[turbofan] add new x64 addressing modes

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

 // 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.
 
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Adds X64-specific methods for generating operands.
 class X64OperandGenerator FINAL : public OperandGenerator {
  public:
   explicit X64OperandGenerator(InstructionSelector* selector)
       : OperandGenerator(selector) {}
 
   InstructionOperand* TempRegister(Register reg) {
     return new (zone()) UnallocatedOperand(UnallocatedOperand::FIXED_REGISTER,
                                            Register::ToAllocationIndex(reg));
   }
 
-  InstructionOperand* UseByteRegister(Node* node) {
-    // TODO(dcarney): relax constraint.
-    return UseFixed(node, rdx);
-  }
-
   InstructionOperand* UseImmediate64(Node* node) { return UseImmediate(node); }
 
   bool CanBeImmediate(Node* node) {
     switch (node->opcode()) {
       case IrOpcode::kInt32Constant:
         return true;
       default:
         return false;
     }
   }
@@ skipping 14 matching lines @@
         return false;
     }
   }
 
   bool CanBeBetterLeftOperand(Node* node) const {
     return !selector()->IsLive(node);
   }
 };
 
 
+// Matches nodes of form [x * N] for N in {1,2,4,8}
+class ScaleFactorMatcher : public NodeMatcher {
+ public:
+  explicit ScaleFactorMatcher(Node* node)
+      : NodeMatcher(node), matches_(false), power_(0) {
+    Match();
+  }
+
+  bool matches() { return matches_; }
+  int power() {
+    DCHECK(matches_);
+    return power_;
+  }
+  Node* left() {
+    DCHECK(matches_);
+    return InputAt(0);
+  }
+
+ private:
+  void Match() {
+    if (opcode() != IrOpcode::kInt32Mul) return;

[titzer, 2014/09/26 11:04:11]

I think you can use an Int32BinopMatcher here. It will actually put the constant
on the right for you too!

[dcarney, 2014/09/26 12:49:51]

Done.

+    // Assume reduction has put constant on right.
+    Int32Matcher right_matcher(InputAt(1));
+    if (!right_matcher.HasValue()) return;
+    int32_t right_value = right_matcher.Value();
+    switch (right_value) {
+      case 8:
+        power_++;  // Fall through.
+      case 4:
+        power_++;  // Fall through.
+      case 2:
+        power_++;  // Fall through.
+      case 1:
+        break;
+      default:
+        return;
+    }
+    matches_ = true;
+  }
+
+  bool matches_;
+  int power_;
+};
+
+
+// Matches nodes of form:
+//  [x * N]
+//  [x * N + K]
+//  [x + K]

[titzer, 2014/09/26 11:04:12]

This case is redundant since N can be 1.

[dcarney, 2014/09/26 12:49:51]

yeah. but it's matched differently.  so i list it

+//  [x] -- fallback case
+// for N in {1,2,4,8} and K int32_t
+class IndexAndDisplacementMatcher : public NodeMatcher {
+ public:
+  explicit IndexAndDisplacementMatcher(Node* node)
+      : NodeMatcher(node), index_node_(node), displacement_(0), power_(0) {
+    Match();
+  }
+
+  Node* index_node() { return index_node_; }
+  int displacement() { return displacement_; }
+  AddressingMode GetMode(AddressingMode one) {
+    return static_cast<AddressingMode>(static_cast<int>(one) + power_);
+  }
+
+ private:
+  void Match() {
+    if (opcode() == IrOpcode::kInt32Add) {

[titzer, 2014/09/26 11:04:12]

Here also.

[dcarney, 2014/09/26 12:49:51]

Done.

+      // Assume reduction has put constant on the right.
+      Int32Matcher right_matcher(InputAt(1));
+      if (right_matcher.HasValue()) {
+        displacement_ = right_matcher.Value();
+        index_node_ = InputAt(0);
+      }
+    }
+    // Test scale factor.
+    ScaleFactorMatcher scale_matcher(index_node_);
+    if (scale_matcher.matches()) {
+      index_node_ = scale_matcher.left();
+      power_ = scale_matcher.power();
+    }
+  }
+
+  Node* index_node_;
+  int displacement_;
+  int power_;
+};
+
+
+class AddressingModeMatcher {

[titzer, 2014/09/26 11:04:11]

Is it possible to inline IndexAndDisplacement matcher into this class and make
that match routine a method here?

[dcarney, 2014/09/26 12:49:51]

yeah. but i want the 2 above matcher classes to be the arch independent bits,
and AddressingModeMatcher to be the copy and pasted bit

+ public:
+  AddressingModeMatcher(X64OperandGenerator* g, Node* base, Node* index)
+      : base_operand_(NULL),
+        index_operand_(NULL),
+        displacement_operand_(NULL),
+        mode_(kMode_None) {
+    Int32Matcher index_imm(index);
+    if (index_imm.HasValue()) {
+      int32_t value = index_imm.Value();
+      if (value == 0) {
+        mode_ = kMode_MR;
+      } else {
+        mode_ = kMode_MRI;
+        index_operand_ = g->UseImmediate(index);
+      }
+      base_operand_ = g->UseRegister(base);
+    } else {
+      // Compute base operand.
+      Int32Matcher base_imm(base);
+      if (!base_imm.HasValue() || base_imm.Value() != 0) {
+        base_operand_ = g->UseRegister(base);
+      }
+      // Compute index and displacement.
+      IndexAndDisplacementMatcher matcher(index);
+      index_operand_ = g->UseRegister(matcher.index_node());
+      if (matcher.displacement() != 0) {
+        displacement_operand_ = g->TempImmediate(matcher.displacement());
+      }
+      // Compute mode with scale factor one.
+      if (base_operand_ == NULL) {
+        if (displacement_operand_ == NULL) {
+          mode_ = kMode_M1;
+        } else {
+          mode_ = kMode_M1I;
+        }
+      } else {
+        if (displacement_operand_ == NULL) {
+          mode_ = kMode_MR1;
+        } else {
+          mode_ = kMode_MR1I;
+        }
+      }
+      // Adjust mode to actual scale factor.
+      mode_ = matcher.GetMode(mode_);
+    }
+    DCHECK_NE(kMode_None, mode_);
+  }
+
+  size_t SetInputs(InstructionOperand** inputs) {
+    size_t input_count = 0;
+    // Compute inputs_ and input_count.
+    if (base_operand_ != NULL) {
+      inputs[input_count++] = base_operand_;
+    }
+    if (index_operand_ != NULL) {
+      inputs[input_count++] = index_operand_;
+    }
+    if (displacement_operand_ != NULL) {
+      // Pure displacement mode not supported by x64.
+      DCHECK_NE(input_count, 0);
+      inputs[input_count++] = displacement_operand_;
+    }
+    DCHECK_NE(input_count, 0);
+    return input_count;
+  }
+
+  static const int kMaxInputCount = 3;
+  InstructionOperand* base_operand_;
+  InstructionOperand* index_operand_;
+  InstructionOperand* displacement_operand_;
+  AddressingMode mode_;
+};
+
+
 void InstructionSelector::VisitLoad(Node* node) {
   MachineType rep = RepresentationOf(OpParameter<LoadRepresentation>(node));
   MachineType typ = TypeOf(OpParameter<LoadRepresentation>(node));
-  X64OperandGenerator g(this);
   Node* base = node->InputAt(0);
   Node* index = node->InputAt(1);
 
   ArchOpcode opcode;
   // TODO(titzer): signed/unsigned small loads
   switch (rep) {
     case kRepFloat32:
       opcode = kX64Movss;
       break;
     case kRepFloat64:
@@ skipping 10 matching lines @@
       opcode = kX64Movl;
       break;
     case kRepTagged:  // Fall through.
     case kRepWord64:
       opcode = kX64Movq;
       break;
     default:
       UNREACHABLE();
       return;
   }
-  if (g.CanBeImmediate(base)) {
-    // load [#base + %index]
-    Emit(opcode | AddressingModeField::encode(kMode_MRI),
-         g.DefineAsRegister(node), g.UseRegister(index), g.UseImmediate(base));
-  } else if (g.CanBeImmediate(index)) {  // load [%base + #index]
-    Emit(opcode | AddressingModeField::encode(kMode_MRI),
-         g.DefineAsRegister(node), g.UseRegister(base), g.UseImmediate(index));
-  } else {  // load [%base + %index + K]
-    Emit(opcode | AddressingModeField::encode(kMode_MR1I),
-         g.DefineAsRegister(node), g.UseRegister(base), g.UseRegister(index));
-  }
-  // TODO(turbofan): addressing modes [r+r*{2,4,8}+K]
+
+  X64OperandGenerator g(this);
+  AddressingModeMatcher matcher(&g, base, index);
+  InstructionCode code = opcode | AddressingModeField::encode(matcher.mode_);
+  InstructionOperand* outputs[] = {g.DefineAsRegister(node)};
+  InstructionOperand* inputs[AddressingModeMatcher::kMaxInputCount];
+  int input_count = matcher.SetInputs(inputs);
+  Emit(code, 1, outputs, input_count, inputs);
 }
 
 
 void InstructionSelector::VisitStore(Node* node) {
   X64OperandGenerator g(this);
   Node* base = node->InputAt(0);
   Node* index = node->InputAt(1);
   Node* value = node->InputAt(2);
 
   StoreRepresentation store_rep = OpParameter<StoreRepresentation>(node);
   MachineType rep = RepresentationOf(store_rep.machine_type());
   if (store_rep.write_barrier_kind() == kFullWriteBarrier) {
     DCHECK(rep == kRepTagged);
     // TODO(dcarney): refactor RecordWrite function to take temp registers
     //                and pass them here instead of using fixed regs
     // TODO(dcarney): handle immediate indices.
     InstructionOperand* temps[] = {g.TempRegister(rcx), g.TempRegister(rdx)};
     Emit(kX64StoreWriteBarrier, NULL, g.UseFixed(base, rbx),
          g.UseFixed(index, rcx), g.UseFixed(value, rdx), arraysize(temps),
          temps);
     return;
   }
   DCHECK_EQ(kNoWriteBarrier, store_rep.write_barrier_kind());
-  InstructionOperand* val;
-  if (g.CanBeImmediate(value)) {
-    val = g.UseImmediate(value);
-  } else if (rep == kRepWord8 || rep == kRepBit) {
-    val = g.UseByteRegister(value);
-  } else {
-    val = g.UseRegister(value);
-  }
   ArchOpcode opcode;
   switch (rep) {
     case kRepFloat32:
       opcode = kX64Movss;
       break;
     case kRepFloat64:
       opcode = kX64Movsd;
       break;
     case kRepBit:  // Fall through.
     case kRepWord8:
       opcode = kX64Movb;
       break;
     case kRepWord16:
       opcode = kX64Movw;
       break;
     case kRepWord32:
       opcode = kX64Movl;
       break;
     case kRepTagged:  // Fall through.
     case kRepWord64:
       opcode = kX64Movq;
       break;
     default:
       UNREACHABLE();
       return;
   }
-  if (g.CanBeImmediate(base)) {
-    // store [#base + %index], %|#value
-    Emit(opcode | AddressingModeField::encode(kMode_MRI), NULL,
-         g.UseRegister(index), g.UseImmediate(base), val);
-  } else if (g.CanBeImmediate(index)) {  // store [%base + #index], %|#value
-    Emit(opcode | AddressingModeField::encode(kMode_MRI), NULL,
-         g.UseRegister(base), g.UseImmediate(index), val);
-  } else {  // store [%base + %index], %|#value
-    Emit(opcode | AddressingModeField::encode(kMode_MR1I), NULL,
-         g.UseRegister(base), g.UseRegister(index), val);
+
+  InstructionOperand* val;
+  if (g.CanBeImmediate(value)) {
+    val = g.UseImmediate(value);
+  } else {
+    val = g.UseRegister(value);
   }
-  // TODO(turbofan): addressing modes [r+r*{2,4,8}+K]
+
+  AddressingModeMatcher matcher(&g, base, index);
+  InstructionCode code = opcode | AddressingModeField::encode(matcher.mode_);
+  InstructionOperand* inputs[AddressingModeMatcher::kMaxInputCount + 1];
+  int input_count = matcher.SetInputs(inputs);
+  inputs[input_count++] = val;
+  Emit(code, 0, static_cast<InstructionOperand**>(NULL), input_count, inputs);
 }
 
 
 // Shared routine for multiple binary operations.
 static void VisitBinop(InstructionSelector* selector, Node* node,
                        InstructionCode opcode, FlagsContinuation* cont) {
   X64OperandGenerator g(selector);
   Int32BinopMatcher m(node);
   Node* left = m.left().node();
   Node* right = m.right().node();
@@ skipping 508 matching lines @@
   if (descriptor->NeedsFrameState()) {
     frame_state_descriptor = GetFrameStateDescriptor(
         call->InputAt(static_cast<int>(descriptor->InputCount())));
   }
 
   CallBuffer buffer(zone(), descriptor, frame_state_descriptor);
 
   // Compute InstructionOperands for inputs and outputs.
   InitializeCallBuffer(call, &buffer, true, true);
 
-  // TODO(dcarney): stack alignment for c calls.
-  // TODO(dcarney): shadow space on window for c calls.
   // Push any stack arguments.
   for (NodeVectorRIter input = buffer.pushed_nodes.rbegin();
        input != buffer.pushed_nodes.rend(); input++) {
     // TODO(titzer): handle pushing double parameters.
     Emit(kX64Push, NULL,
          g.CanBeImmediate(*input) ? g.UseImmediate(*input) : g.Use(*input));
   }
 
   // Select the appropriate opcode based on the call type.
   InstructionCode opcode;
@@ skipping 19 matching lines @@
   call_instr->MarkAsCall();
   if (deoptimization != NULL) {
     DCHECK(continuation != NULL);
     call_instr->MarkAsControl();
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8