Use constant types to represent the fixed right arg of a MOD.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 900e07ecdf9fa68a32540fc76be401d0b064a343..534f6126b67ba9a415d7c8afc583dee25a114a46 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -8732,11 +8732,9 @@ HValue* HOptimizedGraphBuilder::BuildBinaryOperation(
   Handle<Type> left_type = expr->left()->bounds().lower;
   Handle<Type> right_type = expr->right()->bounds().lower;
   Handle<Type> result_type = expr->bounds().lower;
-  Maybe<int> fixed_right_arg = expr->fixed_right_arg();
 
   HValue* result = HGraphBuilder::BuildBinaryOperation(
-      expr->op(), left, right, left_type, right_type,
-      result_type, fixed_right_arg);
+      expr->op(), left, right, left_type, right_type, result_type);
   // Add a simulate after instructions with observable side effects, and
   // after phis, which are the result of BuildBinaryOperation when we
   // inlined some complex subgraph.
@@ -8755,34 +8753,45 @@ HValue* HGraphBuilder::BuildBinaryOperation(
     HValue* right,
     Handle<Type> left_type,
     Handle<Type> right_type,
-    Handle<Type> result_type,
-    Maybe<int> fixed_right_arg) {
+    Handle<Type> result_type) {
 
   Representation left_rep = Representation::FromType(left_type);
   Representation right_rep = Representation::FromType(right_type);
 
-  bool maybe_string_add = op == Token::ADD &&
-                          (left_type->Maybe(Type::String()) ||
-                           right_type->Maybe(Type::String()));
-
   if (left_type->Is(Type::None())) {
     Add<HDeoptimize>("Insufficient type feedback for LHS of binary operation",
                      Deoptimizer::SOFT);
     // TODO(rossberg): we should be able to get rid of non-continuous
     // defaults.
     left_type = handle(Type::Any(), isolate());
-  } else {
-    if (!maybe_string_add) left = TruncateToNumber(left, &left_type);
-    left_rep = Representation::FromType(left_type);
+  } else if (left_type->IsConstant()) {
+    HConstant* c_left = Add<HConstant>(left_type->AsConstant());
+    IfBuilder if_same(this);
+    if (c_left->HasDoubleValue()) {
+      if_same.If<HCompareNumericAndBranch>(left, c_left, Token::EQ);
+    } else {
+      if_same.If<HCompareObjectEqAndBranch>(left, c_left);
+    }
+    if_same.Then();
+    if_same.ElseDeopt("Unexpected LHS of binary operation");
+    left = c_left;
   }
 
   if (right_type->Is(Type::None())) {
     Add<HDeoptimize>("Insufficient type feedback for RHS of binary operation",
                      Deoptimizer::SOFT);
     right_type = handle(Type::Any(), isolate());
-  } else {
-    if (!maybe_string_add) right = TruncateToNumber(right, &right_type);
-    right_rep = Representation::FromType(right_type);
+  } else if (right_type->IsConstant()) {
+    HConstant* c_right = Add<HConstant>(right_type->AsConstant());
+    IfBuilder if_same(this);
+    if (c_right->HasDoubleValue()) {
+      if_same.If<HCompareNumericAndBranch>(right, c_right, Token::EQ);
+    } else {
+      if_same.If<HCompareObjectEqAndBranch>(right, c_right);
+    }
+    if_same.Then();
+    if_same.ElseDeopt("Unexpected RHS of binary operation");
+    right = c_right;
   }
 
   // Special case for string addition here.
@@ -8825,6 +8834,11 @@ HValue* HGraphBuilder::BuildBinaryOperation(
     return AddUncasted<HStringAdd>(left, right, STRING_ADD_CHECK_NONE);
   }
 
+  left = TruncateToNumber(left, &left_type);
+  left_rep = Representation::FromType(left_type);
+  right = TruncateToNumber(right, &right_type);
+  right_rep = Representation::FromType(right_type);
+
   if (graph()->info()->IsStub()) {
     left = EnforceNumberType(left, left_type);
     right = EnforceNumberType(right, right_type);
@@ -8856,22 +8870,6 @@ HValue* HGraphBuilder::BuildBinaryOperation(
         instr = AddUncasted<HMul>(left, right);
         break;
       case Token::MOD: {
-        if (fixed_right_arg.has_value) {
-          if (right->IsConstant()) {
-            HConstant* c_right = HConstant::cast(right);
-            if (c_right->HasInteger32Value()) {
-              ASSERT_EQ(fixed_right_arg.value, c_right->Integer32Value());
-            }
-          } else {
-            HConstant* fixed_right = Add<HConstant>(
-                static_cast<int>(fixed_right_arg.value));
-            IfBuilder if_same(this);
-            if_same.If<HCompareNumericAndBranch>(right, fixed_right, Token::EQ);
-            if_same.Then();
-            if_same.ElseDeopt("Unexpected RHS of binary operation");
-            right = fixed_right;
-          }
-        }
         instr = AddUncasted<HMod>(left, right);
         break;
       }