Reorganize code for range analysis and suppress unnecessary debug printing of unknown ranges.

Review URL: http://codereview.chromium.org/6611020

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7060 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-instructions.cc

@@ -120,6 +120,44 @@ void Range::AddConstant(int32_t value) {
 }
 
 
+void Range::Intersect(Range* other) {
+  upper_ = Min(upper_, other->upper_);
+  lower_ = Max(lower_, other->lower_);
+  bool b = CanBeMinusZero() && other->CanBeMinusZero();
+  set_can_be_minus_zero(b);
+}
+
+
+void Range::Union(Range* other) {
+  upper_ = Max(upper_, other->upper_);
+  lower_ = Min(lower_, other->lower_);
+  bool b = CanBeMinusZero() || other->CanBeMinusZero();
+  set_can_be_minus_zero(b);
+}
+
+
+void Range::Sar(int32_t value) {
+  int32_t bits = value & 0x1F;
+  lower_ = lower_ >> bits;
+  upper_ = upper_ >> bits;
+  set_can_be_minus_zero(false);
+}
+
+
+void Range::Shl(int32_t value) {
+  int32_t bits = value & 0x1F;
+  int old_lower = lower_;
+  int old_upper = upper_;
+  lower_ = lower_ << bits;
+  upper_ = upper_ << bits;
+  if (old_lower != lower_ >> bits || old_upper != upper_ >> bits) {
+    upper_ = kMaxInt;
+    lower_ = kMinInt;
+  }
+  set_can_be_minus_zero(false);
+}
+
+
 bool Range::AddAndCheckOverflow(Range* other) {
   bool may_overflow = false;
   lower_ = AddWithoutOverflow(lower_, other->lower(), &may_overflow);
@@ -415,7 +453,9 @@ void HInstruction::PrintTo(StringStream* stream) {
   stream->Add(" ");
   PrintDataTo(stream);
 
-  if (range() != NULL) {
+  if (range() != NULL &&
+      !range()->IsMostGeneric() &&
+      !range()->CanBeMinusZero()) {
     stream->Add(" range[%d,%d,m0=%d]",
                 range()->lower(),
                 range()->upper(),
@@ -739,6 +779,8 @@ Range* HValue::InferRange() {
   } else if (representation().IsNone()) {
     return NULL;
   } else {
+    // Untagged integer32 cannot be -0 and we don't compute ranges for
+    // untagged doubles.
     return new Range();
   }
 }
@@ -750,7 +792,7 @@ Range* HConstant::InferRange() {
     result->set_can_be_minus_zero(false);
     return result;
   }
-  return HInstruction::InferRange();
+  return HValue::InferRange();
 }
 
 
@@ -784,7 +826,7 @@ Range* HAdd::InferRange() {
     res->set_can_be_minus_zero(m0);
     return res;
   } else {
-    return HArithmeticBinaryOperation::InferRange();
+    return HValue::InferRange();
   }
 }
 
@@ -800,7 +842,7 @@ Range* HSub::InferRange() {
     res->set_can_be_minus_zero(a->CanBeMinusZero() && b->CanBeZero());
     return res;
   } else {
-    return HArithmeticBinaryOperation::InferRange();
+    return HValue::InferRange();
   }
 }
 
@@ -818,7 +860,7 @@ Range* HMul::InferRange() {
     res->set_can_be_minus_zero(m0);
     return res;
   } else {
-    return HArithmeticBinaryOperation::InferRange();
+    return HValue::InferRange();
   }
 }
 
@@ -843,7 +885,7 @@ Range* HDiv::InferRange() {
     }
     return result;
   } else {
-    return HArithmeticBinaryOperation::InferRange();
+    return HValue::InferRange();
   }
 }
 
@@ -860,7 +902,7 @@ Range* HMod::InferRange() {
     }
     return result;
   } else {
-    return HArithmeticBinaryOperation::InferRange();
+    return HValue::InferRange();
   }
 }
 
@@ -1021,34 +1063,30 @@ void HBinaryOperation::PrintDataTo(StringStream* stream) {
 
 
 Range* HBitAnd::InferRange() {
-  Range* a = left()->range();
-  Range* b = right()->range();
-  int32_t a_mask = 0xffffffff;
-  int32_t b_mask = 0xffffffff;
-  if (a != NULL) a_mask = a->Mask();
-  if (b != NULL) b_mask = b->Mask();
-  int32_t result_mask = a_mask & b_mask;
-  if (result_mask >= 0) {
-    return new Range(0, result_mask);
-  } else {
-    return HBinaryOperation::InferRange();
-  }
+  int32_t left_mask = (left()->range() != NULL)
+      ? left()->range()->Mask()
+      : 0xffffffff;
+  int32_t right_mask = (right()->range() != NULL)
+      ? right()->range()->Mask()
+      : 0xffffffff;
+  int32_t result_mask = left_mask & right_mask;
+  return (result_mask >= 0)
+      ? new Range(0, result_mask)
+      : HValue::InferRange();
 }
 
 
 Range* HBitOr::InferRange() {
-  Range* a = left()->range();
-  Range* b = right()->range();
-  int32_t a_mask = 0xffffffff;
-  int32_t b_mask = 0xffffffff;
-  if (a != NULL) a_mask = a->Mask();
-  if (b != NULL) b_mask = b->Mask();
-  int32_t result_mask = a_mask | b_mask;
-  if (result_mask >= 0) {
-    return new Range(0, result_mask);
-  } else {
-    return HBinaryOperation::InferRange();
-  }
+  int32_t left_mask = (left()->range() != NULL)
+      ? left()->range()->Mask()
+      : 0xffffffff;
+  int32_t right_mask = (right()->range() != NULL)
+      ? right()->range()->Mask()
+      : 0xffffffff;
+  int32_t result_mask = left_mask | right_mask;
+  return (result_mask >= 0)
+      ? new Range(0, result_mask)
+      : HValue::InferRange();
 }
 
 
@@ -1056,20 +1094,14 @@ Range* HSar::InferRange() {
   if (right()->IsConstant()) {
     HConstant* c = HConstant::cast(right());
     if (c->HasInteger32Value()) {
-      int32_t val = c->Integer32Value();
-      Range* result = NULL;
-      Range* left_range = left()->range();
-      if (left_range == NULL) {
-        result = new Range();
-      } else {
-        result = left_range->Copy();
-      }
-      result->Sar(val);
+      Range* result = (left()->range() != NULL)
+          ? left()->range()->Copy()
+          : new Range();
+      result->Sar(c->Integer32Value());
       return result;
     }
   }
-
-  return HBinaryOperation::InferRange();
+  return HValue::InferRange();
 }
 
 
@@ -1077,20 +1109,14 @@ Range* HShl::InferRange() {
   if (right()->IsConstant()) {
     HConstant* c = HConstant::cast(right());
     if (c->HasInteger32Value()) {
-      int32_t val = c->Integer32Value();
-      Range* result = NULL;
-      Range* left_range = left()->range();
-      if (left_range == NULL) {
-        result = new Range();
-      } else {
-        result = left_range->Copy();
-      }
-      result->Shl(val);
+      Range* result = (left()->range() != NULL)
+          ? left()->range()->Copy()
+          : new Range();
+      result->Shl(c->Integer32Value());
       return result;
     }
   }
-
-  return HBinaryOperation::InferRange();
+  return HValue::InferRange();
 }
 
 

src/hydrogen-instructions.h

@@ -190,81 +190,48 @@ class LChunkBuilder;
 
 class Range: public ZoneObject {
  public:
-  Range() : lower_(kMinInt),
-            upper_(kMaxInt),
-            next_(NULL),
-            can_be_minus_zero_(false) { }
+  Range()
+      : lower_(kMinInt),
+        upper_(kMaxInt),
+        next_(NULL),
+        can_be_minus_zero_(false) { }
 
   Range(int32_t lower, int32_t upper)
-      : lower_(lower), upper_(upper), next_(NULL), can_be_minus_zero_(false) { }
+      : lower_(lower),
+        upper_(upper),
+        next_(NULL),
+        can_be_minus_zero_(false) { }
 
-  bool IsInSmiRange() const {
-    return lower_ >= Smi::kMinValue && upper_ <= Smi::kMaxValue;
-  }
-  void KeepOrder();
-  void Verify() const;
   int32_t upper() const { return upper_; }
   int32_t lower() const { return lower_; }
   Range* next() const { return next_; }
   Range* CopyClearLower() const { return new Range(kMinInt, upper_); }
   Range* CopyClearUpper() const { return new Range(lower_, kMaxInt); }
-  void ClearLower() { lower_ = kMinInt; }
-  void ClearUpper() { upper_ = kMaxInt; }
   Range* Copy() const { return new Range(lower_, upper_); }
-  bool IsMostGeneric() const { return lower_ == kMinInt && upper_ == kMaxInt; }
   int32_t Mask() const;
   void set_can_be_minus_zero(bool b) { can_be_minus_zero_ = b; }
   bool CanBeMinusZero() const { return CanBeZero() && can_be_minus_zero_; }
   bool CanBeZero() const { return upper_ >= 0 && lower_ <= 0; }
   bool CanBeNegative() const { return lower_ < 0; }
-  bool Includes(int value) const {
-    return lower_ <= value && upper_ >= value;
-  }
-
-  void Sar(int32_t value) {
-    int32_t bits = value & 0x1F;
-    lower_ = lower_ >> bits;
-    upper_ = upper_ >> bits;
-    set_can_be_minus_zero(false);
-  }
-
-  void Shl(int32_t value) {
-    int32_t bits = value & 0x1F;
-    int old_lower = lower_;
-    int old_upper = upper_;
-    lower_ = lower_ << bits;
-    upper_ = upper_ << bits;
-    if (old_lower != lower_ >> bits || old_upper != upper_ >> bits) {
-      upper_ = kMaxInt;
-      lower_ = kMinInt;
-    }
-    set_can_be_minus_zero(false);
+  bool Includes(int value) const { return lower_ <= value && upper_ >= value; }
+  bool IsMostGeneric() const { return lower_ == kMinInt && upper_ == kMaxInt; }
+  bool IsInSmiRange() const {
+    return lower_ >= Smi::kMinValue && upper_ <= Smi::kMaxValue;
   }
-
-  // Adds a constant to the lower and upper bound of the range.
-  void AddConstant(int32_t value);
+  void KeepOrder();
+  void Verify() const;
 
   void StackUpon(Range* other) {
     Intersect(other);
     next_ = other;
   }
 
-  void Intersect(Range* other) {
-    upper_ = Min(upper_, other->upper_);
-    lower_ = Max(lower_, other->lower_);
-    bool b = CanBeMinusZero() && other->CanBeMinusZero();
-    set_can_be_minus_zero(b);
-  }
-
-  void Union(Range* other) {
-    upper_ = Max(upper_, other->upper_);
-    lower_ = Min(lower_, other->lower_);
-    bool b = CanBeMinusZero() || other->CanBeMinusZero();
-    set_can_be_minus_zero(b);
-  }
+  void Intersect(Range* other);
+  void Union(Range* other);
 
-  // Compute a new result range and return true, if the operation
-  // can overflow.
+  void AddConstant(int32_t value);
+  void Sar(int32_t value);
+  void Shl(int32_t value);
   bool AddAndCheckOverflow(Range* other);
   bool SubAndCheckOverflow(Range* other);
   bool MulAndCheckOverflow(Range* other);

src/hydrogen.cc

@@ -867,8 +867,8 @@ void HRangeAnalysis::InferControlFlowRange(HTest* test, HBasicBlock* dest) {
 void HRangeAnalysis::InferControlFlowRange(Token::Value op,
                                            HValue* value,
                                            HValue* other) {
-  Range* range = other->range();
-  if (range == NULL) range = new Range();
+  Range temp_range;
+  Range* range = other->range() != NULL ? other->range() : &temp_range;
   Range* new_range = NULL;
 
   TraceRange("Control flow range infer %d %s %d\n",