On Wed, Jan 17, 2018 at 5:00 PM, H.J. Lu <hongjiu...@intel.com> wrote:
> We can use const reference of struct ix86_frame to avoid making a local
> copy of ix86_frame. ix86_expand_epilogue makes a local copy of struct
> ix86_frame and uses the reg_save_offset field as a local variable. This
> patch uses a separate local variable for reg_save_offset.
>
> Tested on x86-64 with ada. OK for trunk?
OK.
Thanks,
Uros.
> H.J.
> --
> PR target/83905
> * config/i386/i386.c (ix86_expand_prologue): Use cost reference
> of struct ix86_frame.
> (ix86_expand_epilogue): Likewise. Add a local variable for
> the reg_save_offset field in struct ix86_frame.
> ---
> gcc/config/i386/i386.c | 24 ++++++++++++------------
> 1 file changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index a301e18ed70..340eca42449 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -13385,7 +13385,6 @@ ix86_expand_prologue (void)
> {
> struct machine_function *m = cfun->machine;
> rtx insn, t;
> - struct ix86_frame frame;
> HOST_WIDE_INT allocate;
> bool int_registers_saved;
> bool sse_registers_saved;
> @@ -13413,7 +13412,7 @@ ix86_expand_prologue (void)
> m->fs.sp_valid = true;
> m->fs.sp_realigned = false;
>
> - frame = m->frame;
> + const struct ix86_frame &frame = cfun->machine->frame;
>
> if (!TARGET_64BIT && ix86_function_ms_hook_prologue
> (current_function_decl))
> {
> @@ -14291,7 +14290,6 @@ ix86_expand_epilogue (int style)
> {
> struct machine_function *m = cfun->machine;
> struct machine_frame_state frame_state_save = m->fs;
> - struct ix86_frame frame;
> bool restore_regs_via_mov;
> bool using_drap;
> bool restore_stub_is_tail = false;
> @@ -14304,7 +14302,7 @@ ix86_expand_epilogue (int style)
> }
>
> ix86_finalize_stack_frame_flags ();
> - frame = m->frame;
> + const struct ix86_frame &frame = cfun->machine->frame;
>
> m->fs.sp_realigned = stack_realign_fp;
> m->fs.sp_valid = stack_realign_fp
> @@ -14348,11 +14346,13 @@ ix86_expand_epilogue (int style)
> + UNITS_PER_WORD);
> }
>
> + HOST_WIDE_INT reg_save_offset = frame.reg_save_offset;
> +
> /* Special care must be taken for the normal return case of a function
> using eh_return: the eax and edx registers are marked as saved, but
> not restored along this path. Adjust the save location to match. */
> if (crtl->calls_eh_return && style != 2)
> - frame.reg_save_offset -= 2 * UNITS_PER_WORD;
> + reg_save_offset -= 2 * UNITS_PER_WORD;
>
> /* EH_RETURN requires the use of moves to function properly. */
> if (crtl->calls_eh_return)
> @@ -14368,11 +14368,11 @@ ix86_expand_epilogue (int style)
> else if (TARGET_EPILOGUE_USING_MOVE
> && cfun->machine->use_fast_prologue_epilogue
> && (frame.nregs > 1
> - || m->fs.sp_offset != frame.reg_save_offset))
> + || m->fs.sp_offset != reg_save_offset))
> restore_regs_via_mov = true;
> else if (frame_pointer_needed
> && !frame.nregs
> - && m->fs.sp_offset != frame.reg_save_offset)
> + && m->fs.sp_offset != reg_save_offset)
> restore_regs_via_mov = true;
> else if (frame_pointer_needed
> && TARGET_USE_LEAVE
> @@ -14440,7 +14440,7 @@ ix86_expand_epilogue (int style)
> rtx t;
>
> if (frame.nregs)
> - ix86_emit_restore_regs_using_mov (frame.reg_save_offset, style == 2);
> + ix86_emit_restore_regs_using_mov (reg_save_offset, style == 2);
>
> /* eh_return epilogues need %ecx added to the stack pointer. */
> if (style == 2)
> @@ -14535,19 +14535,19 @@ ix86_expand_epilogue (int style)
> in epilogues. */
> if (!m->fs.sp_valid || m->fs.sp_realigned
> || (TARGET_SEH
> - && (m->fs.sp_offset - frame.reg_save_offset
> + && (m->fs.sp_offset - reg_save_offset
> >= SEH_MAX_FRAME_SIZE)))
> {
> pro_epilogue_adjust_stack (stack_pointer_rtx,
> hard_frame_pointer_rtx,
> GEN_INT (m->fs.fp_offset
> - - frame.reg_save_offset),
> + - reg_save_offset),
> style, false);
> }
> - else if (m->fs.sp_offset != frame.reg_save_offset)
> + else if (m->fs.sp_offset != reg_save_offset)
> {
> pro_epilogue_adjust_stack (stack_pointer_rtx, stack_pointer_rtx,
> GEN_INT (m->fs.sp_offset
> - - frame.reg_save_offset),
> + - reg_save_offset),
> style,
> m->fs.cfa_reg == stack_pointer_rtx);
> }
> --
> 2.14.3
>
>
