[wasm] Introduce the TrapIf and TrapUnless operators to generate trap code.

src/compiler/code-generator.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_CODE_GENERATOR_H_
 #define V8_COMPILER_CODE_GENERATOR_H_
 
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/unwinding-info-writer.h"
@@ skipping 52 matching lines @@
   InstructionSequence* code() const { return code_; }
   FrameAccessState* frame_access_state() const { return frame_access_state_; }
   const Frame* frame() const { return frame_access_state_->frame(); }
   Isolate* isolate() const;
   Linkage* linkage() const { return linkage_; }
 
   Label* GetLabel(RpoNumber rpo) { return &labels_[rpo.ToSize()]; }
 
   void AddProtectedInstruction(int instr_offset, int landing_offset);
 
+  void AssembleSourcePosition(Instruction* instr);
+
+  // Record a safepoint with the given pointer map.
+  void RecordSafepoint(ReferenceMap* references, Safepoint::Kind kind,
+                       int arguments, Safepoint::DeoptMode deopt_mode);
+
  private:
   MacroAssembler* masm() { return &masm_; }
   GapResolver* resolver() { return &resolver_; }
   SafepointTableBuilder* safepoints() { return &safepoints_; }
   Zone* zone() const { return code()->zone(); }
   CompilationInfo* info() const { return info_; }
 
   // Create the FrameAccessState object. The Frame is immutable from here on.
   void CreateFrameAccessState(Frame* frame);
 
   // Architecture - specific frame finalization.
   void FinishFrame(Frame* frame);
 
   // Checks if {block} will appear directly after {current_block_} when
   // assembling code, in which case, a fall-through can be used.
   bool IsNextInAssemblyOrder(RpoNumber block) const;
 
-  // Record a safepoint with the given pointer map.
-  void RecordSafepoint(ReferenceMap* references, Safepoint::Kind kind,
-                       int arguments, Safepoint::DeoptMode deopt_mode);
-
   // Check if a heap object can be materialized by loading from a heap root,
   // which is cheaper on some platforms than materializing the actual heap
   // object constant.
   bool IsMaterializableFromRoot(Handle<HeapObject> object,
                                 Heap::RootListIndex* index_return);
 
   enum CodeGenResult { kSuccess, kTooManyDeoptimizationBailouts };
 
   // Assemble instructions for the specified block.
   CodeGenResult AssembleBlock(const InstructionBlock* block);
 
   // Assemble code for the specified instruction.
   CodeGenResult AssembleInstruction(Instruction* instr,
                                     const InstructionBlock* block);
-  void AssembleSourcePosition(Instruction* instr);
   void AssembleGaps(Instruction* instr);
 
   // Returns true if a instruction is a tail call that needs to adjust the stack
   // pointer before execution. The stack slot index to the empty slot above the
   // adjusted stack pointer is returned in |slot|.
   bool GetSlotAboveSPBeforeTailCall(Instruction* instr, int* slot);
 
   // ===========================================================================
   // ============= Architecture-specific code generation methods. ==============
   // ===========================================================================
 
   CodeGenResult AssembleArchInstruction(Instruction* instr);
   void AssembleArchJump(RpoNumber target);
   void AssembleArchBranch(Instruction* instr, BranchInfo* branch);
   void AssembleArchBoolean(Instruction* instr, FlagsCondition condition);
+  void AssembleArchTrap(Instruction* instr, FlagsCondition condition);
   void AssembleArchLookupSwitch(Instruction* instr);
   void AssembleArchTableSwitch(Instruction* instr);
 
   CodeGenResult AssembleDeoptimizerCall(int deoptimization_id,
                                         Deoptimizer::BailoutType bailout_type,
                                         SourcePosition pos);
 
   // Generates an architecture-specific, descriptor-specific prologue
   // to set up a stack frame.
   void AssembleConstructFrame();
@@ skipping 154 matching lines @@
   int optimized_out_literal_id_;
   SourcePositionTableBuilder source_position_table_builder_;
   ZoneVector<trap_handler::ProtectedInstructionData>* protected_instructions_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_CODE_GENERATOR_H