For trigonometric functions call to C-libraries: they are faster than x87 operations (3% on Box2D).

runtime/vm/flow_graph_optimizer.cc

Index: runtime/vm/flow_graph_optimizer.cc
===================================================================
--- runtime/vm/flow_graph_optimizer.cc	(revision 27253)
+++ runtime/vm/flow_graph_optimizer.cc	(working copy)
@@ -1732,8 +1732,8 @@
 
 
 void FlowGraphOptimizer::ReplaceWithMathCFunction(
-  InstanceCallInstr* call,
-  MethodRecognizer::Kind recognized_kind) {
+    InstanceCallInstr* call,
+    MethodRecognizer::Kind recognized_kind) {
   AddReceiverCheck(call);
   ZoneGrowableArray<Value*>* args =
       new ZoneGrowableArray<Value*>(call->ArgumentCount());
@@ -2735,14 +2735,11 @@
   if ((recognized_kind == MethodRecognizer::kMathSqrt) ||
       (recognized_kind == MethodRecognizer::kMathSin) ||
       (recognized_kind == MethodRecognizer::kMathCos)) {
-    if ((recognized_kind == MethodRecognizer::kMathSqrt) ||
-        FlowGraphCompiler::SupportsInlinedTrigonometrics()) {
-      MathUnaryInstr* math_unary =
-          new MathUnaryInstr(recognized_kind,
-                             new Value(call->ArgumentAt(0)),
-                             call->deopt_id());
-      ReplaceCall(call, math_unary);
-    }
+    MathUnaryInstr* math_unary =
+        new MathUnaryInstr(recognized_kind,
+                           new Value(call->ArgumentAt(0)),
+                           call->deopt_id());
+    ReplaceCall(call, math_unary);
   } else if ((recognized_kind == MethodRecognizer::kFloat32x4Zero) ||
              (recognized_kind == MethodRecognizer::kFloat32x4Splat) ||
              (recognized_kind == MethodRecognizer::kFloat32x4Constructor)) {