[PATCH] PR target/70439: Properly check conflict between DRAP register and __builtin_eh_return

[Uros Bizjak]

On Tue, Mar 29, 2016 at 8:56 PM, H.J. Lu <hongjiu.lu@intel.com> wrote:
> Since %ecx can't be used for both DRAP register and __builtin_eh_return,
> we need to check if crtl->drap_reg uses %ecx before using %ecx for
> __builtin_eh_return.
>
> Testing on x86-64.  OK for trunk if there are no regressions?
>
>
> H.J.
> ---
>         PR target/70439
>         * config/i386/i386.c (ix86_expand_epilogue): Properly check
>         conflict between DRAP register and __builtin_eh_return.
> ---
>  gcc/config/i386/i386.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index 1639704..aafe171 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -13463,8 +13463,9 @@ ix86_expand_epilogue (int style)
>           rtx sa = EH_RETURN_STACKADJ_RTX;
>           rtx_insn *insn;
>
> -         /* Stack align doesn't work with eh_return.  */
> -         gcc_assert (!stack_realign_drap);
> +         /* %ecx can't be used for both DRAP register and eh_return.  */
> +         gcc_assert (!crtl->drap_reg
> +                     || REGNO (crtl->drap_reg) != CX_REG);

How about:

        if (crtl->drap_reg)
          gcc_assert (REGNO (crtl->drap_reg) != CX_REG));

?

>           /* Neither does regparm nested functions.  */
>           gcc_assert (!ix86_static_chain_on_stack);

This comment needs to be updated, too.

Uros.