LLVM assertion failure with -O1

[JeffBezanson]

I get this running the numbers test with -O1:

julia: /home/jeff/src/julia/deps/srccache/llvm-6.0.0/lib/IR/Value.cpp:404: void llvm::Value::doRAUW(llvm::Value*, bool): Assertion `New->getType() == getType() && "replaceAllUses of value with new value of different type!"' failed.

signal (6): Aborted
in expression starting at /home/jeff/src/julia/test/numbers.jl:1082
raise at /build/buildd/eglibc-2.19/signal/../nptl/sysdeps/unix/sysv/linux/raise.c:56
abort at /build/buildd/eglibc-2.19/stdlib/abort.c:89
__assert_fail_base at /build/buildd/eglibc-2.19/assert/assert.c:92
__assert_fail at /build/buildd/eglibc-2.19/assert/assert.c:101
_ZN4llvm5Value6doRAUWEPS0_b at /home/jeff/src/julia/usr/bin/../lib/libLLVM-6.0.so (unknown line)
_ZN4llvm12InstCombiner3runEv at /home/jeff/src/julia/usr/bin/../lib/libLLVM-6.0.so (unknown line)
_ZL31combineInstructionsOverFunctionRN4llvm8FunctionERNS_19InstCombineWorklistEPNS_9AAResultsERNS_15AssumptionCacheERNS_17TargetLibraryInfoERNS_13DominatorTreeERNS_25OptimizationRemarkEmitterEbPNS_8LoopInfoE at /home/jeff/src/julia/usr/bin/../lib/libLLVM-6.0.so (unknown line)
_ZN4llvm24InstructionCombiningPass13runOnFunctionERNS_8FunctionE at /home/jeff/src/julia/usr/bin/../lib/libLLVM-6.0.so (unknown line)
_ZN4llvm13FPPassManager13runOnFunctionERNS_8FunctionE at /home/jeff/src/julia/usr/bin/../lib/libLLVM-6.0.so (unknown line)
_ZN4llvm13FPPassManager11runOnModuleERNS_6ModuleE at /home/jeff/src/julia/usr/bin/../lib/libLLVM-6.0.so (unknown line)
_ZN4llvm6legacy15PassManagerImpl3runERNS_6ModuleE at /home/jeff/src/julia/usr/bin/../lib/libLLVM-6.0.so (unknown line)
operator() at /home/jeff/src/julia/src/jitlayers.cpp:480
addModule at /home/jeff/src/julia/usr/include/llvm/ExecutionEngine/Orc/IRCompileLayer.h:57 [inlined]
addModule at /home/jeff/src/julia/src/jitlayers.cpp:607
jl_add_to_ee at /home/jeff/src/julia/src/jitlayers.cpp:845 [inlined]
jl_finalize_function at /home/jeff/src/julia/src/jitlayers.cpp:853
getAddressForFunction at /home/jeff/src/julia/src/codegen.cpp:1318
jl_generate_fptr at /home/jeff/src/julia/src/codegen.cpp:1427
jl_compile_method_internal at /home/jeff/src/julia/src/gf.c:1830 [inlined]
jl_fptr_trampoline at /home/jeff/src/julia/src/gf.c:1837
jl_apply_generic at /home/jeff/src/julia/src/gf.c:2167

Will try to investigate.

[JeffBezanson]

Dumped the module that instcombine is failing on: https://gist.github.com/JeffBezanson/09ffede3648a980ba397b4f5435392c1

[JeffBezanson]

Aha, I think I just need to run the PropagateJuliaAddrspaces pass before SROA.

[Keno]

Aha, I think I just need to run the PropagateJuliaAddrspaces pass before SROA.

While that may perhaps fix it, LLVM should not crash if we don't run that pass. It's an optimization pass, not a lowering pass. We should try to fix the LLVM bug.

[JeffBezanson]

I have a promising lead: it looks like InstCombine's code for marking GEPs as inbounds incorrectly skips over addrspace casts, because the code for the prior transform reassigns a variable it uses.

[JeffBezanson]

Upstream patch submitted: https://reviews.llvm.org/D46722

[vchuravy]

Will be part of the next BB release and I will create a PR for this repo as well.