Hello,

We have been working on a genetic programming project, and occasionally the compiler fails and gives an internal error. I've captured and reduced one of these down to a single expression. See http://dpaste.dzfl.pl/e7a66aa067ab (reduced_expr.d)

When I compile this file using: dmd -c -O reduced_expr.d

It says:
DMD 2.066.1] Internal error: backend/cod1.c 1562
DMD 2.067.1] Internal error: backend/cod1.c 1567

The compile succeeds without the '-O' flag.

Am I correct in assuming that an internal error in the compiler should be filed as a bug report?

As you can see, the expression is a massive ugly thing, as is often the case with genetic programming. I'd like to reduce this expression further before filing said bug report. I recall seeing a project on this forum which automatically figures out the simplest program which causes a compile failure. Can someone kindly point me to it?

Thanks,
Saurabh

https://github.com/CyberShadow/DustMite/wiki

On Thursday, 21 May 2015 at 08:28:30 UTC, Saurabh Das wrote:
> Hello,
>
> We have been working on a genetic programming project, and occasionally the compiler fails and gives an internal error. I've captured and reduced one of these down to a single expression. See http://dpaste.dzfl.pl/e7a66aa067ab (reduced_expr.d)
>
> When I compile this file using: dmd -c -O reduced_expr.d
>
> It says:
> DMD 2.066.1] Internal error: backend/cod1.c 1562
> DMD 2.067.1] Internal error: backend/cod1.c 1567
>
> The compile succeeds without the '-O' flag.
>
> Am I correct in assuming that an internal error in the compiler should be filed as a bug report?
>
> As you can see, the expression is a massive ugly thing, as is often the case with genetic programming. I'd like to reduce this expression further before filing said bug report. I recall seeing a project on this forum which automatically figures out the simplest program which causes a compile failure. Can someone kindly point me to it?
>
> Thanks,
> Saurabh

Thanks!

Wow, dustmite is really useful. It reduces the expression down to:

double someFunction(double AvgPriceChangeNormalized, double TicksTenMinutesNormalized)
{
    return (TicksTenMinutesNormalized?1:AvgPriceChangeNormalized)?1:TicksTenMinutesNormalized/(TicksTenMinutesNormalized==0)==0;
}

Which gives a compiler error: Internal error: backend/cod1.c 1562

On Thursday, May 21, 2015 08:28:29 Saurabh Das via Digitalmars-d-learn wrote:
> Am I correct in assuming that an internal error in the compiler should be filed as a bug report?

Yes. You should never see an ICE, and the compiler should never segfault. So, whenever you see either of those happen, please report it.

- Jonathan M Davis

On Thursday, 21 May 2015 at 08:55:45 UTC, Saurabh Das wrote:
> Thanks!
>
> Wow, dustmite is really useful. It reduces the expression down to:
>
> double someFunction(double AvgPriceChangeNormalized, double TicksTenMinutesNormalized)
> {
>     return (TicksTenMinutesNormalized?1:AvgPriceChangeNormalized)?1:TicksTenMinutesNormalized/(TicksTenMinutesNormalized==0)==0;
> }
>
> Which gives a compiler error: Internal error: backend/cod1.c 1562

make that

double foo(double a, double b)
{
    return (b ? 1 : a) ? 1 : b / (b == 0) == 0;
}

and please submit to https://issues.dlang.org

That expression is, not to put too fine a point on it, mad. The operator precedence itself is giving me a headache, let alone the division of a double by a boolean... I'm pretty sure it doesn't do what you want it to, unless what you want is seriously weird.

As a matter of fact, i'm pretty sure that expression evaluates to 1, irrelevant of the values of the two variables.

On Thursday, 21 May 2015 at 10:24:59 UTC, John Colvin wrote:
> On Thursday, 21 May 2015 at 08:55:45 UTC, Saurabh Das wrote:
>> Thanks!
>>
>> Wow, dustmite is really useful. It reduces the expression down to:
>>
>> double someFunction(double AvgPriceChangeNormalized, double TicksTenMinutesNormalized)
>> {
>>    return (TicksTenMinutesNormalized?1:AvgPriceChangeNormalized)?1:TicksTenMinutesNormalized/(TicksTenMinutesNormalized==0)==0;
>> }
>>
>> Which gives a compiler error: Internal error: backend/cod1.c 1562
>
> make that
>
> double foo(double a, double b)
> {
>     return (b ? 1 : a) ? 1 : b / (b == 0) == 0;
> }
>
> and please submit to https://issues.dlang.org
>
> That expression is, not to put too fine a point on it, mad. The operator precedence itself is giving me a headache, let alone the division of a double by a boolean... I'm pretty sure it doesn't do what you want it to, unless what you want is seriously weird.
>
> As a matter of fact, i'm pretty sure that expression evaluates to 1, irrelevant of the values of the two variables.

s/irrelevant/irrespective/

double foo(double b)
{
    return b / (b == 0) == 0;
}

Looks like this fails too.

>>
>> and please submit to https://issues.dlang.org

Submitted: https://issues.dlang.org/show_bug.cgi?id=14613

>>
>> That expression is, not to put too fine a point on it, mad. The operator precedence itself is giving me a headache, let alone the division of a double by a boolean... I'm pretty sure it doesn't do what you want it to, unless what you want is seriously weird.
>>
>> As a matter of fact, i'm pretty sure that expression evaluates to 1, irrelevant of the values of the two variables.
>
> s/irrelevant/irrespective/

The original expression was a candidate in a genetic programming population - a result of trial and error / "natural" selection over a few generations. The dustmite-reduced expression is really weird I agree - I don't know what to make of it. I've reported it as I found it.

The otiginal expression is not so wierd, it just haphazardly long. It doesn't do any strange divides or compares.

In either case, it shouldn't compile normally without the '-O' and fail to compile with it.

We managed a 1000x speed up over Java on our genetic programming system by using D, but this compile failure is preventing us from using the release / optimised builds :((

Thanks,
Saurabh

PS: The original expression: http://dpaste.dzfl.pl/raw/e7a66aa067ab

double someFunction(double AvgPriceChangeNormalized, double DayFactor, double TicksTenMinutesNormalized)
{
    return ((((AvgPriceChangeNormalized)*(0.0868))*((DayFactor)*(TicksTenMinutesNormalized)))*(((AvgPriceChangeNormalized)*(0.0868))*(((((((((TicksTenMinutesNormalized)==0)?(1):((AvgPriceChangeNormalized)/(TicksTenMinutesNormalized)))-((TicksTenMinutesNormalized)+(DayFactor)))==0)?(1):((TicksTenMinutesNormalized)/((((TicksTenMinutesNormalized)==0)?(1):((AvgPriceChangeNormalized)/(TicksTenMinutesNormalized)))-((TicksTenMinutesNormalized)+(DayFactor)))))==0)?(1):(((TicksTenMinutesNormalized)+(-0.865))/((((((TicksTenMinutesNormalized)==0)?(1):((AvgPriceChangeNormalized)/(TicksTenMinutesNormalized)))-((TicksTenMinutesNormalized)+(DayFactor)))==0)?(1):((TicksTenMinutesNormalized)/((((TicksTenMinutesNormalized)==0)?(1):((AvgPriceChangeNormalized)/(TicksTenMinutesNormalized)))-((TicksTenMinutesNormalized)+(DayFactor)))))))*(TicksTenMinutesNormalized))));
}

On Thu, 21 May 2015 11:36:14 +0000, Saurabh Das wrote:

> PS: The original expression: http://dpaste.dzfl.pl/raw/e7a66aa067ab
> 
> double someFunction(double AvgPriceChangeNormalized, double DayFactor,
> double TicksTenMinutesNormalized)
> {
>      return
> ((((AvgPriceChangeNormalized)*(0.0868))*((DayFactor)*
(TicksTenMinutesNormalized)))*(((AvgPriceChangeNormalized)*(0.0868))*
(((((((((TicksTenMinutesNormalized)==0)?(1):((AvgPriceChangeNormalized)/
(TicksTenMinutesNormalized)))-((TicksTenMinutesNormalized)
+(DayFactor)))==0)?(1):((TicksTenMinutesNormalized)/
((((TicksTenMinutesNormalized)==0)?(1):((AvgPriceChangeNormalized)/
(TicksTenMinutesNormalized)))-((TicksTenMinutesNormalized)
+(DayFactor)))))==0)?(1):(((TicksTenMinutesNormalized)+(-0.865))/
((((((TicksTenMinutesNormalized)==0)?(1):((AvgPriceChangeNormalized)/
(TicksTenMinutesNormalized)))-((TicksTenMinutesNormalized)
+(DayFactor)))==0)?(1):((TicksTenMinutesNormalized)/
((((TicksTenMinutesNormalized)==0)?(1):((AvgPriceChangeNormalized)/
(TicksTenMinutesNormalized)))-((TicksTenMinutesNormalized)
+(DayFactor)))))))*(TicksTenMinutesNormalized))));
> }

now i have to find a way to unsee it...