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118 lines
3.8 KiB
ArmAsm
118 lines
3.8 KiB
ArmAsm
/*
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* COPYRIGHT: See COPYING in the top level directory
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* PROJECT: ReactOS kernel
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* PURPOSE: Run-Time Library
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* FILE: lib/sdk/crt/math/i386/allmul_asm.s
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* PROGRAMER: Alex Ionescu (alex@relsoft.net)
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*
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* Copyright (C) 2002 Michael Ringgaard.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the project nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES// LOSS OF USE, DATA, OR PROFITS// OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <asm.inc>
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PUBLIC __allmul
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/* FUNCTIONS ***************************************************************/
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.code
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//
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// llmul - long multiply routine
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//
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// Purpose:
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// Does a long multiply (same for signed/unsigned)
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// Parameters are not changed.
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//
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// Entry:
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// Parameters are passed on the stack:
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// 1st pushed: multiplier (QWORD)
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// 2nd pushed: multiplicand (QWORD)
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//
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// Exit:
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// EDX:EAX - product of multiplier and multiplicand
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// NOTE: parameters are removed from the stack
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//
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// Uses:
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// ECX
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//
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__allmul:
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#define ALO [esp + 4] // stack address of a
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#define AHI [esp + 8] // stack address of a
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#define BLO [esp + 12] // stack address of b
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#define BHI [esp + 16] // stack address of b
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//
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// AHI, BHI : upper 32 bits of A and B
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// ALO, BLO : lower 32 bits of A and B
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//
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// ALO * BLO
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// ALO * BHI
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// + BLO * AHI
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// ---------------------
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//
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mov eax,AHI
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mov ecx,BHI
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or ecx,eax //test for both hiwords zero.
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mov ecx,BLO
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jnz short hard //both are zero, just mult ALO and BLO
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mov eax,ALO
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mul ecx
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ret 16 // callee restores the stack
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hard:
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push ebx
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// must redefine A and B since esp has been altered
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#define A2LO [esp + 8] // stack address of a
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#define A2HI [esp + 12] // stack address of a
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#define B2LO [esp + 16] // stack address of b
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#define B2HI [esp + 20] // stack address of b
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mul ecx //eax has AHI, ecx has BLO, so AHI * BLO
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mov ebx,eax //save result
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mov eax,A2LO
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mul dword ptr B2HI //ALO * BHI
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add ebx,eax //ebx = ((ALO * BHI) + (AHI * BLO))
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mov eax,A2LO //ecx = BLO
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mul ecx //so edx:eax = ALO*BLO
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add edx,ebx //now edx has all the LO*HI stuff
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pop ebx
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ret 16 // callee restores the stack
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END
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