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Diffstat (limited to 'Core/MdePkg/Library/BaseLib/Ia32/RRotU64.c')
-rw-r--r--Core/MdePkg/Library/BaseLib/Ia32/RRotU64.c55
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diff --git a/Core/MdePkg/Library/BaseLib/Ia32/RRotU64.c b/Core/MdePkg/Library/BaseLib/Ia32/RRotU64.c
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index 0000000000..17fde84b9d
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+++ b/Core/MdePkg/Library/BaseLib/Ia32/RRotU64.c
@@ -0,0 +1,55 @@
+/** @file
+ 64-bit right rotation for Ia32
+
+ Copyright (c) 2006 - 2015, 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.
+
+**/
+
+
+
+
+/**
+ Rotates a 64-bit integer right between 0 and 63 bits, filling
+ the high bits with the high low bits that were rotated.
+
+ This function rotates the 64-bit value Operand to the right by Count bits.
+ The high Count bits are fill with the low Count bits of Operand. The rotated
+ value is returned.
+
+ @param Operand The 64-bit operand to rotate right.
+ @param Count The number of bits to rotate right.
+
+ @return Operand >>> Count
+
+**/
+UINT64
+EFIAPI
+InternalMathRRotU64 (
+ IN UINT64 Operand,
+ IN UINTN Count
+ )
+{
+ _asm {
+ mov cl, byte ptr [Count]
+ mov eax, dword ptr [Operand + 0]
+ mov edx, dword ptr [Operand + 4]
+ shrd ebx, eax, cl
+ shrd eax, edx, cl
+ rol ebx, cl
+ shrd edx, ebx, cl
+ test cl, 32 // Count >= 32?
+ jz L0
+ mov ecx, eax
+ mov eax, edx
+ mov edx, ecx
+L0:
+ }
+}
+