Re: [PowerPC 64]r12 is not updated to GEP when control transferred from virtual thunk function .

[Eric Botcazou <ebotcazou@adacore.com>]

> like above the control  from "_ZThn8_N12Intermediate1vEv" (support
> function for this pointer update)  is transferred
> "_ZN12Intermediate1vEv" by b  inst (where its not updating the r12)
> and in the beginning  of   "_ZN12Intermediate1vEv" we are loading the
> toc base from r12 (which is incorrect ) ,we are investigating the
> issue and one way to fix the issue is that make THUNK to update the
> r12 ,the cal like bctrl  or  load the r12 with the function address in
> the _ZN12Intermediate1vEv prologue code .

Is that on VxWorks in kernel mode?  If so, the loader doesn't abide by the 
ELFv2 ABI so the simple way out is to disable asm thunks altogether:

#undef TARGET_ASM_CAN_OUTPUT_MI_THUNK
#define TARGET_ASM_CAN_OUTPUT_MI_THUNK rs6000_can_output_mi_thunk

/* Return true if rs6000_output_mi_thunk would be able to output the
   assembler code for the thunk function specified by the arguments
   it is passed, and false otherwise.  */

static bool
rs6000_can_output_mi_thunk (const_tree, HOST_WIDE_INT, HOST_WIDE_INT,
			    const_tree)
{
  /* The only possible issue is for VxWorks in kernel mode.  */
  if (!TARGET_VXWORKS || TARGET_VXWORKS_RTP)
    return true;

  /* The loader neither creates the glue code sequence that loads r12 nor uses
     the local entry point for the sibcall's target in the ELFv2 ABI.  */
  return DEFAULT_ABI != ABI_ELFv2;
}

-- 
Eric Botcazou