Support inlining and crankshaft optimization of Math.random.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 25f63ea7f56f76ec1b6d3164f679fe8b0056009f..a9967a6f926fd6a9c7d73ab4754a0e9dd5297c34 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -146,6 +146,7 @@ class LChunkBuilder;
   V(Parameter)                                 \
   V(Power)                                     \
   V(PushArgument)                              \
+  V(Random)                                    \
   V(RegExpLiteral)                             \
   V(Return)                                    \
   V(Sar)                                       \
@@ -2998,6 +2999,25 @@ class HPower: public HTemplateInstruction<2> {
 };
 
 
+class HRandom: public HTemplateInstruction<1> {
+ public:
+  explicit HRandom(HValue* global_object) {
+    SetOperandAt(0, global_object);
+    set_representation(Representation::Double());
+  }
+
+  HValue* global_object() { return OperandAt(0); }
+
+  virtual Representation RequiredInputRepresentation(int index) {
+    return index == 0
+        ? Representation::Tagged()
+        : Representation::None();

[Jakob Kummerow, 2012/01/11 08:10:40]

"return Representation::Tagged();" should suffice, as index == 0 is always true.

[Mads Ager (chromium), 2012/01/11 10:24:46]

Done.

+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(Random)
+};
+
+
 class HAdd: public HArithmeticBinaryOperation {
  public:
   HAdd(HValue* context, HValue* left, HValue* right)