1 files changed, 45 insertions, 0 deletions
diff --git a/roms/edk2/MdePkg/Library/BaseLib/Ia32/LShiftU64.c b/roms/edk2/MdePkg/Library/BaseLib/Ia32/LShiftU64.c
new file mode 100644
index 000000000..1604e7e2f
--- /dev/null
+++ b/roms/edk2/MdePkg/Library/BaseLib/Ia32/LShiftU64.c
@@ -0,0 +1,45 @@
+/** @file
+  64-bit left shift function for IA-32.
+
+  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+
+
+/**
+  Shifts a 64-bit integer left between 0 and 63 bits. The low bits
+  are filled with zeros. The shifted value is returned.
+
+  This function shifts the 64-bit value Operand to the left by Count bits. The
+  low Count bits are set to zero. The shifted value is returned.
+
+  @param  Operand The 64-bit operand to shift left.
+  @param  Count   The number of bits to shift left.
+
+  @return Operand << Count
+
+**/
+UINT64
+EFIAPI
+InternalMathLShiftU64 (
+  IN      UINT64                    Operand,
+  IN      UINTN                     Count
+  )
+{
+  _asm {
+    mov     cl, byte ptr [Count]
+    xor     eax, eax
+    mov     edx, dword ptr [Operand + 0]
+    test    cl, 32                      // Count >= 32?
+    jnz     L0
+    mov     eax, edx
+    mov     edx, dword ptr [Operand + 4]
+L0:
+    shld    edx, eax, cl
+    shl     eax, cl
+  }
+}
+