[turbofan] Initial support for Switch.

src/compiler/x64/code-generator-x64.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/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/scopes.h"
@@ skipping 514 matching lines @@
         __ cmpp(rsi, FieldOperand(func, JSFunction::kContextOffset));
         __ Assert(equal, kWrongFunctionContext);
       }
       __ Call(FieldOperand(func, JSFunction::kCodeEntryOffset));
       AddSafepointAndDeopt(instr);
       break;
     }
     case kArchJmp:
       AssembleArchJump(i.InputRpo(0));
       break;
+    case kArchSwitch:
+      AssembleArchSwitch(instr);
+      break;
     case kArchNop:
       // don't emit code for nops.
       break;
     case kArchRet:
       AssembleReturn();
       break;
     case kArchStackPointer:
       __ movq(i.OutputRegister(), rsp);
       break;
     case kArchTruncateDoubleToI: {
@@ skipping 515 matching lines @@
   }
   if (!branch->fallthru) __ jmp(flabel, flabel_distance);
 }
 
 
 void CodeGenerator::AssembleArchJump(BasicBlock::RpoNumber target) {
   if (!IsNextInAssemblyOrder(target)) __ jmp(GetLabel(target));
 }
 
 
+void CodeGenerator::AssembleArchSwitch(Instruction* instr) {
+  X64OperandConverter i(this, instr);
+  size_t const label_count = instr->InputCount() - 1;
+  Label** labels = zone()->NewArray<Label*>(static_cast<int>(label_count));
+  for (size_t index = 0; index < label_count; ++index) {
+    labels[index] = GetLabel(i.InputRpo(static_cast<int>(index + 1)));
+  }
+  Label* const table = AddJumpTable(labels, label_count);
+  __ leaq(kScratchRegister, Operand(table));
+  __ jmp(Operand(kScratchRegister, i.InputRegister(0), times_8, 0));
+}
+
+
 // Assembles boolean materializations after this instruction.
 void CodeGenerator::AssembleArchBoolean(Instruction* instr,
                                         FlagsCondition condition) {
   X64OperandConverter i(this, instr);
   Label done;
 
   // Materialize a full 64-bit 1 or 0 value. The result register is always the
   // last output of the instruction.
   Label check;
   DCHECK_NE(0, static_cast<int>(instr->OutputCount()));
@@ skipping 293 matching lines @@
     __ movsd(xmm0, src);
     __ movsd(src, dst);
     __ movsd(dst, xmm0);
   } else {
     // No other combinations are possible.
     UNREACHABLE();
   }
 }
 
 
+void CodeGenerator::AssembleJumpTable(Label** targets, size_t target_count) {
+  for (size_t index = 0; index < target_count; ++index) {
+    __ dq(targets[index]);
+  }
+}
+
+
 void CodeGenerator::AddNopForSmiCodeInlining() { __ nop(); }
 
 
 void CodeGenerator::EnsureSpaceForLazyDeopt() {
   int space_needed = Deoptimizer::patch_size();
   if (!info()->IsStub()) {
     // Ensure that we have enough space after the previous lazy-bailout
     // instruction for patching the code here.
     int current_pc = masm()->pc_offset();
     if (current_pc < last_lazy_deopt_pc_ + space_needed) {
       int padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
       __ Nop(padding_size);
     }
   }
   MarkLazyDeoptSite();
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace compiler
 }  // namespace v8