Bug 1331092 - Part 8: Support JSOP_TOASYNCITER in JIT. r=jandem

js/src/jit/BaselineCompiler.cpp

@@ -3945,6 +3945,28 @@ BaselineCompiler::emit_JSOP_TOASYNCGEN()
     return true;
 }
 
+typedef JSObject* (*ToAsyncIterFn)(JSContext*, HandleObject);
+static const VMFunction ToAsyncIterInfo =
+    FunctionInfo<ToAsyncIterFn>(js::CreateAsyncFromSyncIterator, "ToAsyncIter");
+
+bool
+BaselineCompiler::emit_JSOP_TOASYNCITER()
+{
+    frame.syncStack(0);
+    masm.unboxObject(frame.addressOfStackValue(frame.peek(-1)), R0.scratchReg());
+
+    prepareVMCall();
+    pushArg(R0.scratchReg());
+
+    if (!callVM(ToAsyncIterInfo))
+        return false;
+
+    masm.tagValue(JSVAL_TYPE_OBJECT, ReturnReg, R0);
+    frame.pop();
+    frame.push(R0);
+    return true;
+}
+
 typedef bool (*ThrowObjectCoercibleFn)(JSContext*, HandleValue);
 static const VMFunction ThrowObjectCoercibleInfo =
     FunctionInfo<ThrowObjectCoercibleFn>(ThrowObjectCoercible, "ThrowObjectCoercible");

js/src/jit/BaselineCompiler.h

@@ -198,6 +198,7 @@ namespace jit {
     _(JSOP_REST)               \
     _(JSOP_TOASYNC)            \
     _(JSOP_TOASYNCGEN)         \
+    _(JSOP_TOASYNCITER)        \
     _(JSOP_TOID)               \
     _(JSOP_TOSTRING)           \
     _(JSOP_TABLESWITCH)        \

js/src/jit/CodeGenerator.cpp

@@ -10708,6 +10708,17 @@ CodeGenerator::visitToAsyncGen(LToAsyncGen* lir)
     callVM(ToAsyncGenInfo, lir);
 }
 
+typedef JSObject* (*ToAsyncIterFn)(JSContext*, HandleObject);
+static const VMFunction ToAsyncIterInfo =
+    FunctionInfo<ToAsyncIterFn>(js::CreateAsyncFromSyncIterator, "ToAsyncIter");
+
+void
+CodeGenerator::visitToAsyncIter(LToAsyncIter* lir)
+{
+    pushArg(ToRegister(lir->unwrapped()));
+    callVM(ToAsyncIterInfo, lir);
+}
+
 typedef bool (*ToIdFn)(JSContext*, HandleScript, jsbytecode*, HandleValue,
                        MutableHandleValue);
 static const VMFunction ToIdInfo = FunctionInfo<ToIdFn>(ToIdOperation, "ToIdOperation");

js/src/jit/CodeGenerator.h

@@ -297,6 +297,7 @@ class CodeGenerator final : public CodeGeneratorSpecific
     void visitOutOfLineTypeOfV(OutOfLineTypeOfV* ool);
     void visitToAsync(LToAsync* lir);
     void visitToAsyncGen(LToAsyncGen* lir);
+    void visitToAsyncIter(LToAsyncIter* lir);
     void visitToIdV(LToIdV* lir);
     template<typename T> void emitLoadElementT(LLoadElementT* lir, const T& source);
     void visitLoadElementT(LLoadElementT* lir);

js/src/jit/IonBuilder.cpp

@@ -2215,6 +2215,9 @@ IonBuilder::inspectOpcode(JSOp op)
       case JSOP_TOASYNCGEN:
         return jsop_toasyncgen();
 
+      case JSOP_TOASYNCITER:
+        return jsop_toasynciter();
+
       case JSOP_TOID:
         return jsop_toid();
 
@@ -12274,6 +12277,20 @@ IonBuilder::jsop_toasyncgen()
     return resumeAfter(ins);
 }
 
+AbortReasonOr<Ok>
+IonBuilder::jsop_toasynciter()
+{
+    MDefinition* unwrapped = current->pop();
+    MOZ_ASSERT(unwrapped->type() == MIRType::Object);
+
+    MToAsyncIter* ins = MToAsyncIter::New(alloc(), unwrapped);
+
+    current->add(ins);
+    current->push(ins);
+
+    return resumeAfter(ins);
+}
+
 AbortReasonOr<Ok>
 IonBuilder::jsop_toid()
 {

js/src/jit/IonBuilder.h

@@ -570,6 +570,7 @@ class IonBuilder
     AbortReasonOr<Ok> jsop_typeof();
     AbortReasonOr<Ok> jsop_toasync();
     AbortReasonOr<Ok> jsop_toasyncgen();
+    AbortReasonOr<Ok> jsop_toasynciter();
     AbortReasonOr<Ok> jsop_toid();
     AbortReasonOr<Ok> jsop_iter(uint8_t flags);
     AbortReasonOr<Ok> jsop_itermore();

js/src/jit/Lowering.cpp

@@ -1218,6 +1218,14 @@ LIRGenerator::visitToAsyncGen(MToAsyncGen* ins)
     assignSafepoint(lir, ins);
 }
 
+void
+LIRGenerator::visitToAsyncIter(MToAsyncIter* ins)
+{
+    LToAsyncIter* lir = new(alloc()) LToAsyncIter(useRegisterAtStart(ins->input()));
+    defineReturn(lir, ins);
+    assignSafepoint(lir, ins);
+}
+
 void
 LIRGenerator::visitToId(MToId* ins)
 {

js/src/jit/Lowering.h

@@ -122,6 +122,7 @@ class LIRGenerator : public LIRGeneratorSpecific
     void visitTypeOf(MTypeOf* ins);
     void visitToAsync(MToAsync* ins);
     void visitToAsyncGen(MToAsyncGen* ins);
+    void visitToAsyncIter(MToAsyncIter* ins);
     void visitToId(MToId* ins);
     void visitBitNot(MBitNot* ins);
     void visitBitAnd(MBitAnd* ins);

js/src/jit/MIR.h

@@ -5840,6 +5840,21 @@ class MToAsyncGen
     TRIVIAL_NEW_WRAPPERS
 };
 
+class MToAsyncIter
+  : public MUnaryInstruction,
+    public SingleObjectPolicy::Data
+{
+    explicit MToAsyncIter(MDefinition* unwrapped)
+      : MUnaryInstruction(unwrapped)
+    {
+        setResultType(MIRType::Object);
+    }
+
+  public:
+    INSTRUCTION_HEADER(ToAsyncIter)
+    TRIVIAL_NEW_WRAPPERS
+};
+
 class MToId
   : public MUnaryInstruction,
     public BoxInputsPolicy::Data

js/src/jit/MOpcodes.h

@@ -80,6 +80,7 @@ namespace jit {
     _(TypeOf)                                                               \
     _(ToAsync)                                                              \
     _(ToAsyncGen)                                                           \
+    _(ToAsyncIter)                                                          \
     _(ToId)                                                                 \
     _(BitAnd)                                                               \
     _(BitOr)                                                                \

js/src/jit/shared/LIR-shared.h

@@ -1631,6 +1631,19 @@ class LToAsyncGen : public LCallInstructionHelper<1, 1, 0>
     }
 };
 
+class LToAsyncIter : public LCallInstructionHelper<1, 1, 0>
+{
+  public:
+    LIR_HEADER(ToAsyncIter)
+    explicit LToAsyncIter(const LAllocation& input) {
+        setOperand(0, input);
+    }
+
+    const LAllocation* unwrapped() {
+        return getOperand(0);
+    }
+};
+
 class LToIdV : public LInstructionHelper<BOX_PIECES, BOX_PIECES, 1>
 {
   public:

js/src/jit/shared/LOpcodes-shared.h

@@ -364,6 +364,7 @@
     _(TypeOfV)                      \
     _(ToAsync)                      \
     _(ToAsyncGen)                   \
+    _(ToAsyncIter)                  \
     _(ToIdV)                        \
     _(Floor)                        \
     _(FloorF)                       \