[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 `premerge-monolithic-linux` running on `premerge-linux-1` while building `llvm` at step 7 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/153/builds/3733

Here is the relevant piece of the build log for the reference:
```
Step 7 (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: /build/buildbot/premerge-monolithic-linux/build/bin/llc -mtriple=aarch64-linux-gnu -mattr=+sve < /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/CodeGen/AArch64/sve-i1-add-reduce.ll | /build/buildbot/premerge-monolithic-linux/build/bin/FileCheck /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/CodeGen/AArch64/sve-i1-add-reduce.ll
+ /build/buildbot/premerge-monolithic-linux/build/bin/llc -mtriple=aarch64-linux-gnu -mattr=+sve
+ /build/buildbot/premerge-monolithic-linux/build/bin/FileCheck /build/buildbot/premerge-monolithic-linux/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: /build/buildbot/premerge-monolithic-linux/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 0x00005a55127315d8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/Support/Unix/Signals.inc:723:13
 #1 0x00005a551272f10e llvm::sys::RunSignalHandlers() /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/Support/Signals.cpp:106:18
 #2 0x00005a5512731c88 SignalHandler(int) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/Support/Unix/Signals.inc:413:1
 #3 0x000079c0b01d2520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x000079c0b02269fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x000079c0b01d2476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x000079c0b01b87f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x00005a551269bf4c llvm::report_fatal_error(llvm::Twine const&, bool) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/Support/ErrorHandling.cpp:125:5
 #8 0x00005a5512540f48 getValueType /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/include/llvm/CodeGen/SelectionDAGNodes.h:1032:5
 #9 0x00005a5512540f48 getValueType /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/include/llvm/CodeGen/SelectionDAGNodes.h:1187:16
#10 0x00005a5512540f48 llvm::SelectionDAGISel::CannotYetSelect(llvm::SDNode*) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:4371:43
#11 0x00005a551253feca llvm::SelectionDAGISel::SelectCodeCommon(llvm::SDNode*, unsigned char const*, unsigned int) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:4096:9
#12 0x00005a550ff68bab (anonymous namespace)::AArch64DAGToDAGISel::Select(llvm::SDNode*) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp:7002:1
#13 0x00005a5512534f6f begin /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/include/llvm/ADT/SmallVector.h:280:45
#14 0x00005a5512534f6f end /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/include/llvm/ADT/SmallVector.h:282:27
#15 0x00005a5512534f6f ~SmallVector /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/include/llvm/ADT/SmallVector.h:1215:46
#16 0x00005a5512534f6f llvm::SelectionDAGISel::DoInstructionSelection() /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:1327:5
#17 0x00005a5512533f8b ~TimeRegion /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/include/llvm/Support/Timer.h:155:9
#18 0x00005a5512533f8b llvm::SelectionDAGISel::CodeGenAndEmitDAG() /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:1096:3
#19 0x00005a551253195c llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:1620:8
#20 0x00005a551252ec08 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:632:7
#21 0x00005a551252c5b6 llvm::SelectionDAGISelLegacy::runOnMachineFunction(llvm::MachineFunction&) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:374:20
#22 0x00005a551183cc66 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/CodeGen/MachineFunctionPass.cpp:94:13
#23 0x00005a5511d4353c llvm::FPPassManager::runOnFunction(llvm::Function&) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1442:27
#24 0x00005a5511d4ba42 llvm::FPPassManager::runOnModule(llvm::Module&) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1488:13
#25 0x00005a5511d4409c runOnModule /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1557:27
#26 0x00005a5511d4409c llvm::legacy::PassManagerImpl::run(llvm::Module&) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:542:44
#27 0x00005a550fb77c12 compileModule /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/tools/llc/llc.cpp:742:17
#28 0x00005a550fb77c12 main /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/tools/llc/llc.cpp:409:22
#29 0x000079c0b01b9d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#30 0x000079c0b01b9e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
...

```

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