LLVM 16 CTS SPIRV failures

[franz]

92% tests passed, 11 tests failed out of 144

The following tests FAILED:
598 - conformance_spirv_allocations_image (Failed)
599 - conformance_spirv_api (Failed)
600 - conformance_spirv_api_ocl_30 (Failed)
605 - conformance_spirv_basic_image (Failed)
607 - conformance_spirv_basic_other_ocl_30 (Failed)
615 - conformance_spirv_buffers_var2 (Failed)
877 - conformance_spirv_profiling (Failed)
914 - conformance_spirv_SVM_1 (Failed)
1180 - conformance_spirv_images_micro_samplerless_reads_2D (Failed)
1182 - conformance_spirv_images_micro_samplerless_reads_1Darray (Failed)
1186 - conformance_spirv_basic_micro_other (Failed)
Errors while running CTest
Error: Process completed with exit code 8.

[franz]

Almost all failures are related to image types present in SPIR-V:

647: error: line 116: Result <id> from OpSampledImage instruction must not appear as operand for OpBitcast, since it is not specified as taking an OpTypeSampledImage. Found result <id> '30[%TempSampledImage]' as an operand of <id> '31[%31]'.
647:   %TempSampledImage = OpSampledImage %29 %src %sampler0

647: error: line 797: Expected Result Type to be a pointer or int or float vector or scalar type: Bitcast
647:   %140 = OpBitcast %137 %138
647: 

The ones not related to images:

conformance_spirv_basic_other_ocl_30 -> progvar_prog_scope_init

655: progvar_prog_scope_init...
655:   bool Saved kernel source to file: /home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/writer.reader.7c8d1744.a7cce4c4.cl
655: Saved kernel build options to file: /home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/writer.reader.7c8d1744.a7cce4c4.options
655: Executing command: /home/michal/0/build/b_pocl_16/cl_offline_compiler.sh --mode=spir-v --source=/home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/writer.reader.7c8d1744.a7cce4c4.cl --output=/home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/writer.reader.7c8d1744.a7cce4c4.spv64 --cl-device-info=/home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/clDeviceInfo-b243d248.txt -- -cl-std=CL3.0
655: CL_DEV_INFO: /home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/clDeviceInfo-b243d248.txt
655: test_basic: /home/llvm_build/source/llvm-project/llvm/lib/IR/Instructions.cpp:3356: static llvm::CastInst* llvm::CastInst::Create(llvm::Instruction::CastOps, llvm::Value*, llvm::Type*, const llvm::Twine&, llvm::Instruction*): Assertion `castIsValid(op, S, Ty) && "Invalid cast!"' failed.
1/1 Test #655: conformance_spirv_basic_other_ocl_30 ...Subprocess aborted***Exception:  22.80 sec

conformance_spirv_SVM_1 -> svm_fine_grain_memory_consistency

962: svm_fine_grain_memory_consistency...
962: Saved kernel source to file: /home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/build_hash_table.5dae34cf.b467a359.cl
962: Saved kernel build options to file: /home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/build_hash_table.5dae34cf.b467a359.options
962: Executing command: /home/michal/0/build/b_pocl_16/cl_offline_compiler.sh --mode=spir-v --source=/home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/build_hash_table.5dae34cf.b467a359.cl --output=/home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/build_hash_table.5dae34cf.b467a359.spv64 --cl-device-info=/home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/clDeviceInfo-b243d248.txt --  -cl-std=CL3.0
962: CL_DEV_INFO: /home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/clDeviceInfo-b243d248.txt
962: error: line 107: AtomicCompareExchange: expected Pointer to point to a value of type Result Type
962:   %49 = OpAtomicCompareExchange %ulong %48 %uint_0 %uint_16 %uint_0 %44 %exp
962: 
962: Failed to validate SPIR-V file /home/michal/0/build/b_pocl_16/CTS_FULL_CACHE/build_hash_table.5dae34cf.b467a359.spv64: system() returned 0x100
962: Create program failed: -15, line: 806
962: ERROR: failed to create program! (CL_COMPILE_PROGRAM_FAILURE from /home/michal/0/build/examples/conformance/src/conformance/test_conformance/SVM/main.cpp:257)
962: svm_fine_grain_memory_consistency FAILED

[franz]

I've added a partial fix (missing AS cast) for the conformance_spirv_basic_other_ocl_30 -> progvar_prog_scope_init issue, this issue is now resolved with LLVM 15, but with LLVM 16 it fails in SPIR-V validator.

Created LLVM-SPIRV-Translator issues: progvar_prog_scope_init, svm_fine_grain_memory_consistency, invalid OpBitcast with Images.

[franz]

I've added documentation to PoCL, but since these are issues in upstream Clang and/or translator, AFAICT they need to be fixed upstream.