Initial implementation of sparse conditional constant propagation.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index aebbc47d1bf9c7652db59a4dd1f2bcdecf509b1f..3c6906c14abdf2c0f74e1ae5099245c51c726b0f 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -8727,6 +8727,131 @@ int Integer::CompareWith(const Integer& other) const {
 }
 
 
+// Return the most compact presentation of an integer.
+RawInteger* Integer::AsInteger(const Integer& value) {
+  if (value.IsSmi()) return value.raw();
+  if (value.IsMint()) {
+    Mint& mint = Mint::Handle();
+    mint ^= value.raw();
+    if (Smi::IsValid64(mint.value())) {
+      return Smi::New(mint.value());
+    } else {
+      return value.raw();
+    }
+  }
+  ASSERT(value.IsBigint());
+  Bigint& big_value = Bigint::Handle();
+  big_value ^= value.raw();
+  if (BigintOperations::FitsIntoSmi(big_value)) {
+    return BigintOperations::ToSmi(big_value);
+  } else if (BigintOperations::FitsIntoMint(big_value)) {
+    return Mint::New(BigintOperations::ToMint(big_value));
+  } else {
+    return big_value.raw();
+  }
+}
+
+
+RawInteger* Integer::BinaryOp(Token::Kind operation,
+                              const Integer& left,
+                              const Integer& right) {
+  // In 32-bit mode, the result of any operation between two Smis will fit in a
+  // 32-bit signed result, except the product of two Smis, which will be 64-bit.
+  // In 64-bit mode, the result of any operation between two Smis will fit in a
+  // 64-bit signed result, except the product of two Smis (unless the Smis are
+  // 32-bit or less).
+  if (left.IsSmi() && right.IsSmi()) {
+    Smi& left_smi = Smi::Handle();
+    Smi& right_smi = Smi::Handle();
+    left_smi ^= left.raw();
+    right_smi ^= right.raw();
+    const intptr_t left_value = left_smi.Value();
+    const intptr_t right_value = right_smi.Value();
+    switch (operation) {
+      case Token::kADD:
+        return Integer::New(left_value + right_value);
+      case Token::kSUB:
+        return Integer::New(left_value - right_value);
+      case Token::kMUL: {
+        if (Smi::kBits < 32) {
+          // In 32-bit mode, the product of two Smis fits in a 64-bit result.
+          return Integer::New(static_cast<int64_t>(left_value) *
+                              static_cast<int64_t>(right_value));
+        } else {
+          // In 64-bit mode, the product of two 32-bit signed integers fits in a
+          // 64-bit result.
+          ASSERT(sizeof(intptr_t) == sizeof(int64_t));
+          if (Utils::IsInt(32, left_value) && Utils::IsInt(32, right_value)) {
+            return Integer::New(left_value * right_value);
+          }
+        }
+        // Perform a Bigint multiplication below.
+        break;
+      }
+      case Token::kTRUNCDIV:
+        return Integer::New(left_value / right_value);
+      case Token::kMOD: {
+        const intptr_t remainder = left_value % right_value;
+        if (remainder < 0) {
+          if (right_value < 0) {
+            return Integer::New(remainder - right_value);
+          } else {
+            return Integer::New(remainder + right_value);
+          }
+        }
+        return Integer::New(remainder);
+      }
+      default:
+        UNIMPLEMENTED();
+    }
+  }
+  // In 32-bit mode, the result of any operation between two 63-bit signed
+  // integers (or 32-bit for multiplication) will fit in a 64-bit signed result.
+  // In 64-bit mode, 63-bit signed integers are Smis, already processed above.
+  if ((Smi::kBits < 32) && !left.IsBigint() && !right.IsBigint()) {
+    const int64_t left_value = left.AsInt64Value();
+    if (Utils::IsInt(63, left_value)) {
+      const int64_t right_value = right.AsInt64Value();
+      if (Utils::IsInt(63, right_value)) {
+        switch (operation) {
+        case Token::kADD:
+          return Integer::New(left_value + right_value);
+        case Token::kSUB:
+          return Integer::New(left_value - right_value);
+        case Token::kMUL: {
+          if (Utils::IsInt(32, left_value) && Utils::IsInt(32, right_value)) {
+            return Integer::New(left_value * right_value);
+          }
+          // Perform a Bigint multiplication below.
+          break;
+        }
+        case Token::kTRUNCDIV:
+          return Integer::New(left_value / right_value);
+        case Token::kMOD: {
+          const int64_t remainder = left_value % right_value;
+          if (remainder < 0) {
+            if (right_value < 0) {
+              return Integer::New(remainder - right_value);
+            } else {
+              return Integer::New(remainder + right_value);
+            }
+          }
+          return Integer::New(remainder);
+        }
+        default:
+          UNIMPLEMENTED();
+        }
+      }
+    }
+  }
+  const Bigint& left_big = Bigint::Handle(Bigint::AsBigint(left));
+  const Bigint& right_big = Bigint::Handle(Bigint::AsBigint(right));
+  const Bigint& result =
+      Bigint::Handle(Bigint::BinaryOp(operation, left_big, right_big));
+  return Integer::Handle(AsInteger(result)).raw();
+}
+
+
 bool Smi::Equals(const Instance& other) const {
   if (other.IsNull() || !other.IsSmi()) {
     return false;
@@ -9029,6 +9154,48 @@ const char* Double::ToCString() const {
 }
 
 
+// Returns value in form of a RawBigint.
+RawBigint* Bigint::AsBigint(const Integer& value) {
+  ASSERT(!value.IsNull());
+  if (value.IsSmi()) {
+    Smi& smi = Smi::Handle();
+    smi ^= value.raw();
+    return BigintOperations::NewFromSmi(smi);
+  } else if (value.IsMint()) {
+    Mint& mint = Mint::Handle();
+    mint ^= value.raw();
+    return BigintOperations::NewFromInt64(mint.value());
+  } else {
+    ASSERT(value.IsBigint());
+    Bigint& big = Bigint::Handle();
+    big ^= value.raw();
+    ASSERT(!BigintOperations::FitsIntoSmi(big));
+    return big.raw();
+  }
+}
+
+
+RawBigint* Bigint::BinaryOp(Token::Kind operation,
+                            const Bigint& left,
+                            const Bigint& right) {
+  switch (operation) {
+    case Token::kADD:
+      return BigintOperations::Add(left, right);
+    case Token::kSUB:
+      return BigintOperations::Subtract(left, right);
+    case Token::kMUL:
+      return BigintOperations::Multiply(left, right);
+    case Token::kTRUNCDIV:
+      return BigintOperations::Divide(left, right);
+    case Token::kMOD:
+      return BigintOperations::Modulo(left, right);
+    default:
+      UNIMPLEMENTED();
+      return Bigint::null();
+  }
+}
+
+
 bool Bigint::Equals(const Instance& other) const {
   if (this->raw() == other.raw()) {
     // Both handles point to the same raw instance.