Well, with such a LARGE topic name list this I was curious as to how fast this actually is.....
So I profiled the routine above against a more traditional couple of variations..
` *=-----------------------------------------------------------------------=*
`
` What does this do ?
` -------------------
`
` This is little test of Ironhoofs Hex to Dec function in the spirit of
` obtaining a speed benchmark. So Is it really that fast ?
`
` The test runs various loops converting a fixed 8 digit HEX number to
` Dec. To compare against ironhoof's function I just made up a few
` varations of such a routine. Some general purpose some more ridgid.
`
` So the results? Well, it's somewhat as expected. But it's always
` good to check. While replacing existing structures with goto logic
` in other languages/situations can give a nice performance boost, it
` doesn't in this case.
`
` The Hex_To_dec3 functions comes in a clear winner.. As expected it's
` using a lookup tables. Hex_To_dec2 is prolly the best bet since it's
` generic and gives a pretty good speed up..
`
`
`
` Cya,
` Kevin Picone
` www.uwdesign.50megs.com
`
` *=---------------------------------------------------------------------=*
sync on
sync rate 0
` Number of tests the trial is held over
Convert_tests=1000
` Init the Loop up table Hex To dec 3
gosub Init_Faster_hex_table
` The TEST LOOp
` ==============
do
cls 0
hexnum$="F2F4F6F8"
print "Testing HEX Value";HexNum$
print "Number of tests;";Convert_tests
print
Print "Testing Ironhoofs Fast Hex To Dec Routine:"
ts=timer()
for tests=0 to Convert_tests
r=HexVal(hexnum$)
next tests
Gosub Show_results
Print "Testing Simple Hex To Dec Routine V1:"
ts=timer()
for tests=0 to Convert_tests
r=Hex_String_To_Dec(hexnum$)
next tests
Gosub Show_results
Print "Testing Simple Hex To Dec Routine V2: With if/then opt"
ts=timer()
for tests=0 to Convert_tests
r=Hex_String_To_Dec2(hexnum$)
next tests
Gosub Show_results
Print "Testing Simple Hex To Dec Routine V3: pre-calc"
ts=timer()
for tests=0 to Convert_tests
r=Hex_String_To_Dec3(hexnum$)
next tests
Gosub Show_results
sync
loop
Show_results:
te=timer()
print "Conversion Result:";r
print "Test Time:";te-ts
print
return
` ------------------
` HExVal by Ironhoof
` ------------------
function HexVal(hexnum$)
hexnum$=upper$(hexnum$):LENG=LEN(hexnum$):COUNT=1:V2=0
IF LENG=1 THEN GOTO SINGLE:
MORE:
NYBBLE$=mid$(hexnum$,COUNT):NYB=ASC(NYBBLE$):V=0
if val(NYBBLE$)>0 then V=Val(NYBBLE$)
if NYB>64 and NYB<71 then V=(NYB-65)+10
EMR=(LENG-COUNT):V2=V2+(V*(16^EMR)):V=0
IF COUNT<LENG-1 THEN INC COUNT,1:GOTO MORE:
SINGLE:
NYBBLE$=mid$(hexnum$,LENG):NYB=ASC(NYBBLE$)
if val(NYBBLE$)>0 then V=Val(NYBBLE$)
if NYB>64 and NYB<71 then V=(NYB-65)+10
ENDFUNCTION V2+V
` *=---------------------------------------------------------------------=*
` >> Hex To Dec Routines By Kevin Picone <<
` *=---------------------------------------------------------------------=*
`
Function Hex_String_To_Dec(hexstring$)
Result=0
BaseMult=1
HexString$=lower$(hexstring$)
If Len(hexstring$)>0
If Mid$(hexstring$,1)="$" Then hexstring$=Right$(hexstring$,Len(hexstring$)-1)
For lp=Len(hexstring$) To 1 Step -1
c=Asc(Mid$(hexstring$,lp))
If c>47 And c<58 Then result=result+(basemult*(c-48))
If c>96 And c<103 Then result=result+(basemult*(c-87))
basemult=basemult*16
Next lp
EndIf
EndFunction result
Function Hex_String_To_Dec2(hexstring$)
Result=0
BaseMult=1
HexString$=lower$(hexstring$)
If Len(hexstring$)>0
If Mid$(hexstring$,1)="$" Then hexstring$=Right$(hexstring$,Len(hexstring$)-1)
For lp=Len(hexstring$) To 1 Step -1
c=Asc(Mid$(hexstring$,lp))
if c<58
If c>47 Then result=result+(basemult*(c-48))
else
If c>96 And c<103 Then result=result+(basemult*(c-87))
endif
basemult=basemult*16
Next lp
EndIf
EndFunction result
`
`
` Using a reverse lookup from the chr values avoids the inner loop calcs
`
`
Init_Faster_hex_table:
` Assumes 32bit Max len (8 nibbles)
MaxNibLen=8
Dim HexConvertTable(MaxNibLen,256)
BaseMult=1
For Baselp=MaxNibLen to 1 step -1
For clp=48 to 57
HexConvertTable(Baselp,clp)=(basemult*(clp-48))
next clp
For clp=97 to 102
HexConvertTable(Baselp,clp)=(basemult*(clp-87))
next clp
basemult=basemult*16
next BaseLP
return
Function Hex_String_To_Dec3(hexstring$)
Result=0
BaseMult=1
StringLen=Len(hexstring$)
HexString$=lower$(hexstring$)
If StringLen>1
If Mid$(hexstring$,1)="$" Then hexstring$=Right$(hexstring$,StringLen-1)
BaseOffset=8-StringLen
For lp=StringLen To 1 Step -1
result=result+HexConvertTable(BaseOffset+lp,Asc(Mid$(hexstring$,lp)))
Next lp
else
If StringLen=1
result=HexConvertTable(8,Asc(hexstring$))
endif
EndIf
EndFunction result
l8r,
Kevin Picone
[url]www.uwdesign.50megs.com[/url]
