Hi Segher,
> On 17 Oct 2016, at 09:13, Segher Boessenkool <seg...@kernel.crashing.org>
> wrote:
>
> We cannot use {SAVE,REST}_MULTIPLE and separate shrink-wrapping together,
> not without checking when actually emitting the prologue/epilogue that the
> registers to save/restore are actually still one contiguous block up to
> (and including) 31. So either:
>
> 1) We delay the decision of whether to use lmw/stmw to later;
> 2) We disallow shrink-wrapping separate (integer) components when those
> strategies are selected; or
> 3) We don't use those strategies if we use separate shrink-wrapping.
>
> This patch does 3). In the long term it may be best to do 1) instead,
> it can be slightly more efficient.
>
> This caused problems on darwin (it is the only config that uses lmw/stmw
> instructions by default).
>
> Bootstrapped and tested on powerpc64-linux {-m64,-m32}. I'll commit it
> if Iain's testing (on darwin) also succeeds.
thanks!
All-langs bootstrap was restored with the patch (and others in progress for
existing known issues);
I can’t see any evidence of the assert firing in the test-suite, so it all
looks good to me (there’s quite a bit of stage-1-ish testsuite noise at
present, however).
cheers
Iain
>
>
> 2016-10-17 Segher Boessenkool <seg...@kernel.crashing.org>
>
> * config/rs6000/rs6000.c: Add include of shrink-wrap.h .
> (rs6000_savres_strategy): Do not select {SAVE,REST}_MULTIPLE if
> shrink-wrapping separate components.
> (rs6000_get_separate_components): Assert we do not have those
> strategies selected.
>
> ---
> gcc/config/rs6000/rs6000.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
> index df48980..83a7139 100644
> --- a/gcc/config/rs6000/rs6000.c
> +++ b/gcc/config/rs6000/rs6000.c
> @@ -64,6 +64,7 @@
> #include "target-globals.h"
> #include "builtins.h"
> #include "context.h"
> +#include "shrink-wrap.h"
> #include "tree-pass.h"
> #if TARGET_XCOFF
> #include "xcoffout.h" /* get declarations of xcoff_*_section_name */
> @@ -25506,7 +25507,10 @@ rs6000_savres_strategy (rs6000_stack_t *info,
> if (TARGET_MULTIPLE
> && !TARGET_POWERPC64
> && !(TARGET_SPE_ABI && info->spe_64bit_regs_used)
> - && info->first_gp_reg_save < 31)
> + && info->first_gp_reg_save < 31
> + && !(SHRINK_WRAPPING_ENABLED
> + && flag_shrink_wrap_separate
> + && optimize_function_for_speed_p (cfun)))
> {
> /* Prefer store multiple for saves over out-of-line routines,
> since the store-multiple instruction will always be smaller. */
> @@ -27440,6 +27444,9 @@ rs6000_get_separate_components (void)
> sbitmap components = sbitmap_alloc (32);
> bitmap_clear (components);
>
> + gcc_assert (!(info->savres_strategy & SAVE_MULTIPLE)
> + && !(info->savres_strategy & REST_MULTIPLE));
> +
> /* The GPRs we need saved to the frame. */
> if ((info->savres_strategy & SAVE_INLINE_GPRS)
> && (info->savres_strategy & REST_INLINE_GPRS))
> --
> 1.9.3
>
