CnC_Remastered_Collection/REDALERT/MMX.ASM

329 lines
11 KiB
NASM
Raw Normal View History

;
; Copyright 2020 Electronic Arts Inc.
;
; TiberianDawn.DLL and RedAlert.dll and corresponding source code is free
; software: you can redistribute it and/or modify it under the terms of
; the GNU General Public License as published by the Free Software Foundation,
; either version 3 of the License, or (at your option) any later version.
; TiberianDawn.DLL and RedAlert.dll and corresponding source code is distributed
; in the hope that it will be useful, but with permitted additional restrictions
; under Section 7 of the GPL. See the GNU General Public License in LICENSE.TXT
; distributed with this program. You should have received a copy of the
; GNU General Public License along with permitted additional restrictions
; with this program. If not, see [https://github.com/electronicarts/CnC_Remastered_Collection]>.
;***************************************************************************
;** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S I N C **
;***************************************************************************
;* *
;* Project Name : Command & Conquer *
;* *
;* File Name : MMX.ASM *
;* *
;* Programmer : Steve Tall *
;* *
;* Start Date : May 19th, 1996 *
;* *
;* Last Update : May 19th 1996 [ST] *
;* *
;*-------------------------------------------------------------------------*
;* Functions: *
;* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - *
; include <mmx.inc>
.model flat
;.686
externdef C Detect_MMX_Availability:near
externdef C Single_Line_Trans_Entry:near
externdef C Next_Line:near
externdef C Init_MMX:near
externdef C MMX_Done:near
externdef EndNewShapeJumpTable:byte
externdef NewShapeJumpTable:dword
externdef C Single_Line_Trans:near
externdef MMX_Single_Line_Trans:near
.code
externdef C CPUType:byte
externdef C VendorID:byte
;*********************************************************************************************
;* Detect_MMX_Availability -- Detect the presence of MMX technology. *
;* *
;* *
;* INPUT: Nothing *
;* *
;* OUTPUT: True if MMX technology is available. *
;* *
;* Warnings: *
;* *
;* Note: Based in part on CPUID32.ASM by Intel *
;* *
;* HISTORY: *
;* 05/19/96 ST : Created. *
;*===========================================================================================*
Detect_MMX_Availability proc C
local idflag:byte
local local_cputype:byte
; MMX always available now. ST - 1/3/2019 1:31PM
mov [CPUType], 5
mov eax, 1
ret
;assume processor is at least 386
;
;check whether AC bit in eflags can be toggled.
;If not then processor is 386
mov [idflag],0
pushfd ;get Eflags in EAX
pop eax
mov ecx,eax ;save eflags
xor eax,40000h ;toggle AC bit in eflags
push eax ;new eflags on stack
popfd ;move new value into eflags
pushfd ;get new eflags back into eax
pop eax
xor eax,ecx ;if AC bit not toggled then CPU=386
mov [local_cputype],3
jz @@end_get_cpu ;cpu is 386
push ecx
popfd ;restore AC bit in eflags
;processor is at least 486
;
;Check for ability to set/clear ID flag in EFLAGS
;ID flag indicates ability of processor to execute the CPUID instruction.
;486 not guaranteed to have CPUID inst?
;
mov [local_cputype],4
mov eax,ecx ;original EFLAGS
xor eax,200000h ;toggle ID bit
push eax
popfd
pushfd
pop eax
xor eax,ecx ;check if still toggled
jz @@end_get_cpu
; Execute CPUID instruction to determine vendor, family,
; model and stepping.
;
mov [idflag],1 ;flag ID is available
xor eax,eax
cpuid
mov dword ptr [VendorID],ebx
mov dword ptr [VendorID+4],edx
mov dword ptr [VendorID+8],ecx
mov dword ptr [VendorID+12]," "
cmp eax,1 ;check if 1 is valid
jl @@end_get_cpu ;inp for cpuid inst.
xor eax,eax
inc eax
cpuid ;get stepping, model and family
and ax,0f00H
shr ax,08H
mov [local_cputype],al
@@end_get_cpu: mov al,[local_cputype]
mov [CPUType],al
;
; We have the CPU type in al now.
; If we arent on at least a pentium then we can assume there is no MMX
;
cmp al,5
jl @@no_mmx
mov eax,1
cpuid
test edx,00800000h
jz @@no_mmx
;
; MMX detected - return true
;
mov eax,1
ret
@@no_mmx: xor eax,eax
ret
Detect_MMX_Availability endp
;*********************************************************************************************
;* Init_MMX -- Do any special inits required for MMX support *
;* *
;* *
;* INPUT: Nothing *
;* *
;* OUTPUT: None *
;* *
;* Warnings: *
;* *
;* HISTORY: *
;* 05/19/96 ST : Created. *
;*===========================================================================================*
Init_MMX proc C
mov edi,offset NewShapeJumpTable
mov ecx,offset EndNewShapeJumpTable
sub ecx,edi
shr ecx,2
mov eax,offset Single_Line_Trans
mov ebx,offset MMX_Single_Line_Trans
cld
@@patch_loop: repnz scasd
jnz @@done
mov [edi-4],ebx
test ecx,ecx
jnz @@patch_loop
@@done: ret
Init_MMX endp
;*********************************************************************************************
;* MMX_Done -- Restores floating point capability after MMX usage *
;* *
;* *
;* INPUT: Nothing *
;* *
;* OUTPUT: None *
;* *
;* Warnings: *
;* *
;* HISTORY: *
;* 05/19/96 ST : Created. *
;*===========================================================================================*
MMX_Done proc C
emms
ret
MMX_Done endp
code segment page public use32 'code' ; Need stricter segment alignment
; for pentium optimisations
;*********************************************************************************************
;* MMX_Single_Line_Trans -- draw a single line of transparent pixels using MMX technology *
;* *
;* *
;* INPUT: Esi - ptr to source data *
;* Edi - ptr to destination data *
;* Ecx - width to draw in bytes *
;* *
;* OUTPUT: None *
;* *
;* Warnings: *
;* *
;* HISTORY: *
;* 05/19/96 ST : Created. *
;*===========================================================================================*
align 16
MMX_Single_Line_Trans proc near
;
; If we are doing less than 8 bytes then dont use MMX
;
cmp ecx,8
jge @@mmx_loop
push offset Single_Line_Trans_Entry
ret
;
; Use MMX instructions to mask 8 bytes at once
;
; Creates a bitmask based on the source bytes equality with zero and then uses this to mask
; out the source bytes in the destination data. The advatage that MMX gives us is that there is
; no 'test for zero then jump' required to mask.
;
align 64 ;MMX instructions like 64 byte alignment!
@@mmx_loop:
movq mm0,[esi] ; move 8 bytes of source into mm0
pxor mm1,mm1 ; zero out mm1
pcmpeqb mm1,mm0 ; compare mm0 with 0. Bits get set in mm1
lea esi,[esi+8] ; adjust the source data pointer
pand mm1,[edi] ; and in the destination data to throw away the bytes which arent zero in the source
sub ecx,8 ; adjust the byte counter
por mm1,mm0 ; or in the source with the destination data
movq [edi],mm1 ; write back the destination data
lea edi,[edi+8] ; adjust the destination pointer
cmp ecx,8
jg @@mmx_loop
;
; Jump to the approprite code for drawing the end of this line or going to the next one
;
push offset Next_Line
jcxz @@next_line
push offset Single_Line_Trans_Entry
@@next_line: ret
MMX_Single_Line_Trans endp
code ends
.data
CPUType db 0
VendorID db "Not available",0,0,0,0,0,0
end