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Compostella, Jeremy d25fd8710d BaseMemoryLibSse2: Take advantage of write combining buffers 
The current SSE2 implementation of the ZeroMem(), SetMem(),
SetMem16(), SetMem32 and SetMem64 functions is writing 16 bytes per 16
bytes. It hurts the performances so bad that this is even slower than
a simple 'rep stos' (4% slower) in regular DRAM.

To take full advantages of the 'movntdq' instruction it is better to
"queue" a total of 64 bytes in the write combining buffers.  This
patch implement such a change.  Below is a table where I measured
(with 'rdtsc') the time to write an entire 100MB RAM buffer. These
functions operate almost two times faster.

| Function | Arch | Untouched | 64 bytes | Result |
|----------+------+-----------+----------+--------|
| ZeroMem  | Ia32 |  17765947 |  9136062 | 1.945x |
| ZeroMem  | X64  |  17525170 |  9233391 | 1.898x |
| SetMem   | Ia32 |  17522291 |  9137272 | 1.918x |
| SetMem   | X64  |  17949261 |  9176978 | 1.956x |
| SetMem16 | Ia32 |  18219673 |  9372062 | 1.944x |
| SetMem16 | X64  |  17523331 |  9275184 | 1.889x |
| SetMem32 | Ia32 |  18495036 |  9273053 | 1.994x |
| SetMem32 | X64  |  17368864 |  9285885 | 1.870x |
| SetMem64 | Ia32 |  18564473 |  9241362 | 2.009x |
| SetMem64 | X64  |  17506951 |  9280148 | 1.886x |

Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
 		2020-10-16 01:12:05 +00:00
..
CompareMem.nasm MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
CopyMem.nasm MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
IsZeroBuffer.nasm MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
ScanMem8.nasm MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
ScanMem16.nasm MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
ScanMem32.nasm MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
ScanMem64.nasm MdePkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:13 -07:00
SetMem.nasm BaseMemoryLibSse2: Take advantage of write combining buffers 2020-10-16 01:12:05 +00:00
SetMem16.nasm BaseMemoryLibSse2: Take advantage of write combining buffers 2020-10-16 01:12:05 +00:00
SetMem32.nasm BaseMemoryLibSse2: Take advantage of write combining buffers 2020-10-16 01:12:05 +00:00
SetMem64.nasm BaseMemoryLibSse2: Take advantage of write combining buffers 2020-10-16 01:12:05 +00:00
ZeroMem.nasm BaseMemoryLibSse2: Take advantage of write combining buffers 2020-10-16 01:12:05 +00:00