src/cpu/x86/vm/x86.ad

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

*** 910,934 ****
  
  %}
  
  encode %{
  
-   enc_class preserve_SP %{
-     debug_only(int off0 = cbuf.insts_size());
-     MacroAssembler _masm(&cbuf);
-     // RBP is preserved across all calls, even compiled calls.
-     // Use it to preserve RSP in places where the callee might change the SP.
-     __ movptr(rbp_mh_SP_save, rsp);
-     debug_only(int off1 = cbuf.insts_size());
-     assert(off1 - off0 == preserve_SP_size(), "correct size prediction");
-   %}
- 
-   enc_class restore_SP %{
-     MacroAssembler _masm(&cbuf);
-     __ movptr(rsp, rbp_mh_SP_save);
-   %}
- 
    enc_class call_epilog %{
      if (VerifyStackAtCalls) {
        // Check that stack depth is unchanged: find majik cookie on stack
        int framesize = ra_->reg2offset_unchecked(OptoReg::add(ra_->_matcher._old_SP, -3*VMRegImpl::slots_per_word));
        MacroAssembler _masm(&cbuf);
--- 910,919 ----