src/cpu/x86/vm/stubGenerator_x86_32.cpp

rev 4810 : 8016697: PPC64 (part 5): Use stubs to implement safefetch
Summary: Implement Safefetch as stub routines. This reduces compiler and os dependencies.
Reviewed-by: twisti, kvn

*** 2711,2720 ****
--- 2711,2753 ----
      __ jmp(L_exit);
  
      return start;
    }
  
+   // Safefetch stubs.
+   void generate_safefetch(const char* name, int size, address* entry,
+                           address* fault_pc, address* continuation_pc) {
+     // safefetch signatures:
+     //   int      SafeFetch32(int*      adr, int      errValue);
+     //   intptr_t SafeFetchN (intptr_t* adr, intptr_t errValue);
+ 
+     StubCodeMark mark(this, "StubRoutines", name);
+ 
+     // Entry point, pc or function descriptor.
+     *entry = __ pc();
+ 
+     __ movl(rax, Address(rsp, 0x8));
+     __ movl(rcx, Address(rsp, 0x4));
+     // Load *adr into eax, may fault.
+     *fault_pc = __ pc();
+     switch (size) {
+       case 4:
+         // int32_t
+         __ movl(rax, Address(rcx, 0));
+         break;
+       case 8:
+         // int64_t
+         Unimplemented();
+         break;
+       default:
+         ShouldNotReachHere();
+     }
+ 
+     // Return errValue or *adr.
+     *continuation_pc = __ pc();
+     __ ret(0);
+   }
  
   public:
    // Information about frame layout at time of blocking runtime call.
    // Note that we only have to preserve callee-saved registers since
    // the compilers are responsible for supplying a continuation point
*** 2917,2926 ****
--- 2950,2967 ----
        StubRoutines::_aescrypt_encryptBlock = generate_aescrypt_encryptBlock();
        StubRoutines::_aescrypt_decryptBlock = generate_aescrypt_decryptBlock();
        StubRoutines::_cipherBlockChaining_encryptAESCrypt = generate_cipherBlockChaining_encryptAESCrypt();
        StubRoutines::_cipherBlockChaining_decryptAESCrypt = generate_cipherBlockChaining_decryptAESCrypt();
      }
+ 
+     // Safefetch stubs.
+     generate_safefetch("SafeFetch32", sizeof(int), &StubRoutines::_safefetch32_entry,
+                                                    &StubRoutines::_safefetch32_fault_pc,
+                                                    &StubRoutines::_safefetch32_continuation_pc);
+     StubRoutines::_safefetchN_entry           = StubRoutines::_safefetch32_entry;
+     StubRoutines::_safefetchN_fault_pc        = StubRoutines::_safefetch32_fault_pc;
+     StubRoutines::_safefetchN_continuation_pc = StubRoutines::_safefetch32_continuation_pc;
    }
  
  
   public:
    StubGenerator(CodeBuffer* code, bool all) : StubCodeGenerator(code) {