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| author | Hao Wu <hao.a.wu@intel.com> | 2016-08-17 14:26:25 +0800 |
|---|---|---|
| committer | Hao Wu <hao.a.wu@intel.com> | 2016-08-22 18:54:31 +0800 |
| commit | 02b5cf7fb1824e089f19ca03b685a1f196860bf6 (patch) | |
| tree | 8296c6959dad18b8c08c7b1b74d6d030fa566404 /MdePkg/Library/BaseMemoryLibMmx/X64 | |
| parent | 1944b02b03e14d023e8f2cd3d614df6eca9dc8f0 (diff) | |
| download | edk2-02b5cf7fb1824e089f19ca03b685a1f196860bf6.tar.gz edk2-02b5cf7fb1824e089f19ca03b685a1f196860bf6.tar.bz2 edk2-02b5cf7fb1824e089f19ca03b685a1f196860bf6.zip | |
MdePkg BaseMemoryLib: Add assembly implementation of API IsZeroBuffer()
Add the implementation of API IsZeroBuffer() via assembly for the
following library instances:
BaseMemoryLibMmx
BaseMemoryLibOptDxe
BaseMemoryLibOptPei
BaseMemoryLibRepStr
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/BaseMemoryLibMmx/X64')
| -rw-r--r-- | MdePkg/Library/BaseMemoryLibMmx/X64/IsZeroBuffer.nasm | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseMemoryLibMmx/X64/IsZeroBuffer.nasm b/MdePkg/Library/BaseMemoryLibMmx/X64/IsZeroBuffer.nasm new file mode 100644 index 0000000000..00b1067eee --- /dev/null +++ b/MdePkg/Library/BaseMemoryLibMmx/X64/IsZeroBuffer.nasm @@ -0,0 +1,55 @@ +;------------------------------------------------------------------------------
+;
+; 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:
+;
+;------------------------------------------------------------------------------
+
+ DEFAULT REL
+ SECTION .text
+
+;------------------------------------------------------------------------------
+; BOOLEAN
+; EFIAPI
+; InternalMemIsZeroBuffer (
+; IN CONST VOID *Buffer,
+; IN UINTN Length
+; );
+;------------------------------------------------------------------------------
+global ASM_PFX(InternalMemIsZeroBuffer)
+ASM_PFX(InternalMemIsZeroBuffer):
+ push rdi
+ mov rdi, rcx ; rdi <- Buffer
+ mov rcx, rdx ; rcx <- Length
+ shr rcx, 3 ; rcx <- number of qwords
+ and rdx, 7 ; rdx <- number of trailing bytes
+ xor rax, rax ; rax <- 0, also set ZF
+ repe scasq
+ jnz @ReturnFalse ; ZF=0 means non-zero element found
+ mov rcx, rdx
+ repe scasb
+ jnz @ReturnFalse
+ pop rdi
+ mov rax, 1 ; return TRUE
+ ret
+@ReturnFalse:
+ pop rdi
+ xor rax, rax
+ ret ; return FALSE
+
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