I have a simple GLSL compute shader that performs a parallel reduction on an array, which works as expected on Nvidia and AMD gpus but on my macbook with Iris 6100 graphics it produces slightly wrong results.
I've attached a simple test program, if you inspect the code at the end of main.cpp you can see it reads back the buffer that the shader wrote to, and expects every vec4 entry to be (96, 96, 96, 0). On the Iris 6100 the values that are supposed to be 96, will end up being randomly 95, 96, 97, 98, etc, throughout the array.
System Used: Apple, Macbook Pro Retina 13" (2015)
CPU SKU: i7-5557U
GPU SKU: Iris 6100
Processor Line: U series?
System BIOS Version:
CMOS settings:
Graphics Driver Version: 20.19.15.4352
GOP/VBIOS Version:
Operating System: Windows 10
OS Version: 64-bit
API: OpenGL
Occurs on non-Intel GPUs?: No
Steps to Reproduce:
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1. Build and run attached sample program in debug.
2.
Expected Results:
Assert at end of main function should not fire (because all compute shader outputs match expected result).
Actual Results:
Compute shader produces incorrect results and assert in test program will fire.
Additional Information:
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