RISCV vector intrinsics compilation leads to "fatal error: error in backend: Invalid size request on a scalable vector."

[sh1boot]

qiutsimd-ad8673.c.gz
qiutsimd-ad8673.sh.gz

The failure comes and goes as I mash the code around. First discovered in clang-17 but it seemed to disappear on ToT, until it came back after further mashing.

[llvmbot]

@llvm/issue-subscribers-backend-risc-v

Author: SH (sh1boot)

[qiutsimd-ad8673.c.gz](https://github.com/llvm/llvm-project/files/14143011/qiutsimd-ad8673.c.gz) [qiutsimd-ad8673.sh.gz](https://github.com/llvm/llvm-project/files/14143012/qiutsimd-ad8673.sh.gz)

The failure comes and goes as I mash the code around. First discovered in clang-17 but it seemed to disappear on ToT, until it came back after further mashing.

[michaelmaitland]

Could you share what options you are compiling with?

EDIT: Never mind, I see you have the .sh file

This sounds like an error thrown by TypeSize when trying to convert a scalable-size to a fixed-width size.

[preames]

Got a stack trace privately for this.

#9 0x00007fdfe653e7b6 llvm::TypeSize::operator unsigned long() const (/usr/lib/x86_64-linux-gnu/libLLVM-19.so.1+0xd3e7b6)
#10 0x00007fdfe750d7fa llvm::MemCpyOptPass::processStoreOfLoad(llvm::StoreInst*, llvm::LoadInst*, llvm::DataLayout const&, llvm::ilist_iterator_w_bits<llvm::ilist_detail::node_options<llvm::Instruction, false, false, void, true>, false,
false>&) (/usr/lib/x86_64-linux-gnu/libLLVM-19.so.1+0x1d0d7fa)
#11 0x00007fdfe751315d llvm::MemCpyOptPass::iterateOnFunction(llvm::Function&) (/usr/lib/x86_64-linux-gnu/libLLVM-19.so.1+0x1d1315d)
#12 0x00007fdfe751365a llvm::MemCpyOptPass::runImpl(llvm::Function&, llvm::TargetLibraryInfo*, llvm::AAResults*, llvm::AssumptionCache*, llvm::DominatorTree*, llvm::PostDominatorTree*, llvm::MemorySSA*) (/usr/lib/x86_64-linux-gnu/libLLVM
-19.so.1+0x1d1365a)
#13 0x00007fdfe75134a5 llvm::MemCpyOptPass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/usr/lib/x86_64-linux-gnu/libLLVM-19.so.1+0x1d134a5)

I have a pretty good theory as to the cause and expect to have a patch posted shortly.

[hiraditya]

cc: @alexey-bataev and @nikolaypanchenko