src/cpu/x86/vm/c1_Runtime1_x86.cpp

rev 7386 : 8068945: Use RBP register as proper frame pointer in JIT compiled code on x86
Summary: Introduce the PreserveFramePointer flag to control if RBP is used as the frame pointer or as a general purpose register.
Reviewed-by: kvn, roland, dlong, enevill, shade

*** 752,769 ****
      break;
    case handle_exception_from_callee_id:
      // WIN64_ONLY: No need to add frame::arg_reg_save_area_bytes to SP
      // since we do a leave anyway.
  
!     // Pop the return address since we are possibly changing SP (restoring from BP).
      __ leave();
      __ pop(rcx);
- 
-     // Restore SP from BP if the exception PC is a method handle call site.
-     NOT_LP64(__ get_thread(thread);)
-     __ cmpl(Address(thread, JavaThread::is_method_handle_return_offset()), 0);
-     __ cmovptr(Assembler::notEqual, rsp, rbp_mh_SP_save);
      __ jmp(rcx);  // jump to exception handler
      break;
    default:  ShouldNotReachHere();
    }
  
--- 752,764 ----
      break;
    case handle_exception_from_callee_id:
      // WIN64_ONLY: No need to add frame::arg_reg_save_area_bytes to SP
      // since we do a leave anyway.
  
!     // Pop the return address.
      __ leave();
      __ pop(rcx);
      __ jmp(rcx);  // jump to exception handler
      break;
    default:  ShouldNotReachHere();
    }
  
*** 830,844 ****
    // get throwing pc (= return address).
    // rdx has been destroyed by the call, so it must be set again
    // the pop is also necessary to simulate the effect of a ret(0)
    __ pop(exception_pc);
  
-   // Restore SP from BP if the exception PC is a method handle call site.
-   NOT_LP64(__ get_thread(thread);)
-   __ cmpl(Address(thread, JavaThread::is_method_handle_return_offset()), 0);
-   __ cmovptr(Assembler::notEqual, rsp, rbp_mh_SP_save);
- 
    // continue at exception handler (return address removed)
    // note: do *not* remove arguments when unwinding the
    //       activation since the caller assumes having
    //       all arguments on the stack when entering the
    //       runtime to determine the exception handler
--- 825,834 ----