recent bootstrap regression: arm-linux-musleabihf: LLVM ERROR: Do not know how to promote this operator's result!

[andrewrk]

from https://github.com/ziglang/www.ziglang.org/actions/runs/10786724616

2024-09-10T18:04:54.9953484Z install
2024-09-10T18:04:54.9956392Z +- install zig
2024-09-10T18:04:54.9957321Z    +- zig build-exe zig ReleaseFast arm-linux-musleabihf failure
2024-09-10T18:04:54.9958962Z error: error(link): /home/ci/actions-runner/_work/zig-bootstrap/out/host/bin/zig terminated with stderr:
2024-09-10T18:04:54.9962705Z ld.lld: warning: Linking two modules of different target triples: '/home/ci/actions-runner/_work/zig-bootstrap/out/zig-local-cache/o/5e69a1fcdfd6c314e12fe76e1173b45b/zig.o' is 'arm-unknown-linux-musleabihf' whereas 'ld-temp.o' is 'armv6kz-unknown-linux-musleabihf'
2024-09-10T18:04:54.9965405Z 
2024-09-10T18:04:54.9966055Z LLVM ERROR: Do not know how to promote this operator's result!
2024-09-10T18:04:54.9966862Z 
2024-09-10T18:04:54.9967115Z error: LLDCrashed
2024-09-10T18:04:54.9967505Z 
2024-09-10T18:04:54.9973575Z error: the following command exited with error code 1:
2024-09-10T18:04:55.0000286Z /home/ci/actions-runner/_work/zig-bootstrap/out/host/bin/zig build-exe --stack 33554432 -cflags -std=c++17 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -D_GNU_SOURCE -fno-exceptions -fno-rtti -fno-stack-protector -fvisibility-inlines-hidden -Wno-type-limits -Wno-missing-braces -Wno-comment -DNDEBUG=1 -- /home/ci/actions-runner/_work/zig-bootstrap/zig/src/zig_llvm.cpp /home/ci/actions-runner/_work/zig-bootstrap/zig/src/zig_clang.cpp /home/ci/actions-runner/_work/zig-bootstrap/zig/src/zig_llvm-ar.cpp /home/ci/actions-runner/_work/zig-bootstrap/zig/src/zig_clang_driver.cpp /home/ci/actions-runner/_work/zig-bootstrap/zig/src/zig_clang_cc1_main.cpp /home/ci/actions-runner/_work/zig-bootstrap/zig/src/zig_clang_cc1as_main.cpp -lclangFrontendTool -lclangCodeGen -lclangFrontend -lclangDriver -lclangSerialization -lclangSema -lclangStaticAnalyzerFrontend -lclangStaticAnalyzerCheckers -lclangStaticAnalyzerCore -lclangAnalysis -lclangASTMatchers -lclangAST -lclangParse -lclangAPINotes -lclangBasic -lclangEdit -lclangLex -lclangARCMigrate -lclangRewriteFrontend -lclangRewrite -lclangCrossTU -lclangIndex -lclangToolingCore -lclangExtractAPI -lclangSupport -llldMinGW -llldELF -llldCOFF -llldWasm -llldMachO -llldCommon -lLLVMWindowsManifest -lLLVMXRay -lLLVMLibDriver -lLLVMDlltoolDriver -lLLVMTextAPIBinaryReader -lLLVMCoverage -lLLVMLineEditor -lLLVMXCoreDisassembler -lLLVMXCoreCodeGen -lLLVMXCoreDesc -lLLVMXCoreInfo -lLLVMX86TargetMCA -lLLVMX86Disassembler -lLLVMX86AsmParser -lLLVMX86CodeGen -lLLVMX86Desc -lLLVMX86Info -lLLVMWebAssemblyDisassembler -lLLVMWebAssemblyAsmParser -lLLVMWebAssemblyCodeGen -lLLVMWebAssemblyUtils -lLLVMWebAssemblyDesc -lLLVMWebAssemblyInfo -lLLVMVEDisassembler -lLLVMVEAsmParser -lLLVMVECodeGen -lLLVMVEDesc -lLLVMVEInfo -lLLVMSystemZDisassembler -lLLVMSystemZAsmParser -lLLVMSystemZCodeGen -lLLVMSystemZDesc -lLLVMSystemZInfo -lLLVMSparcDisassembler -lLLVMSparcAsmParser -lLLVMSparcCodeGen -lLLVMSparcDesc -lLLVMSparcInfo -lLLVMRISCVTargetMCA -lLLVMRISCVDisassembler -lLLVMRISCVAsmParser -lLLVMRISCVCodeGen -lLLVMRISCVDesc -lLLVMRISCVInfo -lLLVMPowerPCDisassembler -lLLVMPowerPCAsmParser -lLLVMPowerPCCodeGen -lLLVMPowerPCDesc -lLLVMPowerPCInfo -lLLVMNVPTXCodeGen -lLLVMNVPTXDesc -lLLVMNVPTXInfo -lLLVMMSP430Disassembler -lLLVMMSP430AsmParser -lLLVMMSP430CodeGen -lLLVMMSP430Desc -lLLVMMSP430Info -lLLVMMipsDisassembler -lLLVMMipsAsmParser -lLLVMMipsCodeGen -lLLVMMipsDesc -lLLVMMipsInfo -lLLVMLoongArchDisassembler -lLLVMLoongArchAsmParser -lLLVMLoongArchCodeGen -lLLVMLoongArchDesc -lLLVMLoongArchInfo -lLLVMLanaiDisassembler -lLLVMLanaiCodeGen -lLLVMLanaiAsmParser -lLLVMLanaiDesc -lLLVMLanaiInfo -lLLVMHexagonDisassembler -lLLVMHexagonCodeGen -lLLVMHexagonAsmParser -lLLVMHexagonDesc -lLLVMHexagonInfo -lLLVMBPFDisassembler -lLLVMBPFAsmParser -lLLVMBPFCodeGen -lLLVMBPFDesc -lLLVMBPFInfo -lLLVMAVRDisassembler -lLLVMAVRAsmParser -lLLVMAVRCodeGen -lLLVMAVRDesc -lLLVMAVRInfo -lLLVMARMDisassembler -lLLVMARMAsmParser -lLLVMARMCodeGen -lLLVMARMDesc -lLLVMARMUtils -lLLVMARMInfo -lLLVMAMDGPUTargetMCA -lLLVMAMDGPUDisassembler -lLLVMAMDGPUAsmParser -lLLVMAMDGPUCodeGen -lLLVMAMDGPUDesc -lLLVMAMDGPUUtils -lLLVMAMDGPUInfo -lLLVMAArch64Disassembler -lLLVMAArch64AsmParser -lLLVMAArch64CodeGen -lLLVMAArch64Desc -lLLVMAArch64Utils -lLLVMAArch64Info -lLLVMOrcDebugging -lLLVMOrcJIT -lLLVMWindowsDriver -lLLVMMCJIT -lLLVMJITLink -lLLVMInterpreter -lLLVMExecutionEngine -lLLVMRuntimeDyld -lLLVMOrcTargetProcess -lLLVMOrcShared -lLLVMDWP -lLLVMDebugInfoLogicalView -lLLVMDebugInfoGSYM -lLLVMOption -lLLVMObjectYAML -lLLVMObjCopy -lLLVMMCA -lLLVMMCDisassembler -lLLVMLTO -lLLVMPasses -lLLVMHipStdPar -lLLVMCFGuard -lLLVMCoroutines -lLLVMipo -lLLVMVectorize -lLLVMLinker -lLLVMInstrumentation -lLLVMFrontendOpenMP -lLLVMFrontendOffloading -lLLVMFrontendOpenACC -lLLVMFrontendHLSL -lLLVMFrontendDriver -lLLVMExtensions -lLLVMDWARFLinkerParallel -lLLVMDWARFLinkerClassic -lLLVMDWARFLinker -lLLVMGlobalISel -lLLVMMIRParser -lLLVMAsmPrinter -lLLVMSelectionDAG -lLLVMCodeGen -lLLVMTarget -lLLVMObjCARCOpts -lLLVMCodeGenTypes -lLLVMIRPrinter -lLLVMInterfaceStub -lLLVMFileCheck -lLLVMFuzzMutate -lLLVMScalarOpts -lLLVMInstCombine -lLLVMAggressiveInstCombine -lLLVMTransformUtils -lLLVMBitWriter -lLLVMAnalysis -lLLVMProfileData -lLLVMSymbolize -lLLVMDebugInfoBTF -lLLVMDebugInfoPDB -lLLVMDebugInfoMSF -lLLVMDebugInfoDWARF -lLLVMObject -lLLVMTextAPI -lLLVMMCParser -lLLVMIRReader -lLLVMAsmParser -lLLVMMC -lLLVMDebugInfoCodeView -lLLVMBitReader -lLLVMFuzzerCLI -lLLVMCore -lLLVMRemarks -lLLVMBitstreamReader -lLLVMBinaryFormat -lLLVMTargetParser -lLLVMSupport -lLLVMDemangle -lz -lzstd -fstrip -fno-sanitize-thread -OReleaseFast -target arm-linux-musleabihf -mcpu generic+v7a --dep aro --dep aro_translate_c --dep build_options -Mroot=/home/ci/actions-runner/_work/zig-bootstrap/zig/src/main.zig -Maro=/home/ci/actions-runner/_work/zig-bootstrap/zig/lib/compiler/aro/aro.zig --dep aro -Maro_translate_c=/home/ci/actions-runner/_work/zig-bootstrap/zig/lib/compiler/aro_translate_c.zig -Mbuild_options=/home/ci/actions-runner/_work/zig-bootstrap/out/zig-local-cache/c/b24e958393226ebdae30503b60c0fb43/options.zig -lc++ -lc --cache-dir /home/ci/actions-runner/_work/zig-bootstrap/out/zig-local-cache --global-cache-dir /home/ci/actions-runner/_work/zig-bootstrap/out/zig-global-cache --name zig -L /home/ci/actions-runner/_work/zig-bootstrap/out/arm-linux-musleabihf-generic+v7a/lib -I /home/ci/actions-runner/_work/zig-bootstrap/out/arm-linux-musleabihf-generic+v7a/include --zig-lib-dir /home/ci/actions-runner/_work/zig-bootstrap/out/host/lib/zig/ --listen=- 

This is preventing the downloads page from updating.

cc @alexrp

[jacobly0]

Probably this. or not, some kind of float issue

[alexrp]

I have not actually tried to bootstrap with that commit hash yet, but here's my 10-minute analysis just based on the information available:

The regression was introduced in #21344. This new Aro version added a whole bunch of f16 code that's now exercising features that weren't previously used during bootstrap. The problem is that LLVM has very poor f16 support for Armv7; it only really works properly with the floating-point features introduced in Armv8, or when using soft float. Our CI tests Armv8, not Armv7, but tarballs target Armv7. Incidentally, this kind of regression is exactly why I want us to switch to Armv7 in CI. 😉

The good news is that #21269 should fix this.

[alexrp]

https://github.com/ziglang/www.ziglang.org/actions/runs/10825123499

[andrewrk]

Nice!