On Tue, Apr 17, 2012 at 11:13 AM, Alan Modra <amo...@gmail.com> wrote:
> This continues the prologue and epilogue cleanup. Not many user
> visible changes here, except for:
> - a bugfix to the LR save RTL emitted by rs6000_emit_savres_rtx which
> may affect SPE,
> - a bugfix for SPE code emitted when using a static chain,
> - vector saves will be done using r1 for large frames just over 32k in
> size, and,
> - using r11 as a frame pointer whenever we need to set up r11 for
> out-of-line saves, and merging two pointer reg setup insns.
> The latter is a necessary prerequisite to enabling out-of-line
> save/restore for large frames, as I do in a later patch. Currently
> this will only affect abiv4 -Os when using out-of-line saves.
>
> eg. -m32 -Os -mno-multiple
> int f (double x)
> {
> char a[33];
> __asm __volatile ("#%0" : "=m" (a) : : "fr31", "r27", "r28");
> return (int) x;
> }
> old new
> stwu 1,-96(1) mflr 0
> mflr 0 addi 11,1,-8
> addi 11,1,88 stwu 1,-96(1)
> stw 0,100(1) stw 0,12(11)
> stfd 31,88(1) bl _savegpr_27
> bl _savegpr_27 stfd 31,0(11)
>
>
> * config/rs6000/rs6000.c (rs6000_emit_stack_reset): Delete forward
> decl. Move logic selecting update reg to callers. Update all callers.
> (rs6000_emit_allocate_stack): Add copy_off param.
> (emit_frame_save): Don't handle reg+reg addressing.
> (ptr_regno_for_savres): New function, extracted from..
> (rs6000_emit_savres_rtx): ..here. Add lr_offset param.
> (rs6000_emit_prologue): Generate frame_ptr_rtx as we need it.
> Set frame_reg_rtx to r11 whenever r11 is needed, and merge
> frame offset adjustment for out-of-line save with copy from sp.
> Simplify condition controlling whether cr is saved early or
> late. Use ptr_regno_for_savres to verify correct reg is set
> up for out-of-line saves. Pass the actual pointer reg used to
> rs6000_emit_savres_rtx so rtl matches insns in out-of-line
> function. Rearrange spe vars so code is similar to that
> elsewhere in this function. Don't update frame_off when spe
> save code will restore r11. Use emit_frame_save for spe and
> gpr saves. Consolidate darwin out-of-line gpr setup with that
> for other abis. Don't assume frame_offset is zero and frame
> reg is sp when setting up altivec reg saves, and calculate
> exact offset requirement.
> (rs6000_emit_epilogue): Use HOST_WIDE_INT for frame_off. Tidy
> spe restore code. Consolidate darwin out-of-line gpr setup
> with that for other abis.
This patch is okay.
Thanks, David
