Re: [PATCH 6/9] Emit the prologue/epilogue using frame offsets.

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Tue, Aug 3, 2010 at 4:53 PM, Richard Henderson <rth@twiddle.net> wrote:
> Record register save offsets in ix86_frame.
>
> Move SP/FP offsets into the global state; update them everywhere
> we currently handle CFA offsets.
>
> Use that global state to choose base registers and offsets for
> the register saves and restores.
>
> There is a bug fix contained herein, whereby r11 could be clobbered
> along an indirect sibcall path when the stack frame is very large (>2GB).
> The emit_restore_{sse_,}regs_using_mov functions didn't handle this
> case, but pro_epilogue_adjust_stack does.
> ---
> ?gcc/config/i386/i386.c | ?912 ++++++++++++++++++++++++++++--------------------
> ?gcc/config/i386/i386.h | ? 38 ++-
> ?2 files changed, 556 insertions(+), 394 deletions(-)
>
>
> ? ? ? ?* config/i386/i386.h (struct machine_frame_state): Rename from
> ? ? ? ?machine_cfa_state. ?Add members tracking SP and FP regardless
> ? ? ? ?of the current CFA register.
> ? ? ? ?(ix86_cfa_state): Remove.
> ? ? ? ?* config/i386/i386.c (struct ix86_frame): Add reg_save_offset
> ? ? ? ?and sse_reg_save_offset members.
> ? ? ? ?(ix86_compute_frame_layout): Set them.
> ? ? ? ?(gen_push): Increment sp_offset too.
> ? ? ? ?(choose_baseaddr_len, choose_baseaddr): New.
> ? ? ? ?(ix86_emit_save_reg_using_mov): New.
> ? ? ? ?(ix86_emit_save_regs_using_mov): Use it.
> ? ? ? ?(ix86_emit_save_sse_regs_using_mov): Likewise.
> ? ? ? ?(ix86_add_cfa_restore_note): Take cfa_offset not red_offset argument;
> ? ? ? ?compare vs the saved red_zone_offset.
> ? ? ? ?(pro_epilogue_adjust_stack): Adjust sp_offset.
> ? ? ? ?(ix86_adjust_stack_and_probe): Likewise.
> ? ? ? ?(ix86_expand_prologue): Set up, use, and validate the new
> ? ? ? ?frame_state_info members. ?Use gen_frame_mem.
> ? ? ? ?(ix86_emit_restore_regs_using_pop): Remove red_offset parameter.
> ? ? ? ?(ix86_emit_restore_reg_using_pop): Likewise. ?Use and update the
> ? ? ? ?new frame_state_info members.
> ? ? ? ?(ix86_emit_leave): Likewise.
> ? ? ? ?(ix86_emit_restore_regs_using_mov): Likewise. ?Don't check for
> ? ? ? ?out-of-range stack pointer offsets here.
> ? ? ? ?(ix86_emit_restore_sse_regs_using_mov): Likewise.
> ? ? ? ?(ix86_expand_epilogue): Use and validate the new frame_state_info
> ? ? ? ?members. ?Break up and simplify the logic selecting the
> ? ? ? ?restore_regs_via_mov code path. ?Ensure that there will be no
> ? ? ? ?out-of-range stack pointer offsets.

This caused:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45189


H.J.