Signed-off-by: Yang Rong <rong.r.y...@intel.com> --- docs/optimization-guide.mdwn | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 docs/optimization-guide.mdwn
diff --git a/docs/optimization-guide.mdwn b/docs/optimization-guide.mdwn new file mode 100644 index 0000000..4f620ab --- /dev/null +++ b/docs/optimization-guide.mdwn @@ -0,0 +1,27 @@ +Optimization Guide +==================== + +All the SIMD optimization principle also apply to Beignet optimization. +Furthermore, there are some special tips for Beignet optimization. + +1. Choose the work group size multiple by 16 is recommendation. SLM also affect parallelism. +If kernel use large amount SLM, recommend use large work group size. The following is a recommendations work group size. +| Amount of SLM | 0 | 4K | 8K | 16K | 32K | +| WorkGroup size| 16 | 64 | 128 | 256 | 512 | + +2. GEN7's read/write on global memory with DWORD and DWORD4 are significantly faster than read/write on BYTE/WORD. + Use DWORD or DWORD4 to access data in global memory if possible. If you cannot avoid the byte/word access, try to do it on SLM. + +3. GEN7's float performance is better than that of int, try to operate on float instead of using int if possible. + +4. Avoid using long. GEN7's performance for long integer is poor. + +5. If there is a small constant buffer, define it in the kernel instead of using the constant buffer argument if possible. + The compiler may optimize it if the buffer is defined inside kernel. + +6. Avoid unnecessary synchronizations, both in the runtime and in the kernel. For examples, clFinish and clWaitForEvents in runtime + and barrier() in the kernel. + +7. Consider native version of math built-ins, such as native_sin, native_cos, if your kernel is not precision sensitive. + +8. Try to minimize branching. For example using min, max, clamp or select built-ins instead of if/else if possible. -- 1.8.3.2 _______________________________________________ Beignet mailing list Beignet@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/beignet
