cl_int status;

    status = clGetPlatformIDs(0, NULL, &numPlatforms);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Getting Platforms. (clGetPlatformsIDs)", status);
        return NULL;
    }

    platforms = (cl_platform_id *)alloca(numPlatforms*sizeof(cl_platform_id));
    status = clGetPlatformIDs(numPlatforms, platforms, NULL);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Getting Platform Ids. (clGetPlatformsIDs)", status);
        return NULL;
    }

    if (opt_platform_id >= (int)numPlatforms) {
        applog(LOG_ERR, "Specified platform that does not exist");
        return NULL;
    }

    status = clGetPlatformInfo(platforms[opt_platform_id], CL_PLATFORM_VENDOR, sizeof(pbuff), pbuff, NULL);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Getting Platform Info. (clGetPlatformInfo)", status);
        return NULL;
    }
    platform = platforms[opt_platform_id];

    if (platform == NULL) {
        perror("NULL platform found!\n");
        return NULL;
    }

    applog(LOG_INFO, "CL Platform vendor: %s", pbuff);
    status = clGetPlatformInfo(platform, CL_PLATFORM_NAME, sizeof(pbuff), pbuff, NULL);
    if (status == CL_SUCCESS)
        applog(LOG_INFO, "CL Platform name: %s", pbuff);
    status = clGetPlatformInfo(platform, CL_PLATFORM_VERSION, sizeof(vbuff), vbuff, NULL);
    if (status == CL_SUCCESS)
        applog(LOG_INFO, "CL Platform version: %s", vbuff);

    status = clGetDeviceIDs(platform, CL_DEVICE_TYPE_GPU, 0, NULL, &numDevices);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Getting Device IDs (num)", status);
        return NULL;
    }

    if (numDevices > 0 ) {
        devices = (cl_device_id *)malloc(numDevices*sizeof(cl_device_id));

        /* Now, get the device list data */

        status = clGetDeviceIDs(platform, CL_DEVICE_TYPE_GPU, numDevices, devices, NULL);
        if (status != CL_SUCCESS) {
            applog(LOG_ERR, "Error %d: Getting Device IDs (list)", status);
            return NULL;
        }

        applog(LOG_INFO, "List of devices:");

        unsigned int i;
        for (i = 0; i < numDevices; i++) {
            status = clGetDeviceInfo(devices[i], CL_DEVICE_NAME, sizeof(pbuff), pbuff, NULL);
            if (status != CL_SUCCESS) {
                applog(LOG_ERR, "Error %d: Getting Device Info", status);
                return NULL;
            }

            applog(LOG_INFO, "\t%i\t%s", i, pbuff);
        }

        if (gpu < numDevices) {
            status = clGetDeviceInfo(devices[gpu], CL_DEVICE_NAME, sizeof(pbuff), pbuff, NULL);
            if (status != CL_SUCCESS) {
                applog(LOG_ERR, "Error %d: Getting Device Info", status);
                return NULL;
            }

            applog(LOG_INFO, "Selected %i: %s", gpu, pbuff);
            strncpy(name, pbuff, nameSize);
        } else {
            applog(LOG_ERR, "Invalid GPU %i", gpu);
            return NULL;
        }

    } else return NULL;

    cl_context_properties cps[3] = { CL_CONTEXT_PLATFORM, (cl_context_properties)platform, 0 };

    clState->context = clCreateContextFromType(cps, CL_DEVICE_TYPE_GPU, NULL, NULL, &status);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Creating Context. (clCreateContextFromType)", status);
        return NULL;
    }

    /////////////////////////////////////////////////////////////////
    // Create an OpenCL command queue
    /////////////////////////////////////////////////////////////////
    clState->commandQueue = clCreateCommandQueue(clState->context, devices[gpu],
                             CL_QUEUE_OUT_OF_ORDER_EXEC_MODE_ENABLE, &status);
    if (status != CL_SUCCESS) /* Try again without OOE enable */
        clState->commandQueue = clCreateCommandQueue(clState->context, devices[gpu], 0 , &status);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Creating Command Queue. (clCreateCommandQueue)", status);
        return NULL;
    }

    /* Check for BFI INT support. Hopefully people don't mix devices with
     * and without it! */
    char * extensions = malloc(1024);
    const char * camo = "cl_amd_media_ops";
    char *find;

    status = clGetDeviceInfo(devices[gpu], CL_DEVICE_EXTENSIONS, 1024, (void *)extensions, NULL);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Failed to clGetDeviceInfo when trying to get CL_DEVICE_EXTENSIONS", status);
        return NULL;
    }
    find = strstr(extensions, camo);
    if (find)
        clState->hasBitAlign = true;
        
    /* Check for OpenCL >= 1.0 support, needed for global offset parameter usage. */
    char * devoclver = malloc(1024);
    const char * ocl10 = "OpenCL 1.0";
    const char * ocl11 = "OpenCL 1.1";

    status = clGetDeviceInfo(devices[gpu], CL_DEVICE_VERSION, 1024, (void *)devoclver, NULL);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Failed to clGetDeviceInfo when trying to get CL_DEVICE_VERSION", status);
        return NULL;
    }
    find = strstr(devoclver, ocl10);
    if (!find) {
        clState->hasOpenCL11plus = true;
        find = strstr(devoclver, ocl11);
        if (!find)
            clState->hasOpenCL12plus = true;
    }

    status = clGetDeviceInfo(devices[gpu], CL_DEVICE_PREFERRED_VECTOR_WIDTH_INT, sizeof(cl_uint), (void *)&preferred_vwidth, NULL);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Failed to clGetDeviceInfo when trying to get CL_DEVICE_PREFERRED_VECTOR_WIDTH_INT", status);
        return NULL;
    }
    applog(LOG_DEBUG, "Preferred vector width reported %d", preferred_vwidth);

    status = clGetDeviceInfo(devices[gpu], CL_DEVICE_MAX_WORK_GROUP_SIZE, sizeof(size_t), (void *)&clState->max_work_size, NULL);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Failed to clGetDeviceInfo when trying to get CL_DEVICE_MAX_WORK_GROUP_SIZE", status);
        return NULL;
    }
    applog(LOG_DEBUG, "Max work group size reported %d", (int)(clState->max_work_size));
    
    size_t compute_units = 0;
    status = clGetDeviceInfo(devices[gpu], CL_DEVICE_MAX_COMPUTE_UNITS, sizeof(size_t), (void *)&compute_units, NULL);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Failed to clGetDeviceInfo when trying to get CL_DEVICE_MAX_COMPUTE_UNITS", status);
        return NULL;
    }
    // AMD architechture got 64 compute shaders per compute unit.
    // Source: http://www.amd.com/us/Documents/GCN_Architecture_whitepaper.pdf
    clState->compute_shaders = compute_units * 64;
    applog(LOG_DEBUG, "Max shaders calculated %d", (int)(clState->compute_shaders));

    status = clGetDeviceInfo(devices[gpu], CL_DEVICE_MAX_MEM_ALLOC_SIZE , sizeof(cl_ulong), (void *)&cgpu->max_alloc, NULL);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Failed to clGetDeviceInfo when trying to get CL_DEVICE_MAX_MEM_ALLOC_SIZE", status);
        return NULL;
    }
    applog(LOG_DEBUG, "Max mem alloc size is %lu", (long unsigned int)(cgpu->max_alloc));

    /* Create binary filename based on parameters passed to opencl
     * compiler to ensure we only load a binary that matches what would
     * have otherwise created. The filename is:
     * name + kernelname +/- g(offset) + v + vectors + w + work_size + l + sizeof(long) + .bin
     * For scrypt the filename is:
     * name + kernelname + g + lg + lookup_gap + tc + thread_concurrency + w + work_size + l + sizeof(long) + .bin
     */
    char binaryfilename[255];
    char filename[255];
    char numbuf[16];

    if (cgpu->kernel == KL_NONE) {
        if (opt_scrypt) {
            applog(LOG_INFO, "Selecting scrypt kernel");
            clState->chosen_kernel = KL_SCRYPT;
        } else if (opt_keccak) {
            applog(LOG_INFO, "Selecting keccak kernel");
            clState->chosen_kernel = KL_KECCAK;
        } else if (opt_skein) {
            applog(LOG_INFO, "Selecting skein kernel");
            clState->chosen_kernel = KL_SKEIN;
        } else if (opt_heavy) {
            applog(LOG_INFO, "Selecting heavy kernel");
            clState->chosen_kernel = KL_HEAVY;
        } else if (opt_hefty) {
            applog(LOG_INFO, "Selecting hefty kernel");
            clState->chosen_kernel = KL_HEFTY;
        } else if (!strstr(name, "Tahiti") &&
            /* Detect all 2.6 SDKs not with Tahiti and use diablo kernel */
            (strstr(vbuff, "844.4") ||  // Linux 64 bit ATI 2.6 SDK
             strstr(vbuff, "851.4") ||  // Windows 64 bit ""
             strstr(vbuff, "831.4") ||
             strstr(vbuff, "898.1") ||  // 12.2 driver SDK 
             strstr(vbuff, "923.1") ||  // 12.4
             strstr(vbuff, "938.2") ||  // SDK 2.7
             strstr(vbuff, "1113.2"))) {// SDK 2.8
                applog(LOG_INFO, "Selecting diablo kernel");
                clState->chosen_kernel = KL_DIABLO;
        /* Detect all 7970s, older ATI and NVIDIA and use poclbm */
        } else if (strstr(name, "Tahiti") || !clState->hasBitAlign) {
            applog(LOG_INFO, "Selecting poclbm kernel");
            clState->chosen_kernel = KL_POCLBM;
        /* Use phatk for the rest R5xxx R6xxx */
        } else {
            applog(LOG_INFO, "Selecting phatk kernel");
            clState->chosen_kernel = KL_PHATK;
        }
        cgpu->kernel = clState->chosen_kernel;
    } else {
        clState->chosen_kernel = cgpu->kernel;
        if (clState->chosen_kernel == KL_PHATK &&
            (strstr(vbuff, "844.4") || strstr(vbuff, "851.4") ||
             strstr(vbuff, "831.4") || strstr(vbuff, "898.1") ||
             strstr(vbuff, "923.1") || strstr(vbuff, "938.2") ||
             strstr(vbuff, "1113.2"))) {
            applog(LOG_WARNING, "WARNING: You have selected the phatk kernel.");
            applog(LOG_WARNING, "You are running SDK 2.6+ which performs poorly with this kernel.");
            applog(LOG_WARNING, "Downgrade your SDK and delete any .bin files before starting again.");
            applog(LOG_WARNING, "Or allow cgminer to automatically choose a more suitable kernel.");
        }
    }

    /* For some reason 2 vectors is still better even if the card says
     * otherwise, and many cards lie about their max so use 256 as max
     * unless explicitly set on the command line. Tahiti prefers 1 */
    if (strstr(name, "Tahiti"))
        preferred_vwidth = 1;
    else if (preferred_vwidth > 2)
        preferred_vwidth = 2;

    if (cgpu->cl_filename) {
        strcpy(filename, cgpu->cl_filename);
        strcat(filename, ".cl");
        strcpy(binaryfilename, cgpu->cl_filename);
        applog(LOG_WARNING, "GPU %d using cl_filename: %s", cgpu->device_id, filename);
        /* Scrypt only supports vector 1 */
        if ((clState->chosen_kernel) == KL_SCRYPT)
            cgpu->vwidth = 1;
    } else {
        switch (clState->chosen_kernel) {
            case KL_POCLBM:
                strcpy(filename, POCLBM_KERNNAME".cl");
                strcpy(binaryfilename, POCLBM_KERNNAME);
                break;
            case KL_PHATK:
                strcpy(filename, PHATK_KERNNAME".cl");
                strcpy(binaryfilename, PHATK_KERNNAME);
                break;
            case KL_DIAKGCN:
                strcpy(filename, DIAKGCN_KERNNAME".cl");
                strcpy(binaryfilename, DIAKGCN_KERNNAME);
                break;
            case KL_SCRYPT:
                strcpy(filename, SCRYPT_KERNNAME".cl");
                strcpy(binaryfilename, SCRYPT_KERNNAME);
                /* Scrypt only supports vector 1 */
                cgpu->vwidth = 1;
                break;
            case KL_KECCAK:
                strcpy(filename, KECCAK_KERNNAME".cl");
                strcpy(binaryfilename, KECCAK_KERNNAME);
                /* Keccak only supports vector 1 */
                cgpu->vwidth = 1;
                break;
            case KL_SKEIN:
                strcpy(filename, SKEIN_KERNNAME".cl");
                strcpy(binaryfilename, SKEIN_KERNNAME);
                cgpu->vwidth = 1;
                break;
            case KL_HEAVY:
                strcpy(filename, HEAVY_KERNNAME".cl");
                strcpy(binaryfilename, HEAVY_KERNNAME);
                cgpu->vwidth = 1;
                break;
            case KL_HEFTY:
                strcpy(filename, HEFTY_KERNNAME".cl");
                strcpy(binaryfilename, HEFTY_KERNNAME);
                cgpu->vwidth = 1;
                break;
            case KL_NONE: /* Shouldn't happen */
            case KL_DIABLO:
                strcpy(filename, DIABLO_KERNNAME".cl");
                strcpy(binaryfilename, DIABLO_KERNNAME);
                break;
        }
    }

    if (cgpu->vwidth)
        clState->vwidth = cgpu->vwidth;
    else {
        clState->vwidth = preferred_vwidth;
        cgpu->vwidth = preferred_vwidth;
    }

    if (((clState->chosen_kernel == KL_POCLBM || clState->chosen_kernel == KL_DIABLO || clState->chosen_kernel == KL_DIAKGCN) &&
        clState->vwidth == 1 && clState->hasOpenCL11plus) || opt_scrypt || opt_keccak || opt_skein || opt_heavy || opt_hefty)
            clState->goffset = true;

    if (cgpu->work_size && cgpu->work_size <= clState->max_work_size)
        clState->wsize = cgpu->work_size;
    else if (opt_scrypt)
        clState->wsize = 256;
    else if (strstr(name, "Tahiti"))
        clState->wsize = 64;
    else
        clState->wsize = (clState->max_work_size <= 256 ? clState->max_work_size : 256) / clState->vwidth;
    cgpu->work_size = clState->wsize;

#ifdef USE_SCRYPT
    if (opt_scrypt) {
        if (!cgpu->opt_lg) {
            applog(LOG_DEBUG, "GPU %d: selecting lookup gap of 2", gpu);
            cgpu->lookup_gap = 2;
        } else
            cgpu->lookup_gap = cgpu->opt_lg;

        if (!cgpu->opt_tc) {
            unsigned int sixtyfours;

            sixtyfours =  cgpu->max_alloc / 131072 / 64 - 1;
            cgpu->thread_concurrency = sixtyfours * 64;
            if (cgpu->shaders && cgpu->thread_concurrency > cgpu->shaders) {
                cgpu->thread_concurrency -= cgpu->thread_concurrency % cgpu->shaders;
                if (cgpu->thread_concurrency > cgpu->shaders * 5)
                    cgpu->thread_concurrency = cgpu->shaders * 5;
            }
            applog(LOG_DEBUG, "GPU %d: selecting thread concurrency of %d", gpu, (int)(cgpu->thread_concurrency));
        } else
            cgpu->thread_concurrency = cgpu->opt_tc;
    }
#endif

    FILE *binaryfile;
    size_t *binary_sizes;
    char **binaries;
    int pl;
    char *source = file_contents(filename, &pl);
    size_t sourceSize[] = {(size_t)pl};
    cl_uint slot, cpnd;

    slot = cpnd = 0;

    if (!source)
        return NULL;

    binary_sizes = calloc(sizeof(size_t) * MAX_GPUDEVICES * 4, 1);
    if (unlikely(!binary_sizes)) {
        applog(LOG_ERR, "Unable to calloc binary_sizes");
        return NULL;
    }
    binaries = calloc(sizeof(char *) * MAX_GPUDEVICES * 4, 1);
    if (unlikely(!binaries)) {
        applog(LOG_ERR, "Unable to calloc binaries");
        return NULL;
    }

    strcat(binaryfilename, name);
    if (clState->goffset)
        strcat(binaryfilename, "g");
    if (opt_scrypt) {
#ifdef USE_SCRYPT
        sprintf(numbuf, "lg%utc%u", cgpu->lookup_gap, (unsigned int)cgpu->thread_concurrency);
        strcat(binaryfilename, numbuf);
#endif
    } else {
        sprintf(numbuf, "v%d", clState->vwidth);
        strcat(binaryfilename, numbuf);
    }
    sprintf(numbuf, "w%d", (int)clState->wsize);
    strcat(binaryfilename, numbuf);
    sprintf(numbuf, "l%d", (int)sizeof(long));
    strcat(binaryfilename, numbuf);
    strcat(binaryfilename, ".bin");

    binaryfile = fopen(binaryfilename, "rb");
    if (!binaryfile) {
        applog(LOG_DEBUG, "No binary found, generating from source");
    } else {
        struct stat binary_stat;

        if (unlikely(stat(binaryfilename, &binary_stat))) {
            applog(LOG_DEBUG, "Unable to stat binary, generating from source");
            fclose(binaryfile);
            goto build;
        }
        if (!binary_stat.st_size)
            goto build;

        binary_sizes[slot] = binary_stat.st_size;
        binaries[slot] = (char *)calloc(binary_sizes[slot], 1);
        if (unlikely(!binaries[slot])) {
            applog(LOG_ERR, "Unable to calloc binaries");
            fclose(binaryfile);
            return NULL;
        }

        if (fread(binaries[slot], 1, binary_sizes[slot], binaryfile) != binary_sizes[slot]) {
            applog(LOG_ERR, "Unable to fread binaries");
            fclose(binaryfile);
            free(binaries[slot]);
            goto build;
        }

        clState->program = clCreateProgramWithBinary(clState->context, 1, &devices[gpu], &binary_sizes[slot], (const unsigned char **)binaries, &status, NULL);
        if (status != CL_SUCCESS) {
            applog(LOG_ERR, "Error %d: Loading Binary into cl_program (clCreateProgramWithBinary)", status);
            fclose(binaryfile);
            free(binaries[slot]);
            goto build;
        }

        fclose(binaryfile);
        applog(LOG_DEBUG, "Loaded binary image %s", binaryfilename);

        goto built;
    }

    /////////////////////////////////////////////////////////////////
    // Load CL file, build CL program object, create CL kernel object
    /////////////////////////////////////////////////////////////////

build:
    clState->program = clCreateProgramWithSource(clState->context, 1, (const char **)&source, sourceSize, &status);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Loading Binary into cl_program (clCreateProgramWithSource)", status);
        return NULL;
    }

    /* create a cl program executable for all the devices specified */
    char *CompilerOptions = calloc(1, 256);

#ifdef USE_SCRYPT
    if (opt_scrypt)
        sprintf(CompilerOptions, "-D LOOKUP_GAP=%d -D CONCURRENT_THREADS=%d -D WORKSIZE=%d",
            cgpu->lookup_gap, (unsigned int)cgpu->thread_concurrency, (int)clState->wsize);
    else
#endif
    {
        sprintf(CompilerOptions, "-D WORKSIZE=%d -D VECTORS%d -D WORKVEC=%d",
            (int)clState->wsize, clState->vwidth, (int)clState->wsize * clState->vwidth);
    }
    applog(LOG_DEBUG, "Setting worksize to %d", (int)(clState->wsize));
    if (clState->vwidth > 1)
        applog(LOG_DEBUG, "Patched source to suit %d vectors", clState->vwidth);

    if (clState->hasBitAlign && !opt_keccak && !opt_skein) {
        strcat(CompilerOptions, " -D BITALIGN");
        applog(LOG_DEBUG, "cl_amd_media_ops found, setting BITALIGN");
        if (!clState->hasOpenCL12plus &&
            (strstr(name, "Cedar") ||
             strstr(name, "Redwood") ||
             strstr(name, "Juniper") ||
             strstr(name, "Cypress" ) ||
             strstr(name, "Hemlock" ) ||
             strstr(name, "Caicos" ) ||
             strstr(name, "Turks" ) ||
             strstr(name, "Barts" ) ||
             strstr(name, "Cayman" ) ||
             strstr(name, "Antilles" ) ||
             strstr(name, "Wrestler" ) ||
             strstr(name, "Zacate" ) ||
             strstr(name, "WinterPark" )))
            patchbfi = true;
    } else
        applog(LOG_DEBUG, "cl_amd_media_ops not found, will not set BITALIGN");

    if (patchbfi) {
        strcat(CompilerOptions, " -D BFI_INT");
        applog(LOG_DEBUG, "BFI_INT patch requiring device found, patched source with BFI_INT");
    } else
        applog(LOG_DEBUG, "BFI_INT patch requiring device not found, will not BFI_INT patch");

    if (clState->goffset)
        strcat(CompilerOptions, " -D GOFFSET");

    if (!clState->hasOpenCL11plus)
        strcat(CompilerOptions, " -D OCL1");
#if defined(USE_HEAVY) || defined(USE_HEFTY)
    if ((opt_heavy || opt_hefty)&& strstr(name, "Cedar") ||
             strstr(name, "Redwood") ||
             strstr(name, "Juniper") ||
             strstr(name, "Cypress" ) ||
             strstr(name, "Hemlock" ) ||
             strstr(name, "Caicos" ) ||
             strstr(name, "Turks" ) ||
             strstr(name, "Barts" ) ||
             strstr(name, "Cayman" ) ||
             strstr(name, "Antilles" ) ||
             strstr(name, "Wrestler" ) ||
             strstr(name, "Zacate" ) ||
             strstr(name, "WinterPark" )) {
        applog(LOG_DEBUG, "Const-to-local copy broken on device, disabling");
        strcat(CompilerOptions, " -D BROKEN_LOCAL");
    }
#endif

    applog(LOG_DEBUG, "CompilerOptions: %s", CompilerOptions);
    status = clBuildProgram(clState->program, 1, &devices[gpu], CompilerOptions , NULL, NULL);
    free(CompilerOptions);

    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Building Program (clBuildProgram)", status);
        size_t logSize;
        status = clGetProgramBuildInfo(clState->program, devices[gpu], CL_PROGRAM_BUILD_LOG, 0, NULL, &logSize);

        char *log = malloc(logSize);
        status = clGetProgramBuildInfo(clState->program, devices[gpu], CL_PROGRAM_BUILD_LOG, logSize, log, NULL);
        applog(LOG_ERR, "%s", log);
        return NULL;
    }

    prog_built = true;

#ifdef __APPLE__
    /* OSX OpenCL breaks reading off binaries with >1 GPU so always build
     * from source. */
    goto built;
#endif

    status = clGetProgramInfo(clState->program, CL_PROGRAM_NUM_DEVICES, sizeof(cl_uint), &cpnd, NULL);
    if (unlikely(status != CL_SUCCESS)) {
        applog(LOG_ERR, "Error %d: Getting program info CL_PROGRAM_NUM_DEVICES. (clGetProgramInfo)", status);
        return NULL;
    }

    status = clGetProgramInfo(clState->program, CL_PROGRAM_BINARY_SIZES, sizeof(size_t)*cpnd, binary_sizes, NULL);
    if (unlikely(status != CL_SUCCESS)) {
        applog(LOG_ERR, "Error %d: Getting program info CL_PROGRAM_BINARY_SIZES. (clGetProgramInfo)", status);
        return NULL;
    }

    /* The actual compiled binary ends up in a RANDOM slot! Grr, so we have
     * to iterate over all the binary slots and find where the real program
     * is. What the heck is this!? */
    for (slot = 0; slot < cpnd; slot++)
        if (binary_sizes[slot])
            break;

    /* copy over all of the generated binaries. */
    applog(LOG_DEBUG, "Binary size for gpu %d found in binary slot %d: %d", gpu, slot, (int)(binary_sizes[slot]));
    if (!binary_sizes[slot]) {
        applog(LOG_ERR, "OpenCL compiler generated a zero sized binary, FAIL!");
        return NULL;
    }
    binaries[slot] = calloc(sizeof(char) * binary_sizes[slot], 1);
    status = clGetProgramInfo(clState->program, CL_PROGRAM_BINARIES, sizeof(char *) * cpnd, binaries, NULL );
    if (unlikely(status != CL_SUCCESS)) {
        applog(LOG_ERR, "Error %d: Getting program info. CL_PROGRAM_BINARIES (clGetProgramInfo)", status);
        return NULL;
    }

    /* Patch the kernel if the hardware supports BFI_INT but it needs to
     * be hacked in */
    if (patchbfi && !(opt_heavy || opt_hefty)) {
        unsigned remaining = binary_sizes[slot];
        char *w = binaries[slot];
        unsigned int start, length;

        /* Find 2nd incidence of .text, and copy the program's
        * position and length at a fixed offset from that. Then go
        * back and find the 2nd incidence of \x7ELF (rewind by one
        * from ELF) and then patch the opcocdes */
        if (!advance(&w, &remaining, ".text"))
            goto build;
        w++; remaining--;
        if (!advance(&w, &remaining, ".text")) {
            /* 32 bit builds only one ELF */
            w--; remaining++;
        }
        memcpy(&start, w + 285, 4);
        memcpy(&length, w + 289, 4);
        w = binaries[slot]; remaining = binary_sizes[slot];
        if (!advance(&w, &remaining, "ELF"))
            goto build;
        w++; remaining--;
        if (!advance(&w, &remaining, "ELF")) {
            /* 32 bit builds only one ELF */
            w--; remaining++;
        }
        w--; remaining++;
        w += start; remaining -= start;
        applog(LOG_DEBUG, "At %p (%u rem. bytes), to begin patching",
            w, remaining);
        patch_opcodes(w, length);

        status = clReleaseProgram(clState->program);
        if (status != CL_SUCCESS) {
            applog(LOG_ERR, "Error %d: Releasing program. (clReleaseProgram)", status);
            return NULL;
        }

        clState->program = clCreateProgramWithBinary(clState->context, 1, &devices[gpu], &binary_sizes[slot], (const unsigned char **)&binaries[slot], &status, NULL);
        if (status != CL_SUCCESS) {
            applog(LOG_ERR, "Error %d: Loading Binary into cl_program (clCreateProgramWithBinary)", status);
            return NULL;
        }

        /* Program needs to be rebuilt */
        prog_built = false;
    }

    free(source);

    /* Save the binary to be loaded next time */
    binaryfile = fopen(binaryfilename, "wb");
    if (!binaryfile) {
        /* Not a fatal problem, just means we build it again next time */
        applog(LOG_DEBUG, "Unable to create file %s", binaryfilename);
    } else {
        if (unlikely(fwrite(binaries[slot], 1, binary_sizes[slot], binaryfile) != binary_sizes[slot])) {
            applog(LOG_ERR, "Unable to fwrite to binaryfile");
            return NULL;
        }
        fclose(binaryfile);
    }
built:
    if (binaries[slot])
        free(binaries[slot]);
    free(binaries);
    free(binary_sizes);

    applog(LOG_INFO, "Initialising kernel %s with%s bitalign, %d vectors and worksize %d",
           filename, clState->hasBitAlign ? "" : "out", clState->vwidth, (int)(clState->wsize));

    if (!prog_built) {
        /* create a cl program executable for all the devices specified */
        status = clBuildProgram(clState->program, 1, &devices[gpu], NULL, NULL, NULL);
        if (status != CL_SUCCESS) {
            applog(LOG_ERR, "Error %d: Building Program (clBuildProgram)", status);
            size_t logSize;
            status = clGetProgramBuildInfo(clState->program, devices[gpu], CL_PROGRAM_BUILD_LOG, 0, NULL, &logSize);

            char *log = malloc(logSize);
            status = clGetProgramBuildInfo(clState->program, devices[gpu], CL_PROGRAM_BUILD_LOG, logSize, log, NULL);
            applog(LOG_ERR, "%s", log);
            return NULL;
        }
    }

    /* get a kernel object handle for a kernel with the given name */
    clState->kernel = clCreateKernel(clState->program, "search", &status);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: Creating Kernel from program. (clCreateKernel)", status);
        return NULL;
    }

#ifdef USE_SCRYPT
    if (opt_scrypt) {
        size_t ipt = (1024 / cgpu->lookup_gap + (1024 % cgpu->lookup_gap > 0));
        size_t bufsize = 128 * ipt * cgpu->thread_concurrency;

        /* Use the max alloc value which has been rounded to a power of
         * 2 greater >= required amount earlier */
        if (bufsize > cgpu->max_alloc) {
            applog(LOG_WARNING, "Maximum buffer memory device %d supports says %lu",
                        gpu, (long unsigned int)(cgpu->max_alloc));
            applog(LOG_WARNING, "Your scrypt settings come to %d", (int)bufsize);
        }
        applog(LOG_DEBUG, "Creating scrypt buffer sized %d", (int)bufsize);
        clState->padbufsize = bufsize;

        /* This buffer is weird and might work to some degree even if
         * the create buffer call has apparently failed, so check if we
         * get anything back before we call it a failure. */
        clState->padbuffer8 = NULL;
        clState->padbuffer8 = clCreateBuffer(clState->context, CL_MEM_READ_WRITE, bufsize, NULL, &status);
        if (status != CL_SUCCESS && !clState->padbuffer8) {
            applog(LOG_ERR, "Error %d: clCreateBuffer (padbuffer8), decrease TC or increase LG", status);
            return NULL;
        }

        clState->CLbuffer0 = clCreateBuffer(clState->context, CL_MEM_READ_ONLY, 128, NULL, &status);
        if (status != CL_SUCCESS) {
            applog(LOG_ERR, "Error %d: clCreateBuffer (CLbuffer0)", status);
            return NULL;
        }
        clState->outputBuffer = clCreateBuffer(clState->context, CL_MEM_WRITE_ONLY, SCRYPT_BUFFERSIZE, NULL, &status);
    } else
#endif
#ifdef USE_KECCAK
    if (opt_keccak) {
        clState->keccak_CLbuffer = clCreateBuffer(clState->context, CL_MEM_READ_ONLY, KECCAK_BUFFER_SIZE, NULL, &status);
        if (status != CL_SUCCESS) {
            applog(LOG_ERR, "Error %d: clCreateBuffer (keccak_CLbuffer)", status);
        return NULL;
        }
        clState->outputBuffer = clCreateBuffer(clState->context, CL_MEM_WRITE_ONLY, BUFFERSIZE, NULL, &status);
    } else
#endif
#ifdef USE_HEAVY
    if (opt_heavy) {
        clState->heavy_CLbuffer = clCreateBuffer(clState->context, CL_MEM_READ_ONLY, HEAVY_BUFFER_SIZE, NULL, &status);
        if (status != CL_SUCCESS) {
            applog(LOG_ERR, "Error %d: clCreateBuffer (heavy_CLbuffer)", status);
        return NULL;
        }
        clState->outputBuffer = clCreateBuffer(clState->context, CL_MEM_WRITE_ONLY, BUFFERSIZE, NULL, &status);
    } else
#endif
#ifdef USE_HEFTY
    if (opt_hefty) {
        clState->hefty_CLbuffer = clCreateBuffer(clState->context, CL_MEM_READ_ONLY, HEFTY_BUFFER_SIZE, NULL, &status);
        if (status != CL_SUCCESS) {
            applog(LOG_ERR, "Error %d: clCreateBuffer (hefty_CLbuffer)", status);
        return NULL;
        }
        clState->outputBuffer = clCreateBuffer(clState->context, CL_MEM_WRITE_ONLY, BUFFERSIZE, NULL, &status);
    } else
#endif

    clState->outputBuffer = clCreateBuffer(clState->context, CL_MEM_WRITE_ONLY, BUFFERSIZE, NULL, &status);
    if (status != CL_SUCCESS) {
        applog(LOG_ERR, "Error %d: clCreateBuffer (outputBuffer)", status);
        return NULL;
    }

    return clState;
}
#endif /* HAVE_OPENCL */