From: Richard Sandiford Date: Wed, 6 Jul 2016 08:11:31 +0000 (+0000) Subject: [2/7] Clean up vectorizer load/store costs X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=892a981f1efb398768ad5a138fb7c971462d1e79;p=gcc.git [2/7] Clean up vectorizer load/store costs Add a bit more commentary and try to make the structure more obvious. The horrendous: if (grouped_access_p && represents_group_p && !store_lanes_p && !STMT_VINFO_STRIDED_P (stmt_info) && !slp_node) checks go away in patch 6. Tested on aarch64-linux-gnu and x86_64-linux-gnu. gcc/ * tree-vect-stmts.c (vect_cost_group_size): Delete. (vect_model_store_cost): Avoid calling it. Use first_stmt_p variable to indicate when once-per-group costs are being used. (vect_model_load_cost): Likewise. Fix comment and misindented code. From-SVN: r238034 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 5c9ecb21f3e..408f4af44a2 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2016-07-06 Richard Sandiford + + * tree-vect-stmts.c (vect_cost_group_size): Delete. + (vect_model_store_cost): Avoid calling it. Use first_stmt_p + variable to indicate when once-per-group costs are being used. + (vect_model_load_cost): Likewise. Fix comment and misindented code. + 2016-07-06 Richard Sandiford * tree-vect-stmts.c (vectorizable_load): Remove unnecessary diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c index d0a3892bc1e..aff0cc6851f 100644 --- a/gcc/tree-vect-stmts.c +++ b/gcc/tree-vect-stmts.c @@ -865,24 +865,6 @@ vect_model_promotion_demotion_cost (stmt_vec_info stmt_info, "prologue_cost = %d .\n", inside_cost, prologue_cost); } -/* Function vect_cost_group_size - - For grouped load or store, return the group_size only if it is the first - load or store of a group, else return 1. This ensures that group size is - only returned once per group. */ - -static int -vect_cost_group_size (stmt_vec_info stmt_info) -{ - gimple *first_stmt = GROUP_FIRST_ELEMENT (stmt_info); - - if (first_stmt == STMT_VINFO_STMT (stmt_info)) - return GROUP_SIZE (stmt_info); - - return 1; -} - - /* Function vect_model_store_cost Models cost for stores. In the case of grouped accesses, one access @@ -895,47 +877,43 @@ vect_model_store_cost (stmt_vec_info stmt_info, int ncopies, stmt_vector_for_cost *prologue_cost_vec, stmt_vector_for_cost *body_cost_vec) { - int group_size; unsigned int inside_cost = 0, prologue_cost = 0; - struct data_reference *first_dr; - gimple *first_stmt; + struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info); + gimple *first_stmt = STMT_VINFO_STMT (stmt_info); + bool grouped_access_p = STMT_VINFO_GROUPED_ACCESS (stmt_info); if (dt == vect_constant_def || dt == vect_external_def) prologue_cost += record_stmt_cost (prologue_cost_vec, 1, scalar_to_vec, stmt_info, 0, vect_prologue); - /* Grouped access? */ - if (STMT_VINFO_GROUPED_ACCESS (stmt_info)) + /* Grouped stores update all elements in the group at once, + so we want the DR for the first statement. */ + if (!slp_node && grouped_access_p) { - if (slp_node) - { - first_stmt = SLP_TREE_SCALAR_STMTS (slp_node)[0]; - group_size = 1; - } - else - { - first_stmt = GROUP_FIRST_ELEMENT (stmt_info); - group_size = vect_cost_group_size (stmt_info); - } - - first_dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt)); - } - /* Not a grouped access. */ - else - { - group_size = 1; - first_dr = STMT_VINFO_DATA_REF (stmt_info); + first_stmt = GROUP_FIRST_ELEMENT (stmt_info); + dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt)); } + /* True if we should include any once-per-group costs as well as + the cost of the statement itself. For SLP we only get called + once per group anyhow. */ + bool first_stmt_p = (first_stmt == STMT_VINFO_STMT (stmt_info)); + /* We assume that the cost of a single store-lanes instruction is equivalent to the cost of GROUP_SIZE separate stores. If a grouped access is instead being provided by a permute-and-store operation, - include the cost of the permutes. */ - if (!store_lanes_p && group_size > 1 - && !STMT_VINFO_STRIDED_P (stmt_info)) + include the cost of the permutes. + + For SLP, the caller has already counted the permutation, if any. */ + if (grouped_access_p + && first_stmt_p + && !store_lanes_p + && !STMT_VINFO_STRIDED_P (stmt_info) + && !slp_node) { /* Uses a high and low interleave or shuffle operations for each needed permute. */ + int group_size = GROUP_SIZE (vinfo_for_stmt (first_stmt)); int nstmts = ncopies * ceil_log2 (group_size) * group_size; inside_cost = record_stmt_cost (body_cost_vec, nstmts, vec_perm, stmt_info, 0, vect_body); @@ -957,7 +935,7 @@ vect_model_store_cost (stmt_vec_info stmt_info, int ncopies, scalar_store, stmt_info, 0, vect_body); } else - vect_get_store_cost (first_dr, ncopies, &inside_cost, body_cost_vec); + vect_get_store_cost (dr, ncopies, &inside_cost, body_cost_vec); if (STMT_VINFO_STRIDED_P (stmt_info)) inside_cost += record_stmt_cost (body_cost_vec, @@ -1026,8 +1004,8 @@ vect_get_store_cost (struct data_reference *dr, int ncopies, /* Function vect_model_load_cost - Models cost for loads. In the case of grouped accesses, the last access - has the overhead of the grouped access attributed to it. Since unaligned + Models cost for loads. In the case of grouped accesses, one access has + the overhead of the grouped access attributed to it. Since unaligned accesses are supported for loads, we also account for the costs of the access scheme chosen. */ @@ -1037,34 +1015,39 @@ vect_model_load_cost (stmt_vec_info stmt_info, int ncopies, stmt_vector_for_cost *prologue_cost_vec, stmt_vector_for_cost *body_cost_vec) { - int group_size; - gimple *first_stmt; - struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info), *first_dr; + gimple *first_stmt = STMT_VINFO_STMT (stmt_info); + struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info); unsigned int inside_cost = 0, prologue_cost = 0; + bool grouped_access_p = STMT_VINFO_GROUPED_ACCESS (stmt_info); - /* Grouped accesses? */ - first_stmt = GROUP_FIRST_ELEMENT (stmt_info); - if (STMT_VINFO_GROUPED_ACCESS (stmt_info) && first_stmt && !slp_node) + /* Grouped loads read all elements in the group at once, + so we want the DR for the first statement. */ + if (!slp_node && grouped_access_p) { - group_size = vect_cost_group_size (stmt_info); - first_dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt)); - } - /* Not a grouped access. */ - else - { - group_size = 1; - first_dr = dr; + first_stmt = GROUP_FIRST_ELEMENT (stmt_info); + dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt)); } + /* True if we should include any once-per-group costs as well as + the cost of the statement itself. For SLP we only get called + once per group anyhow. */ + bool first_stmt_p = (first_stmt == STMT_VINFO_STMT (stmt_info)); + /* We assume that the cost of a single load-lanes instruction is equivalent to the cost of GROUP_SIZE separate loads. If a grouped access is instead being provided by a load-and-permute operation, - include the cost of the permutes. */ - if (!load_lanes_p && group_size > 1 - && !STMT_VINFO_STRIDED_P (stmt_info)) + include the cost of the permutes. + + For SLP, the caller has already counted the permutation, if any. */ + if (grouped_access_p + && first_stmt_p + && !load_lanes_p + && !STMT_VINFO_STRIDED_P (stmt_info) + && !slp_node) { /* Uses an even and odd extract operations or shuffle operations for each needed permute. */ + int group_size = GROUP_SIZE (vinfo_for_stmt (first_stmt)); int nstmts = ncopies * ceil_log2 (group_size) * group_size; inside_cost = record_stmt_cost (body_cost_vec, nstmts, vec_perm, stmt_info, 0, vect_body); @@ -1086,14 +1069,12 @@ vect_model_load_cost (stmt_vec_info stmt_info, int ncopies, scalar_load, stmt_info, 0, vect_body); } else - vect_get_load_cost (first_dr, ncopies, - ((!STMT_VINFO_GROUPED_ACCESS (stmt_info)) - || group_size > 1 || slp_node), + vect_get_load_cost (dr, ncopies, first_stmt_p, &inside_cost, &prologue_cost, prologue_cost_vec, body_cost_vec, true); if (STMT_VINFO_STRIDED_P (stmt_info)) - inside_cost += record_stmt_cost (body_cost_vec, ncopies, vec_construct, - stmt_info, 0, vect_body); + inside_cost += record_stmt_cost (body_cost_vec, ncopies, vec_construct, + stmt_info, 0, vect_body); if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location,