Bug 867471 - Part 1: Compile rest parameter in Baseline. (r=djvj)

js/src/ion/BaselineCompiler.cpp

@@ -2434,3 +2434,21 @@ BaselineCompiler::emit_JSOP_ARGUMENTS()
     frame.push(R0);
     return true;
 }
+
+bool
+BaselineCompiler::emit_JSOP_REST()
+{
+    frame.syncStack(0);
+
+    RootedTypeObject type(cx, types::TypeScript::InitObject(cx, script, pc, JSProto_Array));
+    if (!type)
+        return false;
+    masm.movePtr(ImmGCPtr(type), R0.scratchReg());
+
+    ICRest_Fallback::Compiler stubCompiler(cx);
+    if (!emitOpIC(stubCompiler.getStub(&stubSpace_)))
+        return false;
+
+    frame.push(R0);
+    return true;
+}

js/src/ion/BaselineCompiler.h

@@ -152,6 +152,7 @@ namespace ion {
     _(JSOP_EXCEPTION)          \
     _(JSOP_DEBUGGER)           \
     _(JSOP_ARGUMENTS)          \
+    _(JSOP_REST)               \
     _(JSOP_TOID)               \
     _(JSOP_TABLESWITCH)        \
     _(JSOP_ITER)               \

js/src/ion/BaselineIC.cpp

@@ -7995,6 +7995,46 @@ ICTypeOf_Typed::Compiler::generateStubCode(MacroAssembler &masm)
     return true;
 }
 
+//
+// Rest_Fallback
+//
+
+static bool
+DoCreateRestParameter(JSContext *cx, BaselineFrame *frame, ICRest_Fallback *stub,
+                      HandleTypeObject type, MutableHandleValue res)
+{
+    FallbackICSpew(cx, stub, "Rest");
+
+    unsigned numFormals = frame->numFormalArgs() - 1;
+    unsigned numActuals = frame->numActualArgs();
+    unsigned numRest = numActuals > numFormals ? numActuals - numFormals : 0;
+
+    JSObject *obj = NewDenseCopiedArray(cx, numRest, frame->actuals() + numFormals, NULL);
+    if (!obj)
+        return false;
+    obj->setType(type);
+
+    res.setObject(*obj);
+    return true;
+}
+
+typedef bool(*DoCreateRestParameterFn)(JSContext *cx, BaselineFrame *, ICRest_Fallback *,
+                                       HandleTypeObject, MutableHandleValue);
+static const VMFunction DoCreateRestParameterInfo =
+    FunctionInfo<DoCreateRestParameterFn>(DoCreateRestParameter);
+
+bool
+ICRest_Fallback::Compiler::generateStubCode(MacroAssembler &masm)
+{
+    EmitRestoreTailCallReg(masm);
+
+    masm.push(R0.scratchReg()); // type
+    masm.push(BaselineStubReg); // stub
+    masm.pushBaselineFramePtr(BaselineFrameReg, R0.scratchReg()); // frame pointer
+
+    return tailCallVM(DoCreateRestParameterInfo, masm);
+}
+
 ICProfiler_PushFunction::ICProfiler_PushFunction(IonCode *stubCode, const char *str,
                                                  HandleScript script)
   : ICStub(ICStub::Profiler_PushFunction, stubCode),

js/src/ion/BaselineIC.h

@@ -388,7 +388,9 @@ class ICEntry
     _(InstanceOf_Fallback)      \
                                 \
     _(TypeOf_Fallback)          \
-    _(TypeOf_Typed)
+    _(TypeOf_Typed)             \
+                                \
+    _(Rest_Fallback)
 
 #define FORWARD_DECLARE_STUBS(kindName) class IC##kindName;
     IC_STUB_KIND_LIST(FORWARD_DECLARE_STUBS)
@@ -5480,6 +5482,38 @@ class ICTypeOf_Typed : public ICFallbackStub
     };
 };
 
+// Rest
+//      JSOP_REST
+class ICRest_Fallback : public ICFallbackStub
+{
+    friend class ICStubSpace;
+
+    ICRest_Fallback(IonCode *stubCode)
+      : ICFallbackStub(ICStub::Rest_Fallback, stubCode)
+    { }
+
+  public:
+    static inline ICRest_Fallback *New(ICStubSpace *space, IonCode *code) {
+        if (!code)
+            return NULL;
+        return space->allocate<ICRest_Fallback>(code);
+    }
+
+    class Compiler : public ICStubCompiler {
+      protected:
+        bool generateStubCode(MacroAssembler &masm);
+
+      public:
+        Compiler(JSContext *cx)
+          : ICStubCompiler(cx, ICStub::Rest_Fallback)
+        { }
+
+        ICStub *getStub(ICStubSpace *space) {
+            return ICRest_Fallback::New(space, getStubCode());
+        }
+    };
+};
+
 } // namespace ion
 } // namespace js