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>
		
			
				
	
	
		
			66 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			NASM
		
	
	
	
	
	
			
		
		
	
	
			66 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			NASM
		
	
	
	
	
	
| ;------------------------------------------------------------------------------
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| ;
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| ; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
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| ; SPDX-License-Identifier: BSD-2-Clause-Patent
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| ;
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| ; Module Name:
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| ;
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| ;   SetMem32.nasm
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| ;
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| ; Abstract:
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| ;
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| ;   SetMem32 function
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| ;
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| ; Notes:
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| ;
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| ;------------------------------------------------------------------------------
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| 
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|     DEFAULT REL
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|     SECTION .text
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| 
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| ;------------------------------------------------------------------------------
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| ;  VOID *
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| ;  InternalMemSetMem32 (
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| ;    IN VOID   *Buffer,
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| ;    IN UINTN  Count,
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| ;    IN UINT8  Value
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| ;    )
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| ;------------------------------------------------------------------------------
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| global ASM_PFX(InternalMemSetMem32)
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| ASM_PFX(InternalMemSetMem32):
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|     push    rdi
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|     mov     rdi, rcx
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|     mov     r9, rdi
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|     xor     rcx, rcx
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|     sub     rcx, rdi
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|     and     rcx, 15
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|     mov     rax, r8
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|     jz      .0
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|     shr     rcx, 2
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|     cmp     rcx, rdx
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|     cmova   rcx, rdx
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|     sub     rdx, rcx
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|     rep     stosd
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| .0:
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|     mov     rcx, rdx
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|     and     edx, 15
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|     shr     rcx, 4
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|     jz      @SetDwords
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|     movd    xmm0, eax
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|     pshufd  xmm0, xmm0, 0
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| .1:
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|     movntdq [rdi], xmm0
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|     movntdq [rdi + 16], xmm0
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|     movntdq [rdi + 32], xmm0
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|     movntdq [rdi + 48], xmm0
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|     add     rdi, 64
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|     loop    .1
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|     mfence
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| @SetDwords:
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|     mov     ecx, edx
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|     rep     stosd
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|     mov     rax, r9
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|     pop     rdi
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|     ret
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| 
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