Floating point multiplication

hello everybody!
I use OpenSPARC T1. In floating point multiplication the upper 64 bit (64 to 128) where they compute and stored? ...in the fpu or it uses the SPU unit?
thanx in advance

Hi,
According with the OpenSparc T1 micro-architecture specifications (pag 204):
The FPU includes three independent execution pipelines:
Floating-point adder (FPA) adds, subtracts, compares, conversions
Floating-point multiplier (FPM) multiplies
Floating-point divider (FPD) divides
However, keep in mind that all the registers for the floating point operations are kept in the cores.
This is what the specs (pag 31) say about the SPU: "Stream processing unit (SPU) is used for modular arithmetic functions for crypto."

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Floating point operations is slower when small values are used?

I have the following simple program that multiplies two different floating point numbers many times. As you can see, one of the numbers is very small. When I calculate the time of executing both multiplications, I was surprised that the little number takes much longer than the other one. It seems that working with small doubles is slower... Does anyone know what is happening?
public static void main(String[] args) throws Exception
        long iterations = 10000000;
        double result;
        double number = 0.1D;
        double numberA = Double.MIN_VALUE;
        double numberB = 0.0008D;
        long startTime, endTime,elapsedTime;
        //Multiply numberA
        startTime = System.currentTimeMillis();
        for(int i=0; i < iterations; i++)
            result = number * numberA;
        endTime = System.currentTimeMillis();
        elapsedTime = endTime - startTime;
        System.out.println("
        System.out.println("Number A)
Time elapsed: " + elapsedTime + " ms");
        //Multiply numberB
        startTime = System.currentTimeMillis();
        for(int i=0; i < iterations; i++)
            result = number * numberB;
        endTime = System.currentTimeMillis();
        elapsedTime = endTime - startTime;
        System.out.println("
        System.out.println("Number B)
Time elapsed: " + elapsedTime + " ms");
    } Result:
Number A) Time elapsed: 3546 ms
Number B) Time elapsed: 110 ms
Thanks,
Diego

Verrry interrresting... After a few tweaks (sum & print multiplication result to prevent Hotspot from removing the entire loop, move stuff to one method to avoid code alignment effects or such, loop to get Hotspot compile everything; code below),
I find that "java -server" gives the same times for both the small and the big value, whereas "java -Xint" and "java -client" exhibit the unsymmetry. So should I conclude that my CPU floating point unit treats both values the same, but the client/server compilers do something ...what?
(You may need to add or remove a zero in "iterations" so that you get sane times with -client and -server.)
public class t
    public static void main(String[] args)
     for (int n = 0; n < 10; n++) {
         doit(Double.MIN_VALUE);
         doit(0.0008D);
    static void doit(double x)
        long iterations = 100000000;
        double result = 0;
        double number = 0.1D;
        long start = System.currentTimeMillis();
        for (int i=0; i < iterations; i++)
            result += number * x;
        long end = System.currentTimeMillis();
        System.out.println("time for " + x + ": " + (end - start) + " ms, result " + result);
}

Floating Point vs. Fixed Point

I'm reading discussions that say multiple instances of plugins degrades the overall audio quality.
Is this a possible limitation of floating-point ?

One Ohm wrote:
I'm reading discussions that say multiple instances of plugins degrades the overall audio quality.
Is this a possible limitation of floating-point ?
LOL!!!
I don't know what forums you're reading this from, but that is an absolute lie.
Cheers

Question in floating point operation

Hi,
I have question in java floating point operation.
public class test
     public static void main(String args[])
          double d1 = 243.35 ;
          double d2 = 2.3 ;
          System.out.println(d1 * d2) ;
          System.out.println((float)d1 * (float)d2) ;
The result is,
java version "1.4.1_02"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1_02-b06)
Java HotSpot(TM) Client VM (build 1.4.1_02-b06, mixed mode)
5.597049999999999E8
5.5970502E8
Though the multiplication does not result irrational number like 1/3, the result of the first statement is not accurate enough. In our project, this multiplication involves with money and we cannot ignore this.
Can anyone suggest why this is happening? Do I need to convert all the numbers to float to avoid this...Or Is it a bug?
~ Sathiya Dhanapal.

The underlying problem is that not all numbers can be represented exactly in a floating point representation. But if you perform all calculations using doubles and then round to two fractional digits at the end you should get a "correct" result UNLESS you have used ill-conditioned formulas introducing other kinds of arithmetic errors.
There's another way around this when it comes to counting money and that's to use integers (long or int). You convert every number to the lowest monetary unit (like a cent or whatever). Every money-amount can now be represented exactly but you still have to be careful because the rounding problem is still there (What do you do with the last cent when you split 100 cents in 3).
In your example the "more correct" you've got from using floats instead of doubles is only an illusion. The result has been implictly rounded becasuse fewer bits have been used. If you round the double result to the same precision as the float result, they're the same.
The important lesson in all this is TO KNOW WHEN TO ROUND.

Parse string to floating points

Hi,
I'm trying unsucessfully to parse the following string out to multiple outputs of floating point. Any idea?
Input String:
              Data     1            5           8          11
                      15.134 12.682   3.583    0.534
Want output to look like
output1: 15.134
output2: 12.682
output3: 3.583
output4: 0.534
thanks,
Anh

Anh
If thats what you want then you can get around it. Just wire the error out from the scan from string to a case statement selector. It will automatically fill out the error and no error. Pass through the scan from string values through both cases. Like this
David
Message Edited by David Crawford on 05-12-2006 10:28 AM
Attachments:
Scan From String Error Defaults.jpg ‏13 KB

32-bit floating point HDR support for LR4.1 RC2

Folks,
In the event you haven't discovered it, LR4.1 RC2 has added support for importing and adjusting a 32-bit floating point TIFF file. Which means LR4 can tonemap an HDR image. To use this, you'll need to use Photoshop's HDR Pro to put together the multiple exposed images, then set the options to make a 32-bit HDR image in HDR Pro and save that as a TIFF file. Then import the TIFF into LR4.1 RC2 for toning...note: nothing you do to the HRD in HDR Pro will impact the 32-bit FP TIFF. If you do some initial adjustments of the original raw files in LR 4.1, I'm pretty sure most of the toning in LR4.1 on the raw files is ignored. But white balance works (haven't tested spot healing and lens corrections yet).
Note, to do the HDR process, the raw images will end up being demosaiced and the saved HDR TIFF will be a linear ProPhoto RGB image.
Try it...the ability to use LR (and eventually ACR–it's not hooked up in the ACR 7 beta yet) to toning HDR images is actually pretty impressive. Also note, that you don't really need to feed HDR Pro a ton of multiple exposures...2 (normal and under to preserve highlight detail) or 3-5 depending on the scene contrast range is all you need. More isn't really better (unless you really need to shoot a very high dynamic range scene...

I will try that in the morning, but when checking the properties today it did say 16-bit for each clip. I have gotten around this by taking each clip offline, opening it in STP, applying the effects, doing a save as and then reconnecting each clip with the new file. It seems to work with no sync issues. Just doesn't work as easily as it should. Ideally I should be able to send each section to an STP script and allow it to do its work and have it work.
I sure hope to find out exactly what is going on.
K

Floating point Collsion Detection

I have an player that move around in a 2D map. The value of x and y are in floating points. Now i want it to collide with another player that move around too in the map. Both the player can rotate around too. I have tried many ways including rectangle drawing to detect collsion but its not accurate or very wrong.
Is there any hint on how to do the collsion detection? I really need help..Or is there anyone with similar situatio please give some tips or codes....
Any help will be greatly appreciated. Thank You!!!!

I would suggest using spheres around your "objects", or rectangles depending on the shape of your objects. Then you can use basic math to check if two objects collide.
You may want to look up the math behind this yourself, but I'm sure you can find a math library that you can either use or port to java. Looking around sites such as gamasutra.com and gamedev.net might give you some valuable clues.
If your objects have odd shapes (a gun sticking out for example), you may want to use multiple collision tests per object, having multiple bounding boxes or spheres.

SQL Loader and Floating Point Numbers

Hi
I have a problem loading floating point numbers using SQL Loader. If the number has more than 8 significant digits SQL Loader rounds the number i.e. 1100000.69 becomes 1100000.7. The CTL file looks as follows
LOAD DATA
INFILE '../data/test.csv' "str X'0A'"
BADFILE '../bad/test.bad'
APPEND
INTO TABLE test
FIELDS TERMINATED BY "," OPTIONALLY ENCLOSED BY '"'
Amount CHAR
and the data file as follows
"100.15 "
"100100.57 "
"1100000.69 "
"-2000000.33"
"-100000.43 "
the table defined as follows
CREATE TABLE test
Amount number(15,4)
) TABLESPACE NNUT050M1;
after loading a select returns the following
100.15
100100.57
1100000.7
-2000000
-100000.4
Thanks in advance
Russell

Actually if you format the field to display as (say) 999,999,999.99, you will see the correct numbers loaded via SQL Loader.
null

R6002 - floating point not loaded / C++ Runtime Error

Good Evening,
I have been having this problem with Adobe Bridge for a while and tonight sat down to try and solve it. Fresh version of Windows XP reinstalled all programs and this is still happening! Any Ideas?
This error only occurs with Adobe Bridge, I can load Photoshop etc.. all fine.
Error:
"Runtime Error!
Program: C:\ProgramFiles\Adobe\Adobe Bridge CS3\Bridge.exe
R6002
- floating point not loaded"
Here is a print screen..
http://images.unbrokenphotography.co.uk/BridgeError.jpg

Is there are answer to this problem? This error message is appearing on an entire lab full of computers. We are running Web Premium CS4
I have tried to reset the Bridge Preferences:
Hold down the Ctrl key and click on Bridge icon to start.
Should get a reset window with 3 options.
Choose the first option
I still get "Runtime Error! Program: C:\Prgram Files\Adobe\Adobe Bridge CS4\Bridge.exe R6002 -floating point support not loaded"

Invalid Floating Point Error

I have one Captivate 3 project published as a Stand Alone
project with Flash 8 selected. There are 36 slides, no audio, no
eLearning, SWF size and quality are high.
One person who runs this gets an "Invalid Floating Point"
error when he tries to run it the first time. He is running Windows
XP SP2, Firefox 3.0.4. and Flash Player 10.0.12.36. Other Captivate
projects I've created run fine for him. This one sometimes runs
after the first Error message.
Any thoughts on the cause and fix?
Thanks,
Janet

iMediaTouch probably doesn't support Floating Point formats - it certainly doesn't mention them in the advertising. Try saving your files as 24-bit PCMs, and they should import fine.

Pack and Floating Point Data Type in ABAP

Dear All,
I am new to ABAP. Started with data types. Came across pack and floating point.
Please let me know what PACK and Floating Point stands for with few examples and the main difference between them.
Regards
Arun V

Hi,
You'd better ask this question in ABAP forum http://forums.sdn.sap.com/forum.jspa?forumID=50 .
Best Regards,
Ada

Conversion of a floating point type field

Hi,
I'm fetching field ATFLV from table AUSP for a particular value of ATINN.ATFLV is a floating point type field.
Can anyone please guide me as to how to convert this field(ATFLV) from floating point no. to a simple no.?
Helpful answers will be rewarded.
Regards,
Sipra

hi,
Do like this,
float f = 234.33;
int i = (int) f; // i has value 234.
reward points if helpful..

Maximum size of a floating-point number

Morning all,
Does anyone know what the maximum size of a floating point number can be under Solaris 8 running on
a V880?
Regards,
Richard Breckon

I'm not sure what you're asking.
The maximum size is 128 bits.
The maximum value is as given in /usr/include/float.h: 1.189731495357231765085759326628007016E+4932L

Check Floating Point Number

Hello All,
I am having some trouble checking the value of a field with Key Figure type Number with 8 byte floating point. I want to read that field and populate another field with an X if true. For example if that field is equal to 5,0000000000000000E+07 then i want to mark the other field with an 'X'.
The problem is in my code, how do i read that number in the fltp field, such as the number above. my code reads as follows for the 'X' field.
    if SOURCE_FIELDS-abc123 eq 5000000.
      RESULT = 'X'.
    endif.
Thanks everyone in advance

You don't need to worry about converting the code into standard format or floating, just implement your code as you want and it will automatically take care of the conversion. Basically 5,0000000000000000E+07 = 50,000,000.
thanks.
Wond

32 bit Floating Point

Hello,
Running FCP 5.1
Having audio sync issues and was double checking my settings.
Although the sequence presets are at 16 bit, they are showing up in the browser as 32bit Floating Point.
Any thoughts?
I generally capture now at 30 minute increments and actually have always had this issue. FCP 4.5 and 5.1
all settings are where they should be.
although I do notice, obviously when the device is off, the audio output defaults to 'default' not to firewire dv.
thanks
iMac intel Mac OS X (10.4.8)

Some more details please. What hardware device are you sourcing the audio clips from? The likely culprit is your capture settings. What preset are you using? Check Audio/Video Settings-Capture Presets and see if the preset you've selected records audio as 32 bit. It will say in the right column after you've selected your preset.
If it says 32 bit there, click Edit to get the Capture Preset Editor. Under Quicktime Audio Settings, the Format field should give you a selection of sample rates and possibly alternate bit depths. If your only choice is 32 bit, (as it is for me when I capture audio via my RME, 32 bit Integer in my case) then you'd be well served by bringing those files into Peak or Quicktime and saving them as 16 bit Integer files to match your sequence settings.
If you've imported these files into FCP from an audio editor that can create 32 bit floating point audio files, eg Kyma, Sequoia, Nuendo, etc. then the same advice applies. The 32 bit files are much larger than they need to be and may upset the apple cart (he he, pun) when pulled into a sequence with different settings. More cpu overhead for sure.
Let us know what you find.

Floating point multiplication

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