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Bugs in 13.4 GL 4.3 exts:compute shader, SBOs and no_attachments

Question asked by oscarbarenys1 on Apr 29, 2013

Hi,

I have been testing new OGL compute shader and storage buffer objects extension and found following bugs (13.4 on 7950):

(please note all the samples I use for testing this work correctly on Nvidia OGL 4.3 cards)

*using atomicMax and atomicMin on shared variables hang the GLSL compiler others like atomicOr are OK!

 

groupshared uint ldsZMax;

uint z;

atomicMax( ldsZMax, z );

 

*using a compute shader with following launch size and shared arrays usage:

#define BLOCK_SIZE 32

layout (local_size_x = BLOCK_SIZE, local_size_y = BLOCK_SIZE) in;

shared double As[BLOCK_SIZE*BLOCK_SIZE];

shared double Bs[BLOCK_SIZE*BLOCK_SIZE];

crashes with:

Compute shader(s) failed to link.

Compute link error: HW_UNSUPPORTED.

Compute shader not supported by hardware

 

diminishing BLOCK_SIZE to less than 32 seems to work.. I have tested using

layout (local_size_x = 32, local_size_y = 32) in;

isn't a issue so 32 should work as for this conf each of this two shared arrays is size 8192 (sizeof(double)*32*32) so total shared mem usage is

 

2*8192 and is equal to reported max size (GL_MAX_COMPUTE_SHARED_MEMORY_SIZE: 32768).. I verify this issue is on shared mem size usage as using something like

(with BLOCK_SIZE=32):

shared double As[BLOCK_SIZE*BLOCK_SIZE-1];

shared double Bs[BLOCK_SIZE*BLOCK_SIZE];

seems to compile so please fix to be able to use not only 32767 bytes of shared mem but full 32768 bytes..

 

*using sbo on non compute shaders (like fragment shaders seems no be not correct)

*getting GL_MAX_COMPUTE_WORK_GROUP_COUNT and GL_MAX_COMPUTE_WORK_GROUP_SIZE I get using debug_output bug:

glGetIntegerv parameter <pname> has an invalid enum '0x91be' (GL_INVALID_ENUM)

other new like GL_MAX_COMPUTE_ATOMIC_COUNTERS seem to work..

 

Related altough no_attachments extension is not adversited new entry points are present so I played with it using default and seems a simple test works on 79xx but not on 58xx

 

series..

glGenFramebuffers(1,&noat);

glBindFramebuffer(GL_FRAMEBUFFER_EXT,noat);

glFramebufferParameteri(GL_FRAMEBUFFER_EXT,GL_FRAMEBUFFER_DEFAULT_WIDTH, w);

glFramebufferParameteri (GL_FRAMEBUFFER_EXT,GL_FRAMEBUFFER_DEFAULT_HEIGHT, h);

a sample using this works on 7xxx series but not on 5xxx series..

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