commit 9e3d3cf765ba3f761b2507950039bcdd2dd3ece8
author Martin Kustermann <kustermann@google.com> Thu Nov 15 15:37:58 2018 +0000
committer Martin Kustermann <kustermann@google.com> Thu Nov 15 15:37:58 2018 +0000
tree 771bbedefe8e86e9d373f735ea042e40cdffbd72
parent 6914a86177d5478d77b9c8a69bd73c0bb5f3fcf3

[VM] Use strict compare instruction only if receiver is nullable int

Since in Dart 1 == 1.0 is true.

Change-Id: I05faebb31c6c725095a54020a9665cf40cc55a4b
Reviewed-on: https://dart-review.googlesource.com/c/84531
Reviewed-by: Martin Kustermann <kustermann@google.com>

runtime/vm/compiler/aot/aot_call_specializer.cc

diff --git a/runtime/vm/compiler/aot/aot_call_specializer.cc b/runtime/vm/compiler/aot/aot_call_specializer.cc
index d905077..571be51 100644
--- a/runtime/vm/compiler/aot/aot_call_specializer.cc
+++ b/runtime/vm/compiler/aot/aot_call_specializer.cc
@@ -432,16 +432,18 @@
     CompileType* right_type = right_value->Type();
 
     const bool is_equality_op = Token::IsEqualityOperator(op_kind);
-    const bool receiver_is_nullable_numeric = left_type->IsNullableNumeric();
-    const bool can_use_strict_compare =
-        is_equality_op && receiver_is_nullable_numeric &&
-        (left_type->IsNullableSmi() || right_type->IsNullableSmi());
     const bool has_nullable_int_args =
         left_type->IsNullableInt() && right_type->IsNullableInt();
 
+    // NOTE: We cannot use strict comparisons if the receiver has an overridden
+    // == operator or if either side can be a double, since 1.0 == 1.
+    const bool can_use_strict_compare =
+        is_equality_op && has_nullable_int_args &&
+        (left_type->IsNullableSmi() || right_type->IsNullableSmi());
+
     // We only support binary operations if both operands are nullable integers
     // or when we can use a cheap strict comparison operation.
-    if (!has_nullable_int_args && !can_use_strict_compare) {
+    if (!has_nullable_int_args) {
       return false;
     }
 

runtime/vm/compiler/backend/il.h

diff --git a/runtime/vm/compiler/backend/il.h b/runtime/vm/compiler/backend/il.h
index 32415aa..dff225c 100644
--- a/runtime/vm/compiler/backend/il.h
+++ b/runtime/vm/compiler/backend/il.h
@@ -226,18 +226,6 @@
     return false;
   }
 
-  // Returns true if value of this type is either Smi, Mint, Double or null.
-  bool IsNullableNumeric() {
-    if (cid_ == kSmiCid || cid_ == kMintCid || cid_ == kDoubleCid) {
-      return true;
-    }
-    if (cid_ == kIllegalCid || cid_ == kDynamicCid) {
-      return type_ != NULL && (type_->IsIntType() || type_->IsDoubleType() ||
-                               type_->IsNumberType());
-    }
-    return false;
-  }
-
   void PrintTo(BufferFormatter* f) const;
   const char* ToCString() const;