A64: Increase the margin for veneer checks.

src/a64/macro-assembler-a64.h

 // Copyright 2013 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 2188 matching lines @@
   // in the label chain) is out of range. In that case the caller is responsible
   // for generating appropriate code.
   // Otherwise it returns false.
   // This function also checks wether veneers need to be emitted.
   bool NeedExtraInstructionsOrRegisterBranch(Label *label,
                                              ImmBranchType branch_type);
 
  private:
   // We generate a veneer for a branch if we reach within this distance of the
   // limit of the range.
-  static const int kVeneerDistanceMargin = 2 * KB;
+  static const int kVeneerDistanceMargin = 4 * KB;
   int unresolved_branches_first_limit() const {
     ASSERT(!unresolved_branches_.empty());
     return unresolved_branches_.begin()->first;
   }
 };
 
 
 // Use this scope when you need a one-to-one mapping bewteen methods and
 // instructions. This scope prevents the MacroAssembler from being called and
 // literal pools from being emitted. It also asserts the number of instructions
@@ skipping 103 matching lines @@
 #error "Unsupported option"
 #define CODE_COVERAGE_STRINGIFY(x) #x
 #define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 #endif  // V8_A64_MACRO_ASSEMBLER_A64_H_