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| author | Yang Rong <rong.r.yang@intel.com> | 2017-03-13 15:08:42 +0800 |
|---|---|---|
| committer | Yang Rong <rong.r.yang@intel.com> | 2017-03-13 15:13:30 +0800 |
| commit | 4dda7fb21acb8a400af73f56c5ef1c242523f564 (patch) | |
| tree | 24197bfea8e5cb0b54e495a8494c3e34ffebbfea /docs | |
| parent | 83b9db68f5725902bd1d665c23bcd66dbeaaa216 (diff) | |
| download | beignet-4dda7fb21acb8a400af73f56c5ef1c242523f564.tar.gz | |
Docs: Update Readme OpenCL 2.0 section.
Contributor: Rebecca N. Palmer <rebecca_palmer@zoho.com>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/Beignet.mdwn | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/docs/Beignet.mdwn b/docs/Beignet.mdwn index 3f3e02e4..a2a3af4f 100644 --- a/docs/Beignet.mdwn +++ b/docs/Beignet.mdwn @@ -161,15 +161,9 @@ Supported Targets OpenCL 2.0 ---------- -From release v1.3.0, beignet support OpenCL 2.0. By default, OpenCL 2.0 support is disabled, you can enable it when cmake with option --DENABLE_OPENCL_20=1. Please remember that to enable OpenCL 2.0, there are some dependencies. First, OpenCL 2.0 only support the targets -from Skylake, include Skylake, Kabylake and Apollolake. Then, clang supports all OpenCL 2.0 feature from 3.9. So to enable OpenCL 2.0, -you must update LLVM/clang to 3.9 or later. And also requeires libdrm at least 2.4.66. -After enable OpenCL 2.0, beignet complies with OpenCL 2.0 spec, but some OpenCL 2.0 features are simulated by software, there is no performance -gain, such as pipe and device queues, especially device queues. -If you build beignet with OpenCL 2.0 enabled and your kernel don't use the OpenCL 2.0 features, please pass a build option -cl-std=CL1.2 for -performance, the OpenCL 2.0 uses more registers and has lots of int64 operations, which may hurt performance, and beignet will continue to improve -OpenCL 2.0 performance. +From release v1.3.0, beignet supports OpenCL 2.0 on Skylake and later hardware. +This requires LLVM/Clang 3.9 or later and libdrm 2.4.66 or later; because of this, it is not available in jessie-backports. +As required by the OpenCL specification, kernels are compiled as OpenCL C 1.2 by default; to use 2.0 they must explicitly request it with the -cl-std=CL2.0 build option. As OpenCL 2.0 is likely to be slower than 1.2, we recommend that this is used only where needed. (This is because 2.0 uses more registers and has lots of int64 operations, and some of the 2.0 features (pipes and especially device queues) are implemented in software so do not provide any performance gain.) Beignet will continue to improve OpenCL 2.0 performance. Known Issues ------------ |