optimizing a huge Select Case block using On ... Goto

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Mike Chambers
Posts: 85
Joined: Jun 18, 2006 19:48

optimizing a huge Select Case block using On ... Goto

Post by Mike Chambers »

before the Goto haters shoot me in the head, i don't like using Gotos if i can help it but with this particular bit of code.. speed optimization is CRITICAL!

it's part of an 8086 PC emulator, where it checks what opcode is about to be run, and then takes appropriate action. according to the wiki, FB is "not yet an optimizing compiler" so if that's the case, then this should drastically speed up my code since it wouldn't be turning the select case into a jump table.

here is the original select case block: (Sorry some of the indentation looks messed up, i accidentally used spaces in some part instead of tabs so it looks goofy when pasted here. it looks good in FbEdit)

Code: Select all

	Select Case opcode
		Case &H0  '00 ADD Eb Gb
			modregrm()
			oper1b = readrm8(rm): oper2b = getreg8(reg)
			res8 = oper1b + oper2b
			flag_add8 oper1b, oper2b
			writerm8(rm, res8)
		Case &H1  '01 ADD Ev Gv
			modregrm()
			oper1 = readrm16(rm): oper2 = getreg16(reg)
			res16 = oper1 + oper2
			flag_add16 oper1, oper2
			writerm16(rm, res16)
		Case &H2  '02 ADD Gb Eb
			modregrm()
			oper1b = getreg8(reg): oper2b = readrm8(rm)
			res8 = oper1b + oper2b
			flag_add8 oper1b, oper2b
			putreg8(reg, res8)
		Case &H3  '03 ADD Gv Ev
			modregrm()
			oper1 = getreg16(reg): oper2 = readrm16(rm)
			res16 = oper1 + oper2
			flag_add16 oper1, oper2
			putreg16(reg, res16)
		Case &H4  '04 ADD regal Ib
			oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
			res8 = oper1b + oper2b
			flag_add8 oper1b, oper2b
			regal = res8
		Case &H5  '05 ADD eAX Iv
			oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
			res16 = oper1 + oper2
			flag_add16 oper1, oper2
			regah = res16 Shr 8: regal = res16 And 255
		Case &H6  '06 PUSH reges
			push reges
		Case &H7  '07 POP reges
			reges = pop
		Case &H8  '08 OR Eb Gb
			modregrm()
			oper1b = readrm8(rm): oper2b = getreg8(reg)
			res8 = oper1b Or oper2b
			flag_log8(res8)
			writerm8(rm, res8)
		Case &H9  '09 OR Ev Gv
			modregrm()
			oper1 = readrm16(rm): oper2 = getreg16(reg)
			res16 = oper1 Or oper2
			flag_log16(res16)
			writerm16(rm, res16)
		Case &HA  '0A OR Gb Eb
			modregrm()
			oper1b = getreg8(reg): oper2b = readrm8(rm)
			res8 = oper1b Or oper2b
			flag_log8(res8)
			putreg8(reg, res8)
		Case &HB  '0B OR Gv Ev
			modregrm()
			oper1 = getreg16(reg): oper2 = readrm16(rm)
			res16 = oper1 Or oper2
			flag_log16(res16)
			putreg16(reg, res16)
		Case &HC  '0C OR regal Ib
			oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
			res8 = oper1b Or oper2b
			flag_log8(res8)
			regal = res8
		Case &HD  '0D OR eAX Iv
			oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
			res16 = oper1 Or oper2
			flag_log16(res16)
			regah = res16 Shr 8: regal = res16 And 255
		Case &HE  '0E PUSH regcs
			push regcs
		Case &H10  '10 ADC Eb Gb
			modregrm()
			oper1b = readrm8(rm): oper2b = getreg8(reg)
			res8 = oper1b + oper2b + cf
			flag_adc8 oper1b, oper2b, cf
			writerm8(rm, res8)
		Case &H11  '11 ADC Ev Gv
			modregrm()
			oper1 = readrm16(rm): oper2 = getreg16(reg)
			res16 = oper1 + oper2 + cf
			flag_adc16 oper1, oper2, cf
			writerm16(rm, res16)
		Case &H12  '12 ADC Gb Eb
			modregrm()
			oper1b = getreg8(reg): oper2b = readrm8(rm)
			res8 = oper1b + oper2b + cf
			flag_adc8 oper1b, oper2b, cf
			putreg8(reg, res8)
		Case &H13  '13 ADC Gv Ev
			modregrm()
			oper1 = getreg16(reg): oper2 = readrm16(rm)
			res16 = oper1 + oper2 + cf
			flag_adc16 oper1, oper2, cf
			putreg16(reg, res16)
		Case &H14  '14 ADC regal Ib
			oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
			res8 = oper1b + oper2b + cf
			flag_adc8 oper1b, oper2b, cf
			regal = res8
		Case &H15  '15 ADC eAX Iv
			oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
			res16 = oper1 + oper2 + cf
			flag_adc16 oper1, oper2, cf
			regah = res16 Shr 8: regal = res16 And 255

		Case &H16 '16 PUSH regss
			push regss
		Case &H17 '17 POP regss
			regss = pop
		Case &H18 '18 SBB Eb Gb
			modregrm()
			oper1b = readrm8(rm): oper2b = getreg8(reg)
			res8 = oper1b - (oper2b + cf)
			flag_sbb8 oper1b, oper2b, cf
			writerm8(rm, res8)
		Case &H19 '19 SBB Ev Gv
			modregrm()
			oper1 = readrm16(rm): oper2 = getreg16(reg)
			res16 = oper1 - (oper2 + cf)
			flag_sbb16 oper1, oper2, cf
			writerm16(rm, res16)
		Case &H1A '1A SBB Gb Eb
			modregrm()
			oper1b = getreg8(reg): oper2b = readrm8(rm)
			res8 = oper1b - (oper2b + cf)
			flag_sbb8 oper1b, oper2b, cf
			putreg8(reg, res8)
		Case &H1B '1B SBB Gv Ev
			modregrm()
			oper1 = getreg16(reg): oper2 = readrm16(rm)
			res16 = oper1 - (oper2 + cf)
			flag_sbb16 oper1, oper2, cf
			putreg16(reg, res16)
		Case &H1C '1C SBB regal Ib
			oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
			res8 = oper1b - (oper2b + cf)
			flag_sbb8 oper1b, oper2b, cf
			regal = res8
		Case &H1D '1D SBB eAX Iv
			oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
			res16 = oper1 - (oper2 + cf)
			flag_sbb16 oper1, oper2, cf
			regah = res16 Shr 8: regal = res16 And 255
		Case &H1E '1E PUSH regds
			push regds
		Case &H1F '1F POP regds
			regds = pop
		Case &H20 '20 AND Eb Gb
			modregrm()
			oper1b = readrm8(rm): oper2b = getreg8(reg)
			res8 = oper1b And oper2b
			flag_log8(res8)
			writerm8(rm, res8)
		Case &H21 '21 AND Ev Gv
			modregrm()
			oper1 = readrm16(rm): oper2 = getreg16(reg)
			res16 = oper1 And oper2
			flag_log16(res16)
			writerm16(rm, res16)
		Case &H22 '22 AND Gb Eb
			modregrm()
			oper1b = getreg8(reg): oper2b = readrm8(rm)
			res8 = oper1b And oper2b
			flag_log8(res8)
			putreg8(reg, res8)
		Case &H23 '23 AND Gv Ev
			modregrm()
			oper1 = getreg16(reg): oper2 = readrm16(rm)
			res16 = oper1 And oper2
			flag_log16(res16)
			putreg16(reg, res16)
		Case &H24 '24 AND regal Ib
			oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
			res8 = oper1b And oper2b
			flag_log8(res8)
			regal = res8
		Case &H25 '25 AND eAX Iv
			oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
			res16 = oper1 And oper2
			flag_log16(res16)
			regah = res16 Shr 8: regal = res16 And 255
		Case &H27 '27 DAA
        If ((regal And &HF&) > 9) Or (af = 1) Then
            oper1 = regal + 6
            regal = oper1 And 255
            If (oper1 And &HFF00&) Then cf = 1 Else cf = 0
            af = 1
        Else
            af = 0
        End If
        If ((regal And &HF0&) > &H90&) Or (cf = 1) Then
            regal = regal + &H60&
            cf = 1
        Else
            cf = 0
        End If
        regal = regal And 255
        flag_szp8(regal)
		Case &H28 '28 SUB Eb Gb
			modregrm()
			oper1b = readrm8(rm): oper2b = getreg8(reg)
			res8 = oper1b - oper2b
			flag_sub8 oper1b, oper2b
			writerm8(rm, res8)
		Case &H29 '29 SUB Ev Gv
			modregrm()
			oper1 = readrm16(rm): oper2 = getreg16(reg)
			res16 = oper1 - oper2
			flag_sub16 oper1, oper2
			writerm16(rm, res16)
		Case &H2A '2A SUB Gb Eb
			modregrm()
			oper1b = getreg8(reg): oper2b = readrm8(rm)
			res8 = oper1b - oper2b
			flag_sub8 oper1b, oper2b
			putreg8(reg, res8)
		Case &H2B '2B SUB Gv Ev
			modregrm()
			oper1 = getreg16(reg): oper2 = readrm16(rm)
			res16 = oper1 - oper2
			flag_sub16 oper1, oper2
			putreg16(reg, res16)
		Case &H2C '2C SUB regal Ib
			oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
			res8 = oper1b - oper2b
			flag_sub8 oper1b, oper2b
			regal = res8
		Case &H2D '2D SUB eAX Iv
			oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
			res16 = oper1 - oper2
			flag_sub16 oper1, oper2
			regah = res16 Shr 8: regal = res16 And 255
		Case &H2F '2F DAS
        If ((regal And 15) > 9) Or (af = 1) Then
            oper1 = regal - 6
            regal = oper1 And 255
            If (oper1 And &HFF00&) Then cf = 1 Else cf = 0
            af = 1
        Else
            af = 0
        End If
        If ((regal And &HF0) > &H90&) Or (cf = 1) Then
            regal = regal - &H60&
            cf = 1
        Else
            cf = 0
        End If
        flag_szp8(regal)
		Case &H30 '30 XOR Eb Gb
			modregrm()
			oper1b = readrm8(rm): oper2b = getreg8(reg)
			res8 = oper1b Xor oper2b
			flag_log8(res8)
			writerm8(rm, res8)
		Case &H31 '31 XOR Ev Gv
			modregrm()
			oper1 = readrm16(rm): oper2 = getreg16(reg)
			res16 = oper1 Xor oper2
			flag_log16(res16)
			writerm16(rm, res16)
		Case &H32 '32 XOR Gb Eb
			modregrm()
			oper1b = getreg8(reg): oper2b = readrm8(rm)
			res8 = oper1b Xor oper2b
			flag_log8(res8)
			putreg8(reg, res8)
		Case &H33 '33 XOR Gv Ev
			modregrm()
			oper1 = getreg16(reg): oper2 = readrm16(rm)
			res16 = oper1 Xor oper2
			flag_log16(res16)
			putreg16(reg, res16)
		Case &H34 '34 XOR regal Ib
			oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
			res8 = oper1b Xor oper2b
			flag_log8(res8)
			regal = res8
		Case &H35 '35 XOR eAX Iv
			oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
			res16 = oper1 Xor oper2
			flag_log16(res16)
			regah = res16 Shr 8: regal = res16 And 255
		Case &H37 '37 AAA ASCII
        If ((regal And &HF&) > 9) Or (af = 1) Then
            regal = regal + 6
            regah = regah + 1
            af = 1
            cf = 1
        Else
            af = 0
            cf = 0
        End If
        regal = regal And &HF&
		Case &H38 '38 CMP Eb Gb
			modregrm()
			oper1b = readrm8(rm): oper2b = getreg8(reg)
			flag_sub8 oper1b, oper2b
			If debugmode = 1 Then dprint "  CMP 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
		Case &H39 '39 CMP Ev Gv
			modregrm()
			oper1 = readrm16(rm): oper2 = getreg16(reg)
			flag_sub16 oper1, oper2
			If debugmode = 1 Then dprint "  CMP 16-bit: oper1 = " + Hex$(oper1) + "h, oper2 = " + Hex$(oper2) + "h"
		Case &H3A '3A CMP Gb Eb
			modregrm()
			oper1b = getreg8(reg): oper2b = readrm8(rm)
			flag_sub8 oper1b, oper2b
			If debugmode = 1 Then dprint "  CMP 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
		Case &H3B '3B CMP Gv Ev
			modregrm()
			oper1 = getreg16(reg): oper2 = readrm16(rm)
			flag_sub16 oper1, oper2
			If debugmode = 1 Then dprint "  CMP 16-bit: oper1 = " + Hex$(oper1) + "h, oper2 = " + Hex$(oper2) + "h"
		Case &H3C '3C CMP regal Ib
			oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
			flag_sub8 oper1b, oper2b
			If debugmode = 1 Then dprint "  CMP 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
		Case &H3D '3D CMP eAX Iv
			oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
			flag_sub16 oper1, oper2
			If debugmode = 1 Then dprint "  CMP 16-bit: oper1 = " + Hex$(oper1) + "h, oper2 = " + Hex$(oper2) + "h"
		Case &H3F '3F AAS ASCII
        If ((regal And &HF&) > 9) Or (af = 1) Then
            regal = regal - 6
            regah = regah - 1
            af = 1
            cf = 1
        Else
            af = 0
            cf = 0
        End If
        regal = regal And &HF&
		Case &H40 '40 INC eAX
			oldcf = cf
			oper1 = ((regah Shl 8) Or regal): oper2 = 1
			res16 = oper1 + oper2
			flag_add16 oper1, oper2
			cf = oldcf
			regah = res16 Shr 8: regal = res16 And 255
		Case &H41 '41 INC eCX
			oldcf = cf
			oper1 = ((regch Shl 8) Or regcl): oper2 = 1
			res16 = oper1 + oper2
			flag_add16 oper1, oper2
			cf = oldcf
			putreg16(regcx, res16)
		Case &H42 '42 INC eDX
			oldcf = cf
			oper1 = ((regdh Shl 8) Or regdl): oper2 = 1
			res16 = oper1 + oper2
			flag_add16 oper1, oper2
			cf = oldcf
			putreg16(regdx, res16)
		Case &H43 '43 INC eBX
			oldcf = cf
			oper1 = ((regbh Shl 8) Or regbl): oper2 = 1
			res16 = oper1 + oper2
			flag_add16 oper1, oper2
			cf = oldcf
			putreg16(regbx, res16)
		Case &H44 '44 INC eSP
			oldcf = cf
			oper1 = regsp: oper2 = 1
			res16 = oper1 + oper2
			flag_add16 oper1, oper2
			cf = oldcf
			regsp = res16
		Case &H45 '45 INC eBP
			oldcf = cf
			oper1 = regbp: oper2 = 1
			res16 = oper1 + oper2
			flag_add16 oper1, oper2
			cf = oldcf
			regbp = res16
		Case &H46 '46 INC eSI
			oldcf = cf
			oper1 = regsi: oper2 = 1
			res16 = oper1 + oper2
			flag_add16 oper1, oper2
			cf = oldcf
			regsi = res16
		Case &H47 '47 INC eDI
			oldcf = cf
			oper1 = regdi: oper2 = 1
			res16 = oper1 + oper2
			flag_add16 oper1, oper2
			cf = oldcf
			regdi = res16
		Case &H48 '48 DEC eAX
			oldcf = cf
			oper1 = ((regah Shl 8) Or regal): oper2 = 1
			res16 = oper1 - oper2
			flag_sub16 oper1, oper2
			cf = oldcf
			regah = res16 Shr 8: regal = res16 And 255
		Case &H49 '49 DEC eCX
			oldcf = cf
			oper1 = ((regch Shl 8) Or regcl): oper2 = 1
			res16 = oper1 - oper2
			flag_sub16 oper1, oper2
			cf = oldcf
			putreg16(regcx, res16)
		Case &H4A '4A DEC eDX
			oldcf = cf
			oper1 = ((regdh Shl 8) Or regdl): oper2 = 1
			res16 = oper1 - oper2
			flag_sub16 oper1, oper2
			cf = oldcf
			putreg16(regdx, res16)
		Case &H4B '4B DEC eBX
			oldcf = cf
			oper1 = ((regbh Shl 8) Or regbl): oper2 = 1
			res16 = oper1 - oper2
			flag_sub16 oper1, oper2
			cf = oldcf
			putreg16(regbx, res16)
		Case &H4C '4C DEC eSP
			oldcf = cf
			oper1 = regsp: oper2 = 1
			res16 = oper1 - oper2
			flag_sub16 oper1, oper2
			cf = oldcf
			regsp = res16
		Case &H4D '4D DEC eBP
			oldcf = cf
			oper1 = regbp: oper2 = 1
			res16 = oper1 - oper2
			flag_sub16 oper1, oper2
			cf = oldcf
			regbp = res16
		Case &H4E '4E DEC eSI
			oldcf = cf
			oper1 = regsi: oper2 = 1
			res16 = oper1 - oper2
			flag_sub16 oper1, oper2
			cf = oldcf
			regsi = res16
		Case &H4F '4F DEC eDI
			oldcf = cf
			oper1 = regdi: oper2 = 1
			res16 = oper1 - oper2
			flag_sub16 oper1, oper2
			cf = oldcf
			regdi = res16
		Case &H50 '50 PUSH eAX
			push ((regah Shl 8) Or regal)
		Case &H51 '51 PUSH eCX
			push ((regch Shl 8) Or regcl)
		Case &H52 '52 PUSH eDX
			push ((regdh Shl 8) Or regdl)
		Case &H53 '53 PUSH eBX
			push ((regbh Shl 8) Or regbl)
		Case &H54 '54 PUSH eSP
			push regsp
		Case &H55 '55 PUSH eBP
			push regbp
		Case &H56 '56 PUSH eSI
			push regsi
		Case &H57 '57 PUSH eDI
			push regdi
		Case &H58 '58 POP eAX
		   res16 = pop
			regah = res16 Shr 8: regal = res16 And 255
		Case &H59 '59 POP eCX
		   res16 = pop
			regch = res16 Shr 8: regcl = res16 And 255
		Case &H5A '5A POP eDX
		   res16 = pop
			regdh = res16 Shr 8: regdl = res16 And 255
		Case &H5B '5B POP eBX
		   res16 = pop
			regbh = res16 Shr 8: regbl = res16 And 255
		Case &H5C '5C POP eSP
			regsp = getmem16(regss, regsp)
		Case &H5D '5D POP eBP
			regbp = pop
		Case &H5E '5E POP eSI
			regsi = pop
		Case &H5F '5F POP eDI
			regdi = pop
		Case &H60 '60 PUSHA (80186+)
			oldsp = regsp
         push ((regah Shl 8) Or regal)
         push ((regch Shl 8) Or regcl)
         push ((regdh Shl 8) Or regdl)
         push ((regbh Shl 8) Or regbl)
         push oldsp: push regbp: push regsi: push regdi
		Case &H61 '61 POPA (80186+)
         regdi = pop: regsi = pop: regbp = pop: dummy = pop
         putreg16(regbx, pop): putreg16(regdx, pop): putreg16(regcx, pop): putreg16(regax, pop)
		Case &H68 '68 PUSH Iv (80186+)
			push getmem16(regcs, ip): StepIP 2
		
		Case &h69 '69 IMUL Ev Iv (80186+)
		   modregrm()
         temp1 = readrm16(rm)
         temp2 = getmem16(regcs, ip): StepIP 2
         If (temp1 And &H8000&) = &H8000& Then temp1 = temp1 Or &HFFFF0000
         If (temp2 And &H8000&) = &H8000& Then temp2 = temp2 Or &HFFFF0000
         temp3 = (temp1 * temp2) And &HFFFFFFFF
         putreg16(regax, temp3 And &HFFFF&)
         putreg16(regdx, temp3 Shr 16)
         If ((regdh Shl 8) Or regdl) <> 0 Then cf = 1: of = 1 Else cf = 0: of = 0

		Case &h6A '6A PUSH Ib (80186+)
			push getmem8(regcs, ip): StepIP 1
		
		Case &h6B '6B IMUL Eb Ib (80186+)
		   modregrm()
		   oper1 = signext(readrm8(rm))
         temp1 = signext(getmem8(regcs, ip)): StepIP 1
         temp2 = oper1
         If (temp1 And &H80&) = &H80& Then temp1 = temp1 Or &HFFFFFF00
         If (temp2 And &H80&) = &H80& Then temp2 = temp2 Or &HFFFFFF00
         temp3 = (temp1 * temp2) And &HFFFF&
         putreg16(regax, temp3)
         If regah <> 0 Then cf = 1: of = 1 Else cf = 0: of = 0
		
		Case &h6C To &h6F '80186 port operations, just act as if they're NOPs for now...
		   StepIP(1) 'they have a modregrm() byte we must skip...
	Case &H70 '70 JO Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If of <> 0 Then ip = ip + temp16

    Case &H71 '71 JNO Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If of = 0 Then ip = ip + temp16

    Case &H72 '72 JB Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If cf <> 0 Then ip = ip + temp16

    Case &H73 '73 JNB Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If cf = 0 Then ip = ip + temp16

    Case &H74 '74 JZ Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If zf <> 0 Then ip = ip + temp16

    Case &H75 '75 JNZ Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If zf = 0 Then ip = ip + temp16
    
    Case &H76 '76 JBE Jb
         temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If (cf <> 0) Or (zf <> 0) Then ip = ip + temp16

    Case &H77 '77 JA Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If (cf = 0) And (zf = 0) Then ip = ip + temp16

    Case &H78 '78 JS Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If sf <> 0 Then ip = ip + temp16
    
    Case &H79 '79 JNS Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If sf = 0 Then ip = ip + temp16
    
    Case &H7A '7A JPE Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If pf <> 0 Then ip = ip + temp16
    
    Case &H7B '7B JPO Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If pf = 0 Then ip = ip + temp16
    
    Case &H7C '7C JL Jb
        temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If (sf <> of) Then ip = ip + temp16
    
    Case &H7D '7D JGE Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If (sf = of) Then ip = ip + temp16
    
    Case &H7E '7E JLE Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If (sf <> of) Or (zf <> 0) Then ip = ip + temp16
    
    Case &H7F '7F JG Jb
          temp16 = signext(getmem8(regcs, ip)): StepIP 1
        If (zf = 0) And (sf = of) Then ip = ip + temp16
		Case &H80, &H82 '80/82 GRP1 Eb Ib
			modregrm()
			oper1b = readrm8(rm): oper2b = getmem8(regcs, ip): StepIP 1
			op_grp1(0)
			If reg < 7 Then
				writerm8(rm, res8)
			End If
		Case &H81 '81 GRP1 Ev Iv
			modregrm()
			oper1 = readrm16(rm): oper2 = getmem16(regcs, ip): StepIP 2
			op_grp1(1)
			If reg < 7 Then
				writerm16(rm, res16)
			End If
		Case &H83 '83 GRP1 Ev Ib
			modregrm()
			oper1 = readrm16(rm): oper2 = signext(getmem8(regcs, ip)): StepIP 1
			op_grp1(1)
			If reg < 7 Then
				writerm16(rm, res16)
			End If
		Case &H84 '84 TEST Gb Eb
			modregrm()
			oper1b = getreg8(reg): oper2b = readrm8(rm)
			flag_log8(oper1b And oper2b)
			If debugmode = 1 Then dprint "  TEST 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
		Case &H85 '85 TEST Gv Ev
			modregrm()
			oper1 = getreg16(reg): oper2 = readrm16(rm)
			flag_log16(oper1 And oper2)
		Case &H86 '86 XCHG Gb Eb
			modregrm()
			oper1b = getreg8(reg)
			putreg8(reg, readrm8(rm))
			writerm8(rm, oper1b)
		Case &H87 '87 XCHG Gv Ev
			modregrm()
			oper1 = getreg16(reg)
			putreg16(reg, readrm16(rm))
			writerm16(rm, oper1)
		Case &H88 '88 MOV Eb Gb
			modregrm()
			writerm8(rm, getreg8(reg))
		Case &H89 '89 MOV Ev Gv
			modregrm()
			writerm16(rm, getreg16(reg))
		Case &H8A '8A MOV Gb Eb
			modregrm()
			putreg8(reg, readrm8(rm))
		Case &H8B '8B MOV Gv Ev
			modregrm()
			putreg16(reg, readrm16(rm))
		Case &H8C '8C MOV Ew Sw
			modregrm()
			writerm16(rm, getsegreg(reg))
		Case &H8D '8D LEA Gv M
			modregrm()
			getea(rm)
			putreg16(reg, ea - useseg * 16)
		Case &H8E '8E MOV Sw Ew
			modregrm()
			putsegreg(reg, readrm16(rm))
		Case &H8F '8F POP Ev
			modregrm()
			writerm16(rm, pop)
		Case &H90 '90 NOP
		Case &H91 '91 XCHG eCX eAX
			oper1b = regch
			oper2b = regcl
			regch = regah
			regcl = regal
			regah = oper1b
			regal = oper2b
		Case &H92 '92 XCHG eDX eAX
			oper1b = regdh
			oper2b = regdl
			regdh = regah
			regdl = regal
			regah = oper1b
			regal = oper2b
		Case &H93 '93 XCHG eBX eAX
			oper1b = regbh
			oper2b = regbl
			regbh = regah
			regbl = regal
			regah = oper1b
			regal = oper2b
		Case &H94 '94 XCHG eSP eAX
			oper1 = regsp
			regsp = ((regah Shl 8) Or regal)
			regah = oper1 Shr 8: regal = oper1 And 255
		Case &H95 '95 XCHG eBP eAX
			oper1 = regbp
			regbp = ((regah Shl 8) Or regal)
			regah = oper1 Shr 8: regal = oper1 And 255
		Case &H96 '96 XCHG eSI eAX
			oper1 = regsi
			regsi = ((regah Shl 8) Or regal)
			regah = oper1 Shr 8: regal = oper1 And 255
		Case &H97 '97 XCHG eDI eAX
			oper1 = regdi
			regdi = ((regah Shl 8) Or regal)
			regah = oper1 Shr 8: regal = oper1 And 255
		Case &H98 '98 CBW
			If (regal And &h80) = &h80 Then regah = &hFF Else regah = 0
		Case &H99 '99 CWD
			If (regah And &h80) = &h80 Then
				putreg16(regdx, &hFFFF)
			Else
				putreg16(regdx, 0)
			End If
		Case &h9A '9A CALL Ap
        	oper1 = getmem16(regcs, ip): StepIP 2
        	oper2 = getmem16(regcs, ip): StepIP 2
        	push regcs: push ip: ip = oper1: regcs = oper2
		Case &H9B '9B WAIT
		Case &H9C '9C PUSHF
			push makeflagsword And &hFFF
		Case &H9D '9D POPF
			decodeflagsword pop
		Case &H9E '9E SAHF
			decodeflagsword (makeflagsword And &HFF00&) + regah
		Case &H9F '9F LAHF
			regah = makeflagsword And &hFF
		Case &HA0 'A0 MOV regal Ob
			regal = getmem8(useseg, getmem16(regcs, ip)): StepIP 2
		Case &HA1 'A1 MOV eAX Ov
			oper1 = getmem16(useseg, getmem16(regcs, ip)): StepIP 2
			regah = oper1 Shr 8: regal = oper1 And 255
		Case &HA2 'A2 MOV Ob regal
			putmem8 useseg, getmem16(regcs, ip), regal: StepIP 2
		Case &HA3 'A3 MOV Ov eAX
			putmem16 useseg, getmem16(regcs, ip), ((regah Shl 8) Or regal): StepIP 2
		Case &HA4 'A4 MOVSB
			Do
				If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
				putmem8 reges, regdi, getmem8(useseg, regsi)
				If df Then regsi = regsi - 1: regdi = regdi - 1 Else regsi = regsi + 1: regdi = regdi + 1
				If (reptype <> 0) Then
					putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
				End If
			Loop Until reptype = 0
		Case &HA5 'A5 MOVSW
			Do
				If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
				putmem16 reges, regdi, getmem16(useseg, regsi)
				If df Then regsi = regsi - 2: regdi = regdi - 2 Else regsi = regsi + 2: regdi = regdi + 2
				If (reptype <> 0) Then
					putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
				End If
			Loop Until reptype = 0
		Case &HA6 'A6 CMPSB
			Do
				If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
				oper1b = getmem8(useseg, regsi): oper2b = getmem8(reges, regdi)
				If df Then regsi = regsi - 1: regdi = regdi - 1 Else regsi = regsi + 1: regdi = regdi + 1
				flag_sub8 oper1b, oper2b
			If debugmode = 1 Then dprint "  CMP 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
				If (reptype <> 0) Then
					putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
				End If
				If (reptype = 1) And (zf = 0) Then Exit Do
				If (reptype = 2) And (zf = 1) Then Exit Do
			Loop Until reptype = 0
		Case &HA7 'A7 CMPSW
			Do
				If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
				oper1 = getmem16(useseg, regsi): oper2 = getmem16(reges, regdi)
				If df Then regsi = regsi - 2: regdi = regdi - 2 Else regsi = regsi + 2: regdi = regdi + 2
				flag_sub16 oper1, oper2
			If debugmode = 1 Then dprint "  CMP 16-bit: oper1 = " + Hex$(oper1) + "h, oper2 = " + Hex$(oper2) + "h"
				If (reptype <> 0) Then
					putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
				End If
				If (reptype = 1) And (zf = 0) Then Exit Do
				If (reptype = 2) And (zf = 1) Then Exit Do
			Loop Until reptype = 0
		Case &HA8 'A8 TEST regal Ib
			oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
			flag_log8(oper1b And oper2b)
			If debugmode = 1 Then dprint "  TEST 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
		Case &HA9 'A9 TEST eAX Iv
			oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
			flag_log16(oper1 And oper2)
		Case &HAA 'AA STOSB
			Do
				If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
				putmem8 reges, regdi, regal
				If df Then regdi = regdi - 1 Else regdi = regdi + 1
				If (reptype <> 0) Then
					putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
				End If
			Loop Until reptype = 0
		Case &HAB 'AB STOSW
			Do
				If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
				putmem16 reges, regdi, ((regah Shl 8) Or regal)
				If df Then regdi = regdi - 2 Else regdi = regdi + 2
				If (reptype <> 0) Then
					putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
				End If
			Loop Until reptype = 0
		Case &HAC 'AC LODSB
			Do
				If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
				regal = getmem8(useseg, regsi)
				If df Then regsi = regsi - 1 Else regsi = regsi + 1
				If (reptype <> 0) Then
					putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
				End If
			Loop Until reptype = 0
		Case &HAD 'AD LODSW
			Do
				If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
				oper1 = getmem16(useseg, regsi)
				regah = oper1 Shr 8: regal = oper1 And 255
				If df Then regsi = regsi - 2 Else regsi = regsi + 2
				If (reptype <> 0) Then
					putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
				End If
			Loop Until reptype = 0
		Case &HAE 'AE SCASB
			Do
				If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
				oper1b = getmem8(reges, regdi): oper2b = regal
				flag_sub8 oper1b, oper2b
			If debugmode = 1 Then dprint "  CMP 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
				If df Then regdi = regdi - 1 Else regdi = regdi + 1
				If (reptype <> 0) Then
					putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
				End If
				If (reptype = 1) And (zf = 0) Then Exit Do
				If (reptype = 2) And (zf = 1) Then Exit Do
			Loop Until reptype = 0
		Case &HAF 'AF SCASW
			Do
				If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
				oper1 = getmem16(reges, regdi): oper2 = ((regah Shl 8) Or regal)
				flag_sub16 oper1, oper2
			If debugmode = 1 Then dprint "  CMP 16-bit: oper1 = " + Hex$(oper1) + "h, oper2 = " + Hex$(oper2) + "h"
				If df Then regdi = regdi - 2 Else regdi = regdi + 2
				If (reptype <> 0) Then
					putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
				End If
				If (reptype = 1) And (zf = 0) Then Exit Do
				If (reptype = 2) And (zf = 1) Then Exit Do
			Loop Until reptype = 0
		Case &HB0 'B0 MOV regal Ib
			regal = getmem8(regcs, ip): StepIP 1
		Case &HB1 'B1 MOV regcl Ib
			regcl = getmem8(regcs, ip): StepIP 1
		Case &HB2 'B2 MOV regdl Ib
			regdl = getmem8(regcs, ip): StepIP 1
		Case &HB3 'B3 MOV regbl Ib
			regbl = getmem8(regcs, ip): StepIP 1
		Case &HB4 'B4 MOV regah Ib
			regah = getmem8(regcs, ip): StepIP 1
		Case &HB5 'B5 MOV regch Ib
			regch = getmem8(regcs, ip): StepIP 1
		Case &HB6 'B6 MOV regdh Ib
			regdh = getmem8(regcs, ip): StepIP 1
		Case &HB7 'B7 MOV regbh Ib
			regbh = getmem8(regcs, ip): StepIP 1
		Case &HB8 'B8 MOV eAX Iv
			oper1 = getmem16(regcs, ip): StepIP 2
			regah = oper1 Shr 8: regal = oper1 And 255
		Case &HB9 'B9 MOV eCX Iv
			oper1 = getmem16(regcs, ip): StepIP 2
			regch = oper1 Shr 8: regcl = oper1 And 255
		Case &HBA 'BA MOV eDX Iv
			oper1 = getmem16(regcs, ip): StepIP 2
			regdh = oper1 Shr 8: regdl = oper1 And 255
		Case &HBB 'BB MOV eBX Iv
			oper1 = getmem16(regcs, ip): StepIP 2
			regbh = oper1 Shr 8: regbl = oper1 And 255
		Case &HBC 'BC MOV eSP Iv
			regsp = getmem16(regcs, ip): StepIP 2
		Case &HBD 'BD MOV eBP Iv
			regbp = getmem16(regcs, ip): StepIP 2
		Case &HBE 'BE MOV eSI Iv
			regsi = getmem16(regcs, ip): StepIP 2
		Case &HBF 'BF MOV eDI Iv
			regdi = getmem16(regcs, ip): StepIP 2
		Case &HC0 'C0 GRP2 byte imm8 (80186+)
			modregrm()
			oper1b = readrm8(rm)
			oper2b = getmem8(regcs, ip): StepIP 1
			writerm8(rm, op_grp2_8(oper2b))

		Case &HC1 'C1 GRP2 word imm8 (80186+)
			modregrm()
			oper1 = readrm16(rm)
			oper2 = getmem8(regcs, ip): StepIP 1
			writerm16(rm, op_grp2_16(oper2))

		Case &HC2 'C2 RET Iw
			oper1 = getmem16(regcs, ip)
			ip = pop
			regsp = regsp + oper1 
			
		Case &HC3 'C3 RET
			ip = pop
		Case &HC4 'C4 LES Gv Mp
        modregrm()
        getea(rm)
        putreg16(reg, read86(ea) + read86(ea + 1) * 256)
        reges = read86(ea + 2) + read86(ea + 3) * 256
		Case &HC5 'C5 LDS Gv Mp
        modregrm()
        getea(rm)
        putreg16(reg, read86(ea) + read86(ea + 1) * 256)
        regds = read86(ea + 2) + read86(ea + 3) * 256
		Case &HC6 'C6 MOV Eb Ib
			modregrm()
			writerm8(rm, getmem8(regcs, ip)): StepIP 1
		Case &HC7 'C7 MOV Ev Iv
			modregrm()
			writerm16(rm, getmem16(regcs, ip)): StepIP 2
			
	Case &hC8 'C8 ENTER (80186+)
		  stacksize = getmem16(regcs, ip): StepIP 2
    	  nestlev = getmem8(regcs, ip): StepIP 1
    	  push regbp
    	  frametemp = regsp
		  If nestlev <> 0 Then
    	  		For temp16 = 1 To nestlev - 1
    	  			regbp = regbp - 2
    	  			push regbp
    	  		Next temp16
    	  		push regsp
		  End If
		  regbp = frametemp
		  regsp = regbp - stacksize
    	  
	Case &HC9 'C9 LEAVE (80186+)
             regsp = regbp
             regbp = pop

		Case &HCA 'CA RETF Iw
			oper1 = getmem16(regcs, ip)
			ip = pop: regcs = pop
			regsp = regsp + oper1
		Case &HCB 'CB RETF
			ip = pop: regcs = pop
		Case &HCC 'CC INT 3
			intcall86 3
		Case &HCD 'CD INT Ib
			oper1 = getmem8(regcs, ip): StepIP 1
			intcall86 oper1
		Case &HCE 'CE INTO
			If of Then intcall86 4
		Case &HCF 'CF IRET
			ip = pop: regcs = pop
			decodeflagsword pop
		Case &HD0 'D0 GRP2 Eb 1
			modregrm()
			oper1b = readrm8(rm)
			writerm8(rm, op_grp2_8(1))
		Case &HD1 'D1 GRP2 Ev 1
			modregrm()
			oper1 = readrm16(rm)
			writerm16(rm, op_grp2_16(1))
		Case &HD2 'D2 GRP2 Eb regcl
			modregrm()
			oper1b = readrm8(rm)
			writerm8(rm, op_grp2_8(regcl))
		Case &HD3 'D3 GRP2 Ev regcl
			modregrm()
			oper1 = readrm16(rm)
			writerm16(rm, op_grp2_16(regcl))
		Case &HD4 'D4 AAM I0
        oper1 = getmem8(regcs, ip): StepIP 1
        If oper1 = 0 Then intcall86 0: Exit Sub 'division by zero
        regah = (regal \ oper1) And 255
        regal = (regal Mod oper1) And 255
        flag_szp16 ((regah Shl 8) Or regal)

		Case &HD5 'D5 AAD I0
        oper1 = getmem8(regcs, ip): StepIP 1
        regal = (regah * oper1 + regal) And 255
        regah = 0
        flag_szp16(regah * oper1 + regal)
        sf = 0
		Case &HD7 'D7 XLAT
			regal = read86(useseg * 16 + ((regbh Shl 8) Or regbl) + regal)
		Case &hD8 To &hDF 'escape
			StepIP 1
		Case &HE0 'E0 LOOPNZ Jb
      	temp16 = signext(getmem8(regcs, ip)): StepIP 1
        	putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
        	If (((regch Shl 8) Or regcl) <> 0) And (zf = 0) Then ip = ip + temp16

		Case &HE1 'E1 LOOPZ Jb
        	temp16 = signext(getmem8(regcs, ip)): StepIP 1
        	putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
        	If (((regch Shl 8) Or regcl) <> 0) And (zf = 1) Then ip = ip + temp16
      
		Case &HE2 'E2 LOOP Jb
      	temp16 = signext(getmem8(regcs, ip)): StepIP 1
        	putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
        	If ((regch Shl 8) Or regcl) <> 0 Then ip = ip + temp16

		Case &HE3 'E3 JCXZ Jb
      	temp16 = signext(getmem8(regcs, ip)): StepIP 1
        	If ((regch Shl 8) Or regcl) = 0 Then ip = ip + temp16

		Case &HE4 'E4 IN regal Ib
        oper1b = getmem8(regcs, ip)
        StepIP 1
        regal = portin(oper1b)
		Case &HE5 'E5 IN eAX Ib
        oper1b = getmem8(regcs, ip)
        StepIP 1
        putreg16(regax, portin(oper1b))
		Case &HE6 'E6 OUT Ib regal
        oper1b = getmem8(regcs, ip)
      	StepIP 1
      	portout16 = 0
     		portout oper1b, regal
		Case &HE7 'E7 OUT Ib eAX
        oper1b = getmem8(regcs, ip)
      	StepIP 1
      	portout16 = 1
      	portout oper1b, ((regah Shl 8) Or regal)

		Case &HE8 'E8 CALL Jv
			oper1 = getmem16(regcs, ip): StepIP 2
			push ip
			ip = ip + oper1
		Case &HE9 'E9 JMP Jv
			oper1 = getmem16(regcs, ip): StepIP 2
			ip = ip + oper1
		Case &HEA 'EA JMP Ap
			oper1 = getmem16(regcs, ip): StepIP 2
			oper2 = getmem16(regcs, ip)
			ip = oper1: regcs = oper2
		Case &HEB 'EB JMP Jb
			oper1 = signext(getmem8(regcs, ip)): StepIP 1
			ip = ip + oper1
		Case &HEC 'EC IN regal regdx
        oper1 = ((regdh Shl 8) Or regdl)
        regal = portin(oper1)
		Case &HED 'ED IN eAX regdx
        oper1 = ((regdh Shl 8) Or regdl)
        putreg16(regax, portin(oper1))
		Case &HEE 'EE OUT regdx regal
        oper1 = ((regdh Shl 8) Or regdl)
        portout16 = 0
        portout oper1, regal
		Case &HEF 'EF OUT regdx eAX
        oper1 = ((regdh Shl 8) Or regdl)
        portout16 = 1
        portout oper1, ((regah Shl 8) Or regal)
		Case &HF0 'F0 LOCK
		Case &HF4 'F4 HLT
			ip = ip - 1
			If running <> 2 Then
				cprint "HLT executed."
				SDL_WM_SetCaption("Fake86 [halted]", 0)
				running = 2
			End If
		Case &HF5 'F5 CMC
			If cf = 0 Then cf = 1 Else cf = 0
		Case &HF6 'F6 GRP3a Eb
        modregrm()
        oper1b = readrm8(rm)
        op_grp3(0)
        If (reg > 1) And (reg < 4) Then
        		writerm8(rm, res8)
        End If

		Case &HF7 'F7 GRP3b Ev
        modregrm()
        oper1 = readrm16(rm)
        op_grp3(1)
        If (reg > 1) And (reg < 4) Then
        		writerm16(rm, res16)
        End If
		Case &HF8 'F8 CLC
			cf = 0
		Case &HF9 'F9 STC
			cf = 1
		Case &HFA 'FA CLI
			ifl = 0
		Case &HFB 'FB STI
			ifl = 1
		Case &HFC 'FC CLD
			df = 0
		Case &HFD 'FD STD
			df = 1
		Case &HFE 'FE GRP4 Eb
        modregrm()
        oper1b = readrm8(rm): oper2b = 1
        If reg = 0 Then
            temp = cf
            			res8 = oper1b + oper2b
			flag_add8 oper1b, oper2b
            cf = temp: writerm8(rm, res8)
        ElseIf reg = 1 Then
            temp = cf
            			res8 = oper1b - oper2b
			flag_sub8 oper1b, oper2b
            cf = temp: writerm8(rm, res8)
        Else
        		intcall86 6
        End If
		Case &HFF 'FF GRP5 Ev
        modregrm()
        oper1 = readrm16(rm)
        op_grp5()
		Case Else
			intcall86 6
	End Select

EDIT: gotta split this into 2 posts, it's too big to fit in 1...
Top
Mike Chambers
Posts: 85
Joined: Jun 18, 2006 19:48

Post by Mike Chambers »

now, here's what i've done to convert it into an On ... Goto jump table. problem is, things aren't jumping to the right places and i can't figure out why for the life of me. i've never used On ... Goto before, but it looks like it should be really straightforward on the wiki:

Code: Select all

	opjump = opcode + 1
	On opjump Goto op_0,op_1,op_2,op_3,op_4,op_5,op_6,op_7,op_8,op_9,op_A,op_B,op_C,op_D,op_E,op_unknown,op_10,op_11,op_12,op_13,op_14,op_15,op_16,op_17,op_18,op_19,op_1A,op_1B,op_1C,op_1D,op_1E,op_1F,op_20,_
	op_21,op_22,op_23,op_24,op_25,op_unknown,op_27,op_28,op_29,op_2A,op_2B,op_2C,op_2D,op_unknown,op_2F,op_30,op_31,op_32,op_33,op_34,op_35,op_unknown,op_37,op_38,op_39,op_3A,op_3B,op_3C,op_3D,op_unknown,op_3F,_
	op_40,op_41,op_42,op_43,op_44,op_45,op_46,op_47,op_48,op_49,op_4A,op_4B,op_4C,op_4D,op_4E,op_4F,op_50,op_51,op_52,op_53,op_54,op_55,op_56,op_57,op_58,op_59,op_5A,op_5B,op_5C,op_5D,op_5E,op_5F,op_60,op_61,_
	op_unknown,op_unknown,op_unknown,op_unknown,op_unknown,op_unknown,op_68,op_69,op_6A,op_6B,op_6C,op_6D,op_6E,op_6F,op_70,op_71,op_72,op_73,op_74,op_75,op_76,op_77,op_78,op_79,op_7A,op_7B,op_7C,op_7D,op_7E,op_7F,_
	op_80,op_81,op_80,op_83,op_84,op_85,op_86,op_87,op_88,op_89,op_8A,op_8B,op_8C,op_8D,op_8E,op_8F,op_90,op_91,op_92,op_93,op_94,op_95,op_96,op_97,op_98,op_99,op_9A,op_9B,op_9C,op_9D,op_9E,op_9F,op_A0,op_A1,op_A2,_
	op_A3,op_A4,op_A5,op_A6,op_A7,op_A8,op_A9,op_AA,op_AB,op_AC,op_AD,op_AE,op_AF,op_B0,op_B1,op_B2,op_B3,op_B4,op_B5,op_B6,op_B7,op_B8,op_B9,op_BA,op_BB,op_BC,op_BD,op_BE,op_BF,op_C0,op_C1,op_C2,op_C3,op_C4,_
	op_C5,op_C6,op_C7,op_C8,op_C9,op_CA,op_CB,op_CC,op_CD,op_CE,op_CF,op_D0,op_D1,op_D2,op_D3,op_D4,op_D5,op_unknown,op_D7,op_D8,op_D9,op_DA,op_DB,op_DC,op_DD,op_DE,op_DF,op_E0,op_E1,op_E2,op_E3,op_E4,op_E5,_
	op_E6,op_E7,op_E8,op_E9,op_EA,op_EB,op_EC,op_ED,op_EE,op_EF,op_F0,op_unknown,op_unknown,op_unknown,op_F4,op_F5,op_F6,op_F7,op_F8,op_F9,op_FA,op_FB,op_FC,op_FD,op_FE,op_FF
	GoTo op_unknown
	op_0:  '00 ADD Eb Gb
		modregrm()
		oper1b = readrm8(rm): oper2b = getreg8(reg)
		res8 = oper1b + oper2b
		flag_add8 oper1b, oper2b
		writerm8(rm, res8)
	goto endofops
	op_1:  '01 ADD Ev Gv
		modregrm()
		oper1 = readrm16(rm): oper2 = getreg16(reg)
		res16 = oper1 + oper2
		flag_add16 oper1, oper2
		writerm16(rm, res16)
	goto endofops
	op_2:  '02 ADD Gb Eb
		modregrm()
		oper1b = getreg8(reg): oper2b = readrm8(rm)
		res8 = oper1b + oper2b
		flag_add8 oper1b, oper2b
		putreg8(reg, res8)
	goto endofops
	op_3:  '03 ADD Gv Ev
		modregrm()
		oper1 = getreg16(reg): oper2 = readrm16(rm)
		res16 = oper1 + oper2
		flag_add16 oper1, oper2
		putreg16(reg, res16)
	goto endofops
	op_4:  '04 ADD regal Ib
		oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
		res8 = oper1b + oper2b
		flag_add8 oper1b, oper2b
		regal = res8
	goto endofops
	op_5:  '05 ADD eAX Iv
		oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
		res16 = oper1 + oper2
		flag_add16 oper1, oper2
		regah = res16 Shr 8: regal = res16 And 255
	goto endofops
	op_6:  '06 PUSH reges
		push reges
	goto endofops
	op_7:  '07 POP reges
		reges = pop
	goto endofops
	op_8:  '08 OR Eb Gb
		modregrm()
		oper1b = readrm8(rm): oper2b = getreg8(reg)
		res8 = oper1b Or oper2b
		flag_log8(res8)
		writerm8(rm, res8)
	goto endofops
	op_9:  '09 OR Ev Gv
		modregrm()
		oper1 = readrm16(rm): oper2 = getreg16(reg)
		res16 = oper1 Or oper2
		flag_log16(res16)
		writerm16(rm, res16)
	goto endofops
	op_A:  '0A OR Gb Eb
		modregrm()
		oper1b = getreg8(reg): oper2b = readrm8(rm)
		res8 = oper1b Or oper2b
		flag_log8(res8)
		putreg8(reg, res8)
	goto endofops
	op_B:  '0B OR Gv Ev
		modregrm()
		oper1 = getreg16(reg): oper2 = readrm16(rm)
		res16 = oper1 Or oper2
		flag_log16(res16)
		putreg16(reg, res16)
	goto endofops
	op_C:  '0C OR regal Ib
		oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
		res8 = oper1b Or oper2b
		flag_log8(res8)
		regal = res8
	goto endofops
	op_D:  '0D OR eAX Iv
		oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
		res16 = oper1 Or oper2
		flag_log16(res16)
		regah = res16 Shr 8: regal = res16 And 255
	goto endofops
	op_E:  '0E PUSH regcs
		push regcs
	goto endofops
	op_10:  '10 ADC Eb Gb
		modregrm()
		oper1b = readrm8(rm): oper2b = getreg8(reg)
		res8 = oper1b + oper2b + cf
		flag_adc8 oper1b, oper2b, cf
		writerm8(rm, res8)
	goto endofops
	op_11:  '11 ADC Ev Gv
		modregrm()
		oper1 = readrm16(rm): oper2 = getreg16(reg)
		res16 = oper1 + oper2 + cf
		flag_adc16 oper1, oper2, cf
		writerm16(rm, res16)
	goto endofops
	op_12:  '12 ADC Gb Eb
		modregrm()
		oper1b = getreg8(reg): oper2b = readrm8(rm)
		res8 = oper1b + oper2b + cf
		flag_adc8 oper1b, oper2b, cf
		putreg8(reg, res8)
	goto endofops
	op_13:  '13 ADC Gv Ev
		modregrm()
		oper1 = getreg16(reg): oper2 = readrm16(rm)
		res16 = oper1 + oper2 + cf
		flag_adc16 oper1, oper2, cf
		putreg16(reg, res16)
	goto endofops
	op_14:  '14 ADC regal Ib
		oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
		res8 = oper1b + oper2b + cf
		flag_adc8 oper1b, oper2b, cf
		regal = res8
	goto endofops
	op_15:  '15 ADC eAX Iv
		oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
		res16 = oper1 + oper2 + cf
		flag_adc16 oper1, oper2, cf
		regah = res16 Shr 8: regal = res16 And 255
	
	goto endofops
	op_16: '16 PUSH regss
		push regss
	goto endofops
	op_17: '17 POP regss
		regss = pop
	goto endofops
	op_18: '18 SBB Eb Gb
		modregrm()
		oper1b = readrm8(rm): oper2b = getreg8(reg)
		res8 = oper1b - (oper2b + cf)
		flag_sbb8 oper1b, oper2b, cf
		writerm8(rm, res8)
	goto endofops
	op_19: '19 SBB Ev Gv
		modregrm()
		oper1 = readrm16(rm): oper2 = getreg16(reg)
		res16 = oper1 - (oper2 + cf)
		flag_sbb16 oper1, oper2, cf
		writerm16(rm, res16)
	goto endofops
	op_1A: '1A SBB Gb Eb
		modregrm()
		oper1b = getreg8(reg): oper2b = readrm8(rm)
		res8 = oper1b - (oper2b + cf)
		flag_sbb8 oper1b, oper2b, cf
		putreg8(reg, res8)
	goto endofops
	op_1B: '1B SBB Gv Ev
		modregrm()
		oper1 = getreg16(reg): oper2 = readrm16(rm)
		res16 = oper1 - (oper2 + cf)
		flag_sbb16 oper1, oper2, cf
		putreg16(reg, res16)
	goto endofops
	op_1C: '1C SBB regal Ib
		oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
		res8 = oper1b - (oper2b + cf)
		flag_sbb8 oper1b, oper2b, cf
		regal = res8
	goto endofops
	op_1D: '1D SBB eAX Iv
		oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
		res16 = oper1 - (oper2 + cf)
		flag_sbb16 oper1, oper2, cf
		regah = res16 Shr 8: regal = res16 And 255
	goto endofops
	op_1E: '1E PUSH regds
		push regds
	goto endofops
	op_1F: '1F POP regds
		regds = pop
	goto endofops
	op_20: '20 AND Eb Gb
		modregrm()
		oper1b = readrm8(rm): oper2b = getreg8(reg)
		res8 = oper1b And oper2b
		flag_log8(res8)
		writerm8(rm, res8)
	goto endofops
	op_21: '21 AND Ev Gv
		modregrm()
		oper1 = readrm16(rm): oper2 = getreg16(reg)
		res16 = oper1 And oper2
		flag_log16(res16)
		writerm16(rm, res16)
	goto endofops
	op_22: '22 AND Gb Eb
		modregrm()
		oper1b = getreg8(reg): oper2b = readrm8(rm)
		res8 = oper1b And oper2b
		flag_log8(res8)
		putreg8(reg, res8)
	goto endofops
	op_23: '23 AND Gv Ev
		modregrm()
		oper1 = getreg16(reg): oper2 = readrm16(rm)
		res16 = oper1 And oper2
		flag_log16(res16)
		putreg16(reg, res16)
	goto endofops
	op_24: '24 AND regal Ib
		oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
		res8 = oper1b And oper2b
		flag_log8(res8)
		regal = res8
	goto endofops
	op_25: '25 AND eAX Iv
		oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
		res16 = oper1 And oper2
		flag_log16(res16)
		regah = res16 Shr 8: regal = res16 And 255
	goto endofops
	op_27: '27 DAA
	        If ((regal And &HF&) > 9) Or (af = 1) Then
	            oper1 = regal + 6
	            regal = oper1 And 255
	            If (oper1 And &HFF00&) Then cf = 1 Else cf = 0
	            af = 1
	        Else
	            af = 0
	        End If
	        If ((regal And &HF0&) > &H90&) Or (cf = 1) Then
	            regal = regal + &H60&
	            cf = 1
	        Else
	            cf = 0
	        End If
	        regal = regal And 255
	        flag_szp8(regal)
	goto endofops
	op_28: '28 SUB Eb Gb
		modregrm()
		oper1b = readrm8(rm): oper2b = getreg8(reg)
		res8 = oper1b - oper2b
		flag_sub8 oper1b, oper2b
		writerm8(rm, res8)
	goto endofops
	op_29: '29 SUB Ev Gv
		modregrm()
		oper1 = readrm16(rm): oper2 = getreg16(reg)
		res16 = oper1 - oper2
		flag_sub16 oper1, oper2
		writerm16(rm, res16)
	goto endofops
	op_2A: '2A SUB Gb Eb
		modregrm()
		oper1b = getreg8(reg): oper2b = readrm8(rm)
		res8 = oper1b - oper2b
		flag_sub8 oper1b, oper2b
		putreg8(reg, res8)
	goto endofops
	op_2B: '2B SUB Gv Ev
		modregrm()
		oper1 = getreg16(reg): oper2 = readrm16(rm)
		res16 = oper1 - oper2
		flag_sub16 oper1, oper2
		putreg16(reg, res16)
	goto endofops
	op_2C: '2C SUB regal Ib
		oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
		res8 = oper1b - oper2b
		flag_sub8 oper1b, oper2b
		regal = res8
	goto endofops
	op_2D: '2D SUB eAX Iv
		oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
		res16 = oper1 - oper2
		flag_sub16 oper1, oper2
		regah = res16 Shr 8: regal = res16 And 255
	goto endofops
	op_2F: '2F DAS
	        If ((regal And 15) > 9) Or (af = 1) Then
	            oper1 = regal - 6
	            regal = oper1 And 255
	            If (oper1 And &HFF00&) Then cf = 1 Else cf = 0
	            af = 1
	        Else
	            af = 0
	        End If
	        If ((regal And &HF0) > &H90&) Or (cf = 1) Then
	            regal = regal - &H60&
	            cf = 1
	        Else
	            cf = 0
	        End If
	        flag_szp8(regal)
	goto endofops
	op_30: '30 XOR Eb Gb
		modregrm()
		oper1b = readrm8(rm): oper2b = getreg8(reg)
		res8 = oper1b Xor oper2b
		flag_log8(res8)
		writerm8(rm, res8)
	goto endofops
	op_31: '31 XOR Ev Gv
		modregrm()
		oper1 = readrm16(rm): oper2 = getreg16(reg)
		res16 = oper1 Xor oper2
		flag_log16(res16)
		writerm16(rm, res16)
	goto endofops
	op_32: '32 XOR Gb Eb
		modregrm()
		oper1b = getreg8(reg): oper2b = readrm8(rm)
		res8 = oper1b Xor oper2b
		flag_log8(res8)
		putreg8(reg, res8)
	goto endofops
	op_33: '33 XOR Gv Ev
		modregrm()
		oper1 = getreg16(reg): oper2 = readrm16(rm)
		res16 = oper1 Xor oper2
		flag_log16(res16)
		putreg16(reg, res16)
	goto endofops
	op_34: '34 XOR regal Ib
		oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
		res8 = oper1b Xor oper2b
		flag_log8(res8)
		regal = res8
	goto endofops
	op_35: '35 XOR eAX Iv
		oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
		res16 = oper1 Xor oper2
		flag_log16(res16)
		regah = res16 Shr 8: regal = res16 And 255
	goto endofops
	op_37: '37 AAA ASCII
	        If ((regal And &HF&) > 9) Or (af = 1) Then
	            regal = regal + 6
	            regah = regah + 1
	            af = 1
	            cf = 1
	        Else
	            af = 0
	            cf = 0
	        End If
	        regal = regal And &HF&
	goto endofops
	op_38: '38 CMP Eb Gb
		modregrm()
		oper1b = readrm8(rm): oper2b = getreg8(reg)
		flag_sub8 oper1b, oper2b
		If debugmode = 1 Then dprint "  CMP 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
	goto endofops
	op_39: '39 CMP Ev Gv
		modregrm()
		oper1 = readrm16(rm): oper2 = getreg16(reg)
		flag_sub16 oper1, oper2
		If debugmode = 1 Then dprint "  CMP 16-bit: oper1 = " + Hex$(oper1) + "h, oper2 = " + Hex$(oper2) + "h"
	goto endofops
	op_3A: '3A CMP Gb Eb
		modregrm()
		oper1b = getreg8(reg): oper2b = readrm8(rm)
		flag_sub8 oper1b, oper2b
		If debugmode = 1 Then dprint "  CMP 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
	goto endofops
	op_3B: '3B CMP Gv Ev
		modregrm()
		oper1 = getreg16(reg): oper2 = readrm16(rm)
		flag_sub16 oper1, oper2
		If debugmode = 1 Then dprint "  CMP 16-bit: oper1 = " + Hex$(oper1) + "h, oper2 = " + Hex$(oper2) + "h"
	goto endofops
	op_3C: '3C CMP regal Ib
		oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
		flag_sub8 oper1b, oper2b
		If debugmode = 1 Then dprint "  CMP 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
	goto endofops
	op_3D: '3D CMP eAX Iv
		oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
		flag_sub16 oper1, oper2
		If debugmode = 1 Then dprint "  CMP 16-bit: oper1 = " + Hex$(oper1) + "h, oper2 = " + Hex$(oper2) + "h"
	goto endofops
	op_3F: '3F AAS ASCII
	        If ((regal And &HF&) > 9) Or (af = 1) Then
	            regal = regal - 6
	            regah = regah - 1
	            af = 1
	            cf = 1
	        Else
	            af = 0
	            cf = 0
	        End If
	        regal = regal And &HF&
	goto endofops
	op_40: '40 INC eAX
		oldcf = cf
		oper1 = ((regah Shl 8) Or regal): oper2 = 1
		res16 = oper1 + oper2
		flag_add16 oper1, oper2
		cf = oldcf
		regah = res16 Shr 8: regal = res16 And 255
	goto endofops
	op_41: '41 INC eCX
		oldcf = cf
		oper1 = ((regch Shl 8) Or regcl): oper2 = 1
		res16 = oper1 + oper2
		flag_add16 oper1, oper2
		cf = oldcf
		putreg16(regcx, res16)
	goto endofops
	op_42: '42 INC eDX
		oldcf = cf
		oper1 = ((regdh Shl 8) Or regdl): oper2 = 1
		res16 = oper1 + oper2
		flag_add16 oper1, oper2
		cf = oldcf
		putreg16(regdx, res16)
	goto endofops
	op_43: '43 INC eBX
		oldcf = cf
		oper1 = ((regbh Shl 8) Or regbl): oper2 = 1
		res16 = oper1 + oper2
		flag_add16 oper1, oper2
		cf = oldcf
		putreg16(regbx, res16)
	goto endofops
	op_44: '44 INC eSP
		oldcf = cf
		oper1 = regsp: oper2 = 1
		res16 = oper1 + oper2
		flag_add16 oper1, oper2
		cf = oldcf
		regsp = res16
	goto endofops
	op_45: '45 INC eBP
		oldcf = cf
		oper1 = regbp: oper2 = 1
		res16 = oper1 + oper2
		flag_add16 oper1, oper2
		cf = oldcf
		regbp = res16
	goto endofops
	op_46: '46 INC eSI
		oldcf = cf
		oper1 = regsi: oper2 = 1
		res16 = oper1 + oper2
		flag_add16 oper1, oper2
		cf = oldcf
		regsi = res16
	goto endofops
	op_47: '47 INC eDI
		oldcf = cf
		oper1 = regdi: oper2 = 1
		res16 = oper1 + oper2
		flag_add16 oper1, oper2
		cf = oldcf
		regdi = res16
	goto endofops
	op_48: '48 DEC eAX
		oldcf = cf
		oper1 = ((regah Shl 8) Or regal): oper2 = 1
		res16 = oper1 - oper2
		flag_sub16 oper1, oper2
		cf = oldcf
		regah = res16 Shr 8: regal = res16 And 255
	goto endofops
	op_49: '49 DEC eCX
		oldcf = cf
		oper1 = ((regch Shl 8) Or regcl): oper2 = 1
		res16 = oper1 - oper2
		flag_sub16 oper1, oper2
		cf = oldcf
		putreg16(regcx, res16)
	goto endofops
	op_4A: '4A DEC eDX
		oldcf = cf
		oper1 = ((regdh Shl 8) Or regdl): oper2 = 1
		res16 = oper1 - oper2
		flag_sub16 oper1, oper2
		cf = oldcf
		putreg16(regdx, res16)
	goto endofops
	op_4B: '4B DEC eBX
		oldcf = cf
		oper1 = ((regbh Shl 8) Or regbl): oper2 = 1
		res16 = oper1 - oper2
		flag_sub16 oper1, oper2
		cf = oldcf
		putreg16(regbx, res16)
	goto endofops
	op_4C: '4C DEC eSP
		oldcf = cf
		oper1 = regsp: oper2 = 1
		res16 = oper1 - oper2
		flag_sub16 oper1, oper2
		cf = oldcf
		regsp = res16
	goto endofops
	op_4D: '4D DEC eBP
		oldcf = cf
		oper1 = regbp: oper2 = 1
		res16 = oper1 - oper2
		flag_sub16 oper1, oper2
		cf = oldcf
		regbp = res16
	goto endofops
	op_4E: '4E DEC eSI
		oldcf = cf
		oper1 = regsi: oper2 = 1
		res16 = oper1 - oper2
		flag_sub16 oper1, oper2
		cf = oldcf
		regsi = res16
	goto endofops
	op_4F: '4F DEC eDI
		oldcf = cf
		oper1 = regdi: oper2 = 1
		res16 = oper1 - oper2
		flag_sub16 oper1, oper2
		cf = oldcf
		regdi = res16
	goto endofops
	op_50: '50 PUSH eAX
		push ((regah Shl 8) Or regal)
	goto endofops
	op_51: '51 PUSH eCX
		push ((regch Shl 8) Or regcl)
	goto endofops
	op_52: '52 PUSH eDX
		push ((regdh Shl 8) Or regdl)
	goto endofops
	op_53: '53 PUSH eBX
		push ((regbh Shl 8) Or regbl)
	goto endofops
	op_54: '54 PUSH eSP
		push regsp
	goto endofops
	op_55: '55 PUSH eBP
		push regbp
	goto endofops
	op_56: '56 PUSH eSI
		push regsi
	goto endofops
	op_57: '57 PUSH eDI
		push regdi
	goto endofops
	op_58: '58 POP eAX
		   res16 = pop
		regah = res16 Shr 8: regal = res16 And 255
	goto endofops
	op_59: '59 POP eCX
		   res16 = pop
		regch = res16 Shr 8: regcl = res16 And 255
	goto endofops
	op_5A: '5A POP eDX
		   res16 = pop
		regdh = res16 Shr 8: regdl = res16 And 255
	goto endofops
	op_5B: '5B POP eBX
		   res16 = pop
		regbh = res16 Shr 8: regbl = res16 And 255
	goto endofops
	op_5C: '5C POP eSP
		regsp = getmem16(regss, regsp)
	goto endofops
	op_5D: '5D POP eBP
		regbp = pop
	goto endofops
	op_5E: '5E POP eSI
		regsi = pop
	goto endofops
	op_5F: '5F POP eDI
		regdi = pop
	goto endofops
	op_60: '60 PUSHA (80186+)
		oldsp = regsp
	         push ((regah Shl 8) Or regal)
	         push ((regch Shl 8) Or regcl)
	         push ((regdh Shl 8) Or regdl)
	         push ((regbh Shl 8) Or regbl)
	         push oldsp: push regbp: push regsi: push regdi
	goto endofops
	op_61: '61 POPA (80186+)
	         regdi = pop: regsi = pop: regbp = pop: dummy = pop
	         putreg16(regbx, pop): putreg16(regdx, pop): putreg16(regcx, pop): putreg16(regax, pop)
	goto endofops
	op_68: '68 PUSH Iv (80186+)
		push getmem16(regcs, ip): StepIP 2
	goto endofops
	op_69: '69 IMUL Ev Iv (80186+)
		   modregrm()
	         temp1 = readrm16(rm)
	         temp2 = getmem16(regcs, ip): StepIP 2
	         If (temp1 And &H8000&) = &H8000& Then temp1 = temp1 Or &HFFFF0000
	         If (temp2 And &H8000&) = &H8000& Then temp2 = temp2 Or &HFFFF0000
	         temp3 = (temp1 * temp2) And &HFFFFFFFF
	         putreg16(regax, temp3 And &HFFFF&)
	         putreg16(regdx, temp3 Shr 16)
	         If ((regdh Shl 8) Or regdl) <> 0 Then cf = 1: of = 1 Else cf = 0: of = 0
	
	goto endofops
	op_6A: '6A PUSH Ib (80186+)
		push getmem8(regcs, ip): StepIP 1
		
	goto endofops
	op_6B: '6B IMUL Eb Ib (80186+)
		   modregrm()
		   oper1 = signext(readrm8(rm))
	         temp1 = signext(getmem8(regcs, ip)): StepIP 1
	         temp2 = oper1
	         If (temp1 And &H80&) = &H80& Then temp1 = temp1 Or &HFFFFFF00
	         If (temp2 And &H80&) = &H80& Then temp2 = temp2 Or &HFFFFFF00
	         temp3 = (temp1 * temp2) And &HFFFF&
	         putreg16(regax, temp3)
	         If regah <> 0 Then cf = 1: of = 1 Else cf = 0: of = 0
		
	goto endofops
	op_6C: '80186 port operations, just act as if they're NOPs for now...
		   StepIP(1) 'they have a modregrm() byte we must skip...
	goto endofops
	op_6D: '80186 port operations, just act as if they're NOPs for now...
		   StepIP(1) 'they have a modregrm() byte we must skip...
	goto endofops
	op_6E: '80186 port operations, just act as if they're NOPs for now...
		   StepIP(1) 'they have a modregrm() byte we must skip...
	goto endofops
	op_6F: '80186 port operations, just act as if they're NOPs for now...
		   StepIP(1) 'they have a modregrm() byte we must skip...
	GoTo endofops
	op_70: '70 JO Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If of <> 0 Then ip = ip + temp16
	
	goto endofops
	op_71: '71 JNO Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If of = 0 Then ip = ip + temp16
	
	goto endofops
	op_72: '72 JB Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If cf <> 0 Then ip = ip + temp16
	
	goto endofops
	op_73: '73 JNB Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If cf = 0 Then ip = ip + temp16
	
	goto endofops
	op_74: '74 JZ Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If zf <> 0 Then ip = ip + temp16
	
	goto endofops
	op_75: '75 JNZ Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If zf = 0 Then ip = ip + temp16
	    
	goto endofops
	op_76: '76 JBE Jb
	         temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If (cf <> 0) Or (zf <> 0) Then ip = ip + temp16
	
	goto endofops
	op_77: '77 JA Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If (cf = 0) And (zf = 0) Then ip = ip + temp16
	
	goto endofops
	op_78: '78 JS Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If sf <> 0 Then ip = ip + temp16
	    
	goto endofops
	op_79: '79 JNS Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If sf = 0 Then ip = ip + temp16
	    
	goto endofops
	op_7A: '7A JPE Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If pf <> 0 Then ip = ip + temp16
	    
	goto endofops
	op_7B: '7B JPO Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If pf = 0 Then ip = ip + temp16
	    
	goto endofops
	op_7C: '7C JL Jb
	        temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If (sf <> of) Then ip = ip + temp16
	    
	goto endofops
	op_7D: '7D JGE Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If (sf = of) Then ip = ip + temp16
	    
	goto endofops
	op_7E: '7E JLE Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If (sf <> of) Or (zf <> 0) Then ip = ip + temp16
	    
	goto endofops
	op_7F: '7F JG Jb
	          temp16 = signext(getmem8(regcs, ip)): StepIP 1
	        If (zf = 0) And (sf = of) Then ip = ip + temp16
	goto endofops
	op_80: '80/82 GRP1 Eb Ib
		modregrm()
		oper1b = readrm8(rm): oper2b = getmem8(regcs, ip): StepIP 1
		op_grp1(0)
		If reg < 7 Then
		writerm8(rm, res8)
		End If
	goto endofops
	op_81: '81 GRP1 Ev Iv
		modregrm()
		oper1 = readrm16(rm): oper2 = getmem16(regcs, ip): StepIP 2
		op_grp1(1)
		If reg < 7 Then
		writerm16(rm, res16)
		End If
	goto endofops
	op_83: '83 GRP1 Ev Ib
		modregrm()
		oper1 = readrm16(rm): oper2 = signext(getmem8(regcs, ip)): StepIP 1
		op_grp1(1)
		If reg < 7 Then
		writerm16(rm, res16)
		End If
	goto endofops
	op_84: '84 TEST Gb Eb
		modregrm()
		oper1b = getreg8(reg): oper2b = readrm8(rm)
		flag_log8(oper1b And oper2b)
		If debugmode = 1 Then dprint "  TEST 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
	goto endofops
	op_85: '85 TEST Gv Ev
		modregrm()
		oper1 = getreg16(reg): oper2 = readrm16(rm)
		flag_log16(oper1 And oper2)
	goto endofops
	op_86: '86 XCHG Gb Eb
		modregrm()
		oper1b = getreg8(reg)
		putreg8(reg, readrm8(rm))
		writerm8(rm, oper1b)
	goto endofops
	op_87: '87 XCHG Gv Ev
		modregrm()
		oper1 = getreg16(reg)
		putreg16(reg, readrm16(rm))
		writerm16(rm, oper1)
	goto endofops
	op_88: '88 MOV Eb Gb
		modregrm()
		writerm8(rm, getreg8(reg))
	goto endofops
	op_89: '89 MOV Ev Gv
		modregrm()
		writerm16(rm, getreg16(reg))
	goto endofops
	op_8A: '8A MOV Gb Eb
		modregrm()
		putreg8(reg, readrm8(rm))
	goto endofops
	op_8B: '8B MOV Gv Ev
		modregrm()
		putreg16(reg, readrm16(rm))
	goto endofops
	op_8C: '8C MOV Ew Sw
		modregrm()
		writerm16(rm, getsegreg(reg))
	goto endofops
	op_8D: '8D LEA Gv M
		modregrm()
		getea(rm)
		putreg16(reg, ea - useseg * 16)
	goto endofops
	op_8E: '8E MOV Sw Ew
		modregrm()
		putsegreg(reg, readrm16(rm))
	goto endofops
	op_8F: '8F POP Ev
		modregrm()
		writerm16(rm, pop)
	goto endofops
	op_90: '90 NOP
	goto endofops
	op_91: '91 XCHG eCX eAX
		oper1b = regch
		oper2b = regcl
		regch = regah
		regcl = regal
		regah = oper1b
		regal = oper2b
	goto endofops
	op_92: '92 XCHG eDX eAX
		oper1b = regdh
		oper2b = regdl
		regdh = regah
		regdl = regal
		regah = oper1b
		regal = oper2b
	goto endofops
	op_93: '93 XCHG eBX eAX
		oper1b = regbh
		oper2b = regbl
		regbh = regah
		regbl = regal
		regah = oper1b
		regal = oper2b
	goto endofops
	op_94: '94 XCHG eSP eAX
		oper1 = regsp
		regsp = ((regah Shl 8) Or regal)
		regah = oper1 Shr 8: regal = oper1 And 255
	goto endofops
	op_95: '95 XCHG eBP eAX
		oper1 = regbp
		regbp = ((regah Shl 8) Or regal)
		regah = oper1 Shr 8: regal = oper1 And 255
	goto endofops
	op_96: '96 XCHG eSI eAX
		oper1 = regsi
		regsi = ((regah Shl 8) Or regal)
		regah = oper1 Shr 8: regal = oper1 And 255
	goto endofops
	op_97: '97 XCHG eDI eAX
		oper1 = regdi
		regdi = ((regah Shl 8) Or regal)
		regah = oper1 Shr 8: regal = oper1 And 255
	goto endofops
	op_98: '98 CBW
		If (regal And &h80) = &h80 Then regah = &hFF Else regah = 0
	goto endofops
	op_99: '99 CWD
		If (regah And &h80) = &h80 Then
		putreg16(regdx, &hFFFF)
		Else
		putreg16(regdx, 0)
		End If
	goto endofops
	op_9A: '9A CALL Ap
		oper1 = getmem16(regcs, ip): StepIP 2
		oper2 = getmem16(regcs, ip): StepIP 2
		push regcs: push ip: ip = oper1: regcs = oper2
	goto endofops
	op_9B: '9B WAIT
	goto endofops
	op_9C: '9C PUSHF
		push makeflagsword And &hFFF
	goto endofops
	op_9D: '9D POPF
		decodeflagsword pop
	goto endofops
	op_9E: '9E SAHF
		decodeflagsword (makeflagsword And &HFF00&) + regah
	goto endofops
	op_9F: '9F LAHF
		regah = makeflagsword And &hFF
	goto endofops
	op_A0: 'A0 MOV regal Ob
		regal = getmem8(useseg, getmem16(regcs, ip)): StepIP 2
	goto endofops
	op_A1: 'A1 MOV eAX Ov
		oper1 = getmem16(useseg, getmem16(regcs, ip)): StepIP 2
		regah = oper1 Shr 8: regal = oper1 And 255
	goto endofops
	op_A2: 'A2 MOV Ob regal
		putmem8 useseg, getmem16(regcs, ip), regal: StepIP 2
	goto endofops
	op_A3: 'A3 MOV Ov eAX
		putmem16 useseg, getmem16(regcs, ip), ((regah Shl 8) Or regal): StepIP 2
	goto endofops
	op_A4: 'A4 MOVSB
		Do
		If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
		putmem8 reges, regdi, getmem8(useseg, regsi)
		If df Then regsi = regsi - 1: regdi = regdi - 1 Else regsi = regsi + 1: regdi = regdi + 1
		If (reptype <> 0) Then
			putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		End If
		Loop Until reptype = 0
	goto endofops
	op_A5: 'A5 MOVSW
		Do
		If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
		putmem16 reges, regdi, getmem16(useseg, regsi)
		If df Then regsi = regsi - 2: regdi = regdi - 2 Else regsi = regsi + 2: regdi = regdi + 2
		If (reptype <> 0) Then
			putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		End If
		Loop Until reptype = 0
	goto endofops
	op_A6: 'A6 CMPSB
		Do
		If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
		oper1b = getmem8(useseg, regsi): oper2b = getmem8(reges, regdi)
		If df Then regsi = regsi - 1: regdi = regdi - 1 Else regsi = regsi + 1: regdi = regdi + 1
		flag_sub8 oper1b, oper2b
		If debugmode = 1 Then dprint "  CMP 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
		If (reptype <> 0) Then
			putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		End If
		If (reptype = 1) And (zf = 0) Then Exit Do
		If (reptype = 2) And (zf = 1) Then Exit Do
		Loop Until reptype = 0
	goto endofops
	op_A7: 'A7 CMPSW
		Do
		If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
		oper1 = getmem16(useseg, regsi): oper2 = getmem16(reges, regdi)
		If df Then regsi = regsi - 2: regdi = regdi - 2 Else regsi = regsi + 2: regdi = regdi + 2
		flag_sub16 oper1, oper2
		If debugmode = 1 Then dprint "  CMP 16-bit: oper1 = " + Hex$(oper1) + "h, oper2 = " + Hex$(oper2) + "h"
		If (reptype <> 0) Then
			putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		End If
		If (reptype = 1) And (zf = 0) Then Exit Do
		If (reptype = 2) And (zf = 1) Then Exit Do
		Loop Until reptype = 0
	goto endofops
	op_A8: 'A8 TEST regal Ib
		oper1b = regal: oper2b = getmem8(regcs, ip): StepIP 1
		flag_log8(oper1b And oper2b)
		If debugmode = 1 Then dprint "  TEST 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
	goto endofops
	op_A9: 'A9 TEST eAX Iv
		oper1 = ((regah Shl 8) Or regal): oper2 = getmem16(regcs, ip): StepIP 2
		flag_log16(oper1 And oper2)
	goto endofops
	op_AA: 'AA STOSB
		Do
		If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
		putmem8 reges, regdi, regal
		If df Then regdi = regdi - 1 Else regdi = regdi + 1
		If (reptype <> 0) Then
			putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		End If
		Loop Until reptype = 0
	goto endofops
	op_AB: 'AB STOSW
		Do
		If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
		putmem16 reges, regdi, ((regah Shl 8) Or regal)
		If df Then regdi = regdi - 2 Else regdi = regdi + 2
		If (reptype <> 0) Then
			putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		End If
		Loop Until reptype = 0
	goto endofops
	op_AC: 'AC LODSB
		Do
		If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
		regal = getmem8(useseg, regsi)
		If df Then regsi = regsi - 1 Else regsi = regsi + 1
		If (reptype <> 0) Then
			putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		End If
		Loop Until reptype = 0
	goto endofops
	op_AD: 'AD LODSW
		Do
		If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
		oper1 = getmem16(useseg, regsi)
		regah = oper1 Shr 8: regal = oper1 And 255
		If df Then regsi = regsi - 2 Else regsi = regsi + 2
		If (reptype <> 0) Then
			putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		End If
		Loop Until reptype = 0
	goto endofops
	op_AE: 'AE SCASB
		Do
		If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
		oper1b = getmem8(reges, regdi): oper2b = regal
		flag_sub8 oper1b, oper2b
		If debugmode = 1 Then dprint "  CMP 8-bit: oper1 = " + Hex$(oper1b) + "h, oper2 = " + Hex$(oper2b) + "h"
		If df Then regdi = regdi - 1 Else regdi = regdi + 1
		If (reptype <> 0) Then
			putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		End If
		If (reptype = 1) And (zf = 0) Then Exit Do
		If (reptype = 2) And (zf = 1) Then Exit Do
		Loop Until reptype = 0
	goto endofops
	op_AF: 'AF SCASW
		Do
		If (reptype <> 0) And (((regch Shl 8) Or regcl) = 0) Then Exit Do
		oper1 = getmem16(reges, regdi): oper2 = ((regah Shl 8) Or regal)
		flag_sub16 oper1, oper2
		If debugmode = 1 Then dprint "  CMP 16-bit: oper1 = " + Hex$(oper1) + "h, oper2 = " + Hex$(oper2) + "h"
		If df Then regdi = regdi - 2 Else regdi = regdi + 2
		If (reptype <> 0) Then
			putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		End If
		If (reptype = 1) And (zf = 0) Then Exit Do
		If (reptype = 2) And (zf = 1) Then Exit Do
		Loop Until reptype = 0
	goto endofops
	op_B0: 'B0 MOV regal Ib
		regal = getmem8(regcs, ip): StepIP 1
	goto endofops
	op_B1: 'B1 MOV regcl Ib
		regcl = getmem8(regcs, ip): StepIP 1
	goto endofops
	op_B2: 'B2 MOV regdl Ib
		regdl = getmem8(regcs, ip): StepIP 1
	goto endofops
	op_B3: 'B3 MOV regbl Ib
		regbl = getmem8(regcs, ip): StepIP 1
	goto endofops
	op_B4: 'B4 MOV regah Ib
		regah = getmem8(regcs, ip): StepIP 1
	goto endofops
	op_B5: 'B5 MOV regch Ib
		regch = getmem8(regcs, ip): StepIP 1
	goto endofops
	op_B6: 'B6 MOV regdh Ib
		regdh = getmem8(regcs, ip): StepIP 1
	goto endofops
	op_B7: 'B7 MOV regbh Ib
		regbh = getmem8(regcs, ip): StepIP 1
	goto endofops
	op_B8: 'B8 MOV eAX Iv
		oper1 = getmem16(regcs, ip): StepIP 2
		regah = oper1 Shr 8: regal = oper1 And 255
	goto endofops
	op_B9: 'B9 MOV eCX Iv
		oper1 = getmem16(regcs, ip): StepIP 2
		regch = oper1 Shr 8: regcl = oper1 And 255
	goto endofops
	op_BA: 'BA MOV eDX Iv
		oper1 = getmem16(regcs, ip): StepIP 2
		regdh = oper1 Shr 8: regdl = oper1 And 255
	goto endofops
	op_BB: 'BB MOV eBX Iv
		oper1 = getmem16(regcs, ip): StepIP 2
		regbh = oper1 Shr 8: regbl = oper1 And 255
	goto endofops
	op_BC: 'BC MOV eSP Iv
		regsp = getmem16(regcs, ip): StepIP 2
	goto endofops
	op_BD: 'BD MOV eBP Iv
		regbp = getmem16(regcs, ip): StepIP 2
	goto endofops
	op_BE: 'BE MOV eSI Iv
		regsi = getmem16(regcs, ip): StepIP 2
	goto endofops
	op_BF: 'BF MOV eDI Iv
		regdi = getmem16(regcs, ip): StepIP 2
	goto endofops
	op_C0: 'C0 GRP2 byte imm8 (80186+)
		modregrm()
		oper1b = readrm8(rm)
		oper2b = getmem8(regcs, ip): StepIP 1
		writerm8(rm, op_grp2_8(oper2b))
	
	goto endofops
	op_C1: 'C1 GRP2 word imm8 (80186+)
		modregrm()
		oper1 = readrm16(rm)
		oper2 = getmem8(regcs, ip): StepIP 1
		writerm16(rm, op_grp2_16(oper2))
	
	goto endofops
	op_C2: 'C2 RET Iw
		oper1 = getmem16(regcs, ip)
		ip = pop
		regsp = regsp + oper1 
		
	goto endofops
	op_C3: 'C3 RET
		ip = pop
	goto endofops
	op_C4: 'C4 LES Gv Mp
	        modregrm()
	        getea(rm)
	        putreg16(reg, read86(ea) + read86(ea + 1) * 256)
	        reges = read86(ea + 2) + read86(ea + 3) * 256
	goto endofops
	op_C5: 'C5 LDS Gv Mp
	        modregrm()
	        getea(rm)
	        putreg16(reg, read86(ea) + read86(ea + 1) * 256)
	        regds = read86(ea + 2) + read86(ea + 3) * 256
	goto endofops
	op_C6: 'C6 MOV Eb Ib
		modregrm()
		writerm8(rm, getmem8(regcs, ip)): StepIP 1
	goto endofops
	op_C7: 'C7 MOV Ev Iv
		modregrm()
		writerm16(rm, getmem16(regcs, ip)): StepIP 2
	GoTo endofops
	op_C8: 'C8 ENTER (80186+)
		  stacksize = getmem16(regcs, ip): StepIP 2
	    	  nestlev = getmem8(regcs, ip): StepIP 1
	    	  push regbp
	    	  frametemp = regsp
		  If nestlev <> 0 Then
	    	  	For temp16 = 1 To nestlev - 1
	    	  	regbp = regbp - 2
	    	  	push regbp
	    	  	Next temp16
	    	  	push regsp
		  End If
		  regbp = frametemp
		  regsp = regbp - stacksize
	GoTo endofops
	op_C9: 'C9 LEAVE (80186+)
	             regsp = regbp
	             regbp = pop	
	goto endofops
	op_CA: 'CA RETF Iw
		oper1 = getmem16(regcs, ip)
		ip = pop: regcs = pop
		regsp = regsp + oper1
	goto endofops
	op_CB: 'CB RETF
		ip = pop: regcs = pop
	goto endofops
	op_CC: 'CC INT 3
		intcall86 3
	goto endofops
	op_CD: 'CD INT Ib
		oper1 = getmem8(regcs, ip): StepIP 1
		intcall86 oper1
	goto endofops
	op_CE: 'CE INTO
		If of Then intcall86 4
	goto endofops
	op_CF: 'CF IRET
		ip = pop: regcs = pop
		decodeflagsword pop
	goto endofops
	op_D0: 'D0 GRP2 Eb 1
		modregrm()
		oper1b = readrm8(rm)
		writerm8(rm, op_grp2_8(1))
	goto endofops
	op_D1: 'D1 GRP2 Ev 1
		modregrm()
		oper1 = readrm16(rm)
		writerm16(rm, op_grp2_16(1))
	goto endofops
	op_D2: 'D2 GRP2 Eb regcl
		modregrm()
		oper1b = readrm8(rm)
		writerm8(rm, op_grp2_8(regcl))
	goto endofops
	op_D3: 'D3 GRP2 Ev regcl
		modregrm()
		oper1 = readrm16(rm)
		writerm16(rm, op_grp2_16(regcl))
	goto endofops
	op_D4: 'D4 AAM I0
	        oper1 = getmem8(regcs, ip): StepIP 1
	        If oper1 = 0 Then intcall86 0: Exit Sub 'division by zero
	        regah = (regal \ oper1) And 255
	        regal = (regal Mod oper1) And 255
	        flag_szp16 ((regah Shl 8) Or regal)
	
	goto endofops
	op_D5: 'D5 AAD I0
	        oper1 = getmem8(regcs, ip): StepIP 1
	        regal = (regah * oper1 + regal) And 255
	        regah = 0
	        flag_szp16(regah * oper1 + regal)
	        sf = 0
	goto endofops
	op_D7: 'D7 XLAT
		regal = read86(useseg * 16 + ((regbh Shl 8) Or regbl) + regal)
	goto endofops
	op_D8: 'escape
		StepIP 1
	goto endofops
	op_D9: 'escape
		StepIP 1
	goto endofops
	op_DA: 'escape
		StepIP 1
	goto endofops
	op_DB: 'escape
		StepIP 1
	goto endofops
	op_DC: 'escape
		StepIP 1
	goto endofops
	op_DD: 'escape
		StepIP 1
	goto endofops
	op_DE: 'escape
		StepIP 1
	goto endofops
	op_DF: 'escape
		StepIP 1
	goto endofops
	op_E0: 'E0 LOOPNZ Jb
	      	temp16 = signext(getmem8(regcs, ip)): StepIP 1
		putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		If (((regch Shl 8) Or regcl) <> 0) And (zf = 0) Then ip = ip + temp16
	
	goto endofops
	op_E1: 'E1 LOOPZ Jb
		temp16 = signext(getmem8(regcs, ip)): StepIP 1
		putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		If (((regch Shl 8) Or regcl) <> 0) And (zf = 1) Then ip = ip + temp16
	      
	goto endofops
	op_E2: 'E2 LOOP Jb
	      	temp16 = signext(getmem8(regcs, ip)): StepIP 1
		putreg16(regcx, ((regch Shl 8) Or regcl) - 1)
		If ((regch Shl 8) Or regcl) <> 0 Then ip = ip + temp16
	
	goto endofops
	op_E3: 'E3 JCXZ Jb
	      	temp16 = signext(getmem8(regcs, ip)): StepIP 1
		If ((regch Shl 8) Or regcl) = 0 Then ip = ip + temp16
	
	goto endofops
	op_E4: 'E4 IN regal Ib
	        oper1b = getmem8(regcs, ip)
	        StepIP 1
	        regal = portin(oper1b)
	goto endofops
	op_E5: 'E5 IN eAX Ib
	        oper1b = getmem8(regcs, ip)
	        StepIP 1
	        putreg16(regax, portin(oper1b))
	goto endofops
	op_E6: 'E6 OUT Ib regal
	        oper1b = getmem8(regcs, ip)
	      	StepIP 1
	      	portout16 = 0
	     	portout oper1b, regal
	goto endofops
	op_E7: 'E7 OUT Ib eAX
	        oper1b = getmem8(regcs, ip)
	      	StepIP 1
	      	portout16 = 1
	      	portout oper1b, ((regah Shl 8) Or regal)
	
	goto endofops
	op_E8: 'E8 CALL Jv
		oper1 = getmem16(regcs, ip): StepIP 2
		push ip
		ip = ip + oper1
	goto endofops
	op_E9: 'E9 JMP Jv
		oper1 = getmem16(regcs, ip): StepIP 2
		ip = ip + oper1
	goto endofops
	op_EA: 'EA JMP Ap
		oper1 = getmem16(regcs, ip): StepIP 2
		oper2 = getmem16(regcs, ip)
		ip = oper1: regcs = oper2
	goto endofops
	op_EB: 'EB JMP Jb
		oper1 = signext(getmem8(regcs, ip)): StepIP 1
		ip = ip + oper1
	goto endofops
	op_EC: 'EC IN regal regdx
	        oper1 = ((regdh Shl 8) Or regdl)
	        regal = portin(oper1)
	goto endofops
	op_ED: 'ED IN eAX regdx
	        oper1 = ((regdh Shl 8) Or regdl)
	        putreg16(regax, portin(oper1))
	goto endofops
	op_EE: 'EE OUT regdx regal
	        oper1 = ((regdh Shl 8) Or regdl)
	        portout16 = 0
	        portout oper1, regal
	goto endofops
	op_EF: 'EF OUT regdx eAX
	        oper1 = ((regdh Shl 8) Or regdl)
	        portout16 = 1
	        portout oper1, ((regah Shl 8) Or regal)
	goto endofops
	op_F0: 'F0 LOCK
	goto endofops
	op_F4: 'F4 HLT
		ip = ip - 1
		If running <> 2 Then
		cprint "HLT executed."
		SDL_WM_SetCaption("Fake86 [halted]", 0)
		running = 2
		End If
	goto endofops
	op_F5: 'F5 CMC
		If cf = 0 Then cf = 1 Else cf = 0
	goto endofops
	op_F6: 'F6 GRP3a Eb
	        modregrm()
	        oper1b = readrm8(rm)
	        op_grp3(0)
	        If (reg > 1) And (reg < 4) Then
		writerm8(rm, res8)
	        End If
	
	goto endofops
	op_F7: 'F7 GRP3b Ev
	        modregrm()
	        oper1 = readrm16(rm)
	        op_grp3(1)
	        If (reg > 1) And (reg < 4) Then
		writerm16(rm, res16)
	        End If
	goto endofops
	op_F8: 'F8 CLC
		cf = 0
	goto endofops
	op_F9: 'F9 STC
		cf = 1
	goto endofops
	op_FA: 'FA CLI
		ifl = 0
	goto endofops
	op_FB: 'FB STI
		ifl = 1
	goto endofops
	op_FC: 'FC CLD
		df = 0
	goto endofops
	op_FD: 'FD STD
		df = 1
	goto endofops
	op_FE: 'FE GRP4 Eb
	        modregrm()
	        oper1b = readrm8(rm): oper2b = 1
	        If reg = 0 Then
	            temp = cf
	    	res8 = oper1b + oper2b
		flag_add8 oper1b, oper2b
	            cf = temp: writerm8(rm, res8)
	        ElseIf reg = 1 Then
	            temp = cf
	    	res8 = oper1b - oper2b
		flag_sub8 oper1b, oper2b
	            cf = temp: writerm8(rm, res8)
	        Else
		intcall86 6
	        End If
	goto endofops
	op_FF: 'FF GRP5 Ev
	        modregrm()
	        oper1 = readrm16(rm)
	        op_grp5()
	goto endofops
	op_unknown:
		intcall86 6
	endofops:
can anybody see what i'm doing wrong? i'm not getting the problem...
Top
dkl
Site Admin
Posts: 3235
Joined: Jul 28, 2005 14:45
Location: Germany

Post by dkl »

Maybe not much of an optimizing compiler, but... it has SELECT CASE AS CONST for the jump table thing!
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h4tt3n
Posts: 698
Joined: Oct 22, 2005 21:12
Location: Denmark

Post by h4tt3n »

Isn't if...else supposed to be considerable faster than select case? Maybe some speed could be gained that way without all the jumptable stuff?

Cheers,
Mike
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Mike Chambers
Posts: 85
Joined: Jun 18, 2006 19:48

Post by Mike Chambers »

dkl wrote:Maybe not much of an optimizing compiler, but... it has SELECT CASE AS CONST for the jump table thing!
wow, didn't know about that. based on benchmark programs i'm running inside my emu, that DOUBLED the speed! :D
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Mike Chambers
Posts: 85
Joined: Jun 18, 2006 19:48

Post by Mike Chambers »

h4tt3n wrote:Isn't if...else supposed to be considerable faster than select case? Maybe some speed could be gained that way without all the jumptable stuff?

Cheers,
Mike
yeah i think you're right, it is supposed to be faster. dkl's suggestion worked wonders though!
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dkl
Site Admin
Posts: 3235
Joined: Jul 28, 2005 14:45
Location: Germany

Post by dkl »

The jumping being wrong with ON ... GOTO is actually a bug, the compiler is soft-limited to 64 target labels but it does not check that limit yet but just does something more or less random...
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Mike Chambers
Posts: 85
Joined: Jun 18, 2006 19:48

Post by Mike Chambers »

dkl wrote:The jumping being wrong with ON ... GOTO is actually a bug, the compiler is soft-limited to 64 target labels but it does not check that limit yet but just does something more or less random...
ah, okay then i'm not insane. i wasn't seeing what the problem could have been.

select case as const sped it up so much i've got the emulator playing Wolfenstein 3D smoothly on a Pentium 3 laptop!
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fxm
Moderator
Posts: 12107
Joined: Apr 22, 2009 12:46
Location: Paris suburbs, FRANCE

Post by fxm »

Already under QuickBasic, ON...GOTO accepted a maximum of 60 line labels and line numbers.
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Mike Chambers
Posts: 85
Joined: Jun 18, 2006 19:48

Post by Mike Chambers »

ah, never used it under QB either. i've got lots of QB experience, but the need never arose. i wonder why the small limit.
Top
fxm
Moderator
Posts: 12107
Joined: Apr 22, 2009 12:46
Location: Paris suburbs, FRANCE

Post by fxm »

You can try to break your 256 jumps in 16 jumps multiplied by 16 other jumps.

opjump = opcode + 1
On int(opjump/&H10) Goto op_0x,op_1x,op_2x,.....,op_Dx,op_Ex,op_Fx
op_0x:
On (opjump and &hF) Goto op_0,op_1,op_2,.....,op_D,op_E,op_F
op_1x:
On (opjump and &hF) Goto op_10,op_11,op_12,.....,op_1D,op_1E,op_1F
. . . . .
. . . . .
op_Ex:
On (opjump and &hF) Goto op_E0,op_E1,op_E2,.....,op_ED,op_EE,op_EF
op_Fx:
On (opjump and &hF) Goto op_F0,op_F1,op_F2,.....,op_FD,op_FE,op_FF
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MichaelW
Posts: 3500
Joined: May 16, 2006 22:34
Location: USA

Post by MichaelW »

Code: Select all

'====================================================================
#include once "windows.bi"
#include "counter.bas"
'====================================================================
'' Counter.bas is available here:
''
'' http://www.freebasic.net/forum/viewtopic.php?t=4221#4221
'====================================================================

dim as integer i

sleep 3000

counter_begin( 1000, HIGH_PRIORITY_CLASS )
counter_end
print counter_cycles;" cycles","empty"

i = 1
counter_begin( 1000, HIGH_PRIORITY_CLASS )
select case i
    case 1
    case 2
    case 3
    case 4
    case 5
    case 6
    case 7
    case 8
    case 9
    case 10
    case 11
    case 12
    case 13
    case 14
    case 15
    case 16
end select
counter_end
print counter_cycles;" cycles","select case first"

i = 16
counter_begin( 1000, HIGH_PRIORITY_CLASS )
select case i
    case 1
    case 2
    case 3
    case 4
    case 5
    case 6
    case 7
    case 8
    case 9
    case 10
    case 11
    case 12
    case 13
    case 14
    case 15
    case 16
end select
counter_end
print counter_cycles;" cycles","select case last"

i = 1
counter_begin( 1000, HIGH_PRIORITY_CLASS )
select case as const i
    case 1
    case 2
    case 3
    case 4
    case 5
    case 6
    case 7
    case 8
    case 9
    case 10
    case 11
    case 12
    case 13
    case 14
    case 15
    case 16
end select
counter_end
print counter_cycles;" cycles","select case as const first"

i = 16
counter_begin( 1000, HIGH_PRIORITY_CLASS )
select case as const i
    case 1
    case 2
    case 3
    case 4
    case 5
    case 6
    case 7
    case 8
    case 9
    case 10
    case 11
    case 12
    case 13
    case 14
    case 15
    case 16
end select
counter_end
print counter_cycles;" cycles","select case as const last"

i = 1
counter_begin( 1000, HIGH_PRIORITY_CLASS )
    on i goto X1,X2,X3,X4,X5,X6,X7,X8,X9,X10,X11,X12,X13,X14,X15,X16
  X1:
    goto XL
  X2:
    goto XL
  X3:
    goto XL
  X4:
    goto XL
  X5:
    goto XL
  X6:
    goto XL
  X7:
    goto XL
  X8:
    goto XL
  X9:
    goto XL
  X10:
    goto XL
  X11:
    goto XL
  X12:
    goto XL
  X13:
    goto XL
  X14:
    goto XL
  X15:
    goto XL
  X16:
  XL:
counter_end
print counter_cycles;" cycles","on goto first"

i = 16
counter_begin( 1000, HIGH_PRIORITY_CLASS )
    on i goto Y1,Y2,Y3,Y4,Y5,Y6,Y7,Y8,Y9,Y10,Y11,Y12,Y13,Y14,Y15,Y16
  Y1:
    goto YL
  Y2:
    goto YL
  Y3:
    goto YL
  Y4:
    goto YL
  Y5:
    goto YL
  Y6:
    goto YL
  Y7:
    goto YL
  Y8:
    goto YL
  Y9:
    goto YL
  Y10:
    goto YL
  Y11:
    goto YL
  Y12:
    goto YL
  Y13:
    goto YL
  Y14:
    goto YL
  Y15:
    goto YL
  Y16:
  YL:
counter_end
print counter_cycles;" cycles","on goto last"

sleep
Results running on a P3:

Code: Select all

0 cycles      empty
4 cycles      select case first
41 cycles     select case last
9 cycles      select case as const first
18 cycles     select case as const last
10 cycles     on goto first
17 cycles     on goto last
I don't know if this will affect you, but select case as const also has a limitation, with the maximum range being the smallest value + 4096.
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Mike Chambers
Posts: 85
Joined: Jun 18, 2006 19:48

Post by Mike Chambers »

that crossed my mind actually, fxm. i wonder if it's faster than select case as const. probably not, but it's worth a try.
Top
Mike Chambers
Posts: 85
Joined: Jun 18, 2006 19:48

Post by Mike Chambers »

MichaelW wrote:

Code: Select all

'====================================================================
#include once "windows.bi"
#include "counter.bas"
'====================================================================
'' Counter.bas is available here:
''
'' http://www.freebasic.net/forum/viewtopic.php?t=4221#4221
'====================================================================

dim as integer i

sleep 3000

counter_begin( 1000, HIGH_PRIORITY_CLASS )
counter_end
print counter_cycles;" cycles","empty"

i = 1
counter_begin( 1000, HIGH_PRIORITY_CLASS )
select case i
    case 1
    case 2
    case 3
    case 4
    case 5
    case 6
    case 7
    case 8
    case 9
    case 10
    case 11
    case 12
    case 13
    case 14
    case 15
    case 16
end select
counter_end
print counter_cycles;" cycles","select case first"

i = 16
counter_begin( 1000, HIGH_PRIORITY_CLASS )
select case i
    case 1
    case 2
    case 3
    case 4
    case 5
    case 6
    case 7
    case 8
    case 9
    case 10
    case 11
    case 12
    case 13
    case 14
    case 15
    case 16
end select
counter_end
print counter_cycles;" cycles","select case last"

i = 1
counter_begin( 1000, HIGH_PRIORITY_CLASS )
select case as const i
    case 1
    case 2
    case 3
    case 4
    case 5
    case 6
    case 7
    case 8
    case 9
    case 10
    case 11
    case 12
    case 13
    case 14
    case 15
    case 16
end select
counter_end
print counter_cycles;" cycles","select case as const first"

i = 16
counter_begin( 1000, HIGH_PRIORITY_CLASS )
select case as const i
    case 1
    case 2
    case 3
    case 4
    case 5
    case 6
    case 7
    case 8
    case 9
    case 10
    case 11
    case 12
    case 13
    case 14
    case 15
    case 16
end select
counter_end
print counter_cycles;" cycles","select case as const last"

i = 1
counter_begin( 1000, HIGH_PRIORITY_CLASS )
    on i goto X1,X2,X3,X4,X5,X6,X7,X8,X9,X10,X11,X12,X13,X14,X15,X16
  X1:
    goto XL
  X2:
    goto XL
  X3:
    goto XL
  X4:
    goto XL
  X5:
    goto XL
  X6:
    goto XL
  X7:
    goto XL
  X8:
    goto XL
  X9:
    goto XL
  X10:
    goto XL
  X11:
    goto XL
  X12:
    goto XL
  X13:
    goto XL
  X14:
    goto XL
  X15:
    goto XL
  X16:
  XL:
counter_end
print counter_cycles;" cycles","on goto first"

i = 16
counter_begin( 1000, HIGH_PRIORITY_CLASS )
    on i goto Y1,Y2,Y3,Y4,Y5,Y6,Y7,Y8,Y9,Y10,Y11,Y12,Y13,Y14,Y15,Y16
  Y1:
    goto YL
  Y2:
    goto YL
  Y3:
    goto YL
  Y4:
    goto YL
  Y5:
    goto YL
  Y6:
    goto YL
  Y7:
    goto YL
  Y8:
    goto YL
  Y9:
    goto YL
  Y10:
    goto YL
  Y11:
    goto YL
  Y12:
    goto YL
  Y13:
    goto YL
  Y14:
    goto YL
  Y15:
    goto YL
  Y16:
  YL:
counter_end
print counter_cycles;" cycles","on goto last"

sleep
Results running on a P3:

Code: Select all

0 cycles      empty
4 cycles      select case first
41 cycles     select case last
9 cycles      select case as const first
18 cycles     select case as const last
10 cycles     on goto first
17 cycles     on goto last
I don't know if this will affect you, but select case as const also has a limitation, with the maximum range being the smallest value + 4096.
thanks for those results, interesting. the 4096 limitation is not a problem for this, the maximum possible value of an 8086 opcode is 255.
Top
Richard
Posts: 3096
Joined: Jan 15, 2007 20:44
Location: Australia

Post by Richard »

The fxm suggestion is constant speed for any input.
It takes only two jumps to handle 256 possible labels.
It will be significantly faster than Select Case.
It provides an orderly table of labels.

Code: Select all

Dim As Integer i    ' input opcode
' 16 pages of 16 sequential opcodes
On (i Shr 4)+1 Goto      p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, pA, pB, pC, pD, pE, pF
p0: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
p1: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
p2: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
p3: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
p4: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
p5: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
p6: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
p7: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
p8: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
p9: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
pA: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
pB: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
pC: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
pD: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
pE: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op
pF: On (i And 15)+1 Goto op, op, op, op, op, op, op, op, op, op, op, op, op, op, op, op

op: ' 256 different opcode labels
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