[stubs] Simplify the ArrayConstructorStub.

src/arm64/code-stubs-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 1993 matching lines @@
   Register function = x1;
   Register feedback_vector = x2;
   Register index = x3;
   Register allocation_site = x4;
   Register scratch = x5;
 
   __ LoadNativeContextSlot(Context::ARRAY_FUNCTION_INDEX, scratch);
   __ Cmp(function, scratch);
   __ B(ne, miss);
 
-  __ Mov(x0, Operand(arg_count()));
-
   // Increment the call count for monomorphic function calls.
   IncrementCallCount(masm, feedback_vector, index);
 
   // Set up arguments for the array constructor stub.
   Register allocation_site_arg = feedback_vector;
   Register new_target_arg = index;
   __ Mov(allocation_site_arg, allocation_site);
   __ Mov(new_target_arg, function);
-  ArrayConstructorStub stub(masm->isolate(), arg_count());
+  __ Mov(x0, Operand(arg_count()));
+  ArrayConstructorStub stub(masm->isolate());
   __ TailCallStub(&stub);
 }
 
 
 void CallICStub::Generate(MacroAssembler* masm) {
   ASM_LOCATION("CallICStub");
 
   // x1 - function
   // x3 - slot id (Smi)
   // x2 - vector
@@ skipping 1853 matching lines @@
     InternalArraySingleArgumentConstructorStub stubh2(isolate, kinds[i]);
     stubh2.GetCode();
   }
 }
 
 
 void ArrayConstructorStub::GenerateDispatchToArrayStub(
     MacroAssembler* masm,
     AllocationSiteOverrideMode mode) {
   Register argc = x0;
-  if (argument_count() == ANY) {
-    Label zero_case, n_case;
-    __ Cbz(argc, &zero_case);
-    __ Cmp(argc, 1);
-    __ B(ne, &n_case);
+  Label zero_case, n_case;
+  __ Cbz(argc, &zero_case);
+  __ Cmp(argc, 1);
+  __ B(ne, &n_case);
 
-    // One argument.
-    CreateArrayDispatchOneArgument(masm, mode);
+  // One argument.
+  CreateArrayDispatchOneArgument(masm, mode);
 
-    __ Bind(&zero_case);
-    // No arguments.
-    CreateArrayDispatch<ArrayNoArgumentConstructorStub>(masm, mode);
+  __ Bind(&zero_case);
+  // No arguments.
+  CreateArrayDispatch<ArrayNoArgumentConstructorStub>(masm, mode);
 
-    __ Bind(&n_case);
-    // N arguments.
-    ArrayNArgumentsConstructorStub stub(masm->isolate());
-    __ TailCallStub(&stub);
-  } else if (argument_count() == NONE) {
-    CreateArrayDispatch<ArrayNoArgumentConstructorStub>(masm, mode);
-  } else if (argument_count() == ONE) {
-    CreateArrayDispatchOneArgument(masm, mode);
-  } else if (argument_count() == MORE_THAN_ONE) {
-    ArrayNArgumentsConstructorStub stub(masm->isolate());
-    __ TailCallStub(&stub);
-  } else {
-    UNREACHABLE();
-  }
+  __ Bind(&n_case);
+  // N arguments.
+  ArrayNArgumentsConstructorStub stub(masm->isolate());
+  __ TailCallStub(&stub);
 }
 
 
 void ArrayConstructorStub::Generate(MacroAssembler* masm) {
   ASM_LOCATION("ArrayConstructorStub::Generate");
   // ----------- S t a t e -------------
   //  -- x0 : argc (only if argument_count() is ANY or MORE_THAN_ONE)
   //  -- x1 : constructor
   //  -- x2 : AllocationSite or undefined
   //  -- x3 : new target
@@ skipping 39 matching lines @@
            UntagSmiFieldMemOperand(allocation_site,
                                    AllocationSite::kTransitionInfoOffset));
   __ And(kind, kind, AllocationSite::ElementsKindBits::kMask);
   GenerateDispatchToArrayStub(masm, DONT_OVERRIDE);
 
   __ Bind(&no_info);
   GenerateDispatchToArrayStub(masm, DISABLE_ALLOCATION_SITES);
 
   // Subclassing support.
   __ Bind(&subclassing);
-  switch (argument_count()) {
-    case ANY:
-    case MORE_THAN_ONE:
-      __ Poke(constructor, Operand(x0, LSL, kPointerSizeLog2));
-      __ Add(x0, x0, Operand(3));
-      break;
-    case NONE:
-      __ Poke(constructor, 0 * kPointerSize);
-      __ Mov(x0, Operand(3));
-      break;
-    case ONE:
-      __ Poke(constructor, 1 * kPointerSize);
-      __ Mov(x0, Operand(4));
-      break;
-  }
+  __ Poke(constructor, Operand(x0, LSL, kPointerSizeLog2));
+  __ Add(x0, x0, Operand(3));
   __ Push(new_target, allocation_site);
   __ JumpToExternalReference(ExternalReference(Runtime::kNewArray, isolate()));
 }
 
 
 void InternalArrayConstructorStub::GenerateCase(
     MacroAssembler* masm, ElementsKind kind) {
   Label zero_case, n_case;
   Register argc = x0;
 
@@ skipping 1235 matching lines @@
                            kStackUnwindSpace, NULL, spill_offset,
                            return_value_operand, NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64