Very different result

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nov79
Posts: 47
Joined: Feb 23, 2020 15:31

Very different result

Postby nov79 » Mar 02, 2020 4:20

If I use FreeBasic's standard library function like PRINT, ABS, SQR the program is twice as slow as when using functions from the crt header (printf, fabs, sqrt). Anyone know why there is such a big different?
paul doe
Posts: 1266
Joined: Jul 25, 2017 17:22
Location: Argentina

Re: Very different result

Postby paul doe » Mar 02, 2020 5:41

Which version of fbc are you using? And which compiler switches? When I run this code with fbc -gen gcc -Wc -Ofast I get a small difference (~2%) in favor of the fbc rtl (fbc v1.07.1):

Code: Select all

#include once "crt.bi"

dim as single _
  a => 3.41!, _
  b, c

dim as double _
  t1, sum1, t2, sum2
dim as uinteger _
  count => 100000000

for _
  i as uinteger => 1 _
  to count
 
  t1 => timer()
  b => sqrt( a ) 'fabs( a )
  t1 => timer() - t1
  sum1 +=> t1
next

c => b

for _
  i as integer => 1 _
  to count
 
  t2 => timer()
  b => sqr( a ) 'abs( a )
  t2 => timer() - t2
  sum2 +=> t2
next

dim as integer _
  cps1 => 1.0 / ( sum1 / count ), _
  cps2 => 1.0 / ( sum2 / count )

? "crt calls per second: " & cps1
? "fbrtl calls per second: " & cps2
? "Difference: " & ( cps2 / cps1 ) * 100.0
? "Result: " & c
sleep()

Same with some others I've tested: difference is almost non-existent, much less twice as slow. Can you post how do you measure the timings? Calls per second isn't a good measurement, but raw timings aren't either, so...
nov79
Posts: 47
Joined: Feb 23, 2020 15:31

Re: Very different result

Postby nov79 » Mar 02, 2020 6:00

I measured using Unix's time command.

The binary compiled with fbc -O 3 test.bas

p/s: I use the same version as yours.
nov79
Posts: 47
Joined: Feb 23, 2020 15:31

Re: Very different result

Postby nov79 » Mar 02, 2020 6:42

paul doe wrote:Which version of fbc are you using? And which compiler switches? When I run this code with fbc -gen gcc -Wc -Ofast I get a small difference (~2%) in favor of the fbc rtl (fbc v1.07.1):

Code: Select all

#include once "crt.bi"

dim as single _
  a => 3.41!, _
  b, c

dim as double _
  t1, sum1, t2, sum2
dim as uinteger _
  count => 100000000

for _
  i as uinteger => 1 _
  to count
 
  t1 => timer()
  b => sqrt( a ) 'fabs( a )
  t1 => timer() - t1
  sum1 +=> t1
next

c => b

for _
  i as integer => 1 _
  to count
 
  t2 => timer()
  b => sqr( a ) 'abs( a )
  t2 => timer() - t2
  sum2 +=> t2
next

dim as integer _
  cps1 => 1.0 / ( sum1 / count ), _
  cps2 => 1.0 / ( sum2 / count )

? "crt calls per second: " & cps1
? "fbrtl calls per second: " & cps2
? "Difference: " & ( cps2 / cps1 ) * 100.0
? "Result: " & c
sleep()

Same with some others I've tested: difference is almost non-existent, much less twice as slow. Can you post how do you measure the timings? Calls per second isn't a good measurement, but raw timings aren't either, so...


It's your test. In my test, rebuild with your command it's even slower when build with my fbc -O 3. In any case, the crt version won.

Please note that my code is a recursive for loop iterating from n = 1 to 1000000000 and it took nearly an hour to complete each run on my system with the cpu fan spinning like hell. The final result is always the fbrtl is twice as slow as the crt.

p/s: your code looks weird, I've never seen such syntax before.
paul doe
Posts: 1266
Joined: Jul 25, 2017 17:22
Location: Argentina

Re: Very different result

Postby paul doe » Mar 02, 2020 11:04

Do you have the code handy?
nov79
Posts: 47
Joined: Feb 23, 2020 15:31

Re: Very different result

Postby nov79 » Mar 02, 2020 12:19

paul doe wrote:Do you have the code handy?

Not needed. I diagnosed the problem.

The problem is in the print to screen part, not the calculating of the sequence.

Free Basic's Print is much slower than crt's printf.

I didn't notice that the Free Basic's Print does print the full number, when crt's printf does not print the full number but only up to certain decimal place.

Without the print to screen part there is nearly no different in execution speed.

p/s: you didn't answer me why your code is so weird!

Anyone know why this code is so weird? I have never see such syntax before:

Code: Select all

#include once "crt.bi"

dim as single _
  a => 3.41!, _
  b, c

dim as double _
  t1, sum1, t2, sum2
dim as uinteger _
  count => 100000000

for _
  i as uinteger => 1 _
  to count
 
  t1 => timer()
  b => sqrt( a ) 'fabs( a )
  t1 => timer() - t1
  sum1 +=> t1
next

c => b

for _
  i as integer => 1 _
  to count
 
  t2 => timer()
  b => sqr( a ) 'abs( a )
  t2 => timer() - t2
  sum2 +=> t2
next

dim as integer _
  cps1 => 1.0 / ( sum1 / count ), _
  cps2 => 1.0 / ( sum2 / count )

? "crt calls per second: " & cps1
? "fbrtl calls per second: " & cps2
? "Difference: " & ( cps2 / cps1 ) * 100.0
? "Result: " & c
sleep()
Xusinboy Bekchanov
Posts: 254
Joined: Jul 26, 2018 18:28

Re: Very different result

Postby Xusinboy Bekchanov » Mar 02, 2020 13:47

nov79 wrote:Anyone know why this code is so weird? I have never see such syntax before:

Code: Select all

#include once "crt.bi"

dim as single _
  a => 3.41!, _
  b, c

dim as double _
  t1, sum1, t2, sum2
dim as uinteger _
  count => 100000000

for _
  i as uinteger => 1 _
  to count
 
  t1 => timer()
  b => sqrt( a ) 'fabs( a )
  t1 => timer() - t1
  sum1 +=> t1
next

c => b

for _
  i as integer => 1 _
  to count
 
  t2 => timer()
  b => sqr( a ) 'abs( a )
  t2 => timer() - t2
  sum2 +=> t2
next

dim as integer _
  cps1 => 1.0 / ( sum1 / count ), _
  cps2 => 1.0 / ( sum2 / count )

? "crt calls per second: " & cps1
? "fbrtl calls per second: " & cps2
? "Difference: " & ( cps2 / cps1 ) * 100.0
? "Result: " & c
sleep()

What is the weirdness?
In Freebasic and VB, wrapping to the next line is allowed using the "_" sign.
The sign "=" and "=>" are the same.
nov79
Posts: 47
Joined: Feb 23, 2020 15:31

Re: Very different result

Postby nov79 » Mar 02, 2020 13:56

Xusinboy Bekchanov wrote:
nov79 wrote:Anyone know why this code is so weird? I have never see such syntax before:

Code: Select all

#include once "crt.bi"

dim as single _
  a => 3.41!, _
  b, c

dim as double _
  t1, sum1, t2, sum2
dim as uinteger _
  count => 100000000

for _
  i as uinteger => 1 _
  to count
 
  t1 => timer()
  b => sqrt( a ) 'fabs( a )
  t1 => timer() - t1
  sum1 +=> t1
next

c => b

for _
  i as integer => 1 _
  to count
 
  t2 => timer()
  b => sqr( a ) 'abs( a )
  t2 => timer() - t2
  sum2 +=> t2
next

dim as integer _
  cps1 => 1.0 / ( sum1 / count ), _
  cps2 => 1.0 / ( sum2 / count )

? "crt calls per second: " & cps1
? "fbrtl calls per second: " & cps2
? "Difference: " & ( cps2 / cps1 ) * 100.0
? "Result: " & c
sleep()

What is the weirdness?
In Freebasic and VB, wrapping to the next line is allowed using the "_" sign.
The sign "=" and "=>" are the same.

Except I'm not from Basic, I'm from C. I have read code of people on this forum and never seen such thing .
It looks too cryptic.
fxm
Posts: 9934
Joined: Apr 22, 2009 12:46
Location: Paris suburbs, FRANCE

Re: Very different result

Postby fxm » Mar 02, 2020 14:04

To clearly distinguish the assignment operator (used for setting) from the equality operator (used for testing), some prefer to use the symbol "=>" for the first and the symbol '=' for the second. The opposite ("=>" for equality operator) is not allowed by FreeBASIC.
paul doe
Posts: 1266
Joined: Jul 25, 2017 17:22
Location: Argentina

Re: Very different result

Postby paul doe » Mar 02, 2020 15:06

nov79 wrote:...
It looks too cryptic.

Mildly amusing coming from someone whose first language is C XD:

Code: Select all

#include <iostream>

void
  whatever()
  {
    for(
      int i = 0;     
      i < 10;     
      i++ )
     
      std::cout << "Yay" << std::endl ;
  }

int
  main(
    int argc,
    char **argv)
  {
    int
      a = 3,
      b, c ;
   
    if( a == 3 )
      whatever() ;
  }

Like the other members before pointed out, it is just to distinguish between the assignment operator from the comparison operator. In FreeBasic, this is optional whereas in C/C++ it's required. As for the verticality, the '_' is required to break lines in BASIC due to the 'beginner friendly' syntax used. This is not needed in C, since statements are explicitly separated with a semicolon.
paul doe
Posts: 1266
Joined: Jul 25, 2017 17:22
Location: Argentina

Re: Very different result

Postby paul doe » Mar 02, 2020 15:22

Say, since the thread title is 'Very different result', it may be worth pointing out that, coming from C, there are some things that you should take into account when porting code. For example, this C++ code snippet:

Code: Select all

#include <iostream>

int
  main(
    int argc,
    char **argv)
  {
    int
      a, b ;
   
    a = b = 3 ;
   
    std::cout << a << std::endl ;
    std::cout << b << std::endl ;
  }

The same syntax in FreeBasic yields a very different result:

Code: Select all

dim as integer _
  a, b

a = b = 3

? a
? b

sleep()

That is, the semantics of expressions don't always match 1:1, so you should be very aware of these quirks (so as to avoid a headache or two). There are others too (for example, the for-next behavior of FreeBasic vs C's for() statement)
Lost Zergling
Posts: 333
Joined: Dec 02, 2011 22:51
Location: France

Re: Very different result

Postby Lost Zergling » Mar 02, 2020 15:42

Hello Nov79. What I like about FB is its versatility in terms of syntax and programming style. You have the possibility of a syntax close to c, directly c, integrate an assembler syntax, prefer an object style, make macros, or try to define your own keywords (an approach that I tried with lzle) . Without elegance and thoroughness, language can never do all that. Often, what may seem "weird" is related to some of the "spirit" of the language: ease, versatility, and creativity. Having been able to keep all of this while offering object or low level possibilities is a feat of the developers involved in the design, documentation, maintenance and development of that tool.
angros47
Posts: 1673
Joined: Jun 21, 2005 19:04

Re: Very different result

Postby angros47 » Mar 02, 2020 17:03

nov79 wrote:Not needed. I diagnosed the problem.

The problem is in the print to screen part, not the calculating of the sequence.

Free Basic's Print is much slower than crt's printf.


You are not the first to mention this, actually: https://freebasic.net/forum/viewtopic.php?f=3&t=26204

Are you using Linux or Windows?
nov79
Posts: 47
Joined: Feb 23, 2020 15:31

Re: Very different result

Postby nov79 » Mar 03, 2020 14:18

fxm wrote:To clearly distinguish the assignment operator (used for setting) from the equality operator (used for testing), some prefer to use the symbol "=>" for the first and the symbol '=' for the second. The opposite ("=>" for equality operator) is not allowed by FreeBASIC.

Thank you.

When I see the "=>" I immediately think about the arrow function: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions

Many programming languages out there utilize this arrow to do functional programming. I just think functional has come to Free Basic.

I don't like functional programming at all. It's too hard for me.
Last edited by nov79 on Mar 03, 2020 14:23, edited 2 times in total.
nov79
Posts: 47
Joined: Feb 23, 2020 15:31

Re: Very different result

Postby nov79 » Mar 03, 2020 14:22

paul doe wrote:That is, the semantics of expressions don't always match 1:1, so you should be very aware of these quirks (so as to avoid a headache or two). There are others too (for example, the for-next behavior of FreeBasic vs C's for() statement)


Thanks to remind me about this.

p/s: I don't know C++, only a small subset of plain C.
Last edited by nov79 on Mar 03, 2020 14:58, edited 1 time in total.

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