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RV: A Unified Region Vectorizer for LLVM
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Various Bugfixes. #63

Closed m-kurtenacker closed 1 year ago

m-kurtenacker commented 1 year ago

I don't realy get why fastcc is a problem for sleef, but some tests fail if it is enabled. The results in these tests look as if parts of the code are skipped. e.g.:

float foo (float t) { return fmod(fabs(t), 2); }

float bar (float t) { return fmod(fabs(t), 2) - 1; }

here, vectorized versions of foo and bar would produce the same results. The subtraction is somehow ignored.

simoll commented 1 year ago

Thanks for working on this! My last status for the feature/port-cdl-fixes branch was that i could compile it but that it would fail to run with the classic "this option already registered" problem related to cl::opts and static initializers.. does this mean the branch is working for you? If so, what is your build config?

Just a hunch regarding the fastcc issue: .. there may be a mismatch between call ABIs with fastcc, the ABI sleef was compiled for may dffer from the target you are vectorizing/compiling for.

m-kurtenacker commented 1 year ago

The cl::opt issue seems to be related to LLVM_BUILD_LLVM_DYLIB and LLVM_LINK_LLVM_DYLIB build flags. If I have these enabled, I too see cl::opts being registered twice. My usual "fix" for that is to remove LLVM libraries being linked to rvTool in tools/CMakeLists.txt. Without LLVM_BUILD_LLVM_DYLIB enabled everything seems to work alright.

About fastcc: I was trying to build sleef from source, but that didn't seem change anything about this issue. I have not seen this in release/14.x before.

simoll commented 1 year ago

Made a tentative fix for the dylib issue. Could you check whether https://github.com/cdl-saarland/rv/commit/340e5cf9b2358a5057578dafdbb7b46c62860d31 fixes the cl::opt on your end, too?

simoll commented 1 year ago

Regarding the fastcc issue, cf LLVM LangRef: "The calling convention of any pair of dynamic caller/callee must match, or the behavior of the program is undefined. " In the bitcode i looked into, calls to auto-vectorized SLEEF functions do not carry the fastcc attribute cc but the function definitions do.

simoll commented 1 year ago

Fastcc and cl::opt issues should be resolved with the https://github.com/cdl-saarland/rv/commit/fda63d41fc037446f0e616d961c74693674189ed branch . @m-kurtenacker Please check that this works on your end too, then we can merge.

simoll commented 1 year ago

Another patch for structOpt, fixing for test_070: https://github.com/cdl-saarland/rv/tree/feature/port-cdl-fixes_rvtool-ldylib-patch

test_022 and test_067 are still failing. All others are clean. @m-kurtenacker Could you look into this?

m-kurtenacker commented 1 year ago

I cherry-picked everything over to my branch. Only change I added was to also check for LLVM_LINK_LLVM_DYLIB. Everything but test_067 seems to be working on my side now.