#3577 error 9: FATAL Compiler Internal Error

[Jeff Bill]

I was making a game for the gameboy using the GBDK(which uses sdcc) and I ran into this error:

error 9: FATAL Compiler Internal Error in file '/Users/sdcc-builder/build/sdcc-build/orig/sdcc/src/z80/gen.c' line number '1870' : Symbol in register, but no register assigned. 
Contact Author with source code
Symbol iTemp46 at ic 73.
Caught signal 11: SIGSEGV

My code uses a few structs 1 array and I tried to take away any syntax sugar but to no avail. If you want to see the source let me know.

[Philipp Klaus Krause]

In which version of sdcc did you see the error? Does it still happen with a current version of sdcc?

This looks like an error message from code generation. Most of the time, such errors can be reproduced using a source file containing only the function in which the error is triggered.

Can you reproduce the error using a file with minimal dependencies (i.e. without gbdk)?

[Jeff Bill]

This error only happens with the sdcc shipped with GBDK I have made been able to recreate this without the GBDK headers. If you would like I can give you my source code.

[Jeff Bill]

I only included stdio.h

[Jeff Bill]

I have narrowed it down to where it gives the fatal error when iterating over an array.

[Philipp Klaus Krause]

So you now have a single function that reproduces the issue, and the only #include is stdio.h?
Could you show that source?

[Philipp Klaus Krause]

I don't know which sdcc comes with your gdbk. What is the output of sdcc --version?

[Jeff Bill]

Here is the source code:

#include <stdio.h>

struct Vec3D{
    int x, y, z;
};

int cos(int x){
    int result = 1;
    int term = 1;

    for (int i = 1; i <= 10; i++) {
        term = term * (-1) * x * x / ((2 * i) * (2 * i - 1));
        result = result + term;
    }

    return result;
}

int sin(int x) {
    int result = 0.0;
    int term = x;

    for (int i = 1; i <= 10; i += 2) {
        result = result + term;
        term = term * -(x * x) / (i * (i + 1));
    }

    return result;
}

struct Vec3D points[4];

int projection[2][3] = {
    {1, 0, 0},
    {0, 1, 0}
};

struct Vec3D matrixMult(int projection[2][3], struct Vec3D v){
    struct Vec3D res;

    res.x = projection[0][0] * v.x + projection[0][1] * v.y + projection[0][2] * v.z;
    res.y = projection[1][0] * v.x + projection[1][1] * v.y + projection[1][2] * v.z;

    return res;
}

struct Vec3D projected2D;
struct Vec3D rotated;

void main(){

    int rotation[2][3] = {
        {cos(0), -sin(0), 0}, 
        {sin(0), -cos(0), 0}
    };

    points[0].x = 25; points[0].y = 25; points[0].z = 0;
    points[1].x = 50; points[1].y = 25; points[1].z = 0;
    points[2].x = 50; points[2].y = 50; points[2].z = 0;
    points[3].x = 25; points[3].y = 50; points[3].z = 0;

    while(1){
        for(int i = 0; i < 4; i++){
            projected2D = matrixMult(projection, points[i]);
            rotated = matrixMult(rotation, projected2D);
        }
    }

}

According to GBDK it uses SDCC build #12539.

[Philipp Klaus Krause]

When I compile that source on my Debian GNU/Linux testing system via

sdcc -msm83 test.c

using sdcc 4.2.14 #14011, I do not see the error.

[Philipp Klaus Krause]

There are struct parameters and return values in your code. That was not yet supported in sdcc #12539, so the sdcc you use must be a newer version.