[3/3] PHIOPT: factor out unary operations instead of just conversions

  After using factor_out_conditional_conversion with diamond bb,
we should be able do use it also for all normal unary gimple and not
just conversions. This allows to optimize PR 59424 for an example.
This is also a start to optimize PR 64700 and a few others.

OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

An example of this is:
```
static inline unsigned long long g(int t)
{
  unsigned t1 = t;
  return t1;
}
static int abs1(int a)
{
  if (a < 0)
    a = -a;
  return a;
}
unsigned long long f(int c, int d, int e)
{
  unsigned long long t;
  if (d > e)
    t = g(abs1(d));
  else
    t = g(abs1(e));
  return t;
}
```

Which should be optimized to:
  _9 = MAX_EXPR <d_5(D), e_6(D)>;
  _4 = ABS_EXPR <_9>;
  t_3 = (long long unsigned intD.16) _4;

gcc/ChangeLog:

	* tree-ssa-phiopt.cc (factor_out_conditional_conversion): Rename to ...
	(factor_out_conditional_operation): This and add support for all unary
	operations.
	(pass_phiopt::execute): Update call to factor_out_conditional_conversion
	to call factor_out_conditional_operation instead.

	PR tree-optimization/109424
	PR tree-optimization/59424

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/abs-2.c: Update tree scan for
	details change in wording.
	* gcc.dg/tree-ssa/minmax-17.c: Likewise.
	* gcc.dg/tree-ssa/pr103771.c: Likewise.
	* gcc.dg/tree-ssa/minmax-18.c: New test.
	* gcc.dg/tree-ssa/minmax-19.c: New test.
---
 gcc/testsuite/gcc.dg/tree-ssa/abs-2.c     |  2 +-
 gcc/testsuite/gcc.dg/tree-ssa/minmax-17.c |  2 +-
 gcc/testsuite/gcc.dg/tree-ssa/minmax-18.c | 27 +++++++++++
 gcc/testsuite/gcc.dg/tree-ssa/minmax-19.c | 10 ++++
 gcc/testsuite/gcc.dg/tree-ssa/pr103771.c  |  2 +-
 gcc/tree-ssa-phiopt.cc                    | 56 +++++++++++++----------
 6 files changed, 71 insertions(+), 28 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/minmax-18.c
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/minmax-19.c
  

On Sun, May 7, 2023 at 6:44 AM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> After using factor_out_conditional_conversion with diamond bb,
> we should be able do use it also for all normal unary gimple and not
> just conversions. This allows to optimize PR 59424 for an example.
> This is also a start to optimize PR 64700 and a few others.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

OK.

> An example of this is:
> ```
> static inline unsigned long long g(int t)
> {
>   unsigned t1 = t;
>   return t1;
> }
> static int abs1(int a)
> {
>   if (a < 0)
>     a = -a;
>   return a;
> }
> unsigned long long f(int c, int d, int e)
> {
>   unsigned long long t;
>   if (d > e)
>     t = g(abs1(d));
>   else
>     t = g(abs1(e));
>   return t;
> }
> ```
>
> Which should be optimized to:
>   _9 = MAX_EXPR <d_5(D), e_6(D)>;
>   _4 = ABS_EXPR <_9>;
>   t_3 = (long long unsigned intD.16) _4;
>
> gcc/ChangeLog:
>
>         * tree-ssa-phiopt.cc (factor_out_conditional_conversion): Rename to ...
>         (factor_out_conditional_operation): This and add support for all unary
>         operations.
>         (pass_phiopt::execute): Update call to factor_out_conditional_conversion
>         to call factor_out_conditional_operation instead.
>
>         PR tree-optimization/109424
>         PR tree-optimization/59424
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.dg/tree-ssa/abs-2.c: Update tree scan for
>         details change in wording.
>         * gcc.dg/tree-ssa/minmax-17.c: Likewise.
>         * gcc.dg/tree-ssa/pr103771.c: Likewise.
>         * gcc.dg/tree-ssa/minmax-18.c: New test.
>         * gcc.dg/tree-ssa/minmax-19.c: New test.
> ---
>  gcc/testsuite/gcc.dg/tree-ssa/abs-2.c     |  2 +-
>  gcc/testsuite/gcc.dg/tree-ssa/minmax-17.c |  2 +-
>  gcc/testsuite/gcc.dg/tree-ssa/minmax-18.c | 27 +++++++++++
>  gcc/testsuite/gcc.dg/tree-ssa/minmax-19.c | 10 ++++
>  gcc/testsuite/gcc.dg/tree-ssa/pr103771.c  |  2 +-
>  gcc/tree-ssa-phiopt.cc                    | 56 +++++++++++++----------
>  6 files changed, 71 insertions(+), 28 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/minmax-18.c
>  create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/minmax-19.c
>
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/abs-2.c b/gcc/testsuite/gcc.dg/tree-ssa/abs-2.c
> index 328b1802541..f8bbeb43237 100644
> --- a/gcc/testsuite/gcc.dg/tree-ssa/abs-2.c
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/abs-2.c
> @@ -16,5 +16,5 @@ test_abs(int *cur)
>
>  /* We should figure out that test_abs has an ABS_EXPR in it. */
>  /* { dg-final { scan-tree-dump " = ABS_EXPR" "phiopt1"} } */
> -/* { dg-final { scan-tree-dump-times "changed to factor conversion out from" 1 "phiopt1"} } */
> +/* { dg-final { scan-tree-dump-times "changed to factor operation out from" 1 "phiopt1"} } */
>
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-17.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-17.c
> index bd737e6b4cb..7c76cfc62a9 100644
> --- a/gcc/testsuite/gcc.dg/tree-ssa/minmax-17.c
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-17.c
> @@ -18,4 +18,4 @@ unsigned long long test_max(int c, int d, int e)
>
>  /* We should figure out that test_max has an MAX_EXPR in it. */
>  /* { dg-final { scan-tree-dump " = MAX_EXPR" "phiopt1"} } */
> -/* { dg-final { scan-tree-dump-times "changed to factor conversion out from" 2 "phiopt1"} } */
> +/* { dg-final { scan-tree-dump-times "changed to factor operation out from" 2 "phiopt1"} } */
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-18.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-18.c
> new file mode 100644
> index 00000000000..c8e1670f64a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-18.c
> @@ -0,0 +1,27 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-phiopt1-details" } */
> +
> +static inline unsigned long long g(int t)
> +{
> +  unsigned t1 = t;
> +  return t1;
> +}
> +static inline int abs1(int a)
> +{
> +  if (a < 0)
> +    a = -a;
> +  return a;
> +}
> +unsigned long long f(int c, int d, int e)
> +{
> +  unsigned long long t;
> +  if (d > e)
> +    t = g(abs1(d));
> +  else
> +    t = g(abs1(e));
> +  return t;
> +}
> +
> +/* { dg-final { scan-tree-dump " = MAX_EXPR" "phiopt1"} } */
> +/* { dg-final { scan-tree-dump-times " = ABS_EXPR" 2 "phiopt1"} } */
> +/* { dg-final { scan-tree-dump-times "changed to factor operation out from" 3 "phiopt1"} } */
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-19.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-19.c
> new file mode 100644
> index 00000000000..5ed55fe2e23
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-19.c
> @@ -0,0 +1,10 @@
> +/* PR tree-optimization/109424 */
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-phiopt1-details" } */
> +
> +int f2(int x, int y)
> +{
> +    return (x > y) ? ~x : ~y;
> +}
> +/* { dg-final { scan-tree-dump " = MAX_EXPR" "phiopt1"} } */
> +/* { dg-final { scan-tree-dump-times "changed to factor operation out from" 1 "phiopt1"} } */
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr103771.c b/gcc/testsuite/gcc.dg/tree-ssa/pr103771.c
> index 97c9db846cb..8faa45a8222 100644
> --- a/gcc/testsuite/gcc.dg/tree-ssa/pr103771.c
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr103771.c
> @@ -1,6 +1,6 @@
>  /* { dg-do compile } */
>  /* { dg-options "-O3 -fdump-tree-phiopt1-details" } */
> -/* { dg-final { scan-tree-dump-times "changed to factor conversion out from COND_EXPR." 1 "phiopt1" } } */
> +/* { dg-final { scan-tree-dump-times "changed to factor operation out from COND_EXPR." 1 "phiopt1" } } */
>
>  typedef unsigned char uint8_t;
>
> diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc
> index 7fe088b13ff..2fb28b4e60e 100644
> --- a/gcc/tree-ssa-phiopt.cc
> +++ b/gcc/tree-ssa-phiopt.cc
> @@ -209,13 +209,13 @@ replace_phi_edge_with_variable (basic_block cond_block,
>               bb->index);
>  }
>
> -/* PR66726: Factor conversion out of COND_EXPR.  If the arguments of the PHI
> +/* PR66726: Factor operations out of COND_EXPR.  If the arguments of the PHI
>     stmt are CONVERT_STMT, factor out the conversion and perform the conversion
>     to the result of PHI stmt.  COND_STMT is the controlling predicate.
>     Return the newly-created PHI, if any.  */
>
>  static gphi *
> -factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
> +factor_out_conditional_operation (edge e0, edge e1, gphi *phi,
>                                    tree arg0, tree arg1, gimple *cond_stmt)
>  {
>    gimple *arg0_def_stmt = NULL, *arg1_def_stmt = NULL, *new_stmt;
> @@ -224,7 +224,7 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
>    gphi *newphi;
>    gimple_stmt_iterator gsi, gsi_for_def;
>    location_t locus = gimple_location (phi);
> -  enum tree_code convert_code;
> +  enum tree_code op_code;
>
>    /* Handle only PHI statements with two arguments.  TODO: If all
>       other arguments to PHI are INTEGER_CST or if their defining
> @@ -246,15 +246,17 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
>      return NULL;
>
>    /* Check if arg0 is an SSA_NAME and the stmt which defines arg0 is
> -     a conversion.  */
> +     an unary operation.  */
>    arg0_def_stmt = SSA_NAME_DEF_STMT (arg0);
> -  if (!gimple_assign_cast_p (arg0_def_stmt))
> +  if (!is_gimple_assign (arg0_def_stmt)
> +      || (gimple_assign_rhs_class (arg0_def_stmt) != GIMPLE_UNARY_RHS
> +         && gimple_assign_rhs_code (arg0_def_stmt) != VIEW_CONVERT_EXPR))
>      return NULL;
>
>    /* Use the RHS as new_arg0.  */
> -  convert_code = gimple_assign_rhs_code (arg0_def_stmt);
> +  op_code = gimple_assign_rhs_code (arg0_def_stmt);
>    new_arg0 = gimple_assign_rhs1 (arg0_def_stmt);
> -  if (convert_code == VIEW_CONVERT_EXPR)
> +  if (op_code == VIEW_CONVERT_EXPR)
>      {
>        new_arg0 = TREE_OPERAND (new_arg0, 0);
>        if (!is_gimple_reg_type (TREE_TYPE (new_arg0)))
> @@ -267,10 +269,10 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
>    if (TREE_CODE (arg1) == SSA_NAME)
>      {
>        /* Check if arg1 is an SSA_NAME and the stmt which defines arg1
> -        is a conversion.  */
> +        is an unary operation.  */
>        arg1_def_stmt = SSA_NAME_DEF_STMT (arg1);
> -      if (!is_gimple_assign (arg1_def_stmt)
> -         || gimple_assign_rhs_code (arg1_def_stmt) != convert_code)
> +       if (!is_gimple_assign (arg1_def_stmt)
> +          || gimple_assign_rhs_code (arg1_def_stmt) != op_code)
>         return NULL;
>
>        /* Either arg1_def_stmt or arg0_def_stmt should be conditional.  */
> @@ -281,7 +283,7 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
>
>        /* Use the RHS as new_arg1.  */
>        new_arg1 = gimple_assign_rhs1 (arg1_def_stmt);
> -      if (convert_code == VIEW_CONVERT_EXPR)
> +      if (op_code == VIEW_CONVERT_EXPR)
>         new_arg1 = TREE_OPERAND (new_arg1, 0);
>        if (TREE_CODE (new_arg1) == SSA_NAME
>           && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_arg1))
> @@ -289,6 +291,10 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
>      }
>    else
>      {
> +      /* TODO: handle more than just casts here. */
> +      if (!gimple_assign_cast_p (arg0_def_stmt))
> +       return NULL;
> +
>        /* arg0_def_stmt should be conditional.  */
>        if (dominated_by_p (CDI_DOMINATORS, gimple_bb (phi), gimple_bb (arg0_def_stmt)))
>         return NULL;
> @@ -366,13 +372,13 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
>        fprintf (dump_file, "PHI ");
>        print_generic_expr (dump_file, gimple_phi_result (phi));
>        fprintf (dump_file,
> -              " changed to factor conversion out from COND_EXPR.\n");
> -      fprintf (dump_file, "New stmt with CAST that defines ");
> +              " changed to factor operation out from COND_EXPR.\n");
> +      fprintf (dump_file, "New stmt with OPERATION that defines ");
>        print_generic_expr (dump_file, result);
>        fprintf (dump_file, ".\n");
>      }
>
> -  /* Remove the old cast(s) that has single use.  */
> +  /* Remove the old operation(s) that has single use.  */
>    gsi_for_def = gsi_for_stmt (arg0_def_stmt);
>    gsi_remove (&gsi_for_def, true);
>    release_defs (arg0_def_stmt);
> @@ -387,14 +393,14 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
>    add_phi_arg (newphi, new_arg0, e0, locus);
>    add_phi_arg (newphi, new_arg1, e1, locus);
>
> -  /* Create the conversion stmt and insert it.  */
> -  if (convert_code == VIEW_CONVERT_EXPR)
> +  /* Create the operation stmt and insert it.  */
> +  if (op_code == VIEW_CONVERT_EXPR)
>      {
>        temp = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (result), temp);
>        new_stmt = gimple_build_assign (result, temp);
>      }
>    else
> -    new_stmt = gimple_build_assign (result, convert_code, temp);
> +    new_stmt = gimple_build_assign (result, op_code, temp);
>    gsi = gsi_after_labels (gimple_bb (phi));
>    gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
>
> @@ -402,7 +408,7 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
>    gsi = gsi_for_stmt (phi);
>    gsi_remove (&gsi, true);
>
> -  statistics_counter_event (cfun, "factored out cast", 1);
> +  statistics_counter_event (cfun, "factored out operation", 1);
>
>    return newphi;
>  }
> @@ -3847,11 +3853,11 @@ gate_hoist_loads (void)
>     This pass also performs a fifth transformation of a slightly different
>     flavor.
>
> -   Factor conversion in COND_EXPR
> +   Factor operations in COND_EXPR
>     ------------------------------
>
> -   This transformation factors the conversion out of COND_EXPR with
> -   factor_out_conditional_conversion.
> +   This transformation factors the unary operations out of COND_EXPR with
> +   factor_out_conditional_operation.
>
>     For example:
>     if (a <= CST) goto <bb 3>; else goto <bb 4>;
> @@ -4092,15 +4098,15 @@ pass_phiopt::execute (function *)
>           while (newphi)
>             {
>               phi = newphi;
> -             /* factor_out_conditional_conversion may create a new PHI in
> +             /* factor_out_conditional_operation may create a new PHI in
>                  BB2 and eliminate an existing PHI in BB2.  Recompute values
>                  that may be affected by that change.  */
>               arg0 = gimple_phi_arg_def (phi, e1->dest_idx);
>               arg1 = gimple_phi_arg_def (phi, e2->dest_idx);
>               gcc_assert (arg0 != NULL_TREE && arg1 != NULL_TREE);
> -             newphi = factor_out_conditional_conversion (e1, e2, phi,
> -                                                         arg0, arg1,
> -                                                         cond_stmt);
> +             newphi = factor_out_conditional_operation (e1, e2, phi,
> +                                                        arg0, arg1,
> +                                                        cond_stmt);
>             }
>         }
>
> --
> 2.31.1
>