[SYCL] Remove noreturn function attribute #2165
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asavonic
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@asavonic , can you please add a test where this change shows making a difference?
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Just summarizing my understanding to make sure I got it right: If a function is marked as noreturn, it has to terminate. And since SYCL does not support termination in device code, we detect no-return functions in device code and remove the no-return attributes from them? Also, from clang -cc1 help: |
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It looks like the only change is the removal of the attributes as well? |
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Oh I see. Just preventing the call to EmitUnreachable( ) wasn't enough. You have to remove the attributes as well to prevent optimizations passes from emitting this. That's why the second RUN line in test. Can you update your PR description. The current one is confusing. |
I think the second run line with optimizations enabled is the test for this change. From what I understand, this change is required to ensure unreachable instruction is not emitted even after optimization @asavonic please confirm |
This makes sense, but it wasn't clear. In this case, can @asavonic add a comment line to the test to specify what it tests? |
This is a follow-up to: 74aa9a0 [SYCL] Remove "unreachable" instruction from LLVM IR for SYCL devices (intel#1789) Noreturn function attribute gives LLVM optimization passes an opportunity to re-structure code and insert an unreachable instruction. This happens when optimizations are turned on by -fsycl-enable-optimizations, so noreturn function attribute must be removed. Signed-off-by: Andrew Savonichev <[email protected]>
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Added a check for a noreturn attribute, and another RUN line with optimizations turned on. |
Right. I clarified this in the commit message. |
…rogram * upstream/sycl: (609 commits) [SYCL] Fix fail in the post commit testing (intel#2210) [SYCL] Materialize shadow local variables for byval arguments before use (intel#2200) [SYCL] Support lambda functions passed to reduction (intel#2190) [SYCL][USM] Improve USM Allocator. (intel#2026) [SYCL] Disallow mutable lambdas (intel#1785) [SYCL][ESIMD] Setup compilation pipeline for ESIMD (intel#2134) [SYCL] Fix not found kernel due to empty kernel name when using set_arg(s) (intel#2181) [SYCL] Fixed check for set_arg (intel#2203) Refactor indirect access calls to minimize invocations. (intel#2185) [SYCL][NFC] Fix potential null-pointer access (intel#2197) [SYCL] Propagate attributes from transitive calls to kernel (intel#1878) [SYCL] Fix warnings from static analysis tool (intel#2193) [SYCL][NFC] Fix ac_float test for compilation with FE optimizations (intel#2184) [GitHub Actions] Uplift clang-format version to 10 (intel#2194) [SYCL][ESIMD] Pass to replace simd* parameters with native llvm vectors. (intel#2097) [SYCL][NFC] Fixed SYCL_PI_TRACE output while selecting a device. (intel#2192) [SYCL][FPGA] New spec for controlling load-store units in FPGAs (intel#2158) [SYCL][Doc] Clarify reqd_sub_group_size (intel#2103) [SYCL] Remove noreturn function attribute (intel#2165) [SYCL] Aligned set_arg behaviour with SYCL specification (intel#2159) ...
… matrix (#2165) Implement translation via SPIR-V friendly calls, as: the LLVM instructions are not capable to accept target extension types; cooperative matrix is an opaque object and accessing elements is implementation defined, hence we can't use GEP to which AccessChain naturally maps, since GEP has a different meaning. As for now some BE would need to recognize and define what to do with a call to __spirv_AccessChain(matrix, index). Better option is to map such SPIR-V to an intrinsic or define an appropriate type in LLVM (hence defining rules for GEP and other instructions) , but it's off the table now. Original commit: KhronosGroup/SPIRV-LLVM-Translator@deb6ee9
This is a follow-up to:
74aa9a0 [SYCL] Remove "unreachable" instruction from LLVM IR for SYCL
devices (#1789)
Noreturn function attribute gives LLVM optimization passes an
opportunity to re-structure code and insert an unreachable
instruction.
This happens when optimizations are turned on by
-fsycl-enable-optimizations, so noreturn function attribute must be
removed.
Signed-off-by: Andrew Savonichev [email protected]