[llvm] r355483 - [CodeGen] Omit range checks from jump tables when lowering switches with unreachable default

via llvm-commits llvm-commits at lists.llvm.org
Wed Mar 6 07:15:19 PST 2019


Yes, I'm looking into this.  I will revert shortly.

On 06/03/2019 08:40 PM, Alexander Kornienko wrote:
> I see that the commit was reverted and recommitted. The new one is
> still causing the same problem.
> 
> On Wed, Mar 6, 2019 at 4:05 PM Alexander Kornienko <alexfh at google.com>
> wrote:
> 
>> This commit causes an assertion failure when compiling LLVM sources.
>> A small repro:
>> 
>> $ cat repro.cpp
>> class QQQ {
>> 
>> 
>> public:
>> bool x() const;
>> bool y() const;
>> unsigned getSizeInBits() const {
>> if (y() || x())
>> return getScalarSizeInBits();
>> return getScalarSizeInBits() * 2;
>> }
>> unsigned getScalarSizeInBits() const;
>> };
>> int f(const QQQ &Ty) {
>> switch (Ty.getSizeInBits()) {
>> case 1:
>> case 8:
>> return 0;
>> case 16:
>> return 1;
>> case 32:
>> return 2;
>> case 64:
>> return 3;
>> default:
>> __builtin_unreachable();
>> }
>> }
>> $ clang -O2 -o repro.o repro.cpp
>> assert.h assertion failed at
>> llvm/include/llvm/ADT/ilist_iterator.h:139 in
>> llvm::ilist_iterator::reference
>> 
> llvm::ilist_iterator<llvm::ilist_detail::node_options<llvm::MachineInstr,
>> true, true, void>, true, false>::operator*() const [OptionsT =
>> llvm::ilist_detail::node_options<llvm::MachineInstr, true, true,
>> void>, IsReverse = true, IsConst = false]: !NodePtr->i
>> 
>> sKnownSentinel()
>> *** Check failure stack trace: ***
>> @     0x558aab4afc10  __assert_fail
>> 
>> @     0x558aa885479b  llvm::ilist_iterator<>::operator*()
>> @     0x558aa8854715
>> llvm::MachineInstrBundleIterator<>::operator*()
>> @     0x558aa92c33c3  llvm::X86InstrInfo::optimizeCompareInstr()
>> @     0x558aa9a9c251  (anonymous
>> namespace)::PeepholeOptimizer::optimizeCmpInstr()
>> @     0x558aa9a9b371  (anonymous
>> namespace)::PeepholeOptimizer::runOnMachineFunction()
>> @     0x558aa99a4fc8  llvm::MachineFunctionPass::runOnFunction()
>> @     0x558aab019fc4  llvm::FPPassManager::runOnFunction()
>> @     0x558aab01a3a5  llvm::FPPassManager::runOnModule()
>> @     0x558aab01aa9b  (anonymous
>> namespace)::MPPassManager::runOnModule()
>> @     0x558aab01a635  llvm::legacy::PassManagerImpl::run()
>> @     0x558aab01afe1  llvm::legacy::PassManager::run()
>> @     0x558aa5914769  (anonymous
>> namespace)::EmitAssemblyHelper::EmitAssembly()
>> @     0x558aa5910f44  clang::EmitBackendOutput()
>> @     0x558aa5906135
>> clang::BackendConsumer::HandleTranslationUnit()
>> @     0x558aa6d165ad  clang::ParseAST()
>> @     0x558aa6a94e22  clang::ASTFrontendAction::ExecuteAction()
>> @     0x558aa590255d  clang::CodeGenAction::ExecuteAction()
>> @     0x558aa6a94840  clang::FrontendAction::Execute()
>> @     0x558aa6a38cca  clang::CompilerInstance::ExecuteAction()
>> @     0x558aa4e2294b  clang::ExecuteCompilerInvocation()
>> @     0x558aa4df6200  cc1_main()
>> @     0x558aa4e1b37f  ExecuteCC1Tool()
>> @     0x558aa4e1a725  main
>> @     0x7ff20d56abbd  __libc_start_main
>> @     0x558aa4df51c9  _start
>> 
>> Please revert or fix.
>> 
>> On Wed, Mar 6, 2019 at 8:26 AM Ayonam Ray via llvm-commits
>> <llvm-commits at lists.llvm.org> wrote:
>> 
>>> Author: ayonam
>>> Date: Tue Mar  5 23:27:45 2019
>>> New Revision: 355483
>>> 
>>> URL: http://llvm.org/viewvc/llvm-project?rev=355483&view=rev
>>> Log:
>>> [CodeGen] Omit range checks from jump tables when lowering
>>> switches with unreachable default
>>> 
>>> During the lowering of a switch that would result in the
>>> generation of a
>>> jump table, a range check is performed before indexing into the
>>> jump
>>> table, for the switch value being outside the jump table range and
>>> a
>>> conditional branch is inserted to jump to the default block. In
>>> case the
>>> default block is unreachable, this conditional jump can be
>>> omitted. This
>>> patch implements omitting this conditional branch for unreachable
>>> defaults.
>>> 
>>> Differential Revision: https://reviews.llvm.org/D52002
>>> Reviewers: Hans Wennborg, Eli Freidman, Roman Lebedev
>>> 
>>> Added:
>>> llvm/trunk/test/CodeGen/AArch64/switch-unreachable-default.ll
>>> Modified:
>>> llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
>>> llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
>>> llvm/trunk/test/CodeGen/X86/pr38743.ll
>>> llvm/trunk/test/CodeGen/X86/switch-jump-table.ll
>>> 
>>> Modified:
>>> llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
>>> URL:
>>> 
>> 
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=355483&r1=355482&r2=355483&view=diff
>>> 
>> 
> ==============================================================================
>>> --- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
>>> (original)
>>> +++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
>>> Tue Mar  5 23:27:45 2019
>>> @@ -2388,24 +2388,31 @@ void SelectionDAGBuilder::visitJumpTable
>>> JumpTableReg, SwitchOp);
>>> JT.Reg = JumpTableReg;
>>> 
>>> -  // Emit the range check for the jump table, and branch to the
>>> default block
>>> -  // for the switch statement if the value being switched on
>>> exceeds the largest
>>> -  // case in the switch.
>>> -  SDValue CMP = DAG.getSetCC(
>>> -      dl, TLI.getSetCCResultType(DAG.getDataLayout(),
>>> *DAG.getContext(),
>>> -                                 Sub.getValueType()),
>>> -      Sub, DAG.getConstant(JTH.Last - JTH.First, dl, VT),
>>> ISD::SETUGT);
>>> -
>>> -  SDValue BrCond = DAG.getNode(ISD::BRCOND, dl,
>>> -                               MVT::Other, CopyTo, CMP,
>>> -                               DAG.getBasicBlock(JT.Default));
>>> -
>>> -  // Avoid emitting unnecessary branches to the next block.
>>> -  if (JT.MBB != NextBlock(SwitchBB))
>>> -    BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond,
>>> -                         DAG.getBasicBlock(JT.MBB));
>>> -
>>> -  DAG.setRoot(BrCond);
>>> +  if (!JTH.OmitRangeCheck) {
>>> +    // Emit the range check for the jump table, and branch to the
>>> default block
>>> +    // for the switch statement if the value being switched on
>>> exceeds the
>>> +    // largest case in the switch.
>>> +    SDValue CMP = DAG.getSetCC(
>>> +        dl, TLI.getSetCCResultType(DAG.getDataLayout(),
>>> *DAG.getContext(),
>>> +                                   Sub.getValueType()),
>>> +        Sub, DAG.getConstant(JTH.Last - JTH.First, dl, VT),
>>> ISD::SETUGT);
>>> +
>>> +    SDValue BrCond = DAG.getNode(ISD::BRCOND, dl,
>>> +                                 MVT::Other, CopyTo, CMP,
>>> +                                 DAG.getBasicBlock(JT.Default));
>>> +
>>> +    // Avoid emitting unnecessary branches to the next block.
>>> +    if (JT.MBB != NextBlock(SwitchBB))
>>> +      BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond,
>>> +                           DAG.getBasicBlock(JT.MBB));
>>> +
>>> +    DAG.setRoot(BrCond);
>>> +  } else {
>>> +    SDValue BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, CopyTo,
>>> +                                 DAG.getBasicBlock(JT.MBB));
>>> +    DAG.setRoot(BrCond);
>>> +    SwitchBB->removeSuccessor(JT.Default, true);
>>> +  }
>>> }
>>> 
>>> /// Create a LOAD_STACK_GUARD node, and let it carry the target
>>> specific global
>>> @@ -9790,10 +9797,13 @@ bool SelectionDAGBuilder::buildJumpTable
>>> ->createJumpTableIndex(Table);
>>> 
>>> // Set up the jump table info.
>>> +  bool UnreachableDefault =
>>> +
>>> isa<UnreachableInst>(SI->getDefaultDest()->getFirstNonPHIOrDbg());
>>> +  bool OmitRangeCheck = UnreachableDefault;
>>> JumpTable JT(-1U, JTI, JumpTableMBB, nullptr);
>>> JumpTableHeader JTH(Clusters[First].Low->getValue(),
>>> Clusters[Last].High->getValue(),
>>> SI->getCondition(),
>>> -                      nullptr, false);
>>> +                      nullptr, false, OmitRangeCheck);
>>> JTCases.emplace_back(std::move(JTH), std::move(JT));
>>> 
>>> JTCluster = CaseCluster::jumpTable(Clusters[First].Low,
>>> Clusters[Last].High,
>>> @@ -10599,38 +10609,6 @@ void SelectionDAGBuilder::visitSwitch(co
>>> // if there are many clusters.
>>> sortAndRangeify(Clusters);
>>> 
>>> -  if (TM.getOptLevel() != CodeGenOpt::None) {
>>> -    // Replace an unreachable default with the most popular
>>> destination.
>>> -    // FIXME: Exploit unreachable default more aggressively.
>>> -    bool UnreachableDefault =
>>> -
>>> isa<UnreachableInst>(SI.getDefaultDest()->getFirstNonPHIOrDbg());
>>> -    if (UnreachableDefault && !Clusters.empty()) {
>>> -      DenseMap<const BasicBlock *, unsigned> Popularity;
>>> -      unsigned MaxPop = 0;
>>> -      const BasicBlock *MaxBB = nullptr;
>>> -      for (auto I : SI.cases()) {
>>> -        const BasicBlock *BB = I.getCaseSuccessor();
>>> -        if (++Popularity[BB] > MaxPop) {
>>> -          MaxPop = Popularity[BB];
>>> -          MaxBB = BB;
>>> -        }
>>> -      }
>>> -      // Set new default.
>>> -      assert(MaxPop > 0 && MaxBB);
>>> -      DefaultMBB = FuncInfo.MBBMap[MaxBB];
>>> -
>>> -      // Remove cases that were pointing to the destination that
>>> is now the
>>> -      // default.
>>> -      CaseClusterVector New;
>>> -      New.reserve(Clusters.size());
>>> -      for (CaseCluster &CC : Clusters) {
>>> -        if (CC.MBB != DefaultMBB)
>>> -          New.push_back(CC);
>>> -      }
>>> -      Clusters = std::move(New);
>>> -    }
>>> -  }
>>> -
>>> // The branch probablity of the peeled case.
>>> BranchProbability PeeledCaseProb =
>>> BranchProbability::getZero();
>>> MachineBasicBlock *PeeledSwitchMBB =
>>> 
>>> Modified:
>>> llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
>>> URL:
>>> 
>> 
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h?rev=355483&r1=355482&r2=355483&view=diff
>>> 
>> 
> ==============================================================================
>>> --- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
>>> (original)
>>> +++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h Tue
>>> Mar  5 23:27:45 2019
>>> @@ -277,11 +277,12 @@ private:
>>> const Value *SValue;
>>> MachineBasicBlock *HeaderBB;
>>> bool Emitted;
>>> +    bool OmitRangeCheck;
>>> 
>>> JumpTableHeader(APInt F, APInt L, const Value *SV,
>>> MachineBasicBlock *H,
>>> -                    bool E = false)
>>> +                    bool E = false, bool ORC = false)
>>> : First(std::move(F)), Last(std::move(L)), SValue(SV),
>>> HeaderBB(H),
>>> -          Emitted(E) {}
>>> +          Emitted(E), OmitRangeCheck(ORC) {}
>>> };
>>> using JumpTableBlock = std::pair<JumpTableHeader, JumpTable>;
>>> 
>>> Added:
>>> llvm/trunk/test/CodeGen/AArch64/switch-unreachable-default.ll
>>> URL:
>>> 
>> 
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/switch-unreachable-default.ll?rev=355483&view=auto
>>> 
>> 
> ==============================================================================
>>> --- llvm/trunk/test/CodeGen/AArch64/switch-unreachable-default.ll
>>> (added)
>>> +++ llvm/trunk/test/CodeGen/AArch64/switch-unreachable-default.ll
>>> Tue Mar  5 23:27:45 2019
>>> @@ -0,0 +1,62 @@
>>> +; RUN: llc -O3 -o - %s | FileCheck %s
>>> +
>>> +; Test that the output in the presence of an unreachable default
>>> does not have
>>> +; a compare and branch at the top of the switch to handle the
>>> default case.
>>> +
>>> +target triple = "aarch64-unknown-linux-gnu"
>>> +
>>> +; Function Attrs: nounwind
>>> +define void @fn(i4) {
>>> +  switch i4 %0, label %default [
>>> +    i4 0, label %case_0
>>> +    i4 1, label %case_1
>>> +    i4 2, label %case_2
>>> +    i4 3, label %case_3
>>> +    i4 4, label %case_4
>>> +    i4 5, label %case_5
>>> +  ]
>>> +
>>> +; CHECK-LABEL: fn:
>>> +; CHECK-NOT:    sub
>>> +; CHECK-NOT:    cmp
>>> +; CHECK-NOT:    b.hi
>>> +; CHECK:        ldr {{x[0-9]+}}, [{{x[0-9]+}}, {{x[0-9]+}}, lsl
>>> #3]
>>> +; CHECK:        br {{x[0-9]+}}
>>> +
>>> +default:
>>> +  unreachable
>>> +
>>> +case_0:
>>> +  tail call void @handle_case_00(i4 %0) #2
>>> +  br label %return_label
>>> +
>>> +case_1:
>>> +  tail call void @handle_case_01(i4 %0) #2
>>> +  br label %return_label
>>> +
>>> +case_2:
>>> +  tail call void @handle_case_02(i4 %0) #2
>>> +  br label %return_label
>>> +
>>> +case_3:
>>> +  tail call void @handle_case_03(i4 %0) #2
>>> +  br label %return_label
>>> +
>>> +case_4:
>>> +  tail call void @handle_case_04(i4 %0) #2
>>> +  br label %return_label
>>> +
>>> +case_5:
>>> +  tail call void @handle_case_05(i4 %0) #2
>>> +  br label %return_label
>>> +
>>> +return_label:
>>> +  ret void
>>> +}
>>> +
>>> +declare  void @handle_case_00(i4)
>>> +declare  void @handle_case_01(i4)
>>> +declare  void @handle_case_02(i4)
>>> +declare  void @handle_case_03(i4)
>>> +declare  void @handle_case_04(i4)
>>> +declare  void @handle_case_05(i4)
>>> 
>>> Modified: llvm/trunk/test/CodeGen/X86/pr38743.ll
>>> URL:
>>> 
>> 
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pr38743.ll?rev=355483&r1=355482&r2=355483&view=diff
>>> 
>> 
> ==============================================================================
>>> --- llvm/trunk/test/CodeGen/X86/pr38743.ll (original)
>>> +++ llvm/trunk/test/CodeGen/X86/pr38743.ll Tue Mar  5 23:27:45
>>> 2019
>>> @@ -18,41 +18,43 @@ declare void @llvm.memcpy.p0i8.p0i8.i64(
>>> 
>>> define void @pr38743() #1 align 2 {
>>> ; CHECK-LABEL: pr38743:
>>> -; CHECK:       # %bb.0: # %bb
>>> -; CHECK-NEXT:    cmpl $3, %eax
>>> -; CHECK-NEXT:    je .LBB0_4
>>> -; CHECK-NEXT:  # %bb.1: # %bb
>>> -; CHECK-NEXT:    cmpl $1, %eax
>>> -; CHECK-NEXT:    je .LBB0_2
>>> -; CHECK-NEXT:  # %bb.3: # %bb5
>>> -; CHECK-NEXT:    movzwl .str.17+{{.*}}(%rip), %eax
>>> -; CHECK-NEXT:    movw %ax, -{{[0-9]+}}(%rsp)
>>> -; CHECK-NEXT:    movq {{.*}}(%rip), %rax
>>> -; CHECK-NEXT:    jmp .LBB0_5
>>> -; CHECK-NEXT:  .LBB0_4: # %bb8
>>> -; CHECK-NEXT:    movq .str.18+{{.*}}(%rip), %rax
>>> -; CHECK-NEXT:    movq %rax, -{{[0-9]+}}(%rsp)
>>> -; CHECK-NEXT:    movq {{.*}}(%rip), %rax
>>> -; CHECK-NEXT:    jmp .LBB0_5
>>> -; CHECK-NEXT:  .LBB0_2: # %bb2
>>> -; CHECK-NEXT:    movq .str.16+{{.*}}(%rip), %rax
>>> -; CHECK-NEXT:    movq %rax, -{{[0-9]+}}(%rsp)
>>> -; CHECK-NEXT:    movq {{.*}}(%rip), %rax
>>> -; CHECK-NEXT:  .LBB0_5: # %bb12
>>> -; CHECK-NEXT:    movq %rax, -{{[0-9]+}}(%rsp)
>>> -; CHECK-NEXT:    movq -{{[0-9]+}}(%rsp), %rax
>>> -; CHECK-NEXT:    movq %rax, (%rax)
>>> -; CHECK-NEXT:    movb -{{[0-9]+}}(%rsp), %al
>>> -; CHECK-NEXT:    movq -{{[0-9]+}}(%rsp), %rcx
>>> -; CHECK-NEXT:    movzwl -{{[0-9]+}}(%rsp), %edx
>>> -; CHECK-NEXT:    movl -{{[0-9]+}}(%rsp), %esi
>>> -; CHECK-NEXT:    movb -{{[0-9]+}}(%rsp), %dil
>>> -; CHECK-NEXT:    movb %al, (%rax)
>>> -; CHECK-NEXT:    movq %rcx, 1(%rax)
>>> -; CHECK-NEXT:    movw %dx, 9(%rax)
>>> -; CHECK-NEXT:    movl %esi, 11(%rax)
>>> -; CHECK-NEXT:    movb %dil, 15(%rax)
>>> -; CHECK-NEXT:    retq
>>> +; CHECK:       # %bb.0:                                # %bb
>>> +; CHECK-NEXT:          xorl    %eax, %eax
>>> +; CHECK-NEXT:          jmpq    *.LJTI0_0(,%rax,8)
>>> +; CHECK-NEXT: .[[LABEL1:[A-Z_0-9]+]]:
>>> # %bb5
>>> +; CHECK-NEXT:  movzwl  .str.17+{{.*}}(%rip), %eax
>>> +; CHECK-NEXT:  movw    %ax, -{{[0-9]+}}(%rsp)
>>> +; CHECK-NEXT:  movq    .str.17(%rip), %rax
>>> +; CHECK-NEXT:  jmp     .[[LABEL4:[A-Z_0-9]+]]
>>> +; CHECK-NEXT: .[[LABEL2:[A-Z_0-9]+]]:
>>> # %bb2
>>> +; CHECK-NEXT:  movq    .str.16+{{.*}}(%rip), %rax
>>> +; CHECK-NEXT:  movq    %rax, -{{[0-9]+}}(%rsp)
>>> +; CHECK-NEXT:  movq    .str.16(%rip), %rax
>>> +; CHECK-NEXT:  jmp     .[[LABEL4]]
>>> +; CHECK-NEXT: .[[LABEL3:[A-Z_0-9]+]]:
>>> # %bb8
>>> +; CHECK-NEXT:  movq    .str.18+{{.*}}(%rip), %rax
>>> +; CHECK-NEXT:  movq    %rax, -{{[0-9]+}}(%rsp)
>>> +; CHECK-NEXT:  movq    .str.18(%rip), %rax
>>> +; CHECK-NEXT: .[[LABEL4]]:                                # %bb12
>>> +; CHECK-NEXT:  movq    %rax, -{{[0-9]+}}(%rsp)
>>> +; CHECK-NEXT:  movq    -{{[0-9]+}}(%rsp), %rax
>>> +; CHECK-NEXT:  movq    %rax, (%rax)
>>> +; CHECK-NEXT:  movb    -{{[0-9]+}}(%rsp), %al
>>> +; CHECK-NEXT:  movq    -{{[0-9]+}}(%rsp), %rcx
>>> +; CHECK-NEXT:  movzwl  -{{[0-9]+}}(%rsp), %edx
>>> +; CHECK-NEXT:  movl    -{{[0-9]+}}(%rsp), %esi
>>> +; CHECK-NEXT:  movb    -{{[0-9]+}}(%rsp), %dil
>>> +; CHECK-NEXT:  movb    %al, (%rax)
>>> +; CHECK-NEXT:  movq    %rcx, {{[0-9]+}}(%rax)
>>> +; CHECK-NEXT:  movw    %dx, {{[0-9]+}}(%rax)
>>> +; CHECK-NEXT:  movl    %esi, {{[0-9]+}}(%rax)
>>> +; CHECK-NEXT:  movb    %dil, {{[0-9]+}}(%rax)
>>> +; CHECK-NEXT:  retq
>>> +; CHECK-LABEL: .LJTI0_0:
>>> +; CHECK:       .quad   .[[LABEL2]]
>>> +; CHECK-NEXT:  .quad   .[[LABEL1]]
>>> +; CHECK-NEXT:  .quad   .[[LABEL3]]
>>> +; CHECK-NEXT:  .quad   .[[LABEL1]]
>>> bb:
>>> %tmp = alloca %0, align 16
>>> %tmp1 = bitcast %0* %tmp to i8*
>>> 
>>> Modified: llvm/trunk/test/CodeGen/X86/switch-jump-table.ll
>>> URL:
>>> 
>> 
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/switch-jump-table.ll?rev=355483&r1=355482&r2=355483&view=diff
>>> 
>> 
> ==============================================================================
>>> --- llvm/trunk/test/CodeGen/X86/switch-jump-table.ll (original)
>>> +++ llvm/trunk/test/CodeGen/X86/switch-jump-table.ll Tue Mar  5
>>> 23:27:45 2019
>>> @@ -2,14 +2,12 @@
>>> ; RUN: llc -mtriple=i686-pc-gnu-linux
>>> -print-machineinstrs=expand-isel-pseudos %s -o /dev/null 2>&1 |
>>> FileCheck %s -check-prefix=CHECK-JT-PROB
>>> 
>>> -; An unreachable default destination is replaced with the most
>>> popular case label.
>>> +; An unreachable default destination is ignored and no compare
>>> and branch
>>> +; is generated for the default values.
>>> 
>>> define void @foo(i32 %x, i32* %to) {
>>> ; CHECK-LABEL: foo:
>>> ; CHECK: movl 4(%esp), [[REG:%e[a-z]{2}]]
>>> -; CHECK: cmpl $3, [[REG]]
>>> -; CHECK: ja .LBB0_6
>>> -; CHECK-NEXT: # %bb.1:
>>> ; CHECK-NEXT: jmpl *.LJTI0_0(,[[REG]],4)
>>> ; CHECK: movl $4
>>> ; CHECK: retl
>>> @@ -45,10 +43,12 @@ default:
>>> 
>>> ; The jump table has four entries.
>>> ; CHECK-LABEL: .LJTI0_0:
>>> +; CHECK-NEXT: .long  .LBB0_1
>>> ; CHECK-NEXT: .long  .LBB0_2
>>> ; CHECK-NEXT: .long  .LBB0_3
>>> ; CHECK-NEXT: .long  .LBB0_4
>>> ; CHECK-NEXT: .long  .LBB0_5
>>> +; CHECK-NEXT: .long  .LBB0_5
>>> }
>>> 
>>> ; Check if branch probabilities are correctly assigned to the
>>> jump table.
>>> 
>>> _______________________________________________
>>> llvm-commits mailing list
>>> llvm-commits at lists.llvm.org
>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits


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