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[1/4] Small optimization for complex addition, real/imag parts the same

Message ID 20240701214657.3163066-2-quic_apinski@quicinc.com
State Committed
Commit 578ccc717937178b50db0e35554da3f77f19e304
Headers
Series Some improvements to complex lowering (cabs related) |

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Commit Message

Andrew Pinski July 1, 2024, 9:46 p.m. UTC 
  This is just a small optimization for the case where the real and imag
parts are the same when lowering complex addition/subtraction. We only
need to do the addition once when the real and imag parts are the same (on
both sides of the operator). This gets done later on by FRE/PRE/DOM but
having it done soon allows the cabs lowering to remove the sqrt and
just change it to a multiply by a constant.

Bootstrapped and tested on x86_64-linux-gnu.

gcc/ChangeLog:

	* tree-complex.cc (expand_complex_addition): If both
	operands have the same real and imag parts, only
	add the addition once.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/complex-8.c: New test.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
---
 gcc/testsuite/gcc.dg/tree-ssa/complex-8.c | 12 ++++++++++++
 gcc/tree-complex.cc                       |  7 ++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/complex-8.c

Comments

Richard Biener July 2, 2024, 8:03 a.m. UTC | #1 
On Mon, Jul 1, 2024 at 11:47 PM Andrew Pinski <quic_apinski@quicinc.com> wrote:
>
> This is just a small optimization for the case where the real and imag
> parts are the same when lowering complex addition/subtraction. We only
> need to do the addition once when the real and imag parts are the same (on
> both sides of the operator). This gets done later on by FRE/PRE/DOM but
> having it done soon allows the cabs lowering to remove the sqrt and
> just change it to a multiply by a constant.
>
> Bootstrapped and tested on x86_64-linux-gnu.

OK.

> gcc/ChangeLog:
>
>         * tree-complex.cc (expand_complex_addition): If both
>         operands have the same real and imag parts, only
>         add the addition once.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.dg/tree-ssa/complex-8.c: New test.
>
> Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
> ---
>  gcc/testsuite/gcc.dg/tree-ssa/complex-8.c | 12 ++++++++++++
>  gcc/tree-complex.cc                       |  7 ++++++-
>  2 files changed, 18 insertions(+), 1 deletion(-)
>  create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/complex-8.c
>
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/complex-8.c b/gcc/testsuite/gcc.dg/tree-ssa/complex-8.c
> new file mode 100644
> index 00000000000..a9636ff9e9a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/complex-8.c
> @@ -0,0 +1,12 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O1 -fdump-tree-cplxlower1-raw" } */
> +
> +_Complex double f(double a, double c)
> +{
> +  _Complex double d = __builtin_complex (a, a);
> +  d+=__builtin_complex(c, c);
> +  return d;
> +}
> +
> +/* There should only be one plus as (a+c) is still (a+c) */
> +/* { dg-final { scan-tree-dump-times "plus_expr, " 1 "cplxlower1" } } */
> diff --git a/gcc/tree-complex.cc b/gcc/tree-complex.cc
> index 8a879acffca..dfebec18ec3 100644
> --- a/gcc/tree-complex.cc
> +++ b/gcc/tree-complex.cc
> @@ -984,7 +984,12 @@ expand_complex_addition (gimple_stmt_iterator *gsi, tree inner_type,
>      case PAIR (VARYING, VARYING):
>      general:
>        rr = gimple_build (&stmts, loc, code, inner_type, ar, br);
> -      ri = gimple_build (&stmts, loc, code, inner_type, ai, bi);
> +      /* (a+ai) + (b+bi) -> (a+b)+(a+b)i
> +         small optimization to remove one new statement. */
> +      if (operand_equal_p (ar, ai) && operand_equal_p (br, bi))
> +       ri = rr;
> +      else
> +       ri = gimple_build (&stmts, loc, code, inner_type, ai, bi);
>        break;
>
>      default:
> --
> 2.43.0
>
diff mbox series

Patch

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/complex-8.c b/gcc/testsuite/gcc.dg/tree-ssa/complex-8.c
new file mode 100644
index 00000000000..a9636ff9e9a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/complex-8.c
@@ -0,0 +1,12 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-cplxlower1-raw" } */
+
+_Complex double f(double a, double c)
+{
+  _Complex double d = __builtin_complex (a, a);
+  d+=__builtin_complex(c, c);
+  return d;
+}
+
+/* There should only be one plus as (a+c) is still (a+c) */
+/* { dg-final { scan-tree-dump-times "plus_expr, " 1 "cplxlower1" } } */
diff --git a/gcc/tree-complex.cc b/gcc/tree-complex.cc
index 8a879acffca..dfebec18ec3 100644
--- a/gcc/tree-complex.cc
+++ b/gcc/tree-complex.cc
@@ -984,7 +984,12 @@  expand_complex_addition (gimple_stmt_iterator *gsi, tree inner_type,
     case PAIR (VARYING, VARYING):
     general:
       rr = gimple_build (&stmts, loc, code, inner_type, ar, br);
-      ri = gimple_build (&stmts, loc, code, inner_type, ai, bi);
+      /* (a+ai) + (b+bi) -> (a+b)+(a+b)i
+	  small optimization to remove one new statement. */
+      if (operand_equal_p (ar, ai) && operand_equal_p (br, bi))
+	ri = rr;
+      else
+	ri = gimple_build (&stmts, loc, code, inner_type, ai, bi);
       break;
 
     default: