Xcode: will only fail on 4 inch 64-bit device

Question

I'm building an iOS app in Xcode. I've run into an issue with my build. Specifically, when I run my app on my physical device (iPhone 5) and any simulated 32-bit device, it runs fine. But if I use the 4 inch 64bit device, I get the following error on a specific line of code:

Thread 1: EXC_BAD_ACCESS (code=EXC_I386_GPFLT)

I'm guessing this error means nothing as I don't get it with any other device.

I have tried cleaning my build and build folder, and even reverting to earlier commits that didn't have this issue. That didn't work (much to my surprise).

When I first had this error, I had something along the lines of this StackOverflow question relating to images ("Could not load the "" image referenced from a nib in the bundle with identifier ..."). Specifically, I think my issue is a due to a copy-and-paste of a UIButton in Interface Builder. I have since deleted this button.

How do I resolve this issue?

When I run the program on the only simulated device that causes this problem, I get the following output on the console:

2014-03-16 16:35:54.922 iSparse[3743:60b] 
(lldb)
(lldb) p idx[0]
(int) $0 = 35353
(lldb) p idx[1]
(int) $1 = 17508
(lldb) p colorPlane[0]
(float) $2 = 218
(lldb) p y_r[0]
(float) $3 = 0
(lldb) p y_r[1]
(float) $4 = 0

This tells me that idx and colorPlane appear to be valid arrays and since y_r is not filled with pixel values, that line of code not executed.

The function where this error occurs is

-(void)makeMeasurements2:(UIImage *)image atRate:(float)rate
                     red:(float *)y_r green:(float *)y_b blue:(float *)y_g
                ofLength:(int)length idx:(int *)idx{
    // vDSP_vgathr is equivalent to a[i] = b[c[i]] (!)
    int pix = image.size.height * image.size.width;
    float * array = (float *)malloc(sizeof(float) * pix * 4);
    float * colorPlane = (float *)malloc(sizeof(float) * pix);
    // get data

    [self.dwt imageToRawArray:image into:array pix:length];
    int n;

    // perform wavelet, 2D on image
    // using color planes, all of that
    // vDSP_vgathr is the equivalent of a[i] = b[c[i]]
    for (n=0; n<3; n++) {
        // copy from "array", which is RGBA,RGBA,RGBA...
        // and get the colorplane out
        cblas_scopy(pix, array+n, 4, colorPlane, 1);

        // the do-what-you-want code should go here.
        if (n == 0) {
            vDSP_vgathr(colorPlane, (const vDSP_Length *)idx, 1, y_r, 1, (int)(rate*pix));
        }
        if (n == 1) {
            vDSP_vgathr(colorPlane, (const vDSP_Length *)idx, 1, y_b, 1, (int)(rate*pix));
        }
        if (n == 2) {
            vDSP_vgathr(colorPlane, (const vDSP_Length *)idx, 1, y_g, 1, (int)(rate*pix));
        }
        cblas_scopy(pix, colorPlane, 1, array+n, 4);
    }

    catlas_sset(pix, 255, array+3, 4);

    image = [self.dwt UIImageFromRawArray:array image:image forwardInverseOrNull:@"null"];
    free(array);
    free(colorPlane);

It fails on the first vDSP_vgathr in the for-loop.

Set an exception breakpoint and post both the symbolicated log and the code where the exception occurs. `EXC_BAD_ACCESS` is usually caused by accessing a deallocated object so running with `NSZombies` may also help track down the error. — Robotic Cat, Mar 16 '14 at 02:50
Odd, EXC_I386_GPFLT doesn't sound like an Arm64 error. Or is that in the 64bit simulator? — Rhythmic Fistman, Mar 16 '14 at 23:15

score 0 · Accepted Answer · edited May 23 '17 at 10:26

0

The code you posted does have to do with the error, and it's not Xcode specific. Look at this answer (which uses the same function call!) for more detail.

edited May 23 '17 at 10:26

Community

1
1

answered Mar 23 '14 at 02:01

Scott

2,568
1
27
39

Xcode: will only fail on 4 inch 64-bit device

1 Answers1