[PATCH] i386: Sync tune_string with arch_string for target attribute arch=*

[PATCH] i386: Sync tune_string with arch_string for target attribute arch=*

[Hongyu Wang]

Hi,

For function with target attribute arch=*, current logic will set its
tune to -mtune from command line so all target_clones will get same
tuning flags which would affect the performance for each clone. Override
tune with arch if tune was not explicitly specified to get proper tuning
flags for target_clones.

Bootstrapped/regtested on x86_64-pc-linux-gnu{-m32,}

Ok for trunk and backport to active release branches?

gcc/ChangeLog:

	* config/i386/i386-options.cc (ix86_valid_target_attribute_tree):
	Override tune_string with arch_string if tune_string is not
	explicitly specified.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/mvc17.c: New test.
---
 gcc/config/i386/i386-options.cc       |  6 +++++-
 gcc/testsuite/gcc.target/i386/mvc17.c | 11 +++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/mvc17.c

diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc
index 2cb0bddcd35..7f593cebe76 100644
--- a/gcc/config/i386/i386-options.cc
+++ b/gcc/config/i386/i386-options.cc
@@ -1400,7 +1400,11 @@ ix86_valid_target_attribute_tree (tree fndecl, tree args,
       if (option_strings[IX86_FUNCTION_SPECIFIC_TUNE])
 	opts->x_ix86_tune_string
 	  = ggc_strdup (option_strings[IX86_FUNCTION_SPECIFIC_TUNE]);
-      else if (orig_tune_defaulted)
+      /* If we have explicit arch string and no tune string specified, set
+	 tune_string to NULL and later it will be overriden by arch_string
+	 so target clones can get proper optimization.  */
+      else if (option_strings[IX86_FUNCTION_SPECIFIC_ARCH]
+	       || orig_tune_defaulted)
 	opts->x_ix86_tune_string = NULL;
 
       /* If fpmath= is not set, and we now have sse2 on 32-bit, use it.  */
diff --git a/gcc/testsuite/gcc.target/i386/mvc17.c b/gcc/testsuite/gcc.target/i386/mvc17.c
new file mode 100644
index 00000000000..2c7cc2fdace
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/mvc17.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-require-ifunc "" } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler-times "rep mov" 1 } } */
+
+__attribute__((target_clones("default","arch=icelake-server")))
+void
+foo (char *a, char *b, int size)
+{
+  __builtin_memcpy (a, b, size & 0x7F);
+}
-- 
2.31.1

Re: [PATCH] i386: Sync tune_string with arch_string for target attribute arch=*

[Uros Bizjak]

On Mon, Jun 26, 2023 at 4:31 AM Hongyu Wang <hongyu.wang@intel.com> wrote:
>
> Hi,
>
> For function with target attribute arch=*, current logic will set its
> tune to -mtune from command line so all target_clones will get same
> tuning flags which would affect the performance for each clone. Override
> tune with arch if tune was not explicitly specified to get proper tuning
> flags for target_clones.
>
> Bootstrapped/regtested on x86_64-pc-linux-gnu{-m32,}
>
> Ok for trunk and backport to active release branches?
>
> gcc/ChangeLog:
>
>         * config/i386/i386-options.cc (ix86_valid_target_attribute_tree):
>         Override tune_string with arch_string if tune_string is not
>         explicitly specified.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.target/i386/mvc17.c: New test.

LGTM.

Thanks,
Uros.

> ---
>  gcc/config/i386/i386-options.cc       |  6 +++++-
>  gcc/testsuite/gcc.target/i386/mvc17.c | 11 +++++++++++
>  2 files changed, 16 insertions(+), 1 deletion(-)
>  create mode 100644 gcc/testsuite/gcc.target/i386/mvc17.c
>
> diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc
> index 2cb0bddcd35..7f593cebe76 100644
> --- a/gcc/config/i386/i386-options.cc
> +++ b/gcc/config/i386/i386-options.cc
> @@ -1400,7 +1400,11 @@ ix86_valid_target_attribute_tree (tree fndecl, tree args,
>        if (option_strings[IX86_FUNCTION_SPECIFIC_TUNE])
>         opts->x_ix86_tune_string
>           = ggc_strdup (option_strings[IX86_FUNCTION_SPECIFIC_TUNE]);
> -      else if (orig_tune_defaulted)
> +      /* If we have explicit arch string and no tune string specified, set
> +        tune_string to NULL and later it will be overriden by arch_string
> +        so target clones can get proper optimization.  */
> +      else if (option_strings[IX86_FUNCTION_SPECIFIC_ARCH]
> +              || orig_tune_defaulted)
>         opts->x_ix86_tune_string = NULL;
>
>        /* If fpmath= is not set, and we now have sse2 on 32-bit, use it.  */
> diff --git a/gcc/testsuite/gcc.target/i386/mvc17.c b/gcc/testsuite/gcc.target/i386/mvc17.c
> new file mode 100644
> index 00000000000..2c7cc2fdace
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/mvc17.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile } */
> +/* { dg-require-ifunc "" } */
> +/* { dg-options "-O2" } */
> +/* { dg-final { scan-assembler-times "rep mov" 1 } } */
> +
> +__attribute__((target_clones("default","arch=icelake-server")))
> +void
> +foo (char *a, char *b, int size)
> +{
> +  __builtin_memcpy (a, b, size & 0x7F);
> +}
> --
> 2.31.1
>

Re: [PATCH] i386: Sync tune_string with arch_string for target attribute arch=*

[Hongyu Wang]

Thanks, I'll backport it down to GCC10 after this passed all bootstrap/regtest.

Uros Bizjak via Gcc-patches <gcc-patches@gcc.gnu.org> 于2023年6月26日周一 14:05写道：
>
> On Mon, Jun 26, 2023 at 4:31 AM Hongyu Wang <hongyu.wang@intel.com> wrote:
> >
> > Hi,
> >
> > For function with target attribute arch=*, current logic will set its
> > tune to -mtune from command line so all target_clones will get same
> > tuning flags which would affect the performance for each clone. Override
> > tune with arch if tune was not explicitly specified to get proper tuning
> > flags for target_clones.
> >
> > Bootstrapped/regtested on x86_64-pc-linux-gnu{-m32,}
> >
> > Ok for trunk and backport to active release branches?
> >
> > gcc/ChangeLog:
> >
> >         * config/i386/i386-options.cc (ix86_valid_target_attribute_tree):
> >         Override tune_string with arch_string if tune_string is not
> >         explicitly specified.
> >
> > gcc/testsuite/ChangeLog:
> >
> >         * gcc.target/i386/mvc17.c: New test.
>
> LGTM.
>
> Thanks,
> Uros.
>
> > ---
> >  gcc/config/i386/i386-options.cc       |  6 +++++-
> >  gcc/testsuite/gcc.target/i386/mvc17.c | 11 +++++++++++
> >  2 files changed, 16 insertions(+), 1 deletion(-)
> >  create mode 100644 gcc/testsuite/gcc.target/i386/mvc17.c
> >
> > diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc
> > index 2cb0bddcd35..7f593cebe76 100644
> > --- a/gcc/config/i386/i386-options.cc
> > +++ b/gcc/config/i386/i386-options.cc
> > @@ -1400,7 +1400,11 @@ ix86_valid_target_attribute_tree (tree fndecl, tree args,
> >        if (option_strings[IX86_FUNCTION_SPECIFIC_TUNE])
> >         opts->x_ix86_tune_string
> >           = ggc_strdup (option_strings[IX86_FUNCTION_SPECIFIC_TUNE]);
> > -      else if (orig_tune_defaulted)
> > +      /* If we have explicit arch string and no tune string specified, set
> > +        tune_string to NULL and later it will be overriden by arch_string
> > +        so target clones can get proper optimization.  */
> > +      else if (option_strings[IX86_FUNCTION_SPECIFIC_ARCH]
> > +              || orig_tune_defaulted)
> >         opts->x_ix86_tune_string = NULL;
> >
> >        /* If fpmath= is not set, and we now have sse2 on 32-bit, use it.  */
> > diff --git a/gcc/testsuite/gcc.target/i386/mvc17.c b/gcc/testsuite/gcc.target/i386/mvc17.c
> > new file mode 100644
> > index 00000000000..2c7cc2fdace
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/mvc17.c
> > @@ -0,0 +1,11 @@
> > +/* { dg-do compile } */
> > +/* { dg-require-ifunc "" } */
> > +/* { dg-options "-O2" } */
> > +/* { dg-final { scan-assembler-times "rep mov" 1 } } */
> > +
> > +__attribute__((target_clones("default","arch=icelake-server")))
> > +void
> > +foo (char *a, char *b, int size)
> > +{
> > +  __builtin_memcpy (a, b, size & 0x7F);
> > +}
> > --
> > 2.31.1
> >

Re: [PATCH] i386: Sync tune_string with arch_string for target attribute arch=*

[Hongyu Wang]

The testcase fails with --with-arch=native build on cascadelake, here
is the patch to adjust it

gcc/testsuite/ChangeLog:

* gcc.target/i386/mvc17.c: Add -march=x86-64 to dg-options.
---
 gcc/testsuite/gcc.target/i386/mvc17.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/testsuite/gcc.target/i386/mvc17.c
b/gcc/testsuite/gcc.target/i386/mvc17.c
index 2c7cc2fdace..8b83c1aecb3 100644
--- a/gcc/testsuite/gcc.target/i386/mvc17.c
+++ b/gcc/testsuite/gcc.target/i386/mvc17.c
@@ -1,6 +1,6 @@
 /* { dg-do compile } */
 /* { dg-require-ifunc "" } */
-/* { dg-options "-O2" } */
+/* { dg-options "-O2 -march=x86-64" } */
 /* { dg-final { scan-assembler-times "rep mov" 1 } } */

 __attribute__((target_clones("default","arch=icelake-server")))
---

Will push it as an obvious fix, also will apply to the pending backports.

Hongyu Wang <wwwhhhyyy333@gmail.com> 于2023年6月27日周二 13:43写道：
>
> Thanks, I'll backport it down to GCC10 after this passed all bootstrap/regtest.
>
> Uros Bizjak via Gcc-patches <gcc-patches@gcc.gnu.org> 于2023年6月26日周一 14:05写道：
> >
> > On Mon, Jun 26, 2023 at 4:31 AM Hongyu Wang <hongyu.wang@intel.com> wrote:
> > >
> > > Hi,
> > >
> > > For function with target attribute arch=*, current logic will set its
> > > tune to -mtune from command line so all target_clones will get same
> > > tuning flags which would affect the performance for each clone. Override
> > > tune with arch if tune was not explicitly specified to get proper tuning
> > > flags for target_clones.
> > >
> > > Bootstrapped/regtested on x86_64-pc-linux-gnu{-m32,}
> > >
> > > Ok for trunk and backport to active release branches?
> > >
> > > gcc/ChangeLog:
> > >
> > >         * config/i386/i386-options.cc (ix86_valid_target_attribute_tree):
> > >         Override tune_string with arch_string if tune_string is not
> > >         explicitly specified.
> > >
> > > gcc/testsuite/ChangeLog:
> > >
> > >         * gcc.target/i386/mvc17.c: New test.
> >
> > LGTM.
> >
> > Thanks,
> > Uros.
> >
> > > ---
> > >  gcc/config/i386/i386-options.cc       |  6 +++++-
> > >  gcc/testsuite/gcc.target/i386/mvc17.c | 11 +++++++++++
> > >  2 files changed, 16 insertions(+), 1 deletion(-)
> > >  create mode 100644 gcc/testsuite/gcc.target/i386/mvc17.c
> > >
> > > diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc
> > > index 2cb0bddcd35..7f593cebe76 100644
> > > --- a/gcc/config/i386/i386-options.cc
> > > +++ b/gcc/config/i386/i386-options.cc
> > > @@ -1400,7 +1400,11 @@ ix86_valid_target_attribute_tree (tree fndecl, tree args,
> > >        if (option_strings[IX86_FUNCTION_SPECIFIC_TUNE])
> > >         opts->x_ix86_tune_string
> > >           = ggc_strdup (option_strings[IX86_FUNCTION_SPECIFIC_TUNE]);
> > > -      else if (orig_tune_defaulted)
> > > +      /* If we have explicit arch string and no tune string specified, set
> > > +        tune_string to NULL and later it will be overriden by arch_string
> > > +        so target clones can get proper optimization.  */
> > > +      else if (option_strings[IX86_FUNCTION_SPECIFIC_ARCH]
> > > +              || orig_tune_defaulted)
> > >         opts->x_ix86_tune_string = NULL;
> > >
> > >        /* If fpmath= is not set, and we now have sse2 on 32-bit, use it.  */
> > > diff --git a/gcc/testsuite/gcc.target/i386/mvc17.c b/gcc/testsuite/gcc.target/i386/mvc17.c
> > > new file mode 100644
> > > index 00000000000..2c7cc2fdace
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.target/i386/mvc17.c
> > > @@ -0,0 +1,11 @@
> > > +/* { dg-do compile } */
> > > +/* { dg-require-ifunc "" } */
> > > +/* { dg-options "-O2" } */
> > > +/* { dg-final { scan-assembler-times "rep mov" 1 } } */
> > > +
> > > +__attribute__((target_clones("default","arch=icelake-server")))
> > > +void
> > > +foo (char *a, char *b, int size)
> > > +{
> > > +  __builtin_memcpy (a, b, size & 0x7F);
> > > +}
> > > --
> > > 2.31.1
> > >