[turbofan] add register assignment verifier

src/compiler/register-allocator-verifier.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.h"
+#include "src/compiler/register-allocator-verifier.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+static size_t OperandCount(const Instruction* instr) {
+  return instr->InputCount() + instr->OutputCount() + instr->TempCount();
+}
+
+
+RegisterAllocatorVerifier::RegisterAllocatorVerifier(
+    Zone* zone, const InstructionSequence* sequence)
+    : sequence_(sequence), constraints_(zone) {
+  constraints_.reserve(sequence->instructions().size());
+  for (const auto* instr : sequence->instructions()) {
+    const size_t operand_count = OperandCount(instr);
+    auto* op_constraints =
+        zone->NewArray<OperandConstraint>(static_cast<int>(operand_count));
+    // Construct OperandConstraints for all InstructionOperands, eliminating
+    // kSameAsFirst along the way.
+    size_t count = 0;
+    for (size_t i = 0; i < instr->InputCount(); ++i, ++count) {
+      BuildConstraint(instr->InputAt(i), &op_constraints[count]);
+      CHECK_NE(kSameAsFirst, op_constraints[count].type_);
+    }
+    for (size_t i = 0; i < instr->OutputCount(); ++i, ++count) {
+      BuildConstraint(instr->OutputAt(i), &op_constraints[count]);
+      if (op_constraints[count].type_ == kSameAsFirst) {
+        CHECK(instr->InputCount() > 0);
+        op_constraints[count] = op_constraints[0];
+      }
+    }
+    for (size_t i = 0; i < instr->TempCount(); ++i, ++count) {
+      BuildConstraint(instr->TempAt(i), &op_constraints[count]);
+      CHECK_NE(kSameAsFirst, op_constraints[count].type_);
+    }
+    // All gaps should be totally unallocated at this point.
+    if (instr->IsGapMoves()) {
+      const auto* gap = GapInstruction::cast(instr);
+      for (int i = GapInstruction::FIRST_INNER_POSITION;
+           i <= GapInstruction::LAST_INNER_POSITION; i++) {
+        GapInstruction::InnerPosition inner_pos =
+            static_cast<GapInstruction::InnerPosition>(i);
+        CHECK_EQ(NULL, gap->GetParallelMove(inner_pos));
+      }
+    }
+    InstructionConstraint instr_constraint = {instr, operand_count,
+                                              op_constraints};
+    constraints()->push_back(instr_constraint);
+  }
+}
+
+
+void RegisterAllocatorVerifier::VerifyAssignment() {
+  CHECK(sequence()->instructions().size() == constraints()->size());
+  auto instr_it = sequence()->begin();
+  for (const auto& instr_constraint : *constraints()) {
+    const auto* instr = instr_constraint.instruction_;
+    const size_t operand_count = instr_constraint.operand_constaints_size_;
+    const auto* op_constraints = instr_constraint.operand_constraints_;
+    CHECK_EQ(instr, *instr_it);
+    CHECK(operand_count == OperandCount(instr));
+    size_t count = 0;
+    for (size_t i = 0; i < instr->InputCount(); ++i, ++count) {
+      CheckConstraint(instr->InputAt(i), &op_constraints[count]);
+    }
+    for (size_t i = 0; i < instr->OutputCount(); ++i, ++count) {
+      CheckConstraint(instr->OutputAt(i), &op_constraints[count]);
+    }
+    for (size_t i = 0; i < instr->TempCount(); ++i, ++count) {
+      CheckConstraint(instr->TempAt(i), &op_constraints[count]);
+    }
+    ++instr_it;
+  }
+}
+
+
+void RegisterAllocatorVerifier::BuildConstraint(const InstructionOperand* op,
+                                                OperandConstraint* constraint) {
+  constraint->value_ = kMinInt;
+  if (op->IsConstant()) {
+    constraint->type_ = kConstant;
+    constraint->value_ = ConstantOperand::cast(op)->index();
+  } else if (op->IsImmediate()) {
+    constraint->type_ = kImmediate;
+    constraint->value_ = ImmediateOperand::cast(op)->index();
+  } else {
+    CHECK(op->IsUnallocated());
+    const auto* unallocated = UnallocatedOperand::cast(op);
+    int vreg = unallocated->virtual_register();
+    if (unallocated->basic_policy() == UnallocatedOperand::FIXED_SLOT) {
+      constraint->type_ = kFixedSlot;
+      constraint->value_ = unallocated->fixed_slot_index();
+    } else {
+      switch (unallocated->extended_policy()) {
+        case UnallocatedOperand::ANY:
+          CHECK(false);

[Jarin, 2014/11/10 11:24:59]

What is wrong with the ANY constraint?

[dcarney, 2014/11/10 11:27:17]

it's only used for phi gap moves, not as an instruction argument

+          break;
+        case UnallocatedOperand::NONE:
+          if (sequence()->IsDouble(vreg)) {
+            constraint->type_ = kNoneDouble;
+          } else {
+            constraint->type_ = kNone;
+          }
+          break;
+        case UnallocatedOperand::FIXED_REGISTER:
+          constraint->type_ = kFixedRegister;
+          constraint->value_ = unallocated->fixed_register_index();
+          break;
+        case UnallocatedOperand::FIXED_DOUBLE_REGISTER:
+          constraint->type_ = kFixedDoubleRegister;
+          constraint->value_ = unallocated->fixed_register_index();
+          break;
+        case UnallocatedOperand::MUST_HAVE_REGISTER:
+          if (sequence()->IsDouble(vreg)) {
+            constraint->type_ = kDoubleRegister;
+          } else {
+            constraint->type_ = kRegister;
+          }
+          break;
+        case UnallocatedOperand::SAME_AS_FIRST_INPUT:
+          constraint->type_ = kSameAsFirst;
+          break;
+      }
+    }
+  }
+}
+
+
+void RegisterAllocatorVerifier::CheckConstraint(
+    const InstructionOperand* op, const OperandConstraint* constraint) {
+  switch (constraint->type_) {
+    case kConstant:
+      CHECK(op->IsConstant());
+      CHECK_EQ(op->index(), constraint->value_);
+      return;
+    case kImmediate:
+      CHECK(op->IsImmediate());
+      CHECK_EQ(op->index(), constraint->value_);
+      return;
+    case kRegister:
+      CHECK(op->IsRegister());
+      return;
+    case kFixedRegister:
+      CHECK(op->IsRegister());
+      CHECK_EQ(op->index(), constraint->value_);
+      return;
+    case kDoubleRegister:
+      CHECK(op->IsDoubleRegister());
+      return;
+    case kFixedDoubleRegister:
+      CHECK(op->IsDoubleRegister());
+      CHECK_EQ(op->index(), constraint->value_);
+      return;
+    case kFixedSlot:
+      CHECK(op->IsStackSlot());
+      CHECK_EQ(op->index(), constraint->value_);
+      return;
+    case kNone:
+      CHECK(op->IsRegister() || op->IsStackSlot());
+      return;
+    case kNoneDouble:
+      CHECK(op->IsDoubleRegister() || op->IsDoubleStackSlot());
+      return;
+    case kSameAsFirst:
+      CHECK(false);
+      return;
+  }
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8