MIPS: Avoid unnecessary branches in array constructor stubs.

src/mips/code-stubs-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5665 matching lines @@
                                 AllocationSiteOverrideMode mode) {
   if (mode == DISABLE_ALLOCATION_SITES) {
     T stub(GetInitialFastElementsKind(),
            CONTEXT_CHECK_REQUIRED,
            mode);
     __ TailCallStub(&stub);
   } 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);
+      __ TailCallStub(&stub, eq, a3, Operand(kind));
     }
 
     // If we reached this point there is a problem.
     __ Abort(kUnexpectedElementsKindInArrayConstructor);
   } else {
     UNREACHABLE();
   }
 }
 
 
@@ skipping 55 matching lines @@
     STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
     __ lw(t0, FieldMemOperand(t1, AllocationSite::kTransitionInfoOffset));
     __ Addu(t0, t0, Operand(Smi::FromInt(kFastElementsKindPackedToHoley)));
     __ sw(t0, FieldMemOperand(t1, AllocationSite::kTransitionInfoOffset));
 
 
     __ 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);
+      __ TailCallStub(&stub, eq, a3, Operand(kind));
     }
 
     // If we reached this point there is a problem.
     __ Abort(kUnexpectedElementsKindInArrayConstructor);
   } else {
     UNREACHABLE();
   }
 }
 
 
@@ skipping 121 matching lines @@
   __ And(a3, a3, Operand(AllocationSite::ElementsKindBits::kMask));
   GenerateDispatchToArrayStub(masm, DONT_OVERRIDE);
 
   __ bind(&no_info);
   GenerateDispatchToArrayStub(masm, DISABLE_ALLOCATION_SITES);
 }
 
 
 void InternalArrayConstructorStub::GenerateCase(
     MacroAssembler* masm, ElementsKind kind) {
-  Label not_zero_case, not_one_case;
-  Label normal_sequence;
 
-  __ Branch(&not_zero_case, ne, a0, Operand(zero_reg));
   InternalArrayNoArgumentConstructorStub stub0(kind);
-  __ TailCallStub(&stub0);
+  __ TailCallStub(&stub0, lo, a0, Operand(1));
 
-  __ bind(&not_zero_case);
-  __ Branch(&not_one_case, gt, a0, Operand(1));
+  InternalArrayNArgumentsConstructorStub stubN(kind);
+  __ TailCallStub(&stubN, hi, a0, Operand(1));
 
   if (IsFastPackedElementsKind(kind)) {
     // We might need to create a holey array
     // look at the first argument.
     __ lw(at, MemOperand(sp, 0));
-    __ Branch(&normal_sequence, eq, at, Operand(zero_reg));
 
     InternalArraySingleArgumentConstructorStub
         stub1_holey(GetHoleyElementsKind(kind));
-    __ TailCallStub(&stub1_holey);
+    __ TailCallStub(&stub1_holey, ne, at, Operand(zero_reg));
   }
 
-  __ bind(&normal_sequence);
   InternalArraySingleArgumentConstructorStub stub1(kind);
   __ TailCallStub(&stub1);
-
-  __ bind(&not_one_case);
-  InternalArrayNArgumentsConstructorStub stubN(kind);
-  __ TailCallStub(&stubN);
 }
 
 
 void InternalArrayConstructorStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- a0 : argc
   //  -- a1 : constructor
   //  -- sp[0] : return address
   //  -- sp[4] : last argument
   // -----------------------------------
@@ skipping 38 matching lines @@
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS