Ping^1 [PATCH] Add attribute hot judgement for INLINE_HINT_known_hot hint.

["Cui, Lili" <lili.cui@intel.com>]

Hi Honza,

Gentle ping  https://gcc.gnu.org/pipermail/gcc-patches/2022-September/601934.html

Thanks,
Lili.

> -----Original Message-----
> From: Gcc-patches <gcc-patches-bounces+lili.cui=intel.com@gcc.gnu.org> On
> Behalf Of Cui, Lili via Gcc-patches
> Sent: Wednesday, September 21, 2022 5:22 PM
> To: Jan Hubicka <hubicka@ucw.cz>
> Cc: Lu, Hongjiu <hongjiu.lu@intel.com>; Liu, Hongtao
> <hongtao.liu@intel.com>; gcc-patches@gcc.gnu.org
> Subject: RE: [PATCH] Add attribute hot judgement for
> INLINE_HINT_known_hot hint.
> 
> > Thank you.  Can you please also add a testcase that tests for this.
> > So you modify imagemagick marking attribute hot on the specific inline?
> 
> Thanks Honza. Added the testcase. I didn't modify source code of
> 538.imagic_r, the original source code has attribute like:
> 
> #define magick_hot_spot  __attribute__((__hot__)) static Cache
> *SetPixelCacheNexusPixels( ... ) magick_hot_spot;
> 
> > I will try to also look again at your earlier patch - I had very busy
> > summer and unfortunately lost track on this one.
> >
> NP, I guessed you were busy during that time, my earlier patch was partially
> duplicated with function "Elimination_by_inlining_prob", except "parameter
> points to caller local memory" part, maybe we can find a suitable place to
> add local memory part  to the IPA.
> 
> > Honza
> 
> gcc/ChangeLog
> 
>   * ipa-inline-analysis.cc (do_estimate_edge_time): Add function attribute
>   judgement for INLINE_HINT_known_hot hint.
> 
> gcc/testsuite/ChangeLog:
> 
>   * gcc.dg/ipa/inlinehint-6.c: New test.
> ---
>  gcc/ipa-inline-analysis.cc              | 13 ++++---
>  gcc/testsuite/gcc.dg/ipa/inlinehint-6.c | 47 +++++++++++++++++++++++++
>  2 files changed, 56 insertions(+), 4 deletions(-)  create mode 100644
> gcc/testsuite/gcc.dg/ipa/inlinehint-6.c
> 
> diff --git a/gcc/ipa-inline-analysis.cc b/gcc/ipa-inline-analysis.cc index
> 1ca685d1b0e..7bd29c36590 100644
> --- a/gcc/ipa-inline-analysis.cc
> +++ b/gcc/ipa-inline-analysis.cc
> @@ -48,6 +48,7 @@ along with GCC; see the file COPYING3.  If not see
> #include "ipa-utils.h"
>  #include "cfgexpand.h"
>  #include "gimplify.h"
> +#include "attribs.h"
> 
>  /* Cached node/edge growths.  */
>  fast_call_summary<edge_growth_cache_entry *, va_heap>
> *edge_growth_cache = NULL; @@ -249,15 +250,19 @@
> do_estimate_edge_time (struct cgraph_edge *edge, sreal *ret_nonspec_time)
>        hints = estimates.hints;
>      }
> 
> -  /* When we have profile feedback, we can quite safely identify hot
> -     edges and for those we disable size limits.  Don't do that when
> -     probability that caller will call the callee is low however, since it
> +  /* When we have profile feedback or function attribute, we can quite
> safely
> +     identify hot edges and for those we disable size limits.  Don't do that
> +     when probability that caller will call the callee is low however,
> + since it
>       may hurt optimization of the caller's hot path.  */
> -  if (edge->count.ipa ().initialized_p () && edge->maybe_hot_p ()
> +  if ((edge->count.ipa ().initialized_p () && edge->maybe_hot_p ()
>        && (edge->count.ipa () * 2
>  	  > (edge->caller->inlined_to
>  	     ? edge->caller->inlined_to->count.ipa ()
>  	     : edge->caller->count.ipa ())))
> +      || (lookup_attribute ("hot", DECL_ATTRIBUTES (edge->caller->decl))
> +	  != NULL
> +	 && lookup_attribute ("hot", DECL_ATTRIBUTES (edge->callee->decl))
> +	  != NULL))
>      hints |= INLINE_HINT_known_hot;
> 
>    gcc_checking_assert (size >= 0);
> diff --git a/gcc/testsuite/gcc.dg/ipa/inlinehint-6.c
> b/gcc/testsuite/gcc.dg/ipa/inlinehint-6.c
> new file mode 100644
> index 00000000000..1f3be641c6d
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/ipa/inlinehint-6.c
> @@ -0,0 +1,47 @@
> +/* { dg-options "-O3 -c -fdump-ipa-inline-details -fno-early-inlining
> +-fno-ipa-cp"  } */
> +/* { dg-add-options bind_pic_locally } */
> +
> +#define size_t long long int
> +
> +struct A
> +{
> +  size_t f1, f2, f3, f4;
> +};
> +struct C
> +{
> +  struct A a;
> +  size_t b;
> +};
> +struct C x;
> +
> +__attribute__((hot)) struct C callee (struct A *a, struct C *c) {
> +  c->a=(*a);
> +
> +  if((c->b + 7) & 17)
> +   {
> +      c->a.f1 = c->a.f2 + c->a.f1;
> +      c->a.f2 = c->a.f3 - c->a.f2;
> +      c->a.f3 = c->a.f2 + c->a.f3;
> +      c->a.f4 = c->a.f2 - c->a.f4;
> +      c->b = c->a.f2;
> +
> +    }
> +  return *c;
> +}
> +
> +__attribute__((hot)) struct C caller (size_t d, size_t e, size_t f,
> +size_t g, struct C *c) {
> +  struct A a;
> +  a.f1 = 1 + d;
> +  a.f2 = e;
> +  a.f3 = 12 + f;
> +  a.f4 = 68 + g;
> +  if (c->b > 0)
> +    return callee (&a, c);
> +  else
> +    return *c;
> +}
> +
> +/* { dg-final { scan-ipa-dump "known_hot"  "inline"  } } */
> +
> --
> 2.17.1
> 
> Thanks,
> Lili.