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Date: Wed, 22 Jul 2015 13:59:00 -0000
From: Segher Boessenkool <segher@kernel.crashing.org>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>, Uros Bizjak <ubizjak@gmail.com>
Subject: Re: RFC: [PATCH] Add __builtin_ia32_stack_top
Message-ID: <20150722135516.GF11682@gate.crashing.org>
References: <20150721214539.GA19891@intel.com> <CAMe9rOpdnvRt=M_hDqBE_Oa8bpLRR0QsxTn1fz9OQMq4oaM3wQ@mail.gmail.com>
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On Wed, Jul 22, 2015 at 05:10:04AM -0700, H.J. Lu wrote:
> I got a feedback, suggesting __builtin_stack_top, instead of
> __builtin_ia32_stack_top.  But I don't know if
> 
> +      /* After the prologue, stack top is at -WORD(AP) in the current
> +        frame.  */
> +      emit_insn (gen_rtx_SET (target,
> +                             plus_constant (Pmode, arg_pointer_rtx,
> +                                            -UNITS_PER_WORD)));
> 
> is true for all backends.  If it works on all backends, I can move
> it to builtins.c.

It doesn't afaik.  But can't you define INITIAL_FRAME_ADDRESS_RTX?


Segher