Today i was looking at some javascript source code.
How do i calculate this ?
Math.pow(3.0, 0.4)
I know that "Math.pow(3.0, 4.0)" == 3.0 * 3.0 * 3.0 * 3.0 = 81.0
See if there is a VCRT function that will do powers.
include \masm32\MasmBasic\MasmBasic.inc ; download (http://masm32.com/board/index.php?topic=94.0)
Init
Print Str$("Math.pow(3.0, 0.4) = %f", ExpXY(3, 0.4) (http://www.webalice.it/jj2006/MasmBasicQuickReference.htm#Mb1195))
invoke crt_pow, FP8(3.0), FP8(0.4)
Inkey Str$("CRT Math.pow(3.0, 0.4) = %If\n", ST(0))
Exit
end start
Output:
MB Math.pow(3.0, 0.4) = 1.55184558407721623
CRT Math.pow(3.0, 0.4) = 1.55184557391535971
msvcrt,
pow, powf, powl
Headers downloadable in this site.
sample
you could use 80-bit (64-bit) precision with the FPU via logarithms
i don't know if there's an SSE equiv
XY = alog(Y*log(X))
F2XM1 2 to the X power Minus 1
FSCALE SCALE ST(0) by ST(1)
FYL2X Y*Log2X
FYL2XP1 Y*Log2(X+1)
exponentiation can also be done with a Taylor Series
Quote from: dedndave on September 18, 2014, 03:23:07 AM
you could use 80-bit (64-bit) precision with the FPU via logarithms
include \masm32\MasmBasic\MasmBasic.inc ; download (http://masm32.com/board/index.php?topic=94.0)
Init
PrintLine "Exact (Wolfram Alpha) = 1.55184557391535967427" ; Wolfram Alpha (http://www.wolframalpha.com/input/?i=3%5E0.4)
Print Str$("MB10 Math.pow(3.0, 0.4) = %Jf\n", ExpXY(3, FP10(0.4)))
Print Str$("MB8 Math.pow(3.0, 0.4) = %Jf\n", ExpXY(3, FP8(0.4)))
invoke crt_pow, FP8(3.0), FP8(0.4) ; CRT uses double aka REAL8
Print Str$("CRT8 Math.pow(3.0, 0.4) = %Jf\n", ST(0))
Print Str$("MB4 Math.pow(3.0, 0.4) = %Jf\n", ExpXY(3, 0.4)) ; default is REAL4
Exit
end start
Exact (Wolfram Alpha) = 1.55184557391535967427
MB10 Math.pow(3.0, 0.4) = 1.551845573915359674
MB8 Math.pow(3.0, 0.4) = 1.551845573915359712
CRT8 Math.pow(3.0, 0.4) = 1.551845573915359712
MB4 Math.pow(3.0, 0.4) = 1.551845584077216225
Thanks guys,
I had an older msvcrt.inc file without the pow function ( replaced it with the latest one )
Thanks dave, for the logarithms example
Hi,
Not sure if this is useful for your purposes. But it should show
about the level of effort that might be required. This is not in its
original format as it was modified to work in a (somewhat) newer
assembler.
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
; Figure 7.24 Calculate 10**ST,
; "Assembly Language Programming for the IBM Personal Computer",
; David J. Bradley, 1984, page 218.
;----------------------------------------------;
; This routine takes the top element of ;
; the 8087 stack, and raises ten to that power ;
; Input -- ST0 is X ;
; Output -- ST0 is 10**X ;
; This routine uses two stack positions plus ;
; the parameter, a total of three. ;
;-----------------------------------------------
TEN_TO_X PROC NEAR
;-----ST0-------;-----ST1-------;---ST2-------
; X ; ? ; ?
FLDL2T ; LOG2(10) ; X ; ?
FMUL ;X*LOG2(10) = E ; ? ; ?
FNSTCW [OLD_CW] ;---------------;---------------;-------------
FWAIT ; Get the current status word
MOV AX,[OLD_CW] ; Save it
AND AX, NOT 0C00H ; Set rounding control to
OR AX, 0400H ; round towards -infinity
MOV [NEW_CW],AX
FLDCW [NEW_CW] ;---------------;---------------;-------------
FLD1 ; 1 ; E ; ?
FCHS ; -1 ; E ; ?
FLD ST(1) ; E ; -1 ; E
FRNDINT ; INT(E) = I ; -1 ; E
FLDCW [OLD_CW]
FXCH ST(2) ; E ; -1 ; I
FSUB ST,ST(2) ; E - I = F ; -1 ; I
FSCALE ; F*2**-1 = F/2 ; -1 ; I
F2XM1 ; (2**F/2)-1 ; -1 ; I
FSUBR ; 2**F/2 ; I ; ?
FMUL ST,ST ; 2**F ; I ; ?
FSCALE ; (2**F)*(2**I) ; I ; ?
FXCH ST(1) ; I ; 2**(I+F) ; ?
FCOMP ; 2**(I+F) ; ? ; ?
RET ; 10**X ; ? ; ?
TEN_TO_X ENDP
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
HTH,
Steve N.
Thanks Steve,
And thank you Dave, you put me in the right direction. :t
float1 real4 0.0
fld FLT4(0.4)
fld FLT4(3.0)
fyl2x
fld1
fld st(1)
fprem
f2xm1
faddp
fscale
fxch
fstp st(0)
fstp float1 ; result: 1.551845584077
Marinus
for all the stuff you've shown us, we are still in your debt, Marinus :biggrin:
back in the 80's, i played with the Taylor Series method (16-bit, of course)
as i recall, i ended up with a 5-term polynomial that was fairly accurate for a single precision result
Yeah the 80's, no internet and trying to get things done from reading (school)books and visiting the book library.
Still have my old trigonometry books from highschool and those helped me a lot thru the years.
Those were the days because everything was new and exciting.....
not just that - my brain isn't as sharp - lol
30 years ago, i was young and i still thought math was fun
now, it's a bit of a chore
I know what you mean, i'm also not that sharp anymore.
My short time memory ( hope this is english :biggrin:) is very bad after my motorcycle accident 2 years ago where i knocked my head to a lantern post.
So programming is a good exercise for me, although i'm slow these days.
Hi Marinus,
Quote from: Siekmanski on September 19, 2014, 06:14:09 AM
I know what you mean, i'm also not that sharp anymore.
My short time memory ( hope this is english :biggrin:) is very bad after my motorcycle accident 2 years ago where i knocked my head to a lantern post.
So programming is a good exercise for me, although i'm slow these days.
I'm sad to hear that. I hope you'll have a full recovery in the next time and you'll find back to the old strength.
Gunther
Thanks Gunther.
True confessions, a few years ago I had ridden my pushbike down the road to get a few things and on the way back tried to use a drivway to get from the road onto the footpath, messed it up and flipped the bike upside down and landed on my head. Broke the cycle helmet and ended up with concussion. Worse still I had to wheel the bike home a couple of kilometres and while there was little damage to the bike, I had to buy a new helmet and replace the tube in the front tire. As far as I know the footpath did not feel a thing. :biggrin:
Quote from: Siekmanski on September 19, 2014, 06:14:09 AM
I know what you mean, i'm also not that sharp anymore.
My short time memory ( hope this is english :biggrin:) is very bad after my motorcycle accident 2 years ago where i knocked my head to a lantern post.
So programming is a good exercise for me, although i'm slow these days.
Well, Marinus I'd say that your memory is very sharp yet :t. Programming is a good entertainment for me too, but i have few time also: job, family, live,... Game of Thrones :biggrin:,... But the most truth is that I haven't got the same enthusiasm as when I was younger. Nevertheless I keep on programming in my free time. And would be nice to make here a demo compo or something like this.
Kind regards
Yeah, bikes can be dangerous........
Alfonso, by demo compo you mean sinus scrollers, 3d objects and music etc.?
Yes, a competition on demos (http://en.wikipedia.org/wiki/Demoscene_compo): graphics [+music]
The de3moscene is the best one. I have several examples of the demos from ages.
It is amazing what some people can do. For instance, not to mentiopn the beauty of the apps, the size compression is really extraordinary. I have seen files with 3 or 5 Mb be compacted to a tiny few kbs. How they managed to do it ? I have absolutely no idea.
The graphics are something extremely pretty, specially if you consider some files made back in the 1999 where DX was absolutely nothing. Or some commodore examples that really are amazing.
Take a look at this i´m uploading. Simplistic graphics, but really awesome.
It was common that many of the programmers that wins the contest (if i remember well, it was a time when they payed U$ 10.000 for the 1st prize) were hired to gaming companies.
Also take a look at this 2nd file i uploaded. I succeed to decode it years ago, and convert to Rosasm. I made a recent update of this demo and also uploaded on rosasm board.
The src is embedded inside the app.
The text is made with an Ascii Generator routine. And the letters are made with the function "BuildLetters" embeded to the app. The font used is Times. I changed the original code to allow a fine tune of the fonts and letters.
The links below are the ones i found at the time, to draw the text glyphs
http://gamedev.stackexchange.com/questions/3528/how-do-i-convert-directxs-x-from-binary-encoding-to-text-encoding-and-back
http://www.webestools.com/ascii-text-generator-ascii-art-code-online-txt2ascii-text2ascii-maker-free-text-to-ascii-converter.html
Btw, Marinus, if you want to see how it managed to code the audio. Take a look at the src. Open it in RosAsm, look for the "TITLE AUDIO" section and see the function "BuildMusic". I don´t know how they created the music data, but i succeed to decode the functions that make it work, specially some that are related to the musical note scale.
used to use a compaq portable where i worked
it had a pretty cool banner logo, considering it was monochrome graphics :P
the text came on with a "sparkler" effect
i know - i'm an old fart ::)
Quotei know - i'm an old fart
:greensml: :greensml: :greensml:
I remember the compaq series.Although i didn´t had one. At the time it was to expensive here for me to buy. Back at those times, some friends of mine had old Tk85 etc
My 1st computer was an old MSX from gradiente (Z80 processor). We plug it onto the TV screen, and the programs i did in basic (qbasic or gbasic, if i recall well) and store it on old audio tapes recorders (K7).
(http://www.mci.org.br/micro/outros/expert_01.jpg)
Concerning the commodore and the old times, what really amazes me, is that regarding the demo scenes, it wasn´t really necessary the usage of all of the actual technology. With the hardware we had at the time, people still did amazing things relatively fast.
When i was 13th or 14th years old (In the mid´s 80's), i had a friend whose father gave him an Amiga. The graphics was awesome and was yet, used on TV broadcasting.
that was when i worked at Edge Computer Corp.
before that, i worked at Sperry Flight Systems, and we had a TI terminal with laser printer and acoustic modem - lol
we used PDP-11's for test machines
before that, i worked for Rockwell - they had a little AIM-65 - i wasn't into it, much - it was a toy
although, we did make S-100 bus Z-80 computers for test purposes
before that, i worked at General Instruments - they made IC's (games, calculators, memories)
before that, i worked at Flow Technology, Inc - they used a General Instruments calculator chip - what a joke
before that, i worked at Courrier Terminal Systems - they made smart terminals that used intel 4004 and 8008's
before that, i was in the army :biggrin:
I started coding in assembly on the Amiga 500 in the late 80's.
Saw some Demos and Intros and just wanted to be a coder.....
Quote from: dedndave on September 20, 2014, 04:56:52 AM
we used PDP-11's for test machines
Around 1982 I wrote a FORTRAN IV program on a PDP-11, simulating some complex thermodynamic process. The printout was about 3-4 metres long, huge for my standards. And yes, compile time was just about right for a coffee break :badgrin:
Later, I bought a ZX Spectrum, and around 1986, the time had come to buy The Real Thing: an Atari ST with a whopping one MEGA!! byte of RAM but no harddisk yet. GfaBasic and 68k assembler became my friends ;-)
I split my early history, 1st computer I took any notice of was a Z80 in about 1980 and from memory it was an Osbourne. You laid it on its side, removed the top cover which was also the keyboard and it had a small monochrome screen that showed when you removed the keyboard/cover. I remember dabbling with basic from an early floppy disk but took the view that it was not worth the effort playing with it. My HP 11c calculator was both more powerful and faster. (I still own it and the original batteries still work.)
Started back with a 286 running MS-DOS 5.0 in 1990, jumped into the deep end with Asm, Basic and C in parallel on a 486 a month or so later and have been going ever since. Never touched anything else than x86 from then onwards and was never interested. Started with win32 from NT4 on the promise of FLAT memory model with no segment/offset addressing and have never looked back.
Hi,
In college we had an HP minicomputer with BASIC. A few of us
rebooted it after hours to run FORTRAN. Later I programmed
CDC computers at work (FORTRAN again). We eventually got
some PC/AT's and used X86 systems until retirement.
At home I started with an F8 microprocessor with assembler.
Around 1981 I got a Zenith Z-90 Z-80 system (same as a Heath
H-89) BASIC at first, later assembly and FORTRAN. An Apple ][
showed up sometime later. Graduated to a Zenith Z-110 8088
(and 8085) DOS system when the Air Force gave Zenith the
contract to supply them with computers. There were a bunch
of them for sale used shortly after that. 286, 386 and Pentium
and so forth since then. Using FORTRAN, BASIC, assembly, and
PostScript to have fun on them every so often.
Cheers,
Steve N.
Quote from: jj2007 on September 20, 2014, 06:08:59 PM
Around 1982 I wrote a FORTRAN IV program on a PDP-11, simulating some complex thermodynamic process. The printout was about 3-4 metres long, huge for my standards. And yes, compile time was just about right for a coffee break :badgrin:
Later, I bought a ZX Spectrum, and around 1986, the time had come to buy The Real Thing: an Atari ST with a whopping one MEGA!! byte of RAM but no harddisk yet. GfaBasic and 68k assembler became my friends ;-)
yes, the legendary PDP-11. But GfaBasic wasn't so bad and the Motorola 68000 was an excellent CPU.
Gunther
Hi
I found only this i hope it help
http://www.asmcommunity.net/forums/topic/?id=9853
http://www.jbox.dk/sanos/source/lib/math/pow.asm.html
Hi ragdog,
your second link is NASM/YASM syntax. Although that could be converted simply to masm syntax, that do not like it a lot. I don't know why.
Gunther
Quote from: ragdog on September 21, 2014, 08:30:13 PM
I found only this i hope it help
http://www.asmcommunity.net/forums/topic/?id=9853
Bogdan & bitRake at work :t
My pow() implementation is based on qWord/Agner Fog (http://masm32.com/board/index.php?topic=1783.msg18292#msg18292), and probably a tick faster. If that is not fast enough, e.g. for graphics, one could create once a huge table with ExpXY() (http://www.webalice.it/jj2006/MasmBasicQuickReference.htm#Mb1195) or similar, then interpolate the requested values linearly.
the dead link on that page works if...
http://www.asmcommunity.net/forums/topic/?id=2979 (http://www.asmcommunity.net/forums/topic/?id=2979)
Quotethe dead link on that page works if...
if...??
QuoteNASM/YASM syntax
It easy to convert it
Quote from: ragdog on September 22, 2014, 03:50:08 AM
Quotethe dead link on that page works if...
if...??
when you go to this page...
http://www.asmcommunity.net/forums/topic/?id=9853 (http://www.asmcommunity.net/forums/topic/?id=9853)
btiRAKE has a dead link in the second post
http://www.asmcommunity.net/board/index.php?topic=2979&highlight=exponentbut, you can convert it to a good link, if...
http://www.asmcommunity.net/forums/topic/?id=2979 (http://www.asmcommunity.net/forums/topic/?id=2979)
many of the links in the old masm32 forum are similar
Hi ragdog,
Quote from: ragdog on September 22, 2014, 03:50:08 AM
QuoteNASM/YASM syntax
It easy to convert it
no doubt about it. I'm using YASM very often and I've no problem with the slightly different syntax. But other programmers seem to have difficulties.
Gunther