CryptoPkg Updates to support RFC3161 timestamp signature verification.

[mirror_edk2.git] / CryptoPkg / Library / IntrinsicLib / Ia32 / MathRShiftU64.S

diff --git a/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.S b/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.S
new file mode 100644 (file)
index 0000000..24142b0
--- /dev/null
+++ b/CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.S
@@ -0,0 +1,66 @@
+#------------------------------------------------------------------------------\r
+#\r
+# Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>\r
+# This program and the accompanying materials\r
+# are licensed and made available under the terms and conditions of the BSD License\r
+# which accompanies this distribution.  The full text of the license may be found at\r
+# http://opensource.org/licenses/bsd-license.php.\r
+#\r
+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
+# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
+#\r
+# Module Name:\r
+#\r
+#   MathRShiftU64.S\r
+#\r
+# Abstract:\r
+#\r
+#   64-bit Math Worker Function.\r
+#   Shifts a 64-bit unsigned value right by a certain number of bits.\r
+#\r
+#------------------------------------------------------------------------------\r
+\r
+\r
+    .686:\r
+    .code:\r
+\r
+ASM_GLOBAL ASM_PFX(__ashrdi3)\r
+\r
+#------------------------------------------------------------------------------\r
+#\r
+# void __cdecl __ashrdi3 (void)\r
+#\r
+#------------------------------------------------------------------------------\r
+ASM_PFX(__ashrdi3):\r
+    #\r
+    # Checking: Only handle 64bit shifting or more\r
+    #\r
+    cmpb    $64, %cl\r
+    jae     _Exit\r
+\r
+    #\r
+    # Handle shifting between 0 and 31 bits\r
+    #\r
+    cmpb    $32, %cl\r
+    jae     More32\r
+    shrd    %cl, %edx, %eax\r
+    shr     %cl, %edx\r
+    ret\r
+\r
+    #\r
+    # Handle shifting of 32-63 bits\r
+    #\r
+More32:\r
+    movl    %edx, %eax\r
+    xor     %edx, %edx\r
+    and     $31, %cl\r
+    shr     %cl, %eax\r
+    ret\r
+\r
+    #\r
+    # Invalid number (less then 32bits), return 0\r
+    #\r
+_Exit:\r
+    xor     %eax, %eax\r
+    xor     %edx, %edx\r
+    ret\r