Odd floating point issue, can anone explain it

Hi
Below I have pinpointed an odd problem that I recently found using the newest express build of the compiler. Can
anyone reproduce it ? Can anyone explain what the problem is ?
Thanks a lot in advance,
Cheers, Jacob
jwp@per$ cat foo_simple.f90
program foo
implicit none
integer(4) :: ta(8)
call date_and_time(values=ta)
write(*,*) 'floating issue', (ta(8))*(1.0e-3)
end program
jwp@per$ /data/sw/sunstudio_201006/solstudioex1006/bin/f95 -g -O0 -ftrap=%all -fsimple=0 -fns=no foo_simple.f90
jwp@per$ ./a.out
Floating point exception
jwp@per$

Thanks for getting back. Isn't is so that ta must be an integer to be passed onto date_and_time ? So is your suggestion to do something like
real(4) :: a
call date_and_time(values=ta)
a=real((ta(8)))
write(*,*) 'floating issue', a*(1.0e-3_4)
or
real(8) :: a
call date_and_time(values=ta)
a=dble((ta(8)))
write(*,*) 'floating issue', a*(1.0e-3_8)
??? Unfortunately, both expressions above also gives rise to a floating point exception. Maybe I misread your suggestion.
Cheers, Jacob

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[Solved] Bash and Floating point arithmetic

I didn't realize how troublesome floating point numbers can be until now.
What I want to do should be simple I dare say:
properRounding( ( currentTime - downloadTime ) / ( dueTime - downloadTime ) * 100 )
however best I've been able to achieve so far is this:
echo "($currentTime-$downloadTime)/($dueTime-$downloadTime)*100" | bc -l
Which prints the correct floating point value.
I've tried to put the result in a variable, but I must be doing it wrong as I get the most peculiar error. I can live without it, but it would make life easier.
As for the rounding, that is a must. I've read that if you remove the -l param from bc, then it will round, but in my case something goes wrong as I just get the value 0 in return and besides, concluded after a simple test, bc always rounds down as in integer division, which I can not use.
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Last edited by zacariaz (2012-09-09 14:50:18)

Just for the fun of it, here's my progress thus far... Well, there really isn't much more to do. The rest is a conky thing.
#!/bin/bash
# Variables from unitinfo.txt - date as unix timestamps.
dueTime="$(date +%s -d "$(grep 'Due time: ' ~/unitinfo.txt | cut -c11-)")"
if [ "$1" = "end" ]
then echo $dueTime
fi
downloadTime="$(date +%s -d "$(grep 'Download time: ' ~/unitinfo.txt | cut -c16-)")"
if [ "$1" = "start" ]
then echo $downloadTime
fi
progress="$(grep 'Progress: ' ~/unitinfo.txt | cut -c11-12 | sed 's/ *$//')"
if [ "$1" = "prog1" ]
then echo $progress
fi
# The rest
#progress valued 0-1 for use with conky proress bars
progress2=$( echo 2k $progress 100 / f | dc )
if [ "$1" = "prog2" ]
then echo $progress2
fi
# Current time - unix timestamp.
currentTime="$(date +%s)"
# Remaining time - unix timestamp
remainingTime=$(( dueTime-$currentTime ))
if [ "$1" = "remain" ]
then echo $remainingTime
fi
# Elapsed time - unix timestamp
elapsedTime=$(( currentTime-downloadTime ))
if [ "$1" = "elap1" ]
then echo $elapsedTime
fi
# Total amount of time available - unix timestamp
totalTime=$(( dueTime-downloadTime ))
if [ "$1" = "total" ]
then echo $totalTime
fi
# How much time has elapsed in percent
progress3="$(echo 3k $elapsedTime $totalTime / 100 \* 0k 0.5 + 1 / f | dc)"
if [ "$1" = "elap2" ]
then echo $progress3
fi
# Like the above bur 0-1
progress4=$( echo 2k $progress3 100 / f | dc )
if [ "$1" = "elap3" ]
then echo $progress4
fi
# In percent, expected completion vs $dueTime - less than 100 is better.
expectedCompletion="$( echo 3k $elapsedTime 10000 \* $progress / $totalTime / 0k 0.5 + 1 / f | dc )"
if [ "$1" = "exp1" ]
then echo $expectedCompletion
fi
# Same as above, but unix timestamp
expectedCompletion2=$(( downloadTime+(expectedCompletion*totalTime/100) ))
if [ "$1" = "exp2" ]
then echo $expectedCompletion2
fi
#efficiency
if [ "$1" = "ef1" ]; then
if [ $progress -lt $progress3 ]
then echo "you're behind schedule."
elif [ $progress -eq $progress3 ]
then echo "You're right on schedule."
else
echo "You're ahead of schedule."
fi
fi
if [ "$1" = "ef2" ]; then
if [ $expectedCompletion -gt 100 ]
then echo "You're not going to make it!"
else
echo "You're going to make it!"
fi
fi

Inline functions in C, gcc optimization and floating point arithmetic issues

For several days I really have become a fan of Alchemy. But after intensive testing I have found several issues which I'd like to solve but I can't without any help.
So...I'm porting an old game console emulator written by me in ANSI C. The code is working on both gcc and VisualStudio without any modification or crosscompile macros. The only platform code is the audio and video output which is out of scope, because I have ported audio and video witin AS3.
Here are the issues:
1. Inline functions - Having only a single inline function makes the code working incorrectly (although not crashing) even if any optimization is enabled or not (-O0 or O3). My current workarround is converting the inline functions to macros which achieves the same effect. Any ideas why inline functions break the code?
2. Compiler optimizations - well, my project consists of many C files one of which is called flash.c and it contains the main and exported functions. I build the project as follows:
gcc -c flash.c -O0 -o flash.o     //Please note the -O0 option!!!
gcc -c file1.c -O3 -o file1.o
gcc -c file2.c -O3 -o file2.o
... and so on
gcc *.o -swc -O0 -o emu.swc   //Please note the -O0 option again!!!
mxmlc.exe -library-path+=emu.swc --target-player=10.0.0 Emu.as
or file in $( ls *.o ) //Removes the obj files
    do
        rm $file
    done
If I define any option different from -O0 in gcc -c flash.c -O0 -o flash.o the program stops working correctly exactly as in the inline funtions code (but still does not crash or prints any errors in debug). flash has 4 static functions to be exported to AS3 and the main function. Do you know why?
If I define any option different from -O0 in gcc *.o -swc -O0 -o emu.swc the program stops working correctly exactly as above, but if I specify -O1, -O2 or O3 the SWC file gets smaller up to 2x for O3. Why? Is there a method to optimize all the obj files except flash.o because I suspect a similar issue as when compilling it?
3. Flating point issues - this is the worst one. My code is mainly based on integer arithmetic but on 1-2 places it requires flating point arithmetic. One of them is the conversion of 16-bit 44.1 Khz sound buffer to a float buffer with same sample rate but with samples in the range from -1.0 to 1.0.
My code:
void audio_prepare_as()
    uint32 i;
    for(i=0;i<audioSamples;i+=2)
        audiobuffer[i] = (float)snd.buffer[i]/32768;
        audiobuffer[i+1] = (float)snd.buffer[i+1]/32768;
My audio playback is working perfectly. But not if using the above conversion and I have inspected the float numbers - all incorrect and invalid. I tried other code with simple floats - same story. As if alchemy refuses to work with floats. What is wrong? I have another lace whre I must resize the framebuffer and there I have a float involved - same crap. Please help me?
Found the floating point problem: audiobuffer is written to a ByteArray and then used in AS. But C floats are obviously not the same as those in AS3. Now the floating point is resolved.
The optimization issues remain! I really need to speed up my code.
Thank you in advice!

Dear Bernd,
I am still unable to run the optimizations and turn on the inline functions. None of the inline functions contain any stdli function just pure asignments, reads, simple arithmetic and bitwise operations.
In fact, the file containing the main function and those functions for export in AS3 did have memset and memcpy. I tried your suggestion and put the code above the functions calling memset and memcpy. It did not work soe I put the code in a header which is included topmost in each C file. The only system header I use is malloc.h and it is included topmost. In other C file I use pow, sin and log10 from math.h but I removed it and made the same thing:
//shared.h
#ifndef _SHARED_H_
#define _SHARED_H_
#include <malloc.h>
static void * custom_memmove( void * destination, const void * source, unsigned int num ) {
void *result;
__asm__("%0 memmove(%1, %2, %3)\n" : "=r"(result) : "r"(destination), "r"(source), "r"(num));
return result;
static void * custom_memcpy ( void * destination, const void * source, unsigned int num ) {
void *result;
__asm__("%0 memcpy(%1, %2, %3)\n" : "=r"(result) : "r"(destination), "r"(source), "r"(num));
return result;
static void * custom_memset ( void * ptr, int value, unsigned int num ) {
void *result;
__asm__("%0 memset(%1, %2, %3)\n" : "=r"(result) : "r"(ptr), "r"(value), "r"(num));
return result;
static float custom_pow(float x, int y) {
    float result;
__asm__("%0 pow(%1, %2)\n" : "=r"(result) : "r"(x), "r"(y));
return result;
static double custom_sin(double x) {
    double result;
__asm__("%0 sin(%1)\n" : "=r"(result) : "r"(x));
return result;
static double custom_log10(double x) {
    double result;
__asm__("%0 log10(%1)\n" : "=r"(result) : "r"(x));
return result;
#define memmove custom_memmove
#define memcpy custom_memcpy
#define memset custom_memset
#define pow custom_pow
#define sin custom_sin
#define log10 custom_log10
#include "types.h"
#include "macros.h"
#include "m68k.h"
#include "z80.h"
#include "genesis.h"
#include "vdp.h"
#include "render.h"
#include "mem68k.h"
#include "memz80.h"
#include "membnk.h"
#include "memvdp.h"
#include "system.h"
#include "loadrom.h"
#include "input.h"
#include "io.h"
#include "sound.h"
#include "fm.h"
#include "sn76496.h"
#endif /* _SHARED_H_ */
It still behave the same way as if nothing was changed (works incorrectly - displays jerk which does not move, whereby the image is supposed to move)
As I am porting an emulator (Sega Mega Drive) I use manu arrays of function pointers for implementing the opcodes of the CPU's. Could this be an issue?
I did a workaround for the floating point problem but processing is very slow so I hear only bzzt bzzt but this is for now out of scope. The emulator compiled with gcc runs at 300 fps on a 1.3 GHz machine, whereby my non optimized AVM2 code compiled by alchemy produces 14 fps. The pure rendering is super fast and the problem lies in the computational power of AVM. The frame buffer and the enulation are generated in the C code and only the pixels are copied to AS3, where they are plotted in a BitmapData. On 2.0 GHz Dual core I achieved only 21 fps. Goal is 60 fps to have smooth audio and video. But this is offtopic. After all everything works (slow) without optimization, and I would somehow turn it on. Suggestions?
Here is the file with the main function:
#include "shared.h"
#include "AS3.h"
#define FRAMEBUFFER_LENGTH    (320*240*4)
static uint8* framebuffer;
static uint32 audioSamples;
AS3_Val sega_rom(void* self, AS3_Val args)
    int size, offset, i;
    uint8 hardware;
    uint8 country;
    uint8 header[0x200];
    uint8 *ptr;
    AS3_Val length;
    AS3_Val ba;
    AS3_ArrayValue(args, "AS3ValType", &ba);
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    offset = 0;
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    size = AS3_IntValue(length);
    ptr = (uint8*)malloc(size);
    AS3_SetS(ba, "position", AS3_Int(0));
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    //fwrite(ptr, size, 1, f);
    //fclose(f);
    if((size / 512) & 1)
        size -= 512;
        offset += 512;
        memcpy(header, ptr, 512);
        for(i = 0; i < (size / 0x4000); i += 1)
            deinterleave_block(ptr + offset + (i * 0x4000));
    memset(cart_rom, 0, 0x400000);
    if(size > 0x400000) size = 0x400000;
    memcpy(cart_rom, ptr + offset, size);
    /* Free allocated file data */
    free(ptr);
    hardware = 0;
    for (i = 0x1f0; i < 0x1ff; i++)
        switch (cart_rom[i]) {
     case 'U':
         hardware |= 4;
         break;
     case 'J':
         hardware |= 1;
         break;
     case 'E':
         hardware |= 8;
         break;
    if (cart_rom[0x1f0] >= '1' && cart_rom[0x1f0] <= '9') {
        hardware = cart_rom[0x1f0] - '0';
    } else if (cart_rom[0x1f0] >= 'A' && cart_rom[0x1f0] <= 'F') {
        hardware = cart_rom[0x1f0] - 'A' + 10;
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    //From PicoDrive
    if (hardware&8)
        hw=0xc0; vdp_pal=1;
    } // Europe
    else if (hardware&4)
        hw=0x80; vdp_pal=0;
    } // USA
    else if (hardware&2)
        hw=0x40; vdp_pal=1;
    } // Japan PAL
    else if (hardware&1)
        hw=0x00; vdp_pal=0;
    } // Japan NTSC
    else
        hw=0x80; // USA
    if (vdp_pal) {
        vdp_rate = 50;
        lines_per_frame = 312;
    } else {
        vdp_rate = 60;
        lines_per_frame = 262;
    /*SRAM*/
    if(cart_rom[0x1b1] == 'A' && cart_rom[0x1b0] == 'R')
        save_start = cart_rom[0x1b4] << 24 | cart_rom[0x1b5] << 16 |
            cart_rom[0x1b6] << 8 | cart_rom[0x1b7] << 0;
        save_len = cart_rom[0x1b8] << 24 | cart_rom[0x1b9] << 16 |
            cart_rom[0x1ba] << 8 | cart_rom[0x1bb] << 0;
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        // A ROM that I came across had the start and end bytes of
        // the save ram the same and wouldn't work. Fix this as seen
        // fit, I know it could probably use some work. [PKH]
        if(save_start != save_len)
            if(save_start & 1) --save_start;
            if(!(save_len & 1)) ++save_len;
            save_len -= (save_start - 1);
            saveram = (unsigned char*)malloc(save_len);
            // If save RAM does not overlap main ROM, set it active by default since
            // a few games can't manage to properly switch it on/off.
            if(save_start >= (unsigned)size)
                save_active = 1;
        else
            save_start = save_len = 0;
            saveram = NULL;
    else
        save_start = save_len = 0;
        saveram = NULL;
    return AS3_Int(0);
AS3_Val sega_init(void* self, AS3_Val args)
    system_init();
    audioSamples = (44100 / vdp_rate)*2;
    framebuffer = (uint8*)malloc(FRAMEBUFFER_LENGTH);
    return AS3_Int(vdp_rate);
AS3_Val sega_reset(void* self, AS3_Val args)
    system_reset();
    return AS3_Int(0);
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    uint32 width;
    uint32 height;
    uint32 x, y;
    uint32 di, si, r;
    uint16 p;
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        for(x=0;x<320;x++)
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int main()
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                    Tmp = A / B;
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          lngTimeDiff = lngNewTime - lngOldTime;
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public class TestApp
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returns a long). Sorry you are correct I did miss that.
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also a 64-bit data type - so technically that would
have been a more fair test. The fact that 64-bit
floating point divisions are faster than 32-bit
integer divisions is what confuses me.
Oh, just in case you're interested, using float's in
that same snippet takes only 7,471 milliseconds to
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Message Edited by Jingyan on 08-22-2006 01:45 PM

Jingyan,
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Message was edited by: turingtest2

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Sometimes the payload get catched and sometimes(like 5 executions) it's like nothing is received? How can I check raw frame data to know my payload is received?

You are actually not doing single-point, instead, you are doing Stream Input. This will read into a queue of frames.
In your while loop, you are doing a Frame CAN read w/o a timeout and a quantity of -1. This means, "return all frames that are currently available". Note, if there are no frames available, this will return an empty array.
Here is where it gets tricky and you may need to know more about LabVIEW. You have an empty array, and you are then passing that into "index array". If you index an ampty array, you will get get a valid element (since an element cannot be empty) that contains the values of all zeros. This means that the timestamp will have a value of 0 and the payload will be an empty array.
In the next frame, you are just checking for new timestamp to be different from the old timestamp. If the old timestamp was Feb 8th, 2011 @ 07:03 and the new timestamp is '0', that is indeed different and you will capture that as a frame detection.
The simple fix would probably be to make frame detection only trigger on "(old != new) && (new != 0)". Note you need to also skip "old = new" in the last frame if you did NOT detect a frame.
Other possible fixes:
1. Read for 1 frame with a timeout. This will pause the VI until a frame is actually read.
2. Since this is a queue (and not single-point), you can read and "frame detect" would just be if the array is not empty. With queues, old data is not repeated, so there would be no frames in this case. This dramatically simplifies your VI.

Can the N8 handle FPU (floating point unit) apps?

I've come across a few apps that have an FPU version which, for devices which can handle it, offers greater performance over standard (non-FPU) version. I've seen mentioned that the E73, N95 8GB and 5800XM can handle FPU, but can't find anything said about whether the N8 can handle FPU or not. Any ideas? I can't find any instrument/chromatic tuners that have been developed specifically for S^3, so am looking at S60 versions, such as "Chromatic Tuner v0.25".

I'm sorry, but neither of you have actually answered my question. I know most S60v5 apps will work with S^3...that's not what I asked! I'm asking about apps that have been writen for devices that can manage FPU (floating point unit operations)
The app you linked to in the ovi store is a different app - I'm being quite specific about the app I'm asking about. The following link is for it's download location, and contains description of the non-FPU vs FPU versions.
http://hqh.unlink.org/s60/index.php?p=download
Anyone able to help?

The home button has stopped working on my iphone 5c. Did the same a few months ago and recovered 24hrs later. Can anyone explain this problem. Phone still in warranty. Had steam issue recently but this was after last home button episode.

Have an iphone 5c 8g. The home button has stopped working. Did the same a few months ago and recovered 24hrs later. Can anyone explain this problem. Phone still in warranty. Had steam issue recently but this was after last home button episode and no evidence of damage.

If you are playing in hockey arenas a lot or if you are bringing it into bathroom same time as shower it may not seem like much but overtime the steam can acquire and build up in the phones usb dock flex cable swell as the home button flex cable. Bring again into apple store and should be covered under warranty again. could also be a delay in a 8gb 5c software may just be very lag.

Can I create a java app for my palm zire 71 that uses floating point calc

I am an eclipse user that is looking at studio creator 2 and was wondering if I could create a java app for my palm zire 71. I have read alot about no floating point support in midp... is that true for java on the palm? If so, how does one calculate with floats and doubles to do sqrt functions etc?
Thanks in advance for your time
Dean-O

I looked at netbeans and it does not support floating points in midlets. Not good for palm app if no floating point ability. J2ME supports floating point but in netbeans... is uses midlets and there are no floating points. Now what does one do? Not that dreaded C++
THanks in advance
Dean-O

Odd floating point issue, can anone explain it

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