diff options
Diffstat (limited to 'CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.S')
-rw-r--r-- | CryptoPkg/Library/IntrinsicLib/Ia32/MathRShiftU64.S | 66 |
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 0000000..24142b0 --- /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
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