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Grid-launch updates to 2.0 and cleanup of old.

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_ Use fields from GRID_LAUNCH_20 structure
  (See USE_GRID_LAUNCH_20 define, currently set to 0)
  "1" will require HCC support.
- Remove old DISABLE_GRID_LAUNCH support.

Change-Id: I584ce648d217251789a6283cf27feb24cb7dc8d1
This commit is contained in:
Ben Sander
2016-06-20 23:46:42 -05:00
parent 100a744d92
commit 9f29cc6989
6 changed files with 64 additions and 65 deletions
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docs/markdown/hip_porting_guide.md
-31
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@@ -464,37 +464,6 @@ hipcc-cmd: /opt/hcc/bin/hcc -hc -I/opt/hcc/include -stdlib=libc++ -I../../../..
If you pass a ".cu" file, hcc will attempt to compile it as a Cuda language file. You must tell hcc that it’s in fact a C++ file: use the "-x c++" option.
#### grid_launch kernel dispatch - fallback
HIP uses an hcc language feature called "grid_launch". The [[hc_grid_launch]] attribute that can be attached to a function definition, and the first parameter is of type grid_launch_parm.
When a [[hc_grid_launch]] function is called, hcc runtime uses the grid_launch_parm to control the execution configuration of the kernel
(including the grid and group dimensions, the queue, and dynamic group memory allocations). By default, the hipLaunchKernel macro creates a grid_launch_parm structure and launches a
[[hc_grid_launch]] kernel. grid_launch is a relatively new addition to hcc so this section describes how to fall back to a traditional calling sequence which invokes a standard host function
which calls a hc::parallel_for_each to launch the kernel.
First, set DISABLE_GRID_LAUNCH:
include/hip_common.h
```
// Set this define to disable GRID_LAUNCH
#define DISABLE_GRID_LAUNCH
```
Inside any kernel use the KERNELBEGIN as the first line in the kernel function, and KERNELEND as the last line. For example:
```
__global__ void
MyKernel(hipLaunchParm lp, float *C, const float *A, size_t N)
{
KERNELBEGIN; // Required if hc_grid_launch is disabled
int tid = hipBlockIdx_x*MAX_THREADS_PER_BLOCK + hipThreadIdx_x;
if (tid < N) {
C[tid] = A[tid];
}
KERNELEND; // Required if hc_grid_launch is disabled
}
```
#### HIP Environment Variables
On the HCC path, HIP provides a number of environment variables that control the behavior of HIP. Some of these are useful for appliction development (for example HIP_VISIBLE_DEVICES, HIP_LAUNCH_BLOCKING),