Multiplication Overflow
» > >
»
» View previous topic :: View next topic  
I am getting a bug that sets the value of an int64 to its max.
This code:

Code:

Prices.buttonprice *= 2.5;

After two times, it jumps.
1st Price: 1500000
2nd Price: 3750000
Is there something I'm doing wrong?
01000001 01110010 01110010 01101111 01110111 01100101 01100100 00100001
Can we please see your whole code.
Here:

Code:

#include <stdlib.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <math.h>
#include <tice.h>
#include <time.h>
#include <graphx.h>
#include <keypadc.h>
#include <inttypes.h>
#include <fileioc.h>
#include <debug.h>
#include "gfx/CEClickU.h"
struct player_t {
   uint64_t points;
   uint64_t cps;
   uint64_t clickvalue;
   uint64_t cps_mult;
   uint64_t cvm;
   uint8_t unlocked;
   uint8_t page;
};

struct counts_t {
   uint64_t addcount, studentcount, subcount, cookiecount, multcount, officecount, divcount, phonecount, expcount, spacecount, calccount, buttoncount;
};

struct prices_t
{
   uint64_t addprice;
   uint64_t studentprice;
   uint64_t subprice;
   uint64_t cookieprice;
   uint64_t multprice;
   uint64_t officeprice;
   uint64_t divprice;
   uint64_t phoneprice;
   uint64_t expprice;
   uint64_t spaceprice;
   uint64_t calcprice;
   uint64_t buttonprice;
};
void print_uint64(uint64_t num) {
   char str[21]; // 64-bit numbers have at most 20 decimal digits
   sprintf(str, "%" PRIu64, num);
   gfx_PrintString(str);
}



void missing_appvars(void) {
   gfx_End();
   os_SetCursorPos(0, 0);
   os_PutStrFull("Err: Missing CE Clicker AppVars");
   while (!os_GetCSC());
   exit(0);
}

void draw(struct player_t* Player, struct counts_t* Counts, struct prices_t* Prices, bool prevkey) {
   gfx_FillScreen(7);
   gfx_SetColor(0);
   gfx_TransparentSprite(background, 0, 0);
   gfx_TransparentSprite(background, 32, 0);
   gfx_TransparentSprite(background, 64, 0);
   gfx_TransparentSprite(background, 96, 0);
   gfx_TransparentSprite(background, 128, 0);
   gfx_TransparentSprite(background, 160, 0);
   gfx_TransparentSprite(background, 192, 0);
   gfx_TransparentSprite(background, 224, 0);
   gfx_TransparentSprite(background, 256, 0);
   gfx_TransparentSprite(background, 288, 0);
   gfx_SetTextXY(10, 10);


   gfx_PrintString("Equations: ");
   print_uint64(Player->points);
   gfx_SetTextXY(10, 20);
   gfx_PrintString("EPS: ");
   print_uint64(Player->cps * Player->cps_mult);
   if (prevkey)
   {
      gfx_TransparentSprite(calc_small, 24, 68);
   }
   else
   {
      gfx_TransparentSprite(calc_large, 24, 68);
   }
   gfx_SetTextXY(10, 988);
   gfx_PrintString("Enter: Click, Del : Save + Quit, < > : Scroll Shop,");
   gfx_SetTextXY(10, 998);
   gfx_PrintString("2nd: Buy Top, Alpha : Buy Bottom");
   gfx_TransparentSprite(up_box, 136, 74);
   gfx_TransparentSprite(up_box, 136, 140);
   if (Player->page > 0)
   {
      gfx_TransparentSprite(arrow_right, 112, 126);
   }
   if (Player->page < Player->unlocked)
   {
      gfx_TransparentSprite(arrow_left, 296, 126);
   }
   
   if (Player->page == 0)
   {
      gfx_TransparentSprite(up_add, 140, 74);
      gfx_SetTextXY(170, 80);
      gfx_PrintString("Addition Sign");
      gfx_SetTextXY(170, 90);
      gfx_PrintString("X ");
      print_uint64(Counts->addcount);
      gfx_SetTextXY(142, 104);
      gfx_PrintString("+1 EQU Per Click");
      gfx_SetTextXY(142, 114);
      print_uint64(Prices->addprice);
      gfx_PrintString(" EQU");
      gfx_TransparentSprite(up_stu, 140, 142);
      gfx_SetTextXY(170, 148);
      gfx_PrintString("Bored Student");
      gfx_SetTextXY(170, 158);
      gfx_PrintString("X ");
      print_uint64(Counts->studentcount);
      gfx_SetTextXY(142, 172);
      gfx_PrintString("+1 EPS");
      gfx_SetTextXY(142, 182);
      print_uint64(Prices->studentprice);
      gfx_PrintString(" EQU");
   }
   else if (Player->page == 1)
   {
      gfx_TransparentSprite(up_sub, 140, 74);
      gfx_SetTextXY(170, 80);
      gfx_PrintString("Subtraction Sign");
      gfx_SetTextXY(170, 90);
      gfx_PrintString("X ");
      print_uint64(Counts->subcount);
      gfx_SetTextXY(142, 104);
      gfx_PrintString("+3 EQU Per Click");
      gfx_SetTextXY(142, 114);
      print_uint64(Prices->subprice);
      gfx_PrintString(" EQU");
      gfx_TransparentSprite(up_coo, 140, 142);
      gfx_SetTextXY(170, 148);
      gfx_PrintString("Cookie");
      gfx_SetTextXY(170, 158);
      gfx_PrintString("X ");
      print_uint64(Counts->cookiecount);
      gfx_SetTextXY(142, 172);
      gfx_PrintString("+4 EPS");
      gfx_SetTextXY(142, 182);
      print_uint64(Prices->cookieprice);
      gfx_PrintString(" EQU");
   }
   else if (Player->page == 2)
   {
      gfx_TransparentSprite(up_mul, 140, 74);
      gfx_SetTextXY(170, 80);
      gfx_PrintString("Multiplying Sign");
      gfx_SetTextXY(170, 90);
      gfx_PrintString("X ");
      print_uint64(Counts->multcount);
      gfx_SetTextXY(142, 104);
      gfx_PrintString("+10 EQU Per Click");
      gfx_SetTextXY(142, 114);
      print_uint64(Prices->multprice);
      gfx_PrintString(" EQU");
      gfx_TransparentSprite(up_off, 140, 142);
      gfx_SetTextXY(170, 148);
      gfx_PrintString("Office Worker");
      gfx_SetTextXY(170, 158);
      gfx_PrintString("X ");
      print_uint64(Counts->officecount);
      gfx_SetTextXY(142, 172);
      gfx_PrintString("+27 EPS");
      gfx_SetTextXY(142, 182);
      print_uint64(Prices->officeprice);
      gfx_PrintString(" EQU");
   }
   else if (Player->page == 3)
   {
      gfx_TransparentSprite(up_div, 140, 74);
      gfx_SetTextXY(170, 80);
      gfx_PrintString("Division Sign");
      gfx_SetTextXY(170, 90);
      gfx_PrintString("X ");
      print_uint64(Counts->divcount);
      gfx_SetTextXY(142, 104);
      gfx_PrintString("80 EQU Per Click");
      gfx_SetTextXY(142, 114);
      print_uint64(Prices->divprice);
      gfx_PrintString(" EQU");
      gfx_TransparentSprite(up_pho, 140, 142);
      gfx_SetTextXY(170, 148);
      gfx_PrintString("Phone :0");
      gfx_SetTextXY(170, 158);
      gfx_PrintString("X ");
      print_uint64(Counts->phonecount);
      gfx_SetTextXY(142, 172);
      gfx_PrintString("+101 EPS");
      gfx_SetTextXY(142, 182);
      print_uint64(Prices->phoneprice);
      gfx_PrintString(" EQU");
   }
   else if (Player->page == 4)
   {
      gfx_TransparentSprite(up_exp, 140, 74);
      gfx_SetTextXY(170, 80);
      gfx_PrintString("Exponent Sign");
      gfx_SetTextXY(170, 90);
      gfx_PrintString("X ");
      print_uint64(Counts->expcount);
      gfx_SetTextXY(142, 104);
      gfx_PrintString("750 EQU Per Click");
      gfx_SetTextXY(142, 114);
      print_uint64(Prices->expprice);
      gfx_PrintString(" EQU");
      gfx_TransparentSprite(up_bar, 140, 142);
      gfx_SetTextXY(170, 148);
      gfx_PrintString("Spacebar");
      gfx_SetTextXY(170, 158);
      gfx_PrintString("X ");
      print_uint64(Counts->spacecount);
      gfx_SetTextXY(142, 172);
      gfx_PrintString("+980 EPS");
      gfx_SetTextXY(142, 182);
      print_uint64(Prices->spaceprice);
      gfx_PrintString(" EQU");
   }
   else if (Player->page == 5)
   {
      gfx_TransparentSprite(up_cal, 140, 74);
      gfx_SetTextXY(170, 80);
      gfx_PrintString("Calculator");
      gfx_SetTextXY(170, 90);
      gfx_PrintString("X ");
      print_uint64(Counts->calccount);
      gfx_SetTextXY(142, 104);
      gfx_PrintString("2x EQU Per Click");
      gfx_SetTextXY(142, 114);
      print_uint64(Prices->calcprice);
      gfx_PrintString(" EQU");
      gfx_TransparentSprite(up_but, 140, 142);
      gfx_SetTextXY(170, 148);
      gfx_PrintString("Button");
      gfx_SetTextXY(170, 158);
      gfx_PrintString("X ");
      print_uint64(Counts->buttoncount);
      gfx_SetTextXY(142, 172);
      gfx_PrintString("2x EPS");
      gfx_SetTextXY(142, 182);
      print_uint64(Prices->buttonprice);
      gfx_PrintString(" EQU");
   }
   gfx_SetColor(1);
   gfx_Line(0, 215, 319, 215);
   gfx_Line(0, 216, 319, 216);
   gfx_Line(111, 64, 111, 215);
   gfx_Line(112, 64, 112, 215);
   gfx_BlitBuffer();

}
int load(struct player_t* Player, struct counts_t* Counts, struct prices_t* Prices)
{
   uint8_t var = ti_Open("CEClickS", "r");
   if (var == 0)
   {
      return 1;
   }
   if (ti_GetC(var) != 'a')
   {
      return 1;
   }
   if (ti_Read(Player, sizeof(struct player_t), 1, var) != 1)
   {
      return 1;
   }
   if (ti_GetC(var) != 'b')
   {
      return 1;
   }
   if (ti_Read(Counts, sizeof(struct counts_t), 1, var) != 1)
   {
      return 1;
   }
   if (ti_GetC(var) != 'c')
   {
      return 1;
   }
   if (ti_Read(Prices, sizeof(struct prices_t), 1, var) != 1)
   {
      return 1;
   }
   ti_Close(var);

   return 0;

}
int save(struct player_t* Player, struct counts_t* Counts, struct prices_t* Prices)
{
   if (Player->clickvalue == 0)
   {
      return 1;
   }
   uint8_t var = ti_Open("CEClickS", "w");
   if (ti_PutC('a', var) == EOF)
   {
      os_PutStrFull("a");
      ti_Close(var);
      return 1;
   }
   if (ti_Write(Player, sizeof(struct player_t), 1, var) != 1)
   {
      os_PutStrFull("Player");
      ti_Close(var);
      return 1;
   }
   if (ti_PutC('b', var) == EOF)
   {
      os_PutStrFull("b");
      ti_Close(var);
      return 1;
   }
   if (ti_Write(Counts, sizeof(struct counts_t), 1, var) != 1)
   {
      os_PutStrFull("Count");
      ti_Close(var);
      return 1;
   }
   if (ti_PutC('c', var) == EOF)
   {
      os_PutStrFull("c");
      ti_Close(var);
      return 1;
   }
   if (ti_Write(Prices, sizeof(struct prices_t), 1, var) != 1)
   {
      os_PutStrFull("Price");
      ti_Close(var);
      return 1;
   }
   ti_SetArchiveStatus(true, var);
   ti_Close(var);
   return 0;
}
/* Main function, called first */
int main(void)
{
   struct player_t Player;
   struct counts_t Counts;
   struct prices_t Prices;
   bool key, prevkey = false;
   if (load(&Player, &Counts, &Prices) == 1)
   {
      Player.points = 0;
      Player.cps = 0;
      Player.clickvalue = 1;
      Player.cps_mult = 1;
      Player.cvm = 1;
      Player.unlocked = 0;
      Player.page = 0;
      Counts.addcount = 0;
      Counts.studentcount = 0;
      Counts.subcount = 0;
      Counts.cookiecount = 0;
      Counts.multcount = 0;
      Counts.officecount = 0;
      Counts.divcount = 0;
      Counts.phonecount = 0;
      Counts.expcount = 0;
      Counts.spacecount = 0;
      Counts.calccount = 0;
      Counts.buttoncount = 0;
      Prices.addprice = 25;
      Prices.studentprice = 15;
      Prices.subprice = 250;
      Prices.cookieprice = 150;
      Prices.multprice = 980;
      Prices.officeprice = 1120;
      Prices.divprice = 7000;
      Prices.phoneprice = 7800;
      Prices.expprice = 80000;
      Prices.spaceprice = 90000;
      Prices.calcprice = 1000000;
      Prices.buttonprice = 1500000;
   }

   uint8_t seconds = rtc_Seconds;
   kb_key_t g1_key = kb_Data[1];
   gfx_Begin();
   gfx_SetTransparentColor(0);
   
   if (CEClickU_init() == 0)
   {
      missing_appvars();
   }
   else
   {
      
      gfx_SetPalette(palette, sizeof_palette, 0);
      gfx_SetdrawBuffer(); // draw to the buffer to avoid rendering artifacts
      gfx_ZeroScreen();
      do
      {
         kb_Scan();
         key = (kb_Data[6] & kb_Enter);
         g1_key = kb_Data[1];
         if (key && !prevkey) {
            Player.points += Player.clickvalue * Player.cvm;
         }
         if (rtc_Seconds > seconds || rtc_Seconds > seconds)
         {
            Player.points += Player.cps * Player.cps_mult;
         }
         if (kb_Data[7] & kb_Right)
         {
            if (Player.page < Player.unlocked)
            {
               Player.page++;
            }

         }
         if (kb_Data[7] & kb_Left)
         {
            if (Player.page > 0)
            {
               Player.page--;
            }
         }
         if (Player.points >= 100 && Player.unlocked == 0)
         {
            Player.unlocked++;
         }
         if (Player.points >= 800 && Player.unlocked == 1)
         {
            Player.unlocked++;
         }
         if (Player.points >= 6000 && Player.unlocked == 2)
         {
            Player.unlocked++;
         }
         if (Player.points >= 80000 && Player.unlocked == 3)
         {
            Player.unlocked++;
         }
         if (Player.points >= 900000 && Player.unlocked == 4)
         {
            Player.unlocked++;
         }
         if (kb_2nd & g1_key)
         {
            if (Player.page == 0)
            {
               if (Player.points >= Prices.addprice)
               {
                  Player.points = Player.points - Prices.addprice;
                  Player.clickvalue++;
                  Counts.addcount++;
                  Prices.addprice *= 1.1;
               }
            }
            else if (Player.page == 1)
            {
               if (Player.points >= Prices.subprice)
               {
                  Player.points = Player.points - Prices.subprice;
                  Player.clickvalue += 5;
                  Counts.subcount++;
                  Prices.subprice *= 1.1;
               }
            }
            else if (Player.page == 2)
            {
               if (Player.points >= Prices.multprice)
               {
                  Player.points = Player.points - Prices.multprice;
                  Player.clickvalue += 10;
                  Counts.multcount++;
                  Prices.multprice *= 1.1;
               }
            }
            else if (Player.page == 3)
            {
               if (Player.points >= Prices.divprice)
               {
                  Player.points = Player.points - Prices.divprice;
                  Player.clickvalue += 80;
                  Counts.divcount++;
                  Prices.divprice *= 1.1;
               }
            }
            else if (Player.page == 4)
            {
               if (Player.points >= Prices.expprice)
               {
                  Player.points = Player.points - Prices.expprice;
                  Player.clickvalue += 750;
                  Counts.expcount++;
                  Prices.expprice *= 1.1;
               }
            }
            else if (Player.page == 5)
            {
               if (Player.points >= Prices.calcprice)
               {
                  Player.points = Player.points - Prices.calcprice;
                  Player.cvm *= 2;
                  Counts.calccount++;
                  Prices.calcprice *= 2.5;
               }
            }
         }
         if (kb_Alpha & kb_Data[2])
         {
            if (Player.page == 0)
            {
               if (Player.points >= Prices.studentprice)
               {
                  Player.points = Player.points - Prices.studentprice;
                  Player.cps++;
                  Counts.studentcount++;
                  Prices.studentprice *= 1.1;
               }
            }
            else if (Player.page == 1)
            {
               if (Player.points >= Prices.cookieprice)
               {
                  Player.points = Player.points - Prices.cookieprice;
                  Player.cps += 4;
                  Counts.cookiecount++;
                  Prices.cookieprice *= 1.1;
               }
            }
            else if (Player.page == 2)
            {
               if (Player.points >= Prices.officeprice)
               {
                  Player.points = Player.points - Prices.officeprice;
                  Player.cps += 27;
                  Counts.officecount++;
                  Prices.officeprice *= 1.1;
               }
            }
            else if (Player.page == 3)
            {
               if (Player.points >= Prices.phoneprice)
               {
                  Player.points = Player.points - Prices.phoneprice;
                  Player.cps += 101;
                  Counts.phonecount++;
                  Prices.phoneprice *= 1.1;
               }
            }
            else if (Player.page == 4)
            {
               if (Player.points >= Prices.spaceprice)
               {
                  Player.points = Player.points - Prices.spaceprice;
                  Player.cps += 980;
                  Counts.spacecount++;
                  Prices.spaceprice *= 1.1;
               }
            }
            else if (Player.page == 5)
            {
               if (Player.points >= Prices.buttonprice)
               {
                  Player.points = Player.points - Prices.buttonprice;
                  Player.cps_mult *= 2;
                  Counts.buttoncount++;
                  Prices.buttonprice *= 2.5;
               }
            }
         }
         seconds = rtc_Seconds;
         draw(&Player, &Counts, &Prices, prevkey);

         prevkey = key;
      } while (!(g1_key & kb_Del));
      gfx_End();
      if (save(&Player, &Counts, &Prices) == 1)
      {
         os_SetCursorPos(0, 0);
         os_PutStrFull("Err: CE Clicker Save Fail!Save Data Is Erased!      Please Report This Error  To Github:                  CoolModder/CalcClicker");
         ti_Delete("CEClickS");
         while (!os_GetCSC());
      }

      exit(0);
   }
}



01000001 01110010 01110010 01101111 01110111 01100101 01100100 00100001
CoolModder wrote:
I am getting a bug that sets the value of an int64 to its max.
This code:

Code:

Prices.buttonprice *= 2.5;

After two times, it jumps.
1st Price: 1500000
2nd Price: 3750000
Is there something I'm doing wrong?

It should be noted that involving floating point values here is going to implicitly cast your 64-bit integer to floating point, which (on the CE which uses single-precision floats) reduces it to a 24-bit mantissa, potentially losing precision. One alternative would be instead of multiplying by 2.5, to multiply by 5 and divide by 2.

What's the incorrect value you're getting, by the way? 3750000 times 2.5 shouldn't be an overflow out of anything but a signed 24-bit integer, nor should it have an imprecise result, so I do have to wonder if this is a compiler or toolchain error which is casting the result to a signed 24-bit integer before casting to 64 bits.
calc84maniac wrote:
CoolModder wrote:
I am getting a bug that sets the value of an int64 to its max.
This code:

Code:

Prices.buttonprice *= 2.5;

After two times, it jumps.
1st Price: 1500000
2nd Price: 3750000
Is there something I'm doing wrong?

It should be noted that involving floating point values here is going to implicitly cast your 64-bit integer to floating point, which (on the CE which uses single-precision floats) reduces it to a 24-bit mantissa, potentially losing precision. One alternative would be instead of multiplying by 2.5, to multiply by 5 and divide by 2.

What's the incorrect value you're getting, by the way? 3750000 times 2.5 shouldn't be an overflow out of anything but a signed 24-bit integer, nor should it have an imprecise result, so I do have to wonder if this is a compiler or toolchain error which is casting the result to a signed 24-bit integer before casting to 64 bits.

18446744073702149400
01000001 01110010 01110010 01101111 01110111 01100101 01100100 00100001
That value is not the maximum 64-bit number but 264-7402216, which is apparently being obtained by sign-extending 224-7402216. The correct answer is 9375000, which does overflow a signed 24-bit number but not an unsigned one, so it seems the compiler is doing an unsigned multiplication & then treating the result as signed before doing a sign extension. (Well, it is also doing something with the exponents, but that is irrelevant to what is going wrong.) This is is definitely the wrong sequence of operations, even apart from it being a bad idea to use floats for this due to the potential loss of precision.

(Although you are using uint64_t, I am pretty sure that the C standard specifies that implicit promotions happen with signed types, so that is why it is messing with sign extension at all in there.)

I second the suggestion to multiply by 5 & then divide by 2, since that will keep all the intermediate values as uint64 & thus not lose any precision unless the multiplication by 5 overflows (& I think should also avoid passing through anything being signed, although I am less certain of that). It will also avoid whatever bug in the float-handling code that is being triggered by the multiplication by 2.5.
Fixed it! Thanks for your help, Zeroko, calc84maniac, and mateo!
01000001 01110010 01110010 01101111 01110111 01100101 01100100 00100001
The fix for this is now available on the nightly release of the toolchain.
  
Register to Join the Conversation
Have your own thoughts to add to this or any other topic? Want to ask a question, offer a suggestion, share your own programs and projects, upload a file to the file archives, get help with calculator and computer programming, or simply chat with like-minded coders and tech and calculator enthusiasts via the site-wide AJAX SAX widget? Registration for a free Cemetech account only takes a minute.

» Go to Registration page
Multiplication Overflow
»
» View previous topic :: View next topic  
Page 1 of 1
» All times are UTC - 5 Hours
 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

 

Advertisement