Support for multiple register values

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
diff --git a/runtime/vm/intermediate_language.h b/runtime/vm/intermediate_language.h
index 1177d698a6d5b0920465e0619d3c4d5ac1380e4e..bd31a6812ada468ce5e8ebdcbf8dbe75cc727992 100644
--- a/runtime/vm/intermediate_language.h
+++ b/runtime/vm/intermediate_language.h
@@ -779,6 +779,8 @@ class EmbeddedArray<T, 0> {
   M(Simd64x2Shuffle)                                                           \
   M(Float64x2ZeroArg)                                                          \
   M(Float64x2OneArg)                                                           \
+  M(MergedMath2)                                                               \
+  M(ExtractNthOutput)                                                          \
 
 
 #define FORWARD_DECLARATION(type) class type##Instr;
@@ -1099,6 +1101,7 @@ FOR_EACH_INSTRUCTION(INSTRUCTION_TYPE_CHECK)
   friend class FloatToDoubleInstr;
   friend class InvokeMathCFunctionInstr;
   friend class MergedMathInstr;
+  friend class MergedMath2Instr;
   friend class FlowGraphOptimizer;
   friend class LoadIndexedInstr;
   friend class StoreIndexedInstr;
@@ -1765,6 +1768,11 @@ class Definition : public Instruction {
   bool HasSSATemp() const { return ssa_temp_index_ >= 0; }
   void ClearSSATempIndex() { ssa_temp_index_ = -1; }
 
+  // Definitions which output register pairs need a second SSA index.
+  virtual bool RequiresPairSSAIndex() const { return false; }
+  virtual intptr_t pair_ssa_index() const { return -1; }
+  virtual void set_pair_ssa_index(intptr_t idx) { UNIMPLEMENTED(); }
+
   bool is_used() const { return (use_kind_ != kEffect); }
   void set_use_kind(UseKind kind) { use_kind_ = kind; }
 
@@ -7286,6 +7294,165 @@ class InvokeMathCFunctionInstr : public Definition {
 };
 
 
+class ExtractNthOutputInstr : public TemplateDefinition<1> {
+ public:
+  // Extract the Nth output register from value.
+  ExtractNthOutputInstr(Value* value, intptr_t n, Representation rep)
+      : index_(n),
+        rep_(rep) {
+    SetInputAt(0, value);
+  }
+
+  Value* value() const { return inputs_[0]; }
+
+  DECLARE_INSTRUCTION(ExtractNthOutput)
+
+  virtual CompileType ComputeType() const;
+  virtual void PrintOperandsTo(BufferFormatter* f) const;
+  virtual bool CanDeoptimize() const { return false; }
+
+  intptr_t index() const { return index_; }
+
+  virtual Representation representation() const {
+    return rep_;
+  }
+
+  virtual Representation RequiredInputRepresentation(intptr_t idx) const {
+    ASSERT(idx == 0);
+    if (representation() == kTagged) {
+      return kPairOfTagged;
+    } else if (representation() == kUnboxedDouble) {
+      return kPairOfUnboxedDouble;
+    }
+    UNREACHABLE();
+    return rep_;
+  }
+
+  virtual bool AllowsCSE() const { return true; }
+  virtual EffectSet Effects() const { return EffectSet::None(); }
+  virtual EffectSet Dependencies() const { return EffectSet::None(); }
+  virtual bool AttributesEqual(Instruction* other) const {
+    ExtractNthOutputInstr* other_extract = other->AsExtractNthOutput();
+    return (other_extract->representation() == representation()) &&
+           (other_extract->index() == index());
+  }
+
+  virtual bool MayThrow() const { return false; }
+
+ private:
+  const intptr_t index_;
+  const Representation rep_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtractNthOutputInstr);
+};
+
+
+class MergedMath2Instr : public Definition {
+ public:
+  enum Kind {
+    kTruncDivMod,
+    kSinCos,
+  };
+
+  MergedMath2Instr(ZoneGrowableArray<Value*>* inputs,
+                   intptr_t original_deopt_id,
+                   MergedMath2Instr::Kind kind);
+
+  static intptr_t InputCountFor(MergedMath2Instr::Kind kind) {
+    if (kind == kTruncDivMod) {
+      return 2;
+    } else if (kind == kSinCos) {
+      return 1;
+    } else {
+      UNIMPLEMENTED();
+      return -1;
+    }
+  }
+
+  virtual bool RequiresPairSSAIndex() const { return true; }
+  virtual intptr_t pair_ssa_index() const { return pair_ssa_index_; }
+  virtual void set_pair_ssa_index(intptr_t idx) { pair_ssa_index_ = idx; }
+
+  MergedMath2Instr::Kind kind() const { return kind_; }
+
+  virtual intptr_t InputCount() const { return inputs_->length(); }
+
+  virtual Value* InputAt(intptr_t i) const {
+    return (*inputs_)[i];
+  }
+
+  static intptr_t OutputIndexOf(intptr_t kind);
+  static intptr_t OutputIndexOf(Token::Kind token);
+
+  virtual CompileType ComputeType() const;
+  virtual void PrintOperandsTo(BufferFormatter* f) const;
+
+  virtual bool CanDeoptimize() const {
+    if (kind_ == kTruncDivMod) {
+      return true;
+    } else if (kind_ == kSinCos) {
+      return false;
+    } else {
+      UNIMPLEMENTED();
+      return false;
+    }
+  }
+
+  virtual Representation representation() const {
+    if (kind_ == kTruncDivMod) {
+      return kPairOfTagged;
+    } else if (kind_ == kSinCos) {
+      return kPairOfUnboxedDouble;
+    } else {
+      UNIMPLEMENTED();
+      return kTagged;
+    }
+  }
+
+  virtual Representation RequiredInputRepresentation(intptr_t idx) const {
+    ASSERT((0 <= idx) && (idx < InputCount()));
+    if (kind_ == kTruncDivMod) {
+      return kTagged;
+    } else if (kind_ == kSinCos) {
+      return kUnboxedDouble;
+    } else {
+      UNIMPLEMENTED();
+      return kTagged;
+    }
+  }
+
+  virtual intptr_t DeoptimizationTarget() const { return deopt_id_; }
+
+  DECLARE_INSTRUCTION(MergedMath2)
+
+  virtual bool AllowsCSE() const { return true; }
+  virtual EffectSet Effects() const { return EffectSet::None(); }
+  virtual EffectSet Dependencies() const { return EffectSet::None(); }
+  virtual bool AttributesEqual(Instruction* other) const {
+    MergedMath2Instr* other_invoke = other->AsMergedMath2();
+    return other_invoke->kind() == kind();
+  }
+
+  virtual bool MayThrow() const { return false; }
+
+  static const char* KindToCString(MergedMath2Instr::Kind kind) {
+    if (kind == kTruncDivMod) return "TruncDivMod";
+    if (kind == kSinCos) return "SinCos";
+    UNIMPLEMENTED();
+    return "";
+  }
+
+ private:
+  virtual void RawSetInputAt(intptr_t i, Value* value) {
+    (*inputs_)[i] = value;
+  }
+  intptr_t pair_ssa_index_;
+  ZoneGrowableArray<Value*>* inputs_;
+  MergedMath2Instr::Kind kind_;
+  DISALLOW_COPY_AND_ASSIGN(MergedMath2Instr);
+};
+
+
 class MergedMathInstr : public Definition {
  public:
   enum Kind {