MIPS: Use PC realitive instructions on r6.

src/mips/macro-assembler-mips.h

 // 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.
 
 #ifndef V8_MIPS_MACRO_ASSEMBLER_MIPS_H_
 #define V8_MIPS_MACRO_ASSEMBLER_MIPS_H_
 
 #include "src/assembler.h"
 #include "src/globals.h"
 #include "src/mips/assembler-mips.h"
@@ skipping 190 matching lines @@
   }
 
   bool IsNear(Label* L, Condition cond, int rs_reg);
 
   void Branch(Label* L,
               Condition cond,
               Register rs,
               Heap::RootListIndex index,
               BranchDelaySlot bdslot = PROTECT);
 
+  // GetLabelFunction must be lambda '[](size_t index) -> Label*' or a
+  // functor/function with 'Label *func(size_t index)' declaration.
+  template <typename Func>
+  void GenerateSwitchTable(Register index, size_t case_count,
+                           Func GetLabelFunction);
 #undef COND_ARGS
 
   // Emit code to discard a non-negative number of pointer-sized elements
   // from the stack, clobbering only the sp register.
   void Drop(int count,
             Condition cond = cc_always,
             Register reg = no_reg,
             const Operand& op = Operand(no_reg));
 
   // Trivial case of DropAndRet that utilizes the delay slot and only emits
@@ skipping 1518 matching lines @@
   // instruction unchanged.
   void ChangeBranchCondition(Instr current_instr, uint32_t new_opcode);
 
  private:
   byte* address_;  // The address of the code being patched.
   int size_;  // Number of bytes of the expected patch size.
   MacroAssembler masm_;  // Macro assembler used to generate the code.
   FlushICache flush_cache_;  // Whether to flush the I cache after patching.
 };
 
-
+template <typename Func>
+void MacroAssembler::GenerateSwitchTable(Register index, size_t case_count,
+                                         Func GetLabelFunction) {
+  if (kArchVariant >= kMips32r6) {
+    BlockTrampolinePoolFor(case_count + 5);
+    addiupc(at, 5);
+    lsa(at, at, index, kPointerSizeLog2);
+    lw(at, MemOperand(at));
+  } else {
+    Label here;
+    BlockTrampolinePoolFor(case_count + 6);
+    bal(&here);
+    sll(at, index, kPointerSizeLog2);  // Branch delay slot.
+    bind(&here);
+    addu(at, at, ra);
+    lw(at, MemOperand(at, 4 * v8::internal::Assembler::kInstrSize));
+  }
+  jr(at);
+  nop();  // Branch delay slot nop.
+  for (size_t index = 0; index < case_count; ++index) {
+    dd(GetLabelFunction(index));
+  }
+}
 
 #ifdef GENERATED_CODE_COVERAGE
 #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
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_MIPS_MACRO_ASSEMBLER_MIPS_H_