1 files changed, 66 insertions, 0 deletions
diff --git a/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.S b/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.S
new file mode 100644
index 0000000000..24142b088e
--- /dev/null
+++ b/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.S
@@ -0,0 +1,66 @@
+#------------------------------------------------------------------------------
+#
+# Copyright (c) 2014, 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:
+#
+#   MathRShiftU64.S
+#
+# Abstract:
+#
+#   64-bit Math Worker Function.
+#   Shifts a 64-bit unsigned value right by a certain number of bits.
+#
+#------------------------------------------------------------------------------
+
+
+    .686:
+    .code:
+
+ASM_GLOBAL ASM_PFX(__ashrdi3)
+
+#------------------------------------------------------------------------------
+#
+# void __cdecl __ashrdi3 (void)
+#
+#------------------------------------------------------------------------------
+ASM_PFX(__ashrdi3):
+    #
+    # Checking: Only handle 64bit shifting or more
+    #
+    cmpb    $64, %cl
+    jae     _Exit
+
+    #
+    # Handle shifting between 0 and 31 bits
+    #
+    cmpb    $32, %cl
+    jae     More32
+    shrd    %cl, %edx, %eax
+    shr     %cl, %edx
+    ret
+
+    #
+    # Handle shifting of 32-63 bits
+    #
+More32:
+    movl    %edx, %eax
+    xor     %edx, %edx
+    and     $31, %cl
+    shr     %cl, %eax
+    ret
+
+    #
+    # Invalid number (less then 32bits), return 0
+    #
+_Exit:
+    xor     %eax, %eax
+    xor     %edx, %edx
+    ret