[llvm] [AArch64] Lower scalable i1 vector add reduction to cntp (PR #99031)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-aarch64-darwin` running on `doug-worker-5` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/2326

Here is the relevant piece of the build log for the reference:
```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: CodeGen/AArch64/sve-i1-add-reduce.ll' FAILED ********************
Exit Code: 2

Command Output (stderr):
--
RUN: at line 2: /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc -mtriple=aarch64-linux-gnu -mattr=+sve < /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/CodeGen/AArch64/sve-i1-add-reduce.ll | /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/CodeGen/AArch64/sve-i1-add-reduce.ll
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc -mtriple=aarch64-linux-gnu -mattr=+sve
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/CodeGen/AArch64/sve-i1-add-reduce.ll
LLVM ERROR: Cannot select: t14: nxv2i64 = AArch64ISD::UADDV_PRED t10, t2
  t10: nxv16i1 = AArch64ISD::PTRUE TargetConstant:i32<31>
    t9: i32 = TargetConstant<31>
  t2: nxv16i1,ch = CopyFromReg t0, Register:nxv16i1 %0
    t1: nxv16i1 = Register %0
In function: uaddv_zexti8_nxv16i1
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc -mtriple=aarch64-linux-gnu -mattr=+sve
1.	Running pass 'Function Pass Manager' on module '<stdin>'.
2.	Running pass 'AArch64 Instruction Selection' on function '@uaddv_zexti8_nxv16i1'
 #0 0x000000010228f140 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x10156b140)
 #1 0x000000010228d1c8 llvm::sys::RunSignalHandlers() (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x1015691c8)
 #2 0x000000010228f7fc SignalHandler(int) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x10156b7fc)
 #3 0x000000019fba3584 (/usr/lib/system/libsystem_platform.dylib+0x180477584)
 #4 0x000000019fb72c20 (/usr/lib/system/libsystem_pthread.dylib+0x180446c20)
 #5 0x000000019fa7fa30 (/usr/lib/system/libsystem_c.dylib+0x180353a30)
 #6 0x00000001021f7aac llvm::report_fatal_error(llvm::Twine const&, bool) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x1014d3aac)
 #7 0x0000000102153bdc llvm::SelectionDAGISel::CannotYetSelect(llvm::SDNode*) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x10142fbdc)
 #8 0x0000000102152f40 llvm::SelectionDAGISel::SelectCodeCommon(llvm::SDNode*, unsigned char const*, unsigned int) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x10142ef40)
 #9 0x0000000100ea1b5c (anonymous namespace)::AArch64DAGToDAGISel::Select(llvm::SDNode*) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x10017db5c)
#10 0x0000000102149f30 llvm::SelectionDAGISel::DoInstructionSelection() (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x101425f30)
#11 0x0000000102149074 llvm::SelectionDAGISel::CodeGenAndEmitDAG() (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x101425074)
#12 0x0000000102146f54 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x101422f54)
#13 0x0000000102144b7c llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x101420b7c)
#14 0x00000001021431cc llvm::SelectionDAGISelLegacy::runOnMachineFunction(llvm::MachineFunction&) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x10141f1cc)
#15 0x00000001015fc2c4 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x1008d82c4)
#16 0x0000000101a88618 llvm::FPPassManager::runOnFunction(llvm::Function&) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x100d64618)
#17 0x0000000101a8fa80 llvm::FPPassManager::runOnModule(llvm::Module&) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x100d6ba80)
#18 0x0000000101a88ef4 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x100d64ef4)
#19 0x0000000100d28680 main (/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc+0x100004680)
#20 0x000000019f7ea0e0 
FileCheck error: '<stdin>' is empty.
FileCheck command line:  /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/CodeGen/AArch64/sve-i1-add-reduce.ll

--

********************


```

https://github.com/llvm/llvm-project/pull/99031