On Sun, Jul 4, 2021 at 8:41 PM apinski--- via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> From: Andrew Pinski <apin...@marvell.com>
>
> To move a few things more to match-and-simplify from phiopt,
> we need to allow match_simplify_replacement to run in early
> phiopt. To do this we add a replacement for gimple_simplify
> that is explictly for phiopt.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no
> regressions.
OK.
Richard.
> gcc/ChangeLog:
>
> * tree-ssa-phiopt.c (match_simplify_replacement):
> Add early_p argument. Call gimple_simplify_phiopt
> instead of gimple_simplify.
> (tree_ssa_phiopt_worker): Update call to
> match_simplify_replacement and allow unconditionally.
> (phiopt_early_allow): New function.
> (gimple_simplify_phiopt): New function.
> ---
> gcc/tree-ssa-phiopt.c | 89 ++++++++++++++++++++++++++++++++++---------
> 1 file changed, 70 insertions(+), 19 deletions(-)
>
> diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
> index 71f0019d877..d4449afcdca 100644
> --- a/gcc/tree-ssa-phiopt.c
> +++ b/gcc/tree-ssa-phiopt.c
> @@ -50,13 +50,14 @@ along with GCC; see the file COPYING3. If not see
> #include "gimple-fold.h"
> #include "internal-fn.h"
> #include "gimple-range.h"
> +#include "gimple-match.h"
> #include "dbgcnt.h"
>
> static unsigned int tree_ssa_phiopt_worker (bool, bool, bool);
> static bool two_value_replacement (basic_block, basic_block, edge, gphi *,
> tree, tree);
> static bool match_simplify_replacement (basic_block, basic_block,
> - edge, edge, gphi *, tree, tree);
> + edge, edge, gphi *, tree, tree, bool);
> static gphi *factor_out_conditional_conversion (edge, edge, gphi *, tree,
> tree,
> gimple *);
> static int value_replacement (basic_block, basic_block,
> @@ -347,9 +348,9 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool
> do_hoist_loads, bool early_p)
> /* Do the replacement of conditional if it can be done. */
> if (!early_p && two_value_replacement (bb, bb1, e2, phi, arg0,
> arg1))
> cfgchanged = true;
> - else if (!early_p
> - && match_simplify_replacement (bb, bb1, e1, e2, phi,
> - arg0, arg1))
> + else if (match_simplify_replacement (bb, bb1, e1, e2, phi,
> + arg0, arg1,
> + early_p))
> cfgchanged = true;
> else if (abs_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
> cfgchanged = true;
> @@ -819,6 +820,67 @@ two_value_replacement (basic_block cond_bb, basic_block
> middle_bb,
> return true;
> }
>
> +/* Return TRUE if CODE should be allowed during early phiopt.
> + Currently this is to allow MIN/MAX and ABS/NEGATE. */
> +static bool
> +phiopt_early_allow (enum tree_code code)
> +{
> + switch (code)
> + {
> + case MIN_EXPR:
> + case MAX_EXPR:
> + case ABS_EXPR:
> + case ABSU_EXPR:
> + case NEGATE_EXPR:
> + case SSA_NAME:
> + return true;
> + default:
> + return false;
> + }
> +}
> +
> +/* gimple_simplify_phiopt is like gimple_simplify but designed for PHIOPT.
> + Return NULL if nothing can be simplified or the resulting simplified value
> + with parts pushed if EARLY_P was true. Also rejects non allowed tree code
> + if EARLY_P is set.
> + Takes the comparison from COMP_STMT and two args, ARG0 and ARG1 and tries
> + to simplify CMP ? ARG0 : ARG1. */
> +static tree
> +gimple_simplify_phiopt (bool early_p, tree type, gimple *comp_stmt,
> + tree arg0, tree arg1,
> + gimple_seq *seq)
> +{
> + tree result;
> + enum tree_code comp_code = gimple_cond_code (comp_stmt);
> + location_t loc = gimple_location (comp_stmt);
> + tree cmp0 = gimple_cond_lhs (comp_stmt);
> + tree cmp1 = gimple_cond_rhs (comp_stmt);
> + /* To handle special cases like floating point comparison, it is easier and
> + less error-prone to build a tree and gimplify it on the fly though it is
> + less efficient.
> + Don't use fold_build2 here as that might create (bool)a instead of just
> + "a != 0". */
> + tree cond = build2_loc (loc, comp_code, boolean_type_node,
> + cmp0, cmp1);
> + gimple_match_op op (gimple_match_cond::UNCOND,
> + COND_EXPR, type, cond, arg0, arg1);
> +
> + if (op.resimplify (early_p ? NULL : seq, follow_all_ssa_edges))
> + {
> + /* Early we want only to allow some generated tree codes. */
> + if (!early_p
> + || op.code.is_tree_code ()
> + || phiopt_early_allow ((tree_code)op.code))
> + {
> + result = maybe_push_res_to_seq (&op, seq);
> + if (result)
> + return result;
> + }
> + }
> +
> + return NULL;
> +}
> +
> /* The function match_simplify_replacement does the main work of doing the
> replacement using match and simplify. Return true if the replacement is
> done.
> Otherwise return false.
> @@ -828,10 +890,9 @@ two_value_replacement (basic_block cond_bb, basic_block
> middle_bb,
> static bool
> match_simplify_replacement (basic_block cond_bb, basic_block middle_bb,
> edge e0, edge e1, gphi *phi,
> - tree arg0, tree arg1)
> + tree arg0, tree arg1, bool early_p)
> {
> gimple *stmt;
> - tree cond;
> gimple_stmt_iterator gsi;
> edge true_edge, false_edge;
> gimple_seq seq = NULL;
> @@ -892,15 +953,6 @@ match_simplify_replacement (basic_block cond_bb,
> basic_block middle_bb,
>
> stmt = last_stmt (cond_bb);
>
> - /* To handle special cases like floating point comparison, it is easier and
> - less error-prone to build a tree and gimplify it on the fly though it is
> - less efficient.
> - Don't use fold_build2 here as that might create (bool)a instead of just
> - "a != 0". */
> - cond = build2_loc (gimple_location (stmt),
> - gimple_cond_code (stmt), boolean_type_node,
> - gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
> -
> /* We need to know which is the true edge and which is the false
> edge so that we know when to invert the condition below. */
> extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
> @@ -908,10 +960,9 @@ match_simplify_replacement (basic_block cond_bb,
> basic_block middle_bb,
> std::swap (arg0, arg1);
>
> tree type = TREE_TYPE (gimple_phi_result (phi));
> - result = gimple_simplify (COND_EXPR, type,
> - cond,
> - arg0, arg1,
> - &seq, NULL);
> + result = gimple_simplify_phiopt (early_p, type, stmt,
> + arg0, arg1,
> + &seq);
> if (!result)
> return false;
>
> --
> 2.27.0
>
