complex-lowering: Better handling of PAREN_EXPR [PR68855]

When PAREN_EXPR tree code was added in r0-85884-gdedd42d511b6e4,
a simplified handling was added to complex lowering. Which means
we would get:
```
  _9 = COMPLEX_EXPR <_15, _14>;
  _11 = ((_9));
  _19 = REALPART_EXPR <_11>;
  _20 = IMAGPART_EXPR <_11>;
```

In many cases instead of just simply:
```
  _19 = ((_15));
  _20 = ((_14));
```

So this adds full support for PAREN_EXPR to complex lowering.
It is handled very similar as NEGATE_EXPR; except creating PAREN_EXPR
instead of NEGATE_EXPR for the real/imag parts. This allows for
more optimizations including vectorization, especially with
-ffast-math.
gfortran.dg/vect/pr68855.f90 is an example where this could show up.
It also shows up in SPEC CPU 2006's 465.tonto; though I have not done
any benchmarking there.

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

gcc/ChangeLog:

	PR tree-optimization/68855
	* tree-complex.cc (init_dont_simulate_again): Handle PAREN_EXPR
	like NEGATE_EXPR.
	(complex_propagate::visit_stmt): Likewise.
	(expand_complex_move): Don't handle PAREN_EXPR.
	(expand_complex_paren): New function.
	(expand_complex_operations_1): Handle PAREN_EXPR like
	NEGATE_EXPR. And call expand_complex_paren for PAREN_EXPR.

gcc/testsuite/ChangeLog:

	* gcc.dg/vect/pr68855.c: New test.
	* gfortran.dg/vect/pr68855.f90: New test.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
---
 gcc/testsuite/gcc.dg/vect/pr68855.c        | 17 +++++++++++++
 gcc/testsuite/gfortran.dg/vect/pr68855.f90 | 16 ++++++++++++
 gcc/tree-complex.cc                        | 29 ++++++++++++++++++++--
 3 files changed, 60 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/vect/pr68855.c
 create mode 100644 gcc/testsuite/gfortran.dg/vect/pr68855.f90

> Am 21.06.2024 um 04:35 schrieb Andrew Pinski <quic_apinski@quicinc.com>:
> 
> When PAREN_EXPR tree code was added in r0-85884-gdedd42d511b6e4,
> a simplified handling was added to complex lowering. Which means
> we would get:
> ```
>  _9 = COMPLEX_EXPR <_15, _14>;
>  _11 = ((_9));
>  _19 = REALPART_EXPR <_11>;
>  _20 = IMAGPART_EXPR <_11>;
> ```
> 
> In many cases instead of just simply:
> ```
>  _19 = ((_15));
>  _20 = ((_14));
> ```
> 
> So this adds full support for PAREN_EXPR to complex lowering.
> It is handled very similar as NEGATE_EXPR; except creating PAREN_EXPR
> instead of NEGATE_EXPR for the real/imag parts. This allows for
> more optimizations including vectorization, especially with
> -ffast-math.
> gfortran.dg/vect/pr68855.f90 is an example where this could show up.
> It also shows up in SPEC CPU 2006's 465.tonto; though I have not done
> any benchmarking there.
> 
> Bootstrapped and tested on x86_64-linux-gnu with no regressions.

Ok

Thanks,
Richard 

> gcc/ChangeLog:
> 
>    PR tree-optimization/68855
>    * tree-complex.cc (init_dont_simulate_again): Handle PAREN_EXPR
>    like NEGATE_EXPR.
>    (complex_propagate::visit_stmt): Likewise.
>    (expand_complex_move): Don't handle PAREN_EXPR.
>    (expand_complex_paren): New function.
>    (expand_complex_operations_1): Handle PAREN_EXPR like
>    NEGATE_EXPR. And call expand_complex_paren for PAREN_EXPR.
> 
> gcc/testsuite/ChangeLog:
> 
>    * gcc.dg/vect/pr68855.c: New test.
>    * gfortran.dg/vect/pr68855.f90: New test.
> 
> Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
> ---
> gcc/testsuite/gcc.dg/vect/pr68855.c        | 17 +++++++++++++
> gcc/testsuite/gfortran.dg/vect/pr68855.f90 | 16 ++++++++++++
> gcc/tree-complex.cc                        | 29 ++++++++++++++++++++--
> 3 files changed, 60 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/vect/pr68855.c
> create mode 100644 gcc/testsuite/gfortran.dg/vect/pr68855.f90
> 
> diff --git a/gcc/testsuite/gcc.dg/vect/pr68855.c b/gcc/testsuite/gcc.dg/vect/pr68855.c
> new file mode 100644
> index 00000000000..68a3a1cee36
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/pr68855.c
> @@ -0,0 +1,17 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_float } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +/* PAREN_EXPR should not cause the vectorization of complex float add to be missed. */
> +void foo(_Complex float *a, int n)
> +{
> +  for(int i = 0; i < n; i++)
> +  {
> +    _Complex float t;
> +    t = a[i];
> +    t += 6.0;
> +    t = __builtin_assoc_barrier(t);
> +    a[i] = t;
> +  }
> +}
> diff --git a/gcc/testsuite/gfortran.dg/vect/pr68855.f90 b/gcc/testsuite/gfortran.dg/vect/pr68855.f90
> new file mode 100644
> index 00000000000..90d444c86bf
> --- /dev/null
> +++ b/gcc/testsuite/gfortran.dg/vect/pr68855.f90
> @@ -0,0 +1,16 @@
> +! { dg-do compile }
> +! { dg-require-effective-target vect_float }
> +
> +! { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } }
> +! PAREN_EXPR should not cause the vectorization of complex float add to be missed.
> +
> +subroutine foo(a,n)
> +
> +  complex (kind(1.0)) :: a(*)
> +  integer :: i,n
> +
> +  do i=1,n
> +     a(i)=(a(i)+(6.0,1.0))
> +  enddo
> +  
> +end subroutine foo
> diff --git a/gcc/tree-complex.cc b/gcc/tree-complex.cc
> index 877913972bd..8a879acffca 100644
> --- a/gcc/tree-complex.cc
> +++ b/gcc/tree-complex.cc
> @@ -281,6 +281,7 @@ init_dont_simulate_again (void)
> 
>          case NEGATE_EXPR:
>          case CONJ_EXPR:
> +          case PAREN_EXPR:
>        if (TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
>          saw_a_complex_op = true;
>        break;
> @@ -391,6 +392,7 @@ complex_propagate::visit_stmt (gimple *stmt, edge *taken_edge_p ATTRIBUTE_UNUSED
>       break;
> 
>     case NEGATE_EXPR:
> +    case PAREN_EXPR:
>     case CONJ_EXPR:
>       new_l = find_lattice_value (gimple_assign_rhs1 (stmt));
>       break;
> @@ -852,8 +854,7 @@ expand_complex_move (gimple_stmt_iterator *gsi, tree type)
>      update_complex_components_on_edge (e, lhs, r, i);
>    }
>       else if (is_gimple_call (stmt)
> -           || gimple_has_side_effects (stmt)
> -           || gimple_assign_rhs_code (stmt) == PAREN_EXPR)
> +           || gimple_has_side_effects (stmt))
>    {
>      r = build1 (REALPART_EXPR, inner_type, lhs);
>      i = build1 (IMAGPART_EXPR, inner_type, lhs);
> @@ -1545,6 +1546,25 @@ expand_complex_negation (gimple_stmt_iterator *gsi, tree inner_type,
>   update_complex_assignment (gsi, rr, ri);
> }
> 
> +/* Expand complex paren to scalars:
> +    ((a)) = ((ar)) + i((ai))
> +*/
> +
> +static void
> +expand_complex_paren (gimple_stmt_iterator *gsi, tree inner_type,
> +              tree ar, tree ai)
> +{
> +  tree rr, ri;
> +  gimple_seq stmts = NULL;
> +  location_t loc = gimple_location (gsi_stmt (*gsi));
> +
> +  rr = gimple_build (&stmts, loc, PAREN_EXPR, inner_type, ar);
> +  ri = gimple_build (&stmts, loc, PAREN_EXPR, inner_type, ai);
> +
> +  gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
> +  update_complex_assignment (gsi, rr, ri);
> +}
> +
> /* Expand complex conjugate to scalars:
>    ~a = (ar) + i(-ai)
> */
> @@ -1697,6 +1717,7 @@ expand_complex_operations_1 (gimple_stmt_iterator *gsi)
>     case ROUND_DIV_EXPR:
>     case RDIV_EXPR:
>     case NEGATE_EXPR:
> +    case PAREN_EXPR:
>     case CONJ_EXPR:
>       if (TREE_CODE (type) != COMPLEX_TYPE)
>    return;
> @@ -1815,6 +1836,10 @@ expand_complex_operations_1 (gimple_stmt_iterator *gsi)
>       expand_complex_comparison (gsi, ar, ai, br, bi, code);
>       break;
> 
> +    case PAREN_EXPR:
> +      expand_complex_paren (gsi, inner_type, ar, ai);
> +      break;
> +
>     default:
>       gcc_unreachable ();
>     }
> --
> 2.43.0
>