[turbofan] Make VisitBranch and friends to backend specific.

src/compiler/arm64/instruction-selector-arm64.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 {
@@ skipping 795 matching lines @@
 }
 
 
 void InstructionSelector::VisitFloat64Sqrt(Node* node) {
   Arm64OperandGenerator g(this);
   Emit(kArm64Float64Sqrt, g.DefineAsRegister(node),
        g.UseRegister(node->InputAt(0)));
 }
 
 
-void InstructionSelector::VisitInt32AddWithOverflow(Node* node,
-                                                    FlagsContinuation* cont) {
-  VisitBinop<Int32BinopMatcher>(this, node, kArm64Add32, kArithmeticImm, cont);
+void InstructionSelector::VisitCall(Node* node) {
+  Arm64OperandGenerator g(this);
+  CallDescriptor* descriptor = OpParameter<CallDescriptor*>(node);
+
+  FrameStateDescriptor* frame_state_descriptor = NULL;
+  if (descriptor->NeedsFrameState()) {
+    frame_state_descriptor =
+        GetFrameStateDescriptor(node->InputAt(descriptor->InputCount()));
+  }
+
+  CallBuffer buffer(zone(), descriptor, frame_state_descriptor);
+
+  // Compute InstructionOperands for inputs and outputs.
+  // TODO(turbofan): on ARM64 it's probably better to use the code object in a
+  // register if there are multiple uses of it. Improve constant pool and the
+  // heuristics in the register allocator for where to emit constants.
+  InitializeCallBuffer(node, &buffer, true, false);
+
+  // Push the arguments to the stack.
+  bool pushed_count_uneven = buffer.pushed_nodes.size() & 1;
+  int aligned_push_count = buffer.pushed_nodes.size();
+  // TODO(dcarney): claim and poke probably take small immediates,
+  //                loop here or whatever.
+  // Bump the stack pointer(s).
+  if (aligned_push_count > 0) {
+    // TODO(dcarney): it would be better to bump the csp here only
+    //                and emit paired stores with increment for non c frames.
+    Emit(kArm64Claim | MiscField::encode(aligned_push_count), NULL);
+  }
+  // Move arguments to the stack.
+  {
+    int slot = buffer.pushed_nodes.size() - 1;
+    // Emit the uneven pushes.
+    if (pushed_count_uneven) {
+      Node* input = buffer.pushed_nodes[slot];
+      Emit(kArm64Poke | MiscField::encode(slot), NULL, g.UseRegister(input));
+      slot--;
+    }
+    // Now all pushes can be done in pairs.
+    for (; slot >= 0; slot -= 2) {
+      Emit(kArm64PokePair | MiscField::encode(slot), NULL,
+           g.UseRegister(buffer.pushed_nodes[slot]),
+           g.UseRegister(buffer.pushed_nodes[slot - 1]));
+    }
+  }
+
+  // Select the appropriate opcode based on the call type.
+  InstructionCode opcode;
+  switch (descriptor->kind()) {
+    case CallDescriptor::kCallCodeObject: {
+      opcode = kArchCallCodeObject;
+      break;
+    }
+    case CallDescriptor::kCallJSFunction:
+      opcode = kArchCallJSFunction;
+      break;
+    default:
+      UNREACHABLE();
+      return;
+  }
+  opcode |= MiscField::encode(descriptor->flags());
+
+  // Emit the call instruction.
+  Instruction* call_instr =
+      Emit(opcode, buffer.outputs.size(), &buffer.outputs.front(),
+           buffer.instruction_args.size(), &buffer.instruction_args.front());
+  call_instr->MarkAsCall();
 }
 
 
-void InstructionSelector::VisitInt32SubWithOverflow(Node* node,
-                                                    FlagsContinuation* cont) {
-  VisitBinop<Int32BinopMatcher>(this, node, kArm64Sub32, kArithmeticImm, cont);
-}
-
-
 // Shared routine for multiple compare operations.
 static void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
                          InstructionOperand* left, InstructionOperand* right,
                          FlagsContinuation* cont) {
   Arm64OperandGenerator g(selector);
   opcode = cont->Encode(opcode);
   if (cont->IsBranch()) {
     selector->Emit(opcode, NULL, left, right, g.Label(cont->true_block()),
                    g.Label(cont->false_block()))->MarkAsControl();
   } else {
@@ skipping 19 matching lines @@
     if (!commutative) cont->Commute();
     VisitCompare(selector, opcode, g.UseRegister(right), g.UseImmediate(left),
                  cont);
   } else {
     VisitCompare(selector, opcode, g.UseRegister(left), g.UseRegister(right),
                  cont);
   }
 }
 
 
-void InstructionSelector::VisitWord32Test(Node* node, FlagsContinuation* cont) {
-  switch (node->opcode()) {
-    case IrOpcode::kInt32Add:
-      return VisitWordCompare(this, node, kArm64Cmn32, cont, true);
-    case IrOpcode::kInt32Sub:
-      return VisitWordCompare(this, node, kArm64Cmp32, cont, false);
-    case IrOpcode::kWord32And:
-      return VisitWordCompare(this, node, kArm64Tst32, cont, true);
-    default:
-      break;
-  }
-
-  Arm64OperandGenerator g(this);
-  VisitCompare(this, kArm64Tst32, g.UseRegister(node), g.UseRegister(node),
+static void VisitWord32Compare(InstructionSelector* selector, Node* node,
+                               FlagsContinuation* cont) {
+  VisitWordCompare(selector, node, kArm64Cmp32, cont, false);
+}
+
+
+static void VisitWordTest(InstructionSelector* selector, Node* node,
+                          InstructionCode opcode, FlagsContinuation* cont) {
+  Arm64OperandGenerator g(selector);
+  VisitCompare(selector, opcode, g.UseRegister(node), g.UseRegister(node),
                cont);
 }
 
 
-void InstructionSelector::VisitWord64Test(Node* node, FlagsContinuation* cont) {
-  switch (node->opcode()) {
-    case IrOpcode::kWord64And:
-      return VisitWordCompare(this, node, kArm64Tst, cont, true);
-    default:
-      break;
-  }
-
-  Arm64OperandGenerator g(this);
-  VisitCompare(this, kArm64Tst, g.UseRegister(node), g.UseRegister(node), cont);
-}
-
-
-void InstructionSelector::VisitWord32Compare(Node* node,
-                                             FlagsContinuation* cont) {
-  VisitWordCompare(this, node, kArm64Cmp32, cont, false);
-}
-
-
-void InstructionSelector::VisitWord64Compare(Node* node,
-                                             FlagsContinuation* cont) {
-  VisitWordCompare(this, node, kArm64Cmp, cont, false);
-}
-
-
-void InstructionSelector::VisitFloat64Compare(Node* node,
-                                              FlagsContinuation* cont) {
-  Arm64OperandGenerator g(this);
+static void VisitWord32Test(InstructionSelector* selector, Node* node,
+                            FlagsContinuation* cont) {
+  VisitWordTest(selector, node, kArm64Tst32, cont);
+}
+
+
+static void VisitWord64Test(InstructionSelector* selector, Node* node,
+                            FlagsContinuation* cont) {
+  VisitWordTest(selector, node, kArm64Tst, cont);
+}
+
+
+// Shared routine for multiple float compare operations.
+static void VisitFloat64Compare(InstructionSelector* selector, Node* node,
+                                FlagsContinuation* cont) {
+  Arm64OperandGenerator g(selector);
   Node* left = node->InputAt(0);
   Node* right = node->InputAt(1);
-  VisitCompare(this, kArm64Float64Cmp, g.UseRegister(left),
+  VisitCompare(selector, kArm64Float64Cmp, g.UseRegister(left),
                g.UseRegister(right), cont);
 }
 
 
-void InstructionSelector::VisitCall(Node* call, BasicBlock* continuation,
-                                    BasicBlock* deoptimization) {
-  Arm64OperandGenerator g(this);
-  CallDescriptor* descriptor = OpParameter<CallDescriptor*>(call);
-
-  FrameStateDescriptor* frame_state_descriptor = NULL;
-  if (descriptor->NeedsFrameState()) {
-    frame_state_descriptor =
-        GetFrameStateDescriptor(call->InputAt(descriptor->InputCount()));
-  }
-
-  CallBuffer buffer(zone(), descriptor, frame_state_descriptor);
-
-  // Compute InstructionOperands for inputs and outputs.
-  // TODO(turbofan): on ARM64 it's probably better to use the code object in a
-  // register if there are multiple uses of it. Improve constant pool and the
-  // heuristics in the register allocator for where to emit constants.
-  InitializeCallBuffer(call, &buffer, true, false);
-
-  // Push the arguments to the stack.
-  bool pushed_count_uneven = buffer.pushed_nodes.size() & 1;
-  int aligned_push_count = buffer.pushed_nodes.size();
-  // TODO(dcarney): claim and poke probably take small immediates,
-  //                loop here or whatever.
-  // Bump the stack pointer(s).
-  if (aligned_push_count > 0) {
-    // TODO(dcarney): it would be better to bump the csp here only
-    //                and emit paired stores with increment for non c frames.
-    Emit(kArm64Claim | MiscField::encode(aligned_push_count), NULL);
-  }
-  // Move arguments to the stack.
-  {
-    int slot = buffer.pushed_nodes.size() - 1;
-    // Emit the uneven pushes.
-    if (pushed_count_uneven) {
-      Node* input = buffer.pushed_nodes[slot];
-      Emit(kArm64Poke | MiscField::encode(slot), NULL, g.UseRegister(input));
-      slot--;
-    }
-    // Now all pushes can be done in pairs.
-    for (; slot >= 0; slot -= 2) {
-      Emit(kArm64PokePair | MiscField::encode(slot), NULL,
-           g.UseRegister(buffer.pushed_nodes[slot]),
-           g.UseRegister(buffer.pushed_nodes[slot - 1]));
-    }
-  }
-
-  // Select the appropriate opcode based on the call type.
-  InstructionCode opcode;
-  switch (descriptor->kind()) {
-    case CallDescriptor::kCallCodeObject: {
-      opcode = kArchCallCodeObject;
+void InstructionSelector::VisitBranch(Node* branch, BasicBlock* tbranch,
+                                      BasicBlock* fbranch) {
+  OperandGenerator g(this);
+  Node* user = branch;
+  Node* value = branch->InputAt(0);
+
+  FlagsContinuation cont(kNotEqual, tbranch, fbranch);
+
+  // If we can fall through to the true block, invert the branch.
+  if (IsNextInAssemblyOrder(tbranch)) {
+    cont.Negate();
+    cont.SwapBlocks();
+  }
+
+  // Try to combine with comparisons against 0 by simply inverting the branch.
+  while (CanCover(user, value)) {
+    if (value->opcode() == IrOpcode::kWord32Equal) {
+      Int32BinopMatcher m(value);
+      if (m.right().Is(0)) {
+        user = value;
+        value = m.left().node();
+        cont.Negate();
+      } else {
+        break;
+      }
+    } else if (value->opcode() == IrOpcode::kWord64Equal) {
+      Int64BinopMatcher m(value);
+      if (m.right().Is(0)) {
+        user = value;
+        value = m.left().node();
+        cont.Negate();
+      } else {
+        break;
+      }
+    } else {
       break;
     }
-    case CallDescriptor::kCallJSFunction:
-      opcode = kArchCallJSFunction;
-      break;
-    default:
-      UNREACHABLE();
-      return;
-  }
-  opcode |= MiscField::encode(descriptor->flags());
-
-  // Emit the call instruction.
-  Instruction* call_instr =
-      Emit(opcode, buffer.outputs.size(), &buffer.outputs.front(),
-           buffer.instruction_args.size(), &buffer.instruction_args.front());
-
-  call_instr->MarkAsCall();
-  if (deoptimization != NULL) {
-    DCHECK(continuation != NULL);
-    call_instr->MarkAsControl();
-  }
+  }
+
+  // Try to combine the branch with a comparison.
+  if (CanCover(user, value)) {
+    switch (value->opcode()) {
+      case IrOpcode::kWord32Equal:
+        cont.OverwriteAndNegateIfEqual(kEqual);
+        return VisitWord32Compare(this, value, &cont);
+      case IrOpcode::kInt32LessThan:
+        cont.OverwriteAndNegateIfEqual(kSignedLessThan);
+        return VisitWord32Compare(this, value, &cont);
+      case IrOpcode::kInt32LessThanOrEqual:
+        cont.OverwriteAndNegateIfEqual(kSignedLessThanOrEqual);
+        return VisitWord32Compare(this, value, &cont);
+      case IrOpcode::kUint32LessThan:
+        cont.OverwriteAndNegateIfEqual(kUnsignedLessThan);
+        return VisitWord32Compare(this, value, &cont);
+      case IrOpcode::kUint32LessThanOrEqual:
+        cont.OverwriteAndNegateIfEqual(kUnsignedLessThanOrEqual);
+        return VisitWord32Compare(this, value, &cont);
+      case IrOpcode::kWord64Equal:
+        cont.OverwriteAndNegateIfEqual(kEqual);
+        return VisitWordCompare(this, value, kArm64Cmp, &cont, false);
+      case IrOpcode::kInt64LessThan:
+        cont.OverwriteAndNegateIfEqual(kSignedLessThan);
+        return VisitWordCompare(this, value, kArm64Cmp, &cont, false);
+      case IrOpcode::kInt64LessThanOrEqual:
+        cont.OverwriteAndNegateIfEqual(kSignedLessThanOrEqual);
+        return VisitWordCompare(this, value, kArm64Cmp, &cont, false);
+      case IrOpcode::kUint64LessThan:
+        cont.OverwriteAndNegateIfEqual(kUnsignedLessThan);
+        return VisitWordCompare(this, value, kArm64Cmp, &cont, false);
+      case IrOpcode::kFloat64Equal:
+        cont.OverwriteAndNegateIfEqual(kUnorderedEqual);
+        return VisitFloat64Compare(this, value, &cont);
+      case IrOpcode::kFloat64LessThan:
+        cont.OverwriteAndNegateIfEqual(kUnorderedLessThan);
+        return VisitFloat64Compare(this, value, &cont);
+      case IrOpcode::kFloat64LessThanOrEqual:
+        cont.OverwriteAndNegateIfEqual(kUnorderedLessThanOrEqual);
+        return VisitFloat64Compare(this, value, &cont);
+      case IrOpcode::kProjection:
+        // Check if this is the overflow output projection of an
+        // <Operation>WithOverflow node.
+        if (OpParameter<size_t>(value) == 1u) {
+          // We cannot combine the <Operation>WithOverflow with this branch
+          // unless the 0th projection (the use of the actual value of the
+          // <Operation> is either NULL, which means there's no use of the
+          // actual value, or was already defined, which means it is scheduled
+          // *AFTER* this branch).
+          Node* node = value->InputAt(0);
+          Node* result = node->FindProjection(0);
+          if (result == NULL || IsDefined(result)) {
+            switch (node->opcode()) {
+              case IrOpcode::kInt32AddWithOverflow:
+                cont.OverwriteAndNegateIfEqual(kOverflow);
+                return VisitBinop<Int32BinopMatcher>(this, node, kArm64Add32,
+                                                     kArithmeticImm, &cont);
+              case IrOpcode::kInt32SubWithOverflow:
+                cont.OverwriteAndNegateIfEqual(kOverflow);
+                return VisitBinop<Int32BinopMatcher>(this, node, kArm64Sub32,
+                                                     kArithmeticImm, &cont);
+              default:
+                break;
+            }
+          }
+        }
+        break;
+      case IrOpcode::kInt32Add:
+        return VisitWordCompare(this, value, kArm64Cmn32, &cont, true);
+      case IrOpcode::kInt32Sub:
+        return VisitWordCompare(this, value, kArm64Cmp32, &cont, false);
+      case IrOpcode::kWord32And:
+        return VisitWordCompare(this, value, kArm64Tst32, &cont, true);
+      default:
+        break;
+    }
+  }
+
+  // Branch could not be combined with a compare, emit compare against 0.
+  VisitWord32Test(this, value, &cont);
+}
+
+
+void InstructionSelector::VisitWord32Equal(Node* const node) {
+  Node* const user = node;
+  FlagsContinuation cont(kEqual, node);
+  Int32BinopMatcher m(user);
+  if (m.right().Is(0)) {
+    Node* const value = m.left().node();
+    if (CanCover(user, value)) {
+      switch (value->opcode()) {
+        case IrOpcode::kInt32Add:
+          return VisitWordCompare(this, value, kArm64Cmn32, &cont, true);
+        case IrOpcode::kInt32Sub:
+          return VisitWordCompare(this, value, kArm64Cmp32, &cont, false);
+        case IrOpcode::kWord32And:
+          return VisitWordCompare(this, value, kArm64Tst32, &cont, true);
+        default:
+          break;
+      }
+      return VisitWord32Test(this, value, &cont);
+    }
+  }
+  VisitWord32Compare(this, node, &cont);
+}
+
+
+void InstructionSelector::VisitInt32LessThan(Node* node) {
+  FlagsContinuation cont(kSignedLessThan, node);
+  VisitWord32Compare(this, node, &cont);
+}
+
+
+void InstructionSelector::VisitInt32LessThanOrEqual(Node* node) {
+  FlagsContinuation cont(kSignedLessThanOrEqual, node);
+  VisitWord32Compare(this, node, &cont);
+}
+
+
+void InstructionSelector::VisitUint32LessThan(Node* node) {
+  FlagsContinuation cont(kUnsignedLessThan, node);
+  VisitWord32Compare(this, node, &cont);
+}
+
+
+void InstructionSelector::VisitUint32LessThanOrEqual(Node* node) {
+  FlagsContinuation cont(kUnsignedLessThanOrEqual, node);
+  VisitWord32Compare(this, node, &cont);
+}
+
+
+void InstructionSelector::VisitWord64Equal(Node* const node) {
+  Node* const user = node;
+  FlagsContinuation cont(kEqual, node);
+  Int64BinopMatcher m(user);
+  if (m.right().Is(0)) {
+    Node* const value = m.left().node();
+    if (CanCover(user, value)) {
+      switch (value->opcode()) {
+        case IrOpcode::kWord64And:
+          return VisitWordCompare(this, value, kArm64Tst, &cont, true);
+        default:
+          break;
+      }
+      return VisitWord64Test(this, value, &cont);
+    }
+  }
+  VisitWordCompare(this, node, kArm64Cmp, &cont, false);
+}
+
+
+void InstructionSelector::VisitInt32AddWithOverflow(Node* node) {
+  if (Node* ovf = node->FindProjection(1)) {
+    FlagsContinuation cont(kOverflow, ovf);
+    return VisitBinop<Int32BinopMatcher>(this, node, kArm64Add32,
+                                         kArithmeticImm, &cont);
+  }
+  FlagsContinuation cont;
+  VisitBinop<Int32BinopMatcher>(this, node, kArm64Add32, kArithmeticImm, &cont);
+}
+
+
+void InstructionSelector::VisitInt32SubWithOverflow(Node* node) {
+  if (Node* ovf = node->FindProjection(1)) {
+    FlagsContinuation cont(kOverflow, ovf);
+    return VisitBinop<Int32BinopMatcher>(this, node, kArm64Sub32,
+                                         kArithmeticImm, &cont);
+  }
+  FlagsContinuation cont;
+  VisitBinop<Int32BinopMatcher>(this, node, kArm64Sub32, kArithmeticImm, &cont);
+}
+
+
+void InstructionSelector::VisitInt64LessThan(Node* node) {
+  FlagsContinuation cont(kSignedLessThan, node);
+  VisitWordCompare(this, node, kArm64Cmp, &cont, false);
+}
+
+
+void InstructionSelector::VisitInt64LessThanOrEqual(Node* node) {
+  FlagsContinuation cont(kSignedLessThanOrEqual, node);
+  VisitWordCompare(this, node, kArm64Cmp, &cont, false);
+}
+
+
+void InstructionSelector::VisitUint64LessThan(Node* node) {
+  FlagsContinuation cont(kUnsignedLessThan, node);
+  VisitWordCompare(this, node, kArm64Cmp, &cont, false);
+}
+
+
+void InstructionSelector::VisitFloat64Equal(Node* node) {
+  FlagsContinuation cont(kUnorderedEqual, node);
+  VisitFloat64Compare(this, node, &cont);
+}
+
+
+void InstructionSelector::VisitFloat64LessThan(Node* node) {
+  FlagsContinuation cont(kUnorderedLessThan, node);
+  VisitFloat64Compare(this, node, &cont);
+}
+
+
+void InstructionSelector::VisitFloat64LessThanOrEqual(Node* node) {
+  FlagsContinuation cont(kUnorderedLessThanOrEqual, node);
+  VisitFloat64Compare(this, node, &cont);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8