[AArch64][SVE] No way to convert scalable vector into fixed sized vector #55412
Description
https://godbolt.org/z/ab5YGK595
define <8 x i32> @to_fixed_sized_vector_i32x8_1(<vscale x 8 x i32> %a) #0{
%1 = call <8 x i32> @llvm.experimental.vector.extract.v832.nxv832(<vscale x 8 x i32> %a, i64 0)
ret <8 x i32> %1
}
declare <8 x i32> @llvm.experimental.vector.extract.v832.nxv832(<vscale x 8 x i32>, i64)Crashes with target triple = "aarch64-linux-gnu" -mattr=+sve2 -O3
LLVM ERROR: Extracting a fixed-length vector from an illegal scalable vector is not yet supported
I tried two workaround to avoid illegal length as follows, however both of them resulted in the same crash.
define void @to_fixed_sized_vector_i32x8_2(<vscale x 8 x i32> %a, <8 x i32>* %p1) #0{
%step = tail call <vscale x 8 x i32> @llvm.experimental.stepvector.nxv8i32()
%1 = call <vscale x 4 x i32> @llvm.experimental.vector.extract.nxv4i32.nxv8i32(<vscale x 8 x i32> %step, i64 0)
%2 = call <4 x i32> @llvm.experimental.vector.extract.v4i32.nxv4i32(<vscale x 4 x i32> %1, i64 0)
%3 = call <vscale x 4 x i32> @llvm.experimental.vector.extract.nxv4i32.nxv8i32(<vscale x 8 x i32> %step, i64 4)
%4 = call <4 x i32> @llvm.experimental.vector.extract.v4i32.nxv4i32(<vscale x 4 x i32> %3, i64 0)
%5 = shufflevector <4 x i32> %2, <4 x i32> %4, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
store <8 x i32> %5, <8 x i32>* %p1, align 32
ret void
}define void @to_fixed_sized_vector_i32x8_3(<vscale x 8 x i32> %a110, <8 x i32>* %p1) #0 {
%a165 = tail call <vscale x 8 x i32> @llvm.experimental.stepvector.nxv8i32()
%a166 = add nsw <vscale x 8 x i32> %a165, %a110
%a167 = extractelement <vscale x 8 x i32> %a166, i64 0
%a168 = insertelement <8 x i32> undef, i32 %a167, i64 0
%a169 = extractelement <vscale x 8 x i32> %a166, i64 1
%a170 = insertelement <8 x i32> %a168, i32 %a169, i64 1
%a171 = extractelement <vscale x 8 x i32> %a166, i64 2
%a172 = insertelement <8 x i32> %a170, i32 %a171, i64 2
%a173 = extractelement <vscale x 8 x i32> %a166, i64 3
%a174 = insertelement <8 x i32> %a172, i32 %a173, i64 3
%a175 = extractelement <vscale x 8 x i32> %a166, i64 4
%a176 = insertelement <8 x i32> %a174, i32 %a175, i64 4
%a177 = extractelement <vscale x 8 x i32> %a166, i64 5
%a178 = insertelement <8 x i32> %a176, i32 %a177, i64 5
%a179 = extractelement <vscale x 8 x i32> %a166, i64 6
%a180 = insertelement <8 x i32> %a178, i32 %a179, i64 6
%a181 = extractelement <vscale x 8 x i32> %a166, i64 7
%a182 = insertelement <8 x i32> %a180, i32 %a181, i64 7
store <8 x i32> %a182, <8 x i32>* %p1, align 32
ret void
}LLVM ERROR: Extracting a fixed-length vector from an illegal scalable vector is not yet supported
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0. Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/llc -o /app/output.s -x86-asm-syntax=intel -mattr=+sve2 -O3 <source>
1. Running pass 'Function Pass Manager' on module '<source>'.
2. Running pass 'AArch64 Instruction Selection' on function '@to_fixed_sized_vector_i32x8_1'
#0 0x0000560a927bbb6f PrintStackTraceSignalHandler(void*) Signals.cpp:0:0
#1 0x0000560a927b95dc SignalHandler(int) Signals.cpp:0:0
#2 0x00007fdb640983c0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x143c0)
#3 0x00007fdb63b6503b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4303b)
#4 0x00007fdb63b44859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
#5 0x0000560a926fdce8 llvm::report_fatal_error(llvm::Twine const&, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x30fdce8)
#6 0x0000560a926fde58 (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x30fde58)
#7 0x0000560a92638b65 llvm::DAGTypeLegalizer::SplitVecOp_EXTRACT_SUBVECTOR(llvm::SDNode*) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x3038b65)
#8 0x0000560a9263e08b llvm::DAGTypeLegalizer::SplitVectorOperand(llvm::SDNode*, unsigned int) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x303e08b)
#9 0x0000560a9261d9ee llvm::DAGTypeLegalizer::run() (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x301d9ee)
#10 0x0000560a9261e8c6 llvm::SelectionDAG::LegalizeTypes() (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x301e8c6)
#11 0x0000560a925b1a03 llvm::SelectionDAGISel::CodeGenAndEmitDAG() (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x2fb1a03)
#12 0x0000560a925b54c3 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x2fb54c3)
#13 0x0000560a925b6bf8 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (.part.962) SelectionDAGISel.cpp:0:0
#14 0x0000560a91af98d6 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x24f98d6)
#15 0x0000560a91faae16 llvm::FPPassManager::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x29aae16)
#16 0x0000560a91fab169 llvm::FPPassManager::runOnModule(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x29ab169)
#17 0x0000560a91fabac9 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x29abac9)
#18 0x0000560a9014ea08 compileModule(char**, llvm::LLVMContext&) llc.cpp:0:0
#19 0x0000560a900a9557 main (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0xaa9557)
#20 0x00007fdb63b460b3 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x240b3)
#21 0x0000560a901453da _start (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0xb453da)
Compiler returned: 139