[csa] Introduce CodeAssembler::Branch(condition, true_body, false_body)

Benefit from constant folding, this CL reduce snapshot by 704 bytes
for {Call,Construct}WithArrayLike builtins.

R=tebbi@chromium.org

Change-Id: I34f055c9b46039698150f560644459aa492cde9e
Reviewed-on: https://chromium-review.googlesource.com/1168739
Commit-Queue: Kanghua Yu <kanghua.yu@intel.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55008}

src/builtins/builtins-call-gen.cc

@@ -237,7 +237,6 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructDoubleVarargs(
     TNode<Object> target, SloppyTNode<Object> new_target,
     TNode<FixedDoubleArray> elements, TNode<Int32T> length,
     TNode<Int32T> args_count, TNode<Context> context, TNode<Int32T> kind) {
-  Label if_holey_double(this), if_packed_double(this), if_done(this);
 
   const ElementsKind new_kind = PACKED_ELEMENTS;
   const WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER;
@@ -248,35 +247,25 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructDoubleVarargs(
   TNode<FixedArray> new_elements = AllocateFixedArray(
       new_kind, intptr_length, CodeStubAssembler::kAllowLargeObjectAllocation);
   Branch(Word32Equal(kind, Int32Constant(HOLEY_DOUBLE_ELEMENTS)),
-         &if_holey_double, &if_packed_double);
+         [=] {
+           // Fill the FixedArray with pointers to HeapObjects.
+           CopyFixedArrayElements(HOLEY_DOUBLE_ELEMENTS, elements, new_kind,
+                                  new_elements, intptr_length, intptr_length,
+                                  barrier_mode);
+         },
+         [=] {
+           CopyFixedArrayElements(PACKED_DOUBLE_ELEMENTS, elements, new_kind,
+                                  new_elements, intptr_length, intptr_length,
+                                  barrier_mode);
+         });
 
-  BIND(&if_holey_double);
-  {
-    // Fill the FixedArray with pointers to HeapObjects.
-    CopyFixedArrayElements(HOLEY_DOUBLE_ELEMENTS, elements, new_kind,
-                           new_elements, intptr_length, intptr_length,
-                           barrier_mode);
-    Goto(&if_done);
-  }
-
-  BIND(&if_packed_double);
-  {
-    CopyFixedArrayElements(PACKED_DOUBLE_ELEMENTS, elements, new_kind,
-                           new_elements, intptr_length, intptr_length,
-                           barrier_mode);
-    Goto(&if_done);
-  }
-
-  BIND(&if_done);
-  {
-    if (new_target == nullptr) {
-      Callable callable = CodeFactory::CallVarargs(isolate());
-      TailCallStub(callable, context, target, args_count, new_elements, length);
-    } else {
-      Callable callable = CodeFactory::ConstructVarargs(isolate());
-      TailCallStub(callable, context, target, new_target, args_count,
-                   new_elements, length);
-    }
+  if (new_target == nullptr) {
+    Callable callable = CodeFactory::CallVarargs(isolate());
+    TailCallStub(callable, context, target, args_count, new_elements, length);
+  } else {
+    Callable callable = CodeFactory::ConstructVarargs(isolate());
+    TailCallStub(callable, context, target, new_target, args_count,
+                 new_elements, length);
   }
 }
 

src/compiler/code-assembler.cc

@@ -1384,6 +1384,29 @@ void CodeAssembler::Branch(SloppyTNode<IntegralT> condition, Label* true_label,
                                  false_label->label_);
 }
 
+void CodeAssembler::Branch(TNode<BoolT> condition,
+                           std::function<void()> true_body,
+                           std::function<void()> false_body) {
+  int32_t constant;
+  if (ToInt32Constant(condition, constant)) {
+    return constant ? true_body() : false_body();
+  }
+
+  Label vtrue(this), vfalse(this), end(this);
+  Branch(condition, &vtrue, &vfalse);
+  Bind(&vtrue);
+  {
+    true_body();
+    Goto(&end);
+  }
+  Bind(&vfalse);
+  {
+    false_body();
+    Goto(&end);
+  }
+  Bind(&end);
+}
+
 void CodeAssembler::Switch(Node* index, Label* default_label,
                            const int32_t* case_values, Label** case_labels,
                            size_t case_count) {

src/compiler/code-assembler.h

@@ -773,6 +773,9 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   void Branch(SloppyTNode<IntegralT> condition, Label* true_label,
               Label* false_label);
 
+  void Branch(TNode<BoolT> condition, std::function<void()> true_body,
+              std::function<void()> false_body);
+
   void Switch(Node* index, Label* default_label, const int32_t* case_values,
               Label** case_labels, size_t case_count);