MIPS: Bugfix: array constructors that expect a type feedback cell that points...

MIPS: Bugfix: array constructors that expect a type feedback cell that points to an AllocationSite were being passed the undefined object in some cases. Clearly separate the cases where we have an AllocationSite and where we don't in the general ArrayConstructorStub.

Port r16693 (0852d4ab)

BUG=
R=gergely@homejinni.com

Review URL: https://codereview.chromium.org/23451057

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16698 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/code-stubs-mips.cc

@@ -6968,87 +6968,125 @@ void ProfileEntryHookStub::Generate(MacroAssembler* masm) {
 
 
 template<class T>
-static void CreateArrayDispatch(MacroAssembler* masm) {
-  int last_index = GetSequenceIndexFromFastElementsKind(
-      TERMINAL_FAST_ELEMENTS_KIND);
-  for (int i = 0; i <= last_index; ++i) {
-    Label next;
-    ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
-    __ Branch(&next, ne, a3, Operand(kind));
-    T stub(kind);
+static void CreateArrayDispatch(MacroAssembler* masm,
+                                AllocationSiteOverrideMode mode) {
+  if (mode == DISABLE_ALLOCATION_SITES) {
+    T stub(GetInitialFastElementsKind(),
+           CONTEXT_CHECK_REQUIRED,
+           mode);
     __ TailCallStub(&stub);
-    __ bind(&next);
-  }
+  } else if (mode == DONT_OVERRIDE) {
+    int last_index = GetSequenceIndexFromFastElementsKind(
+        TERMINAL_FAST_ELEMENTS_KIND);
+    for (int i = 0; i <= last_index; ++i) {
+      Label next;
+      ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
+      __ Branch(&next, ne, a3, Operand(kind));
+      T stub(kind);
+      __ TailCallStub(&stub);
+      __ bind(&next);
+    }
 
-  // If we reached this point there is a problem.
-  __ Abort(kUnexpectedElementsKindInArrayConstructor);
+    // If we reached this point there is a problem.
+    __ Abort(kUnexpectedElementsKindInArrayConstructor);
+  } else {
+    UNREACHABLE();
+  }
 }
 
 
-static void CreateArrayDispatchOneArgument(MacroAssembler* masm) {
-  // a2 - type info cell
-  // a3 - kind
+static void CreateArrayDispatchOneArgument(MacroAssembler* masm,
+                                           AllocationSiteOverrideMode mode) {
+  // a2 - type info cell (if mode != DISABLE_ALLOCATION_SITES)
+  // a3 - kind (if mode != DISABLE_ALLOCATION_SITES)
   // a0 - number of arguments
   // a1 - constructor?
   // sp[0] - last argument
-  ASSERT(FAST_SMI_ELEMENTS == 0);
-  ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
-  ASSERT(FAST_ELEMENTS == 2);
-  ASSERT(FAST_HOLEY_ELEMENTS == 3);
-  ASSERT(FAST_DOUBLE_ELEMENTS == 4);
-  ASSERT(FAST_HOLEY_DOUBLE_ELEMENTS == 5);
-
-  // is the low bit set? If so, we are holey and that is good.
   Label normal_sequence;
-  __ And(at, a3, Operand(1));
-  __ Branch(&normal_sequence, ne, at, Operand(zero_reg));
+  if (mode == DONT_OVERRIDE) {
+    ASSERT(FAST_SMI_ELEMENTS == 0);
+    ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
+    ASSERT(FAST_ELEMENTS == 2);
+    ASSERT(FAST_HOLEY_ELEMENTS == 3);
+    ASSERT(FAST_DOUBLE_ELEMENTS == 4);
+    ASSERT(FAST_HOLEY_DOUBLE_ELEMENTS == 5);
+
+    // is the low bit set? If so, we are holey and that is good.
+    __ And(at, a3, Operand(1));
+    __ Branch(&normal_sequence, ne, at, Operand(zero_reg));
+  }
 
   // look at the first argument
   __ lw(t1, MemOperand(sp, 0));
   __ Branch(&normal_sequence, eq, t1, Operand(zero_reg));
 
-  // We are going to create a holey array, but our kind is non-holey.
-  // Fix kind and retry (only if we have an allocation site in the cell).
-  __ Addu(a3, a3, Operand(1));
-  __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
-  __ Branch(&normal_sequence, eq, a2, Operand(at));
-  __ lw(t1, FieldMemOperand(a2, Cell::kValueOffset));
-  __ lw(t1, FieldMemOperand(t1, 0));
-  __ LoadRoot(at, Heap::kAllocationSiteMapRootIndex);
-  __ Branch(&normal_sequence, ne, t1, Operand(at));
+  if (mode == DISABLE_ALLOCATION_SITES) {
+    ElementsKind initial = GetInitialFastElementsKind();
+    ElementsKind holey_initial = GetHoleyElementsKind(initial);
 
-  // Save the resulting elements kind in type info
-  __ SmiTag(a3);
-  __ lw(t1, FieldMemOperand(a2, Cell::kValueOffset));
-  __ sw(a3, FieldMemOperand(t1, AllocationSite::kTransitionInfoOffset));
-  __ SmiUntag(a3);
+    ArraySingleArgumentConstructorStub stub_holey(holey_initial,
+                                                  CONTEXT_CHECK_REQUIRED,
+                                                  DISABLE_ALLOCATION_SITES);
+    __ TailCallStub(&stub_holey);
 
-  __ bind(&normal_sequence);
-  int last_index = GetSequenceIndexFromFastElementsKind(
-      TERMINAL_FAST_ELEMENTS_KIND);
-  for (int i = 0; i <= last_index; ++i) {
-    Label next;
-    ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
-    __ Branch(&next, ne, a3, Operand(kind));
-    ArraySingleArgumentConstructorStub stub(kind);
+    __ bind(&normal_sequence);
+    ArraySingleArgumentConstructorStub stub(initial,
+                                            CONTEXT_CHECK_REQUIRED,
+                                            DISABLE_ALLOCATION_SITES);
     __ TailCallStub(&stub);
-    __ bind(&next);
-  }
+  } else if (mode == DONT_OVERRIDE) {
+    // We are going to create a holey array, but our kind is non-holey.
+    // Fix kind and retry (only if we have an allocation site in the cell).
+    __ Addu(a3, a3, Operand(1));
+    __ lw(t1, FieldMemOperand(a2, Cell::kValueOffset));
+
+    if (FLAG_debug_code) {
+      __ lw(t1, FieldMemOperand(t1, 0));
+      __ LoadRoot(at, Heap::kAllocationSiteMapRootIndex);
+      __ Assert(eq, kExpectedAllocationSiteInCell, t1, Operand(at));
+      __ lw(t1, FieldMemOperand(a2, Cell::kValueOffset));
+    }
 
-  // If we reached this point there is a problem.
-  __ Abort(kUnexpectedElementsKindInArrayConstructor);
+    // Save the resulting elements kind in type info
+    __ SmiTag(a3);
+    __ lw(t1, FieldMemOperand(a2, Cell::kValueOffset));
+    __ sw(a3, FieldMemOperand(t1, AllocationSite::kTransitionInfoOffset));
+    __ SmiUntag(a3);
+
+    __ bind(&normal_sequence);
+    int last_index = GetSequenceIndexFromFastElementsKind(
+        TERMINAL_FAST_ELEMENTS_KIND);
+    for (int i = 0; i <= last_index; ++i) {
+      Label next;
+      ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
+      __ Branch(&next, ne, a3, Operand(kind));
+      ArraySingleArgumentConstructorStub stub(kind);
+      __ TailCallStub(&stub);
+      __ bind(&next);
+    }
+
+    // If we reached this point there is a problem.
+    __ Abort(kUnexpectedElementsKindInArrayConstructor);
+  } else {
+    UNREACHABLE();
+  }
 }
 
 
 template<class T>
 static void ArrayConstructorStubAheadOfTimeHelper(Isolate* isolate) {
+  ElementsKind initial_kind = GetInitialFastElementsKind();
+  ElementsKind initial_holey_kind = GetHoleyElementsKind(initial_kind);
+
   int to_index = GetSequenceIndexFromFastElementsKind(
       TERMINAL_FAST_ELEMENTS_KIND);
   for (int i = 0; i <= to_index; ++i) {
     ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
     T stub(kind);
     stub.GetCode(isolate)->set_is_pregenerated(true);
-    if (AllocationSite::GetMode(kind) != DONT_TRACK_ALLOCATION_SITE) {
+    if (AllocationSite::GetMode(kind) != DONT_TRACK_ALLOCATION_SITE ||
+        (!FLAG_track_allocation_sites &&
+         (kind == initial_kind || kind == initial_holey_kind))) {
       T stub1(kind, CONTEXT_CHECK_REQUIRED, DISABLE_ALLOCATION_SITES);
       stub1.GetCode(isolate)->set_is_pregenerated(true);
     }
@@ -7081,6 +7119,33 @@ void InternalArrayConstructorStubBase::GenerateStubsAheadOfTime(
 }
 
 
+void ArrayConstructorStub::GenerateDispatchToArrayStub(
+    MacroAssembler* masm,
+    AllocationSiteOverrideMode mode) {
+  if (argument_count_ == ANY) {
+    Label not_zero_case, not_one_case;
+    __ And(at, a0, a0);
+    __ Branch(&not_zero_case, ne, at, Operand(zero_reg));
+    CreateArrayDispatch<ArrayNoArgumentConstructorStub>(masm, mode);
+
+    __ bind(&not_zero_case);
+    __ Branch(&not_one_case, gt, a0, Operand(1));
+    CreateArrayDispatchOneArgument(masm, mode);
+
+    __ bind(&not_one_case);
+    CreateArrayDispatch<ArrayNArgumentsConstructorStub>(masm, mode);
+  } else if (argument_count_ == NONE) {
+    CreateArrayDispatch<ArrayNoArgumentConstructorStub>(masm, mode);
+  } else if (argument_count_ == ONE) {
+    CreateArrayDispatchOneArgument(masm, mode);
+  } else if (argument_count_ == MORE_THAN_ONE) {
+    CreateArrayDispatch<ArrayNArgumentsConstructorStub>(masm, mode);
+  } else {
+    UNREACHABLE();
+  }
+}
+
+
 void ArrayConstructorStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- a0 : argc (only if argument_count_ == ANY)
@@ -7114,49 +7179,24 @@ void ArrayConstructorStub::Generate(MacroAssembler* masm) {
     __ bind(&okay_here);
   }
 
-  Label no_info, switch_ready;
+  Label no_info;
   // Get the elements kind and case on that.
   __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
   __ Branch(&no_info, eq, a2, Operand(at));
   __ lw(a3, FieldMemOperand(a2, Cell::kValueOffset));
 
-  // The type cell may have undefined in its value.
-  __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
-  __ Branch(&no_info, eq, a3, Operand(at));
-
-  // The type cell has either an AllocationSite or a JSFunction.
+  // If the type cell is undefined, or contains anything other than an
+  // AllocationSite, call an array constructor that doesn't use AllocationSites.
   __ lw(t0, FieldMemOperand(a3, 0));
   __ LoadRoot(at, Heap::kAllocationSiteMapRootIndex);
   __ Branch(&no_info, ne, t0, Operand(at));
 
   __ lw(a3, FieldMemOperand(a3, AllocationSite::kTransitionInfoOffset));
   __ SmiUntag(a3);
-  __ jmp(&switch_ready);
-  __ bind(&no_info);
-  __ li(a3, Operand(GetInitialFastElementsKind()));
-  __ bind(&switch_ready);
+  GenerateDispatchToArrayStub(masm, DONT_OVERRIDE);
 
-  if (argument_count_ == ANY) {
-    Label not_zero_case, not_one_case;
-    __ And(at, a0, a0);
-    __ Branch(&not_zero_case, ne, at, Operand(zero_reg));
-    CreateArrayDispatch<ArrayNoArgumentConstructorStub>(masm);
-
-    __ bind(&not_zero_case);
-    __ Branch(&not_one_case, gt, a0, Operand(1));
-    CreateArrayDispatchOneArgument(masm);
-
-    __ bind(&not_one_case);
-    CreateArrayDispatch<ArrayNArgumentsConstructorStub>(masm);
-  } else if (argument_count_ == NONE) {
-    CreateArrayDispatch<ArrayNoArgumentConstructorStub>(masm);
-  } else if (argument_count_ == ONE) {
-    CreateArrayDispatchOneArgument(masm);
-  } else if (argument_count_ == MORE_THAN_ONE) {
-    CreateArrayDispatch<ArrayNArgumentsConstructorStub>(masm);
-  } else {
-    UNREACHABLE();
-  }
+  __ bind(&no_info);
+  GenerateDispatchToArrayStub(masm, DISABLE_ALLOCATION_SITES);
 }