[turbofan] Desugar JSUnaryNot(x) to Select(x, false, true).

src/full-codegen/mips64/full-codegen-mips64.cc

 // Copyright 2012 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_MIPS64
 
 // Note on Mips implementation:
 //
 // The result_register() for mips is the 'v0' register, which is defined
 // by the ABI to contain function return values. However, the first
@@ skipping 655 matching lines @@
 }
 
 
 void FullCodeGenerator::DoTest(Expression* condition,
                                Label* if_true,
                                Label* if_false,
                                Label* fall_through) {
   __ mov(a0, result_register());
   Handle<Code> ic = ToBooleanStub::GetUninitialized(isolate());
   CallIC(ic, condition->test_id());
-  __ mov(at, zero_reg);
-  Split(ne, v0, Operand(at), if_true, if_false, fall_through);
+  __ LoadRoot(at, Heap::kTrueValueRootIndex);
+  Split(eq, result_register(), Operand(at), if_true, if_false, fall_through);
 }
 
 
 void FullCodeGenerator::Split(Condition cc,
                               Register lhs,
                               const Operand&  rhs,
                               Label* if_true,
                               Label* if_false,
                               Label* fall_through) {
   if (if_false == fall_through) {
@@ skipping 1374 matching lines @@
       __ Move(load_receiver, v0);
 
       __ push(load_receiver);                               // save result
       __ LoadRoot(load_name, Heap::kdone_stringRootIndex);  // "done"
       __ li(LoadDescriptor::SlotRegister(),
             Operand(SmiFromSlot(expr->DoneFeedbackSlot())));
       CallLoadIC(NOT_INSIDE_TYPEOF);  // v0=result.done
       __ mov(a0, v0);
       Handle<Code> bool_ic = ToBooleanStub::GetUninitialized(isolate());
       CallIC(bool_ic);
-      __ Branch(&l_try, eq, v0, Operand(zero_reg));
+      __ LoadRoot(at, Heap::kTrueValueRootIndex);
+      __ Branch(&l_try, ne, result_register(), Operand(at));
 
       // result.value
       __ pop(load_receiver);                                 // result
       __ LoadRoot(load_name, Heap::kvalue_stringRootIndex);  // "value"
       __ li(LoadDescriptor::SlotRegister(),
             Operand(SmiFromSlot(expr->ValueFeedbackSlot())));
       CallLoadIC(NOT_INSIDE_TYPEOF);                         // v0=result.value
       context()->DropAndPlug(2, v0);                         // drop iter and g
       break;
     }
@@ skipping 2863 matching lines @@
          reinterpret_cast<uint64_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64