DBC: Enables unboxed doubles

runtime/vm/intermediate_language_dbc.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_DBC.
 #if defined(TARGET_ARCH_DBC)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/cpu.h"
@@ skipping 16 matching lines @@
 
 DECLARE_FLAG(bool, emit_edge_counters);
 DECLARE_FLAG(int, optimization_counter_threshold);
 
 // List of instructions that are still unimplemented by DBC backend.
 #define FOR_EACH_UNIMPLEMENTED_INSTRUCTION(M)                                  \
   M(LoadCodeUnits)                                                             \
   M(LoadUntagged)                                                              \
   M(AllocateUninitializedContext)                                              \
   M(BinaryInt32Op)                                                             \
-  M(UnaryDoubleOp)                                                             \
-  M(SmiToDouble)                                                               \
   M(Int32ToDouble)                                                             \
-  M(MintToDouble)                                                              \
   M(DoubleToInteger)                                                           \
   M(DoubleToSmi)                                                               \
   M(DoubleToDouble)                                                            \
   M(DoubleToFloat)                                                             \
   M(FloatToDouble)                                                             \
   M(UnboxedConstant)                                                           \
-  M(BinaryDoubleOp)                                                            \
   M(MathUnary)                                                                 \
   M(MathMinMax)                                                                \
-  M(Box)                                                                       \
-  M(Unbox)                                                                     \
   M(BoxInt64)                                                                  \
-  M(BinaryMintOp)                                                              \
-  M(ShiftMintOp)                                                               \
-  M(UnaryMintOp)                                                               \
   M(InvokeMathCFunction)                                                       \
   M(MergedMath)                                                                \
   M(GuardFieldClass)                                                           \
   M(GuardFieldLength)                                                          \
   M(IfThenElse)                                                                \
+  M(ExtractNthOutput)                                                          \
+  M(BinaryUint32Op)                                                            \
+  M(ShiftUint32Op)                                                             \
+  M(UnaryUint32Op)                                                             \
+  M(UnboxedIntConverter)                                                       \
+  M(BoxInteger32)                                                              \
+  M(UnboxInteger32)                                                            \
+
+// List of instructions that are not used by DBC.
+// Things we aren't planning to implement for DBC:
+// - Unboxed SIMD,
+// - Unboxed Mint,
+// - Optimized RegExps,
+// - Precompilation.
+#define FOR_EACH_UNREACHABLE_INSTRUCTION(M)                                    \
+  M(CaseInsensitiveCompareUC16)                                                \
+  M(GrowRegExpStack)                                                           \
+  M(IndirectGoto)                                                              \
+  M(MintToDouble)                                                              \
+  M(BinaryMintOp)                                                              \
+  M(ShiftMintOp)                                                               \
+  M(UnaryMintOp)                                                               \
   M(BinaryFloat32x4Op)                                                         \
   M(Simd32x4Shuffle)                                                           \
   M(Simd32x4ShuffleMix)                                                        \
   M(Simd32x4GetSignMask)                                                       \
   M(Float32x4Constructor)                                                      \
   M(Float32x4Zero)                                                             \
   M(Float32x4Splat)                                                            \
   M(Float32x4Comparison)                                                       \
   M(Float32x4MinMax)                                                           \
   M(Float32x4Scale)                                                            \
@@ skipping 11 matching lines @@
   M(BinaryInt32x4Op)                                                           \
   M(BinaryFloat64x2Op)                                                         \
   M(Float64x2Zero)                                                             \
   M(Float64x2Constructor)                                                      \
   M(Float64x2Splat)                                                            \
   M(Float32x4ToFloat64x2)                                                      \
   M(Float64x2ToFloat32x4)                                                      \
   M(Simd64x2Shuffle)                                                           \
   M(Float64x2ZeroArg)                                                          \
   M(Float64x2OneArg)                                                           \
-  M(ExtractNthOutput)                                                          \
-  M(BinaryUint32Op)                                                            \
-  M(ShiftUint32Op)                                                             \
-  M(UnaryUint32Op)                                                             \
-  M(UnboxedIntConverter)                                                       \
-  M(BoxInteger32)                                                              \
-  M(UnboxInteger32)                                                            \
   M(CheckedSmiOp)                                                              \
 
-// List of instructions that are not used by DBC.
-#define FOR_EACH_UNREACHABLE_INSTRUCTION(M)                                    \
-  M(CaseInsensitiveCompareUC16)                                                \
-  M(GrowRegExpStack)                                                           \
-  M(IndirectGoto)
-
 // Location summaries actually are not used by the unoptimizing DBC compiler
 // because we don't allocate any registers.
 static LocationSummary* CreateLocationSummary(
     Zone* zone,
     intptr_t num_inputs,
     Location output = Location::NoLocation(),
     LocationSummary::ContainsCall contains_call = LocationSummary::kNoCall) {
   const intptr_t kNumTemps = 0;
   LocationSummary* locs = new(zone) LocationSummary(
       zone, num_inputs, kNumTemps, contains_call);
@@ skipping 1097 matching lines @@
     case Token::kNEGATE: {
       __ Neg(locs()->out(0).reg(), locs()->in(0).reg());
       compiler->EmitDeopt(deopt_id(), ICData::kDeoptUnaryOp);
       break;
     }
     case Token::kBIT_NOT:
       __ BitNot(locs()->out(0).reg(), locs()->in(0).reg());
       break;
     default:
       UNREACHABLE();
+      break;
   }
 }
 
 
+EMIT_NATIVE_CODE(Box, 1, Location::RequiresRegister(), LocationSummary::kCall) {
+  ASSERT(from_representation() == kUnboxedDouble);
+  const Register value = locs()->in(0).reg();
+  const Register out = locs()->out(0).reg();
+  const intptr_t kidx = __ AddConstant(compiler->double_class());
+  __ Allocate(kidx);
+  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther,
+                                 Thread::kNoDeoptId,
+                                 token_pos());
+  compiler->RecordSafepoint(locs());
+  // __ Allocate puts the box at the top of the stack.
+  __ BoxDouble(out, value);
+}
+
+
+EMIT_NATIVE_CODE(Unbox, 1, Location::RequiresRegister()) {
+  ASSERT(representation() == kUnboxedDouble);
+  const intptr_t value_cid = value()->Type()->ToCid();
+  const intptr_t box_cid = BoxCid();
+  const Register box = locs()->in(0).reg();
+  const Register result = locs()->out(0).reg();
+  if (value_cid == box_cid) {
+    __ UnboxDouble(result, box);
+  } else if (CanConvertSmi() && (value_cid == kSmiCid)) {
+    __ SmiToDouble(result, box);
+  } else if ((value()->Type()->ToNullableCid() == box_cid) &&
+              value()->Type()->is_nullable()) {
+    __ IfEqNull(box);
+    compiler->EmitDeopt(GetDeoptId(), ICData::kDeoptCheckClass);
+    __ UnboxDouble(result, box);
+  } else {
+    __ CheckedUnboxDouble(result, box);
+    compiler->EmitDeopt(GetDeoptId(), ICData::kDeoptCheckClass);
+  }
+}
+
+
+EMIT_NATIVE_CODE(SmiToDouble, 1, Location::RequiresRegister()) {
+  const Register value = locs()->in(0).reg();
+  const Register result = locs()->out(0).reg();
+  __ SmiToDouble(result, value);
+}
+
+
+EMIT_NATIVE_CODE(BinaryDoubleOp, 2, Location::RequiresRegister()) {
+  const Register left = locs()->in(0).reg();
+  const Register right = locs()->in(1).reg();
+  const Register result = locs()->out(0).reg();
+  switch (op_kind()) {
+    case Token::kADD: __ DAdd(result, left, right); break;
+    case Token::kSUB: __ DSub(result, left, right); break;
+    case Token::kMUL: __ DMul(result, left, right); break;
+    case Token::kDIV: __ DDiv(result, left, right); break;
+    default: UNREACHABLE();
+  }
+}
+
+
+EMIT_NATIVE_CODE(UnaryDoubleOp, 1, Location::RequiresRegister()) {
+  const Register value = locs()->in(0).reg();
+  const Register result = locs()->out(0).reg();
+  __ DNeg(result, value);
+}
+
+
 static Token::Kind FlipCondition(Token::Kind kind) {
   switch (kind) {
     case Token::kEQ: return Token::kNE;
     case Token::kNE: return Token::kEQ;
     case Token::kLT: return Token::kGTE;
     case Token::kGT: return Token::kLTE;
     case Token::kLTE: return Token::kGT;
     case Token::kGTE: return Token::kLT;
     default:
       UNREACHABLE();
       return Token::kNE;
   }
 }
 
 
-static Bytecode::Opcode OpcodeForCondition(Token::Kind kind) {
+static Bytecode::Opcode OpcodeForSmiCondition(Token::Kind kind) {
   switch (kind) {
     case Token::kEQ: return Bytecode::kIfEqStrict;
     case Token::kNE: return Bytecode::kIfNeStrict;
     case Token::kLT: return Bytecode::kIfLt;
     case Token::kGT: return Bytecode::kIfGt;
     case Token::kLTE: return Bytecode::kIfLe;
     case Token::kGTE: return Bytecode::kIfGe;
     default:
       UNREACHABLE();
       return Bytecode::kTrap;
   }
 }
 
 
+static Bytecode::Opcode OpcodeForDoubleCondition(Token::Kind kind) {
+  switch (kind) {
+    case Token::kEQ: return Bytecode::kIfDEq;
+    case Token::kNE: return Bytecode::kIfDNe;
+    case Token::kLT: return Bytecode::kIfDLt;
+    case Token::kGT: return Bytecode::kIfDGt;
+    case Token::kLTE: return Bytecode::kIfDLe;
+    case Token::kGTE: return Bytecode::kIfDGe;
+    default:
+      UNREACHABLE();
+      return Bytecode::kTrap;
+  }
+}
+
+
 static Condition EmitSmiComparisonOp(FlowGraphCompiler* compiler,
                                      LocationSummary* locs,
                                      Token::Kind kind,
                                      BranchLabels labels) {
   const Register left = locs->in(0).reg();
   const Register right = locs->in(1).reg();
   Token::Kind comparison = kind;
   Condition condition = NEXT_IS_TRUE;
   if (labels.fall_through != labels.false_label) {
     // If we aren't falling through to the false label, we can save a Jump
     // instruction in the case that the true case is the fall through by
     // flipping the sense of the test such that the instruction following the
     // test is the Jump to the false label.
     condition = NEXT_IS_FALSE;
     comparison = FlipCondition(kind);
   }
-  __ Emit(Bytecode::Encode(OpcodeForCondition(comparison), left, right));
+  __ Emit(Bytecode::Encode(OpcodeForSmiCondition(comparison), left, right));
   return condition;
 }
 
+
+static Condition EmitDoubleComparisonOp(FlowGraphCompiler* compiler,
+                                        LocationSummary* locs,
+                                        Token::Kind kind,
+                                        BranchLabels labels) {
+  const Register left = locs->in(0).reg();
+  const Register right = locs->in(1).reg();
+  Token::Kind comparison = kind;
+  Condition condition = NEXT_IS_TRUE;
+  if (labels.fall_through != labels.false_label) {
+    // If we aren't falling through to the false label, we can save a Jump
+    // instruction in the case that the true case is the fall through by
+    // flipping the sense of the test such that the instruction following the
+    // test is the Jump to the false label.
+    condition = NEXT_IS_FALSE;
+    comparison = FlipCondition(kind);
+  }
+  __ Emit(Bytecode::Encode(OpcodeForDoubleCondition(comparison), left, right));
+  return condition;
+}
+
 
 Condition EqualityCompareInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
                                                    BranchLabels labels) {
   if (operation_cid() == kSmiCid) {
     return EmitSmiComparisonOp(compiler, locs(), kind(), labels);
   } else {
     ASSERT(operation_cid() == kDoubleCid);
-    Unsupported(compiler);
-    UNREACHABLE();
-    return NEXT_IS_FALSE;
+    return EmitDoubleComparisonOp(compiler, locs(), kind(), labels);
   }
 }
 
 
 EMIT_NATIVE_CODE(EqualityCompare, 2, Location::RequiresRegister()) {
   ASSERT(compiler->is_optimizing());
   ASSERT((kind() == Token::kEQ) || (kind() == Token::kNE));
   Label is_true, is_false;
   // These labels are not used. They are arranged so that EmitComparisonCode
   // emits a test that executes the following instruction when the test
@@ skipping 15 matching lines @@
   EmitBranchOnCondition(compiler, true_condition, labels);
 }
 
 
 Condition RelationalOpInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
                                                 BranchLabels labels) {
   if (operation_cid() == kSmiCid) {
     return EmitSmiComparisonOp(compiler, locs(), kind(), labels);
   } else {
     ASSERT(operation_cid() == kDoubleCid);
-    Unsupported(compiler);
-    UNREACHABLE();
-    return NEXT_IS_FALSE;
+    return EmitDoubleComparisonOp(compiler, locs(), kind(), labels);
   }
 }
 
 
 EMIT_NATIVE_CODE(RelationalOp, 2, Location::RequiresRegister()) {
   ASSERT(compiler->is_optimizing());
   Label is_true, is_false;
   BranchLabels labels = { &is_true, &is_false, &is_false };
   const Register result = locs()->out(0).reg();
   __ LoadConstant(result, Bool::False());
@@ skipping 17 matching lines @@
   __ IfULe(length, index);
   compiler->EmitDeopt(deopt_id(),
                       ICData::kDeoptCheckArrayBound,
                       (generalized_ ? ICData::kGeneralized : 0) |
                       (licm_hoisted_ ? ICData::kHoisted : 0));
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_DBC