Bug 1641708 - Support IsConstructor in CacheIR r=jandem

Differential Revision: https://phabricator.services.mozilla.com/D77382

js/src/jit/CacheIR.cpp

@@ -5195,6 +5195,34 @@ AttachDecision CallIRGenerator::tryAttachIsCallable(HandleFunction callee) {
   return AttachDecision::Attach;
 }
 
+AttachDecision CallIRGenerator::tryAttachIsConstructor(HandleFunction callee) {
+  // Need a single object argument.
+  if (argc_ != 1 || !args_[0].isObject()) {
+    return AttachDecision::NoAction;
+  }
+
+  // Initialize the input operand.
+  Int32OperandId argcId(writer.setInputOperandId(0));
+
+  // Guard callee is the 'IsConstructor' intrinsic native function.
+  emitNativeCalleeGuard(callee);
+
+  // Guard that the argument is an object.
+  ValOperandId argId = writer.loadArgumentFixedSlot(ArgumentKind::Arg0, argc_);
+  ObjOperandId objId = writer.guardToObject(argId);
+
+  // Check if the argument is a constructor and return result.
+  writer.isConstructorResult(objId);
+
+  // This stub does not need to be monitored, because it always
+  // returns a boolean.
+  writer.returnFromIC();
+  cacheIRStubKind_ = BaselineCacheIRStubKind::Regular;
+
+  trackAttached("IsConstructor");
+  return AttachDecision::Attach;
+}
+
 AttachDecision CallIRGenerator::tryAttachStringChar(HandleFunction callee,
                                                     StringChar kind) {
   // Need one argument.
@@ -5635,6 +5663,8 @@ AttachDecision CallIRGenerator::tryAttachInlinableNative(
       return tryAttachIsObject(callee);
     case InlinableNative::IntrinsicIsCallable:
       return tryAttachIsCallable(callee);
+    case InlinableNative::IntrinsicIsConstructor:
+      return tryAttachIsConstructor(callee);
 
     // String natives.
     case InlinableNative::StringCharCodeAt:

js/src/jit/CacheIR.h

@@ -1527,6 +1527,7 @@ class MOZ_RAII CallIRGenerator : public IRGenerator {
   AttachDecision tryAttachToInteger(HandleFunction callee);
   AttachDecision tryAttachIsObject(HandleFunction callee);
   AttachDecision tryAttachIsCallable(HandleFunction callee);
+  AttachDecision tryAttachIsConstructor(HandleFunction callee);
   AttachDecision tryAttachStringChar(HandleFunction callee, StringChar kind);
   AttachDecision tryAttachStringCharCodeAt(HandleFunction callee);
   AttachDecision tryAttachStringCharAt(HandleFunction callee);

js/src/jit/CacheIRCompiler.cpp

@@ -3751,6 +3751,39 @@ bool CacheIRCompiler::emitIsCallableResult(ValOperandId inputId) {
   return true;
 }
 
+bool CacheIRCompiler::emitIsConstructorResult(ObjOperandId objId) {
+  JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
+
+  AutoOutputRegister output(*this);
+  AutoScratchRegisterMaybeOutput scratch(allocator, masm, output);
+
+  Register obj = allocator.useRegister(masm, objId);
+
+  Label isProxy, done;
+  masm.isConstructor(obj, scratch, &isProxy);
+  masm.jump(&done);
+
+  masm.bind(&isProxy);
+  {
+    LiveRegisterSet volatileRegs(GeneralRegisterSet::Volatile(),
+                                 liveVolatileFloatRegs());
+    masm.PushRegsInMask(volatileRegs);
+
+    masm.setupUnalignedABICall(scratch);
+    masm.passABIArg(obj);
+    masm.callWithABI(JS_FUNC_TO_DATA_PTR(void*, ObjectIsConstructor));
+    masm.storeCallBoolResult(scratch);
+
+    LiveRegisterSet ignore;
+    ignore.add(scratch);
+    masm.PopRegsInMaskIgnore(volatileRegs, ignore);
+  }
+
+  masm.bind(&done);
+  EmitStoreResult(masm, scratch, JSVAL_TYPE_BOOLEAN, output);
+  return true;
+}
+
 bool CacheIRCompiler::emitMathAbsInt32Result(Int32OperandId inputId) {
   JitSpew(JitSpew_Codegen, "%s", __FUNCTION__);
 

js/src/jit/CacheIROps.yaml

@@ -685,6 +685,12 @@
   args:
     input: ValId
 
+- name: IsConstructorResult
+  shared: true
+  transpile: false
+  args:
+    obj: ObjId
+
 - name: MathAbsInt32Result
   shared: true
   transpile: true