shader.txt

If you try to execute spirv-opt <attached file> -o out.spv --loop-unroll on the attached file, the tool will crash. The reason is that LoopUnroller optimization pass doesn't support OpConstantNull instructions.

Note that the attached file demonstrates the case when the initial value of the counter

is an OpConstantNull. The same bug can be observed if we try to use OpConstantNull to limit the number of iterations or as a step of an iteration (ids %7, %13, %21 in the attached file).

The code that causes these crashes is as follows.

Can be reproduced on b78f4b1.