From d592920c89973acd8d9f5b1f6b0526036ce63ccb Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Tue, 13 Jul 2021 10:17:39 +0100 Subject: [PATCH] vect: Add a vect_phi_initial_value helper function This patch adds a helper function called vect_phi_initial_value for returning the incoming value of a given loop phi. The main reason for adding it is to ensure that the right preheader edge is used when vectorising nested loops. (PHI_ARG_DEF_FROM_EDGE itself doesn't assert that the given edge is for the right block, although I guess that would be good to add separately.) gcc/ * tree-vectorizer.h: Include tree-ssa-operands.h. (vect_phi_initial_value): New function. * tree-vect-loop.c (neutral_op_for_slp_reduction): Use it. (get_initial_defs_for_reduction, info_for_reduction): Likewise. (vect_create_epilog_for_reduction, vectorizable_reduction): Likewise. (vect_transform_cycle_phi, vectorizable_induction): Likewise. --- gcc/tree-vect-loop.c | 29 +++++++++-------------------- gcc/tree-vectorizer.h | 21 ++++++++++++++++++++- 2 files changed, 29 insertions(+), 21 deletions(-) diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c index 1bd9a6e..a31d762 100644 --- a/gcc/tree-vect-loop.c +++ b/gcc/tree-vect-loop.c @@ -3288,8 +3288,7 @@ neutral_op_for_slp_reduction (slp_tree slp_node, tree vector_type, has only a single initial value, so that value is neutral for all statements. */ if (reduc_chain) - return PHI_ARG_DEF_FROM_EDGE (stmt_vinfo->stmt, - loop_preheader_edge (loop)); + return vect_phi_initial_value (stmt_vinfo); return NULL_TREE; default: @@ -4829,13 +4828,13 @@ get_initial_defs_for_reduction (vec_info *vinfo, /* Get the def before the loop. In reduction chain we have only one initial value. Else we have as many as PHIs in the group. */ if (reduc_chain) - op = j != 0 ? neutral_op : PHI_ARG_DEF_FROM_EDGE (stmt_vinfo->stmt, pe); + op = j != 0 ? neutral_op : vect_phi_initial_value (stmt_vinfo); else if (((vec_oprnds->length () + 1) * nunits - number_of_places_left_in_vector >= group_size) && neutral_op) op = neutral_op; else - op = PHI_ARG_DEF_FROM_EDGE (stmt_vinfo->stmt, pe); + op = vect_phi_initial_value (stmt_vinfo); /* Create 'vect_ = {op0,op1,...,opn}'. */ number_of_places_left_in_vector--; @@ -4906,9 +4905,7 @@ info_for_reduction (vec_info *vinfo, stmt_vec_info stmt_info) } else if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_nested_cycle) { - edge pe = loop_preheader_edge (gimple_bb (phi)->loop_father); - stmt_vec_info info - = vinfo->lookup_def (PHI_ARG_DEF_FROM_EDGE (phi, pe)); + stmt_vec_info info = vinfo->lookup_def (vect_phi_initial_value (phi)); if (info && STMT_VINFO_DEF_TYPE (info) == vect_double_reduction_def) stmt_info = info; } @@ -5042,8 +5039,7 @@ vect_create_epilog_for_reduction (loop_vec_info loop_vinfo, { /* Get at the scalar def before the loop, that defines the initial value of the reduction variable. */ - initial_def = PHI_ARG_DEF_FROM_EDGE (reduc_def_stmt, - loop_preheader_edge (loop)); + initial_def = vect_phi_initial_value (reduc_def_stmt); /* Optimize: for induction condition reduction, if we can't use zero for induc_val, use initial_def. */ if (STMT_VINFO_REDUC_TYPE (reduc_info) == INTEGER_INDUC_COND_REDUCTION) @@ -5558,9 +5554,7 @@ vect_create_epilog_for_reduction (loop_vec_info loop_vinfo, for MIN and MAX reduction, for example. */ if (!neutral_op) { - tree scalar_value - = PHI_ARG_DEF_FROM_EDGE (orig_phis[i]->stmt, - loop_preheader_edge (loop)); + tree scalar_value = vect_phi_initial_value (orig_phis[i]); scalar_value = gimple_convert (&seq, TREE_TYPE (vectype), scalar_value); vector_identity = gimple_build_vector_from_val (&seq, vectype, @@ -6752,10 +6746,7 @@ vectorizable_reduction (loop_vec_info loop_vinfo, else if (cond_reduc_dt == vect_constant_def) { enum vect_def_type cond_initial_dt; - tree cond_initial_val - = PHI_ARG_DEF_FROM_EDGE (reduc_def_phi, loop_preheader_edge (loop)); - - gcc_assert (cond_reduc_val != NULL_TREE); + tree cond_initial_val = vect_phi_initial_value (reduc_def_phi); vect_is_simple_use (cond_initial_val, loop_vinfo, &cond_initial_dt); if (cond_initial_dt == vect_constant_def && types_compatible_p (TREE_TYPE (cond_initial_val), @@ -7528,8 +7519,7 @@ vect_transform_cycle_phi (loop_vec_info loop_vinfo, { /* Get at the scalar def before the loop, that defines the initial value of the reduction variable. */ - tree initial_def = PHI_ARG_DEF_FROM_EDGE (phi, - loop_preheader_edge (loop)); + tree initial_def = vect_phi_initial_value (phi); /* Optimize: if initial_def is for REDUC_MAX smaller than the base and we can't use zero for induc_val, use initial_def. Similarly for REDUC_MIN and initial_def larger than the base. */ @@ -8175,8 +8165,7 @@ vectorizable_induction (loop_vec_info loop_vinfo, return true; } - init_expr = PHI_ARG_DEF_FROM_EDGE (phi, - loop_preheader_edge (iv_loop)); + init_expr = vect_phi_initial_value (phi); gimple_seq stmts = NULL; if (!nested_in_vect_loop) diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h index fa28336..e2fd360 100644 --- a/gcc/tree-vectorizer.h +++ b/gcc/tree-vectorizer.h @@ -27,7 +27,7 @@ typedef class _stmt_vec_info *stmt_vec_info; #include "tree-hash-traits.h" #include "target.h" #include "internal-fn.h" - +#include "tree-ssa-operands.h" /* Used for naming of new temporaries. */ enum vect_var_kind { @@ -1369,6 +1369,25 @@ nested_in_vect_loop_p (class loop *loop, stmt_vec_info stmt_info) && (loop->inner == (gimple_bb (stmt_info->stmt))->loop_father)); } +/* PHI is either a scalar reduction phi or a scalar induction phi. + Return the initial value of the variable on entry to the containing + loop. */ + +static inline tree +vect_phi_initial_value (gphi *phi) +{ + basic_block bb = gimple_bb (phi); + edge pe = loop_preheader_edge (bb->loop_father); + gcc_assert (pe->dest == bb); + return PHI_ARG_DEF_FROM_EDGE (phi, pe); +} + +static inline tree +vect_phi_initial_value (stmt_vec_info stmt_info) +{ + return vect_phi_initial_value (as_a (stmt_info->stmt)); +} + /* Return true if STMT_INFO should produce a vector mask type rather than a normal nonmask type. */ -- 2.7.4