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

src/compiler/code-generator.cc

 // Copyright 2013 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.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/address-map.h"
 #include "src/base/adapters.h"
 #include "src/compilation-info.h"
 #include "src/compiler/code-generator-impl.h"
@@ skipping 399 matching lines @@
   if (adjust_stack) AssembleTailCallBeforeGap(instr, first_unused_stack_slot);
   AssembleGaps(instr);
   if (adjust_stack) AssembleTailCallAfterGap(instr, first_unused_stack_slot);
   DCHECK_IMPLIES(
       block->must_deconstruct_frame(),
       instr != code()->InstructionAt(block->last_instruction_index()) ||
           instr->IsRet() || instr->IsJump());
   if (instr->IsJump() && block->must_deconstruct_frame()) {
     AssembleDeconstructFrame();
   }
-  AssembleSourcePosition(instr);
+  FlagsMode mode = FlagsModeField::decode(instr->opcode());
+  if (mode != kFlags_trap) {
+    AssembleSourcePosition(instr);
+  }
   // Assemble architecture-specific code for the instruction.
   CodeGenResult result = AssembleArchInstruction(instr);
   if (result != kSuccess) return result;
 
-  FlagsMode mode = FlagsModeField::decode(instr->opcode());
   FlagsCondition condition = FlagsConditionField::decode(instr->opcode());
   switch (mode) {
     case kFlags_branch: {
       // Assemble a branch after this instruction.
       InstructionOperandConverter i(this, instr);
       RpoNumber true_rpo = i.InputRpo(instr->InputCount() - 2);
       RpoNumber false_rpo = i.InputRpo(instr->InputCount() - 1);
 
       if (true_rpo == false_rpo) {
         // redundant branch.
@@ skipping 31 matching lines @@
       // Assemble architecture-specific branch.
       AssembleArchBranch(instr, &branch);
       masm()->bind(&continue_label);
       break;
     }
     case kFlags_set: {
       // Assemble a boolean materialization after this instruction.
       AssembleArchBoolean(instr, condition);
       break;
     }
+    case kFlags_trap: {
+      AssembleArchTrap(instr, condition);
+      break;
+    }
     case kFlags_none: {
       break;
     }
   }
   return kSuccess;
 }
 
 
 void CodeGenerator::AssembleSourcePosition(Instruction* instr) {
   SourcePosition source_position = SourcePosition::Unknown();
@@ skipping 493 matching lines @@
     : frame_(gen->frame()), masm_(gen->masm()), next_(gen->ools_) {
   gen->ools_ = this;
 }
 
 
 OutOfLineCode::~OutOfLineCode() {}
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8