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-rw-r--r--CryptoPkg/Library/IntrinsicLib/Ia32/MathLShiftS64.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/CryptoPkg/Library/IntrinsicLib/Ia32/MathLShiftS64.c b/CryptoPkg/Library/IntrinsicLib/Ia32/MathLShiftS64.c
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+++ b/CryptoPkg/Library/IntrinsicLib/Ia32/MathLShiftS64.c
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+/** @file
+ 64-bit Math Worker Function.
+ The 32-bit versions of C compiler generate calls to library routines
+ to handle 64-bit math. These functions use non-standard calling conventions.
+
+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.
+
+**/
+
+
+/*
+ * Shifts a 64-bit signed value left by a particular number of bits.
+ */
+__declspec(naked) void __cdecl _allshl (void)
+{
+ _asm {
+ ;
+ ; Handle shifting of 64 or more bits (return 0)
+ ;
+ cmp cl, 64
+ jae short ReturnZero
+
+ ;
+ ; Handle shifting of between 0 and 31 bits
+ ;
+ cmp cl, 32
+ jae short More32
+ shld edx, eax, cl
+ shl eax, cl
+ ret
+
+ ;
+ ; Handle shifting of between 32 and 63 bits
+ ;
+More32:
+ mov edx, eax
+ xor eax, eax
+ and cl, 31
+ shl edx, cl
+ ret
+
+ReturnZero:
+ xor eax,eax
+ xor edx,edx
+ ret
+ }
+}