On Mon, Jan 16, 2017 at 03:50:01PM +1030, Alan Modra wrote:
> > > > Okay for trunk if there is nothing unexpected. Thanks!
> > >
> > > I guess I should at least build glibc.
> >
> > Yes exactly, something big that uses pic -- it is pretty obvious it won't
> > change anything for non-pic.
>
> glibc built fine without elf_high/elf_low with no regressions in its
> testsuite.
I meant comparing the generated code, sorry.
> However, there is a problem in rs6000_emit_allocate_stack
> -fstack-limit-symbol=SYMBOL code. This now might ICE if someone tries
> to use the option with -fpic/PIC. I reckon the option combination to
> be little used, so it shouldn't hurt to disable -fstack-limit-symbol
> for PIC. (We were generating non-PIC for the trap, so we probably
> would have gotten a complaint about text relocs in shared libraries.)
>
> This revised patch has been bootstrapped and regression tested as
> before, and tested with glibc too. OK?
>
> PR target/79066
> * config/rs6000/rs6000.md (elf_high, elf_low): Disable when pic.
> * config/rs6000/rs6000.c (rs6000_emit_allocate_stack): Don't allow
> symbolic stack limit when pic.
> testsuite/
> * gcc.target/powerpc/pr79066.c: New.
>
> diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
> index 11394b2..2dd6bbe 100644
> --- a/gcc/config/rs6000/rs6000.c
> +++ b/gcc/config/rs6000/rs6000.c
> @@ -27668,7 +27668,8 @@ rs6000_emit_allocate_stack (HOST_WIDE_INT size, rtx
> copy_reg, int copy_off)
> }
> else if (GET_CODE (stack_limit_rtx) == SYMBOL_REF
> && TARGET_32BIT
> - && DEFAULT_ABI == ABI_V4)
> + && DEFAULT_ABI == ABI_V4
> + && !flag_pic)
> {
> rtx toload = gen_rtx_CONST (VOIDmode,
> gen_rtx_PLUS (Pmode,
Please at least make it sorry() for ABI_V4 && flag_pic. Or what does it
result in with the patch as-is?
Okay with that change (if needed). Thanks!
Segher
