1 files changed, 49 insertions, 0 deletions
diff --git a/roms/edk2/MdePkg/Library/BaseLib/Ia32/RRotU64.c b/roms/edk2/MdePkg/Library/BaseLib/Ia32/RRotU64.c
new file mode 100644
index 000000000..82711a5f8
--- /dev/null
+++ b/roms/edk2/MdePkg/Library/BaseLib/Ia32/RRotU64.c
@@ -0,0 +1,49 @@
+/** @file
+  64-bit right rotation for Ia32
+
+  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+
+
+/**
+  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:
+  }
+}
+