MSL: Terminate function with return value using return if ending in unreachable. #2436
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squidbus
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I had included some unrelated updates to other test files from what the test script generated, but for some reason they're just generating different output on my machine than CI. So I removed them. |
| %44 = OpAccessChain %_ptr_StorageBuffer_int %buff %int_0 %41 | ||
| OpStore %44 %int_1 | ||
| OpDemoteToHelperInvocation | ||
| OpUnreachable |
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This OpUnreachable is completely bogus fwiw. Having Unreachable post-dominate the entry block means that the entire shader is UB to execute, but ... whatever.
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Yes I had the same suspicion and will probably have to visit the generation that results in this in my use case. But it seems to function elsewhere (I think just because discarding eliminates potential side effects?) and I figured also that, while the spec says that executing OpUnreachable is UB, there is no indication that it should fail to compile.
Fix for #2435.
If a function with return value ends in unreachable, insert a return statement to avoid MSL compile errors. This condition already exists for blocks ending in Kill, it just needs to be extended to cover Unreachable as well.