Fix PR lto/49302 (corrected)

Richard, thanks for the comments.  Here's the revised patch for
expanding cabs in gimple.

Given the direction this pass is taking, should it eventually be renamed
from cse_sincos to something more general?

Thanks,
Bill


2011-06-09  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	PR lto/49302
	* tree-ssa-math-opts.c (build_and_insert_ref): New.
	(gimple_expand_builtin_pow): Minor cleanup.
	(gimple_expand_builtin_cabs): New.
	(execute_cse_sincos): Add case for BUILT_IN_CABS.

On Thu, Jun 9, 2011 at 7:34 PM, William J. Schmidt
<wschmidt@linux.vnet.ibm.com> wrote:
> Richard, thanks for the comments.  Here's the revised patch for
> expanding cabs in gimple.
>
> Given the direction this pass is taking, should it eventually be renamed
> from cse_sincos to something more general?

Eventually yes - but names are just - names ;)

Ok with ...

> Thanks,
> Bill
>
>
> 2011-06-09  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
>
>        PR lto/49302
>        * tree-ssa-math-opts.c (build_and_insert_ref): New.
>        (gimple_expand_builtin_pow): Minor cleanup.
>        (gimple_expand_builtin_cabs): New.
>        (execute_cse_sincos): Add case for BUILT_IN_CABS.
>
>
> Index: gcc/tree-ssa-math-opts.c
> ===================================================================
> --- gcc/tree-ssa-math-opts.c    (revision 174845)
> +++ gcc/tree-ssa-math-opts.c    (working copy)
> @@ -1070,6 +1070,22 @@ build_and_insert_binop (gimple_stmt_iterator *gsi,
>   return result;
>  }
>
> +/* Build a gimple reference operation with the given CODE and argument
> +   ARG, assigning the result to a new SSA name for variable TARGET.
> +   Insert the statement prior to GSI's current position, and return
> +   the fresh SSA name.  */
> +
> +static inline tree
> +build_and_insert_ref (gimple_stmt_iterator *gsi, location_t loc, tree type,
> +                     tree target, enum tree_code code, tree arg0)
> +{
> +  tree result = make_ssa_name (target, NULL);
> +  gimple stmt = gimple_build_assign (result, build1 (code, type, arg0));
> +  gimple_set_location (stmt, loc);
> +  gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
> +  return result;
> +}
> +
>  /* ARG0 and ARG1 are the two arguments to a pow builtin call in GSI
>    with location info LOC.  If possible, create an equivalent and
>    less expensive sequence of statements prior to GSI, and return an
> @@ -1124,7 +1140,7 @@ gimple_expand_builtin_pow (gimple_stmt_iterator *g
>      if we don't have a hardware sqrt insn.  */
>   dconst1_4 = dconst1;
>   SET_REAL_EXP (&dconst1_4, REAL_EXP (&dconst1_4) - 2);
> -  hw_sqrt_exists = optab_handler(sqrt_optab, mode) != CODE_FOR_nothing;
> +  hw_sqrt_exists = optab_handler (sqrt_optab, mode) != CODE_FOR_nothing;
>
>   if (flag_unsafe_math_optimizations
>       && sqrtfn
> @@ -1306,6 +1322,42 @@ gimple_expand_builtin_pow (gimple_stmt_iterator *g
>   return NULL_TREE;
>  }
>
> +/* ARG is the argument to a cabs builtin call in GSI with location info
> +   LOC.  Create a sequence of statements prior to GSI that calculates
> +   sqrt(R*R + I*I), where R and I are the real and imaginary components
> +   of ARG, respectively.  Return an expression holding the result.  */
> +
> +static tree
> +gimple_expand_builtin_cabs (gimple_stmt_iterator *gsi, location_t loc, tree arg)
> +{
> +  tree target, real_part, imag_part, addend1, addend2, sum, result;
> +  tree type = TREE_TYPE (TREE_TYPE (arg));
> +  tree sqrtfn = mathfn_built_in (type, BUILT_IN_SQRT);
> +  enum machine_mode mode = TYPE_MODE (type);
> +
> +  if (!flag_unsafe_math_optimizations
> +      || !optimize_bb_for_speed_p (gimple_bb (gsi_stmt (*gsi)))
> +      || !sqrtfn
> +      || optab_handler (sqrt_optab, mode) == CODE_FOR_nothing)
> +    return NULL_TREE;
> +
> +  target = create_tmp_var (type, "cabs");

use create_tmp_reg instead

Thanks,
Richard.

> +  add_referenced_var (target);
> +
> +  real_part = build_and_insert_ref (gsi, loc, type, target,
> +                                   REALPART_EXPR, arg);
> +  addend1 = build_and_insert_binop (gsi, loc, target, MULT_EXPR,
> +                                   real_part, real_part);
> +  imag_part = build_and_insert_ref (gsi, loc, type, target,
> +                                   IMAGPART_EXPR, arg);
> +  addend2 = build_and_insert_binop (gsi, loc, target, MULT_EXPR,
> +                                   imag_part, imag_part);
> +  sum = build_and_insert_binop (gsi, loc, target, PLUS_EXPR, addend1, addend2);
> +  result = build_and_insert_call (gsi, loc, &target, sqrtfn, sum);
> +
> +  return result;
> +}
> +
>  /* Go through all calls to sin, cos and cexpi and call execute_cse_sincos_1
>    on the SSA_NAME argument of each of them.  Also expand powi(x,n) into
>    an optimal number of multiplies, when n is a constant.  */
> @@ -1388,6 +1440,21 @@ execute_cse_sincos (void)
>                    }
>                  break;
>
> +               CASE_FLT_FN (BUILT_IN_CABS):
> +                 arg0 = gimple_call_arg (stmt, 0);
> +                 loc = gimple_location (stmt);
> +                 result = gimple_expand_builtin_cabs (&gsi, loc, arg0);
> +
> +                 if (result)
> +                   {
> +                     tree lhs = gimple_get_lhs (stmt);
> +                     gimple new_stmt = gimple_build_assign (lhs, result);
> +                     gimple_set_location (new_stmt, loc);
> +                     unlink_stmt_vdef (stmt);
> +                     gsi_replace (&gsi, new_stmt, true);
> +                   }
> +                 break;
> +
>                default:;
>                }
>            }
>
>
>