mirror of https://github.com/acidanthera/audk.git
55 lines
1.3 KiB
C
55 lines
1.3 KiB
C
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/** @file
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64-bit Math Worker Function.
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The 32-bit versions of C compiler generate calls to library routines
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to handle 64-bit math. These functions use non-standard calling conventions.
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Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>
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This program and the accompanying materials
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are licensed and made available under the terms and conditions of the BSD License
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which accompanies this distribution. The full text of the license may be found at
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http://opensource.org/licenses/bsd-license.php
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THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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**/
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/*
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* Shifts a 64-bit signed value left by a particular number of bits.
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*/
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__declspec(naked) void __cdecl _allshl (void)
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{
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_asm {
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;
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; Handle shifting of 64 or more bits (return 0)
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;
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cmp cl, 64
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jae short ReturnZero
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;
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; Handle shifting of between 0 and 31 bits
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;
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cmp cl, 32
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jae short More32
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shld edx, eax, cl
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shl eax, cl
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ret
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;
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; Handle shifting of between 32 and 63 bits
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;
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More32:
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mov edx, eax
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xor eax, eax
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and cl, 31
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shl edx, cl
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ret
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ReturnZero:
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xor eax,eax
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xor edx,edx
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ret
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}
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}
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