mirror of https://github.com/acidanthera/audk.git
52 lines
992 B
C
52 lines
992 B
C
/** @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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SPDX-License-Identifier: BSD-2-Clause-Patent
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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
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_allshl (
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void
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)
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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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