[turbofan] Remove unused instruction continuation handling for stack checks.

Bug: v8:5267
Change-Id: I649554733fdbd00c8e82b09aca35b0ff1f823560
Reviewed-on: https://chromium-review.googlesource.com/890262Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50919}

src/compiler/ia32/instruction-selector-ia32.cc

@@ -1276,17 +1276,9 @@ void VisitWordCompare(InstructionSelector* selector, Node* node,
       // Compare(Load(js_stack_limit), LoadStackPointer)
       if (!node->op()->HasProperty(Operator::kCommutative)) cont->Commute();
       InstructionCode opcode = cont->Encode(kIA32StackCheck);
-      if (cont->IsBranch()) {
+      CHECK(cont->IsBranch());
       selector->Emit(opcode, g.NoOutput(), g.Label(cont->true_block()),
                      g.Label(cont->false_block()));
-      } else if (cont->IsDeoptimize()) {
-        selector->EmitDeoptimize(opcode, 0, nullptr, 0, nullptr, cont->kind(),
-                                 cont->reason(), cont->feedback(),
-                                 cont->frame_state());
-      } else {
-        DCHECK(cont->IsSet());
-        selector->Emit(opcode, g.DefineAsRegister(cont->result()));
-      }
       return;
     }
   }

src/compiler/x64/instruction-selector-x64.cc

@@ -1734,19 +1734,9 @@ void VisitWord64Compare(InstructionSelector* selector, Node* node,
       // Compare(Load(js_stack_limit), LoadStackPointer)
       if (!node->op()->HasProperty(Operator::kCommutative)) cont->Commute();
       InstructionCode opcode = cont->Encode(kX64StackCheck);
-      if (cont->IsBranch()) {
+      CHECK(cont->IsBranch());
       selector->Emit(opcode, g.NoOutput(), g.Label(cont->true_block()),
                      g.Label(cont->false_block()));
-      } else if (cont->IsDeoptimize()) {
-        selector->EmitDeoptimize(opcode, 0, nullptr, 0, nullptr, cont->kind(),
-                                 cont->reason(), cont->feedback(),
-                                 cont->frame_state());
-      } else if (cont->IsSet()) {
-        selector->Emit(opcode, g.DefineAsRegister(cont->result()));
-      } else {
-        DCHECK(cont->IsTrap());
-        selector->Emit(opcode, g.NoOutput(), g.UseImmediate(cont->trap_id()));
-      }
       return;
     }
   }

test/unittests/compiler/ia32/instruction-selector-ia32-unittest.cc

@@ -830,26 +830,6 @@ TEST_F(InstructionSelectorTest, Float64BinopArithmetic) {
 // -----------------------------------------------------------------------------
 // Miscellaneous.
 
-
-TEST_F(InstructionSelectorTest, Uint32LessThanWithLoadAndLoadStackPointer) {
-  StreamBuilder m(this, MachineType::Bool());
-  Node* const sl = m.Load(
-      MachineType::Pointer(),
-      m.ExternalConstant(ExternalReference::address_of_stack_limit(isolate())));
-  Node* const sp = m.LoadStackPointer();
-  Node* const n = m.Uint32LessThan(sl, sp);
-  m.Return(n);
-  Stream s = m.Build();
-  ASSERT_EQ(1U, s.size());
-  EXPECT_EQ(kIA32StackCheck, s[0]->arch_opcode());
-  ASSERT_EQ(0U, s[0]->InputCount());
-  ASSERT_EQ(1U, s[0]->OutputCount());
-  EXPECT_EQ(s.ToVreg(n), s.ToVreg(s[0]->Output()));
-  EXPECT_EQ(kFlags_set, s[0]->flags_mode());
-  EXPECT_EQ(kUnsignedGreaterThan, s[0]->flags_condition());
-}
-
-
 TEST_F(InstructionSelectorTest, Word32Clz) {
   StreamBuilder m(this, MachineType::Uint32(), MachineType::Uint32());
   Node* const p0 = m.Parameter(0);

test/unittests/compiler/x64/instruction-selector-x64-unittest.cc

@@ -1463,25 +1463,6 @@ TEST_F(InstructionSelectorTest, Float64BinopArithmetic) {
 // Miscellaneous.
 
 
-TEST_F(InstructionSelectorTest, Uint64LessThanWithLoadAndLoadStackPointer) {
-  StreamBuilder m(this, MachineType::Bool());
-  Node* const sl = m.Load(
-      MachineType::Pointer(),
-      m.ExternalConstant(ExternalReference::address_of_stack_limit(isolate())));
-  Node* const sp = m.LoadStackPointer();
-  Node* const n = m.Uint64LessThan(sl, sp);
-  m.Return(n);
-  Stream s = m.Build();
-  ASSERT_EQ(1U, s.size());
-  EXPECT_EQ(kX64StackCheck, s[0]->arch_opcode());
-  ASSERT_EQ(0U, s[0]->InputCount());
-  ASSERT_EQ(1U, s[0]->OutputCount());
-  EXPECT_EQ(s.ToVreg(n), s.ToVreg(s[0]->Output()));
-  EXPECT_EQ(kFlags_set, s[0]->flags_mode());
-  EXPECT_EQ(kUnsignedGreaterThan, s[0]->flags_condition());
-}
-
-
 TEST_F(InstructionSelectorTest, Word64ShlWithChangeInt32ToInt64) {
   TRACED_FORRANGE(int64_t, x, 32, 63) {
     StreamBuilder m(this, MachineType::Int64(), MachineType::Int32());