CLOC: CL Offline Compiler Generate HSAIL or brig from a cl (Kernel c Language) file. SNACK: Structured No API Compiled Kernels. Launch GPU kernels as host-callable functions with structured launch parameters.

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   cloc.sh: Convert a cl file to brig or hsail using the
            LLVM to HSAIL backend compiler.

   Usage: cloc.sh [ options ] filename.cl

   Options without values:
    -hsail    Generate dissassembled hsail from brig 
    -ll       Generate dissassembled ll from bc, for info only
    -version  Display version of cloc then exit
    -v        Verbose messages
    -n        Dryrun, do nothing, show commands that would execute
    -h        Print this help message
    -k        Keep temporary files

   Options with values:
    -t       <tdir>           Default=/tmp/cloc$$, Temp dir for files
    -o       <outfilename>    Default=<filename>.<ft> ft=brig or hsail
    -opt     <LLVM opt>       Default=2, LLVM optimization level
    -p       <path>           Default=$HSA_LLVM_PATH or /opt/amd/bin
    -clopts  <compiler opts>  Default="-cl-std=CL2.0"
    -lkopts  <LLVM link opts> Default="--prelink-opt -l $HSA_LLVM_PATH/builtins-hsail.bc"

   Examples:
    cloc my.cl              /* create my.brig                   */
    cloc -hsail my.cl       /* create my.hsail and my.brig      */

   You may set environment variables LLVMOPT, HSA_LLVM_PATH, CLOPTS, or 
   LKOPTS instead of providing options -opt -p, -clopts, or -lkopts .
   Command line options will take precedence over environment variables. 

   Copyright (c) 2015 ADVANCED MICRO DEVICES, INC.

   snack: Generate host-callable "snack" functions for GPU kernels.
          Snack generates the source code and headers for each kernel 
          in the input filename.cl file.  The -c option will compile 
          the source with gcc so you can link with your host application.
          Host applicaton requires no API to use snack functions.

   Usage: snack.sh [ options ] filename.cl

   Options without values:
    -c        Compile generated source code to create .o file
    -hsail    Generate text hsail for manual optimization
    -version  Display version of snack then exit
    -v        Verbose messages
    -vv       Get additional verbose messages from cloc.sh
    -n        Dryrun, do nothing, show commands that would execute
    -h        Print this help message
    -k        Keep temporary files
    -fort     Generate fortran function names
    -noglobs  Do not generate global functions 
    -str      Depricated, create .o file needed for okra

   Options with values:
    -opt      <LLVM opt>     Default=2, passed to cloc.sh to build HSAIL 
    -gccopt   <gcc opt>      Default=2, gcc optimization for snack wrapper
    -t        <tempdir>      Default=/tmp/snk_$$, Temp dir for files
    -s        <symbolname>   Default=filename 
    -p1       <path>         Default=$HSA_LLVM_PATH or /opt/amd/bin
    -p2       <path>         Default=$HSA_RUNTIME_PATH or /opt/hsa
    -o        <outfilename>  Default=<filename>.<ft> 

   Examples:
    snack my.cl              /* create my.snackwrap.c and my.h    */
    snack -c my.cl           /* gcc compile to create  my.o       */
    snack -hsail my.cl       /* create hsail and snackwrap.c      */
    snack -c -hsail my.cl    /* create hsail snackwrap.c and .o   */
    snack -t /tmp/foo my.cl  /* will automatically set -k         */

   You may set environment variables HSA_LLVM_PATH, HSA_RUNTIME_PATH, 
   instead of providing options -p1, -p2.
   Command line options will take precedence over environment variables. 

   Copyright (c) 2015 ADVANCED MICRO DEVICES, INC.

This version of cloc supports the SNACK method of writing accelerated kernels in c. With SNACK, a host program can directly call the accelerated function. Here is the c++ source code HelloWorld.cpp using SNACK.

//
//    File:  HelloWorld.cpp
//
#include <string.h>
#include <stdlib.h>
#include <iostream>
using namespace std;
#include "hw.h"
int main(int argc, char* argv[]) {
	const char* input = "Gdkkn\x1FGR@\x1FVnqkc";
	size_t strlength = strlen(input);
	char *output = (char*) malloc(strlength + 1);
        SNK_INIT_LPARM(lparm,strlength);
	decode(input,output,lparm);
	output[strlength] = '\0';
	cout << output << endl;
	free(output);
	return 0;
}

The c source for the accelerated kernel is in file hw.cl.

/*
    File:  hw.cl 
*/
__kernel void decode(__global char* in, __global char* out) {
	int num = get_global_id(0);
	out[num] = in[num] + 1;
}

The host program includes header file "hw.h" that does not exist yet. The -c option of snack.sh will call the gcc compiler and create the object file and the header file. Without -c you get the generated c code hw.snackwrap.c and the header file. The header file has function prototypes for all kernels declared in the .cl file. Use this command to compile the hw.cl file with snack.sh.

snack.sh -c hw.cl

You can now compile and build the binary "HelloWorld" with any c++ compiler. Here is the command to build HelloWorld with g++.

g++ -o HelloWorld hw.o HelloWorld.cpp -L$HSA_RUNTIME_PATH/lib -lhsa-runtime64 -lelf 

Then execute the program as follows.

$ ./HelloWorld
Hello HSA World

This example and other examples can be found in the CLOC repository in the directory examples/snack.

This version of snack supports a process where a programmer can experiment with manual updates to HSAIL. This process has two steps.

The first step compiles the .cl file into the object code needed by a SNACK application. For example, if your kernels are in the file myKernels.cl, then you can run step 1 as follows.

   snack -c -hsail myKernels.cl

When cloc sees the "-c" option and the "-hsail" option, it will save four files in the same directory as myKernels.cl file. The first two files are always created with the -c option.

1. The object file (myKernels.o) to link with your application
2. The header file (myKernels.h) for your host code to compile correctly
3. The c wrapper code (myKernels.snackwrap.c) needed to recreate the .o file in step 2.
4. The HSAIL code (myKernels.hsail) to be manually modified in step 2.

This is a good time to test your host program before making manual changes to the HSAIL. BE WARNED, rerunning step 1 will overwrite these files. A common mistake is to rerun step 1 after you have manually updated your HSAIL code for step 2. This would naturally destroy those edits.

For step 2, make manual edits to the myKernels.hsail file using your favorite editor.
You may not change any of the calling arguments or insert new kernels. This is because the generated wrapper from step 1 will be incorrect if you make these types of changes.
If you want different arguments or new kernels, make those changes in your .cl file and go back to step 1. After your manual edits, rebuild the object code from your modified hsail as follows.

   snack.sh -c  myKernels.hsail

The above will fail if either the myKernels.hsail or myKernels.snackwrap.c file are missing.

Currently cloc does not support the combination of kernel code and host code in the same file. A future utility may provide this. For now, put your kernel and device code (routines called by kernels) into a .cl file for cloc to compile. Put your host code into separate files with appropriate filetypes for your build environment. The host code can be c++, c, or FORTRAN.

One advantage of isolating kernel code from host code is that you can use any compiler for your host code. Any future utility that supports a single source will likely be bound to a specific compiler.