[turbofan] Initial support for Switch.

src/compiler/ia32/code-generator-ia32.cc

Index: src/compiler/ia32/code-generator-ia32.cc
diff --git a/src/compiler/ia32/code-generator-ia32.cc b/src/compiler/ia32/code-generator-ia32.cc
index 54336dc31ee6f8abf1d321b22bfe16d2673cfcf9..f88cd106766c50fa4f3146727e7a7286295841a4 100644
--- a/src/compiler/ia32/code-generator-ia32.cc
+++ b/src/compiler/ia32/code-generator-ia32.cc
@@ -310,6 +310,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kArchJmp:
       AssembleArchJump(i.InputRpo(0));
       break;
+    case kArchSwitch:
+      AssembleArchSwitch(instr);
+      break;
     case kArchNop:
       // don't emit code for nops.
       break;
@@ -758,6 +761,18 @@ void CodeGenerator::AssembleArchJump(BasicBlock::RpoNumber target) {
 }
 
 
+void CodeGenerator::AssembleArchSwitch(Instruction* instr) {
+  IA32OperandConverter i(this, instr);
+  size_t const label_count = instr->InputCount() - 1;
+  Label** labels = zone()->NewArray<Label*>(label_count);
+  for (size_t index = 0; index < label_count; ++index) {
+    labels[index] = GetLabel(i.InputRpo(index + 1));
+  }
+  Label* const table = AddJumpTable(labels, label_count);
+  __ jmp(Operand::JumpTable(i.InputRegister(0), times_4, table));
+}
+
+
 // Assembles boolean materializations after an instruction.
 void CodeGenerator::AssembleArchBoolean(Instruction* instr,
                                         FlagsCondition condition) {
@@ -1214,6 +1229,13 @@ void CodeGenerator::AssembleSwap(InstructionOperand* source,
 }
 
 
+void CodeGenerator::AssembleJumpTable(Label** targets, size_t target_count) {
+  for (size_t index = 0; index < target_count; ++index) {
+    __ dd(targets[index]);
+  }
+}
+
+
 void CodeGenerator::AddNopForSmiCodeInlining() { __ nop(); }