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| author | Hao Wu <hao.a.wu@intel.com> | 2016-08-17 14:27:49 +0800 |
|---|---|---|
| committer | Hao Wu <hao.a.wu@intel.com> | 2016-08-22 18:54:31 +0800 |
| commit | 102b4c7cdd11172d5b7fde35a0c472ecd7fa49e7 (patch) | |
| tree | 542b85f75ff57ffd53563b3aab6f06307fbb9be6 /MdePkg/Library/BaseMemoryLibSse2/Ia32/IsZeroBuffer.nasm | |
| parent | 02b5cf7fb1824e089f19ca03b685a1f196860bf6 (diff) | |
| download | edk2-102b4c7cdd11172d5b7fde35a0c472ecd7fa49e7.tar.gz edk2-102b4c7cdd11172d5b7fde35a0c472ecd7fa49e7.tar.bz2 edk2-102b4c7cdd11172d5b7fde35a0c472ecd7fa49e7.zip | |
MdePkg BaseMemoryLibSse2: Add SSE2 implementation of API IsZeroBuffer()
Add the implementation of API IsZeroBuffer() via assembly in
BaseMemoryLibSse2.
The assembly codes use SSE2 XMM registers and related instructions.
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Diffstat (limited to 'MdePkg/Library/BaseMemoryLibSse2/Ia32/IsZeroBuffer.nasm')
| -rw-r--r-- | MdePkg/Library/BaseMemoryLibSse2/Ia32/IsZeroBuffer.nasm | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseMemoryLibSse2/Ia32/IsZeroBuffer.nasm b/MdePkg/Library/BaseMemoryLibSse2/Ia32/IsZeroBuffer.nasm new file mode 100644 index 0000000000..68c09fedaf --- /dev/null +++ b/MdePkg/Library/BaseMemoryLibSse2/Ia32/IsZeroBuffer.nasm @@ -0,0 +1,74 @@ +;------------------------------------------------------------------------------
+;
+; Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
+; This program and the accompanying materials
+; are licensed and made available under the terms and conditions of the BSD License
+; which accompanies this distribution. The full text of the license may be found at
+; http://opensource.org/licenses/bsd-license.php.
+;
+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+;
+; Module Name:
+;
+; IsZeroBuffer.nasm
+;
+; Abstract:
+;
+; IsZeroBuffer function
+;
+; Notes:
+;
+;------------------------------------------------------------------------------
+
+ SECTION .text
+
+;------------------------------------------------------------------------------
+; BOOLEAN
+; EFIAPI
+; InternalMemIsZeroBuffer (
+; IN CONST VOID *Buffer,
+; IN UINTN Length
+; );
+;------------------------------------------------------------------------------
+global ASM_PFX(InternalMemIsZeroBuffer)
+ASM_PFX(InternalMemIsZeroBuffer):
+ push edi
+ mov edi, [esp + 8] ; edi <- Buffer
+ mov edx, [esp + 12] ; edx <- Length
+ xor ecx, ecx ; ecx <- 0
+ sub ecx, edi
+ and ecx, 15 ; ecx + edi aligns on 16-byte boundary
+ jz @Is16BytesZero
+ cmp ecx, edx
+ cmova ecx, edx ; bytes before the 16-byte boundary
+ sub edx, ecx
+ xor eax, eax ; eax <- 0, also set ZF
+ repe scasb
+ jnz @ReturnFalse ; ZF=0 means non-zero element found
+@Is16BytesZero:
+ mov ecx, edx
+ and edx, 15
+ shr ecx, 4
+ jz @IsBytesZero
+.0:
+ pxor xmm0, xmm0 ; xmm0 <- 0
+ pcmpeqb xmm0, [edi] ; check zero for 16 bytes
+ pmovmskb eax, xmm0 ; eax <- compare results
+ cmp eax, 0xffff
+ jnz @ReturnFalse
+ add edi, 16
+ loop .0
+@IsBytesZero:
+ mov ecx, edx
+ xor eax, eax ; eax <- 0, also set ZF
+ repe scasb
+ jnz @ReturnFalse ; ZF=0 means non-zero element found
+ pop edi
+ mov eax, 1 ; return TRUE
+ ret
+@ReturnFalse:
+ pop edi
+ xor eax, eax
+ ret ; return FALSE
+
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