[PATCH 1/2] Add verification of gimple_assign_nontemporal_move_p [PR112976]

[PATCH 1/2] Add verification of gimple_assign_nontemporal_move_p [PR112976]

[Andrew Pinski]

Currently the middle-end only knows how to support temporal stores
(the undocumented storent optab) so let's verify that the only time
we set nontemporal_move on an assign is if the the lhs is not a
gimple reg.

Bootstrapped and tested on x86_64-linux-gnu no regressions.

gcc/ChangeLog:

	PR middle-end/112976
	* tree-cfg.cc (verify_gimple_assign): Verify that
	nontmporal moves are stores.
	* gimple.h (struct gimple): Note that only
	nontemporal stores are supported.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
---
 gcc/gimple.h    |  3 ++-
 gcc/tree-cfg.cc | 11 +++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/gcc/gimple.h b/gcc/gimple.h
index 8a8ca109bbf..bd315ffc2dd 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -236,7 +236,8 @@ struct GTY((desc ("gimple_statement_structure (&%h)"), tag ("GSS_BASE"),
      for clearing this bit before using it.  */
   unsigned int visited		: 1;
 
-  /* Nonzero if this tuple represents a non-temporal move.  */
+  /* Nonzero if this tuple represents a non-temporal move; currently
+     only stores are supported.  */
   unsigned int nontemporal_move	: 1;
 
   /* Pass local flags.  These flags are free for any pass to use as
diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
index b1ba33018fd..06a96f96be7 100644
--- a/gcc/tree-cfg.cc
+++ b/gcc/tree-cfg.cc
@@ -4837,6 +4837,17 @@ verify_gimple_assign_single (gassign *stmt)
 static bool
 verify_gimple_assign (gassign *stmt)
 {
+  if (gimple_assign_nontemporal_move_p (stmt))
+    {
+      tree lhs = gimple_assign_lhs (stmt);
+      if (is_gimple_reg (lhs))
+	{
+	  error ("nontemporal store lhs cannot a gimple register");
+	  debug_generic_stmt (lhs);
+	  return true;
+	}
+    }
+
   switch (gimple_assign_rhs_class (stmt))
     {
     case GIMPLE_SINGLE_RHS:
-- 
2.43.0

[PATCH 2/2] Remove support for nontemporal stores with ssa_names on lhs [PR112976]

[Andrew Pinski]

When cfgexpand was changed to support expanding from tuple gimple
(r0-95521-g28ed065ef9f345), the code was added to support
doing nontemporal stores with LHS of a SSA_NAME but that will
never be a nontemporal store.
This patch removes that and asserts that expanding with a LHS
of a SSA_NAME is not a nontemporal store.

Bootstrapped and tested on x86_64-linux-gnu.

gcc/ChangeLog:

	PR middle-end/112976
	* cfgexpand.cc (expand_gimple_stmt_1): Remove
	support for expanding nontemporal "moves" with
	ssa names on the LHS.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
---
 gcc/cfgexpand.cc | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/gcc/cfgexpand.cc b/gcc/cfgexpand.cc
index eef565eddb5..cfc5291aa0c 100644
--- a/gcc/cfgexpand.cc
+++ b/gcc/cfgexpand.cc
@@ -4002,17 +4002,16 @@ expand_gimple_stmt_1 (gimple *stmt)
 	else
 	  {
 	    rtx target, temp;
-	    bool nontemporal = gimple_assign_nontemporal_move_p (assign_stmt);
+	    gcc_assert (!gimple_assign_nontemporal_move_p (assign_stmt));
 	    bool promoted = false;
 
 	    target = expand_expr (lhs, NULL_RTX, VOIDmode, EXPAND_WRITE);
 	    if (GET_CODE (target) == SUBREG && SUBREG_PROMOTED_VAR_P (target))
 	      promoted = true;
 
-	   /* If we want to use a nontemporal store, force the value to
-	      register first.  If we store into a promoted register,
-	      don't directly expand to target.  */
-	    temp = nontemporal || promoted ? NULL_RTX : target;
+	   /* If we store into a promoted register, don't directly
+	      expand to target.  */
+	    temp = promoted ? NULL_RTX : target;
 	    temp = expand_expr_real_gassign (assign_stmt, temp,
 					     GET_MODE (target), EXPAND_NORMAL);
 
@@ -4034,8 +4033,6 @@ expand_gimple_stmt_1 (gimple *stmt)
 
 		convert_move (SUBREG_REG (target), temp, unsignedp);
 	      }
-	    else if (nontemporal && emit_storent_insn (target, temp))
-	      ;
 	    else
 	      {
 		temp = force_operand (temp, target);
-- 
2.43.0

Re: [PATCH 1/2] Add verification of gimple_assign_nontemporal_move_p [PR112976]

[Richard Biener]

On Sat, Apr 27, 2024 at 1:04 AM Andrew Pinski <quic_apinski@quicinc.com> wrote:
>
> Currently the middle-end only knows how to support temporal stores
> (the undocumented storent optab) so let's verify that the only time
> we set nontemporal_move on an assign is if the the lhs is not a
> gimple reg.
>
> Bootstrapped and tested on x86_64-linux-gnu no regressions.

OK.

> gcc/ChangeLog:
>
>         PR middle-end/112976
>         * tree-cfg.cc (verify_gimple_assign): Verify that
>         nontmporal moves are stores.
>         * gimple.h (struct gimple): Note that only
>         nontemporal stores are supported.
>
> Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
> ---
>  gcc/gimple.h    |  3 ++-
>  gcc/tree-cfg.cc | 11 +++++++++++
>  2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/gimple.h b/gcc/gimple.h
> index 8a8ca109bbf..bd315ffc2dd 100644
> --- a/gcc/gimple.h
> +++ b/gcc/gimple.h
> @@ -236,7 +236,8 @@ struct GTY((desc ("gimple_statement_structure (&%h)"), tag ("GSS_BASE"),
>       for clearing this bit before using it.  */
>    unsigned int visited         : 1;
>
> -  /* Nonzero if this tuple represents a non-temporal move.  */
> +  /* Nonzero if this tuple represents a non-temporal move; currently
> +     only stores are supported.  */
>    unsigned int nontemporal_move        : 1;
>
>    /* Pass local flags.  These flags are free for any pass to use as
> diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
> index b1ba33018fd..06a96f96be7 100644
> --- a/gcc/tree-cfg.cc
> +++ b/gcc/tree-cfg.cc
> @@ -4837,6 +4837,17 @@ verify_gimple_assign_single (gassign *stmt)
>  static bool
>  verify_gimple_assign (gassign *stmt)
>  {
> +  if (gimple_assign_nontemporal_move_p (stmt))
> +    {
> +      tree lhs = gimple_assign_lhs (stmt);
> +      if (is_gimple_reg (lhs))
> +       {
> +         error ("nontemporal store lhs cannot a gimple register");
> +         debug_generic_stmt (lhs);
> +         return true;
> +       }
> +    }
> +
>    switch (gimple_assign_rhs_class (stmt))
>      {
>      case GIMPLE_SINGLE_RHS:
> --
> 2.43.0
>

Re: [PATCH 2/2] Remove support for nontemporal stores with ssa_names on lhs [PR112976]

[Richard Biener]

On Sat, Apr 27, 2024 at 1:04 AM Andrew Pinski <quic_apinski@quicinc.com> wrote:
>
> When cfgexpand was changed to support expanding from tuple gimple
> (r0-95521-g28ed065ef9f345), the code was added to support
> doing nontemporal stores with LHS of a SSA_NAME but that will
> never be a nontemporal store.
> This patch removes that and asserts that expanding with a LHS
> of a SSA_NAME is not a nontemporal store.
>
> Bootstrapped and tested on x86_64-linux-gnu.

OK.

> gcc/ChangeLog:
>
>         PR middle-end/112976
>         * cfgexpand.cc (expand_gimple_stmt_1): Remove
>         support for expanding nontemporal "moves" with
>         ssa names on the LHS.
>
> Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
> ---
>  gcc/cfgexpand.cc | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/gcc/cfgexpand.cc b/gcc/cfgexpand.cc
> index eef565eddb5..cfc5291aa0c 100644
> --- a/gcc/cfgexpand.cc
> +++ b/gcc/cfgexpand.cc
> @@ -4002,17 +4002,16 @@ expand_gimple_stmt_1 (gimple *stmt)
>         else
>           {
>             rtx target, temp;
> -           bool nontemporal = gimple_assign_nontemporal_move_p (assign_stmt);
> +           gcc_assert (!gimple_assign_nontemporal_move_p (assign_stmt));
>             bool promoted = false;
>
>             target = expand_expr (lhs, NULL_RTX, VOIDmode, EXPAND_WRITE);
>             if (GET_CODE (target) == SUBREG && SUBREG_PROMOTED_VAR_P (target))
>               promoted = true;
>
> -          /* If we want to use a nontemporal store, force the value to
> -             register first.  If we store into a promoted register,
> -             don't directly expand to target.  */
> -           temp = nontemporal || promoted ? NULL_RTX : target;
> +          /* If we store into a promoted register, don't directly
> +             expand to target.  */
> +           temp = promoted ? NULL_RTX : target;
>             temp = expand_expr_real_gassign (assign_stmt, temp,
>                                              GET_MODE (target), EXPAND_NORMAL);
>
> @@ -4034,8 +4033,6 @@ expand_gimple_stmt_1 (gimple *stmt)
>
>                 convert_move (SUBREG_REG (target), temp, unsignedp);
>               }
> -           else if (nontemporal && emit_storent_insn (target, temp))
> -             ;
>             else
>               {
>                 temp = force_operand (temp, target);
> --
> 2.43.0
>