hcc - support for multiple devices

[scchan]

Here are a couple changes to this benchmark to support device selection on a multi-gpu system. It's mostly changing array allocations to allocate memory from the selected device and also to launch kernels to the selected device.

[psteinb]

@scchan just great!
I gave that a shot. and saw this:

$ ./gpu-stream-hcc --list
GPU-STREAM
Version: 2.0
Implementation: HCC

Devices:
0: CPU Device
1: AMD HSA Agent Fiji2
2: AMD HSA Agent Fiji3

Segmentation fault

and

$ ./gpu-stream-hcc --device 1
GPU-STREAM
Version: 2.0
Implementation: HCC
Running kernels 100 times
Precision: double
Array size: 268.4 MB (=0.3 GB)
Total size: 805.3 MB (=0.8 GB)
Using HCC device AMD HSA Agent Fiji2
Function    MBytes/sec  Min (sec)   Max         Average     
Copy        436177.574  0.00123     0.00132     0.00126     
Mul         435922.931  0.00123     0.00132     0.00126     
Add         456735.717  0.00176     0.00223     0.00188     
Triad       456044.606  0.00177     0.00224     0.00188     
Segmentation fault

I like the bandwidths that are reported ;) as we see HBM in action. but the segfault is still annoying.

[psteinb]

this is with:

$ uname -a
Linux gpu006 4.4.0-kfd-compute-rocm-rel-1.2-31 #1 SMP Fri Jul 22 06:06:24 CDT 2016 x86_64 x86_64 x86_64 GNU/Linux
$ lsb_release -a
LSB Version:    core-2.0-amd64:core-2.0-noarch:core-3.0-amd64:core-3.0-noarch:core-3.1-amd64:core-3.1-noarch:core-3.2-amd64:core-3.2-noarch:core-4.0-amd64:core-4.0-noarch:core-4.1-amd64:core-4.1-noarch:security-4.0-amd64:security-4.0-noarch:security-4.1-amd64:security-4.1-noarch
Distributor ID: Ubuntu
Description:    Ubuntu 14.04.3 LTS
Release:        14.04
Codename:       trusty
$ hcc --version
HCC clang version 3.5.0  (based on HCC 0.10.16313-d90738a-10704f4 LLVM 3.5.0svn)
Target: x86_64-unknown-linux-gnu
Thread model: posix