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

@@ -2711,10 +2711,43 @@
     __ 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

@@ -2917,10 +2950,18 @@
       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) {