From 60838d634634a70d65a126166c944b159ac7649c Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Thu, 14 Nov 2019 15:33:49 +0000 Subject: [PATCH] Consider building nodes from scalars in vect_slp_analyze_node_operations If the statements in an SLP node aren't similar enough to be vectorised, or aren't something the vectoriser has code to handle, the BB vectoriser tries building the vector from scalars instead. This patch does the same thing if we're able to build a viable-looking tree but fail later during the analysis phase, e.g. because the target doesn't support a particular vector operation. This is needed to avoid regressions with a later patch. 2019-11-14 Richard Sandiford gcc/ * tree-vect-slp.c (vect_contains_pattern_stmt_p): New function. (vect_slp_convert_to_external): Likewise. (vect_slp_analyze_node_operations): If analysis fails, try building the node from scalars instead. gcc/testsuite/ * gcc.dg/vect/bb-slp-div-2.c: New test. From-SVN: r278246 --- gcc/ChangeLog | 7 +++ gcc/testsuite/ChangeLog | 4 ++ gcc/testsuite/gcc.dg/vect/bb-slp-div-2.c | 14 ++++++ gcc/tree-vect-slp.c | 58 ++++++++++++++++++++++++ 4 files changed, 83 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/vect/bb-slp-div-2.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2798f159cc0..4bccc164947 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2019-11-14 Richard Sandiford + + * tree-vect-slp.c (vect_contains_pattern_stmt_p): New function. + (vect_slp_convert_to_external): Likewise. + (vect_slp_analyze_node_operations): If analysis fails, try building + the node from scalars instead. + 2019-11-14 Richard Sandiford * tree-cfg.c (verify_gimple_assign_unary): Handle conversions diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 29da1f347bd..5af7ea02e5f 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2019-11-14 Richard Sandiford + + * gcc.dg/vect/bb-slp-div-2.c: New test. + 2019-11-14 Richard Sandiford * gcc.dg/vect/bb-slp-pr69907.c: Do not expect BB vectorization diff --git a/gcc/testsuite/gcc.dg/vect/bb-slp-div-2.c b/gcc/testsuite/gcc.dg/vect/bb-slp-div-2.c new file mode 100644 index 00000000000..715c22ac6c6 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/bb-slp-div-2.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ + +int x[4], y[4], z[4]; + +void +f (void) +{ + x[0] += y[0] / z[0] * 2; + x[1] += y[1] / z[1] * 2; + x[2] += y[2] / z[2] * 2; + x[3] += y[3] / z[3] * 2; +} + +/* { dg-final { scan-tree-dump "basic block vectorized" "slp2" { target vect_int } } } */ diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c index a46bba5ec60..1c1e5022c96 100644 --- a/gcc/tree-vect-slp.c +++ b/gcc/tree-vect-slp.c @@ -224,6 +224,19 @@ vect_free_oprnd_info (vec &oprnds_info) } +/* Return true if STMTS contains a pattern statement. */ + +static bool +vect_contains_pattern_stmt_p (vec stmts) +{ + stmt_vec_info stmt_info; + unsigned int i; + FOR_EACH_VEC_ELT (stmts, i, stmt_info) + if (is_pattern_stmt_p (stmt_info)) + return true; + return false; +} + /* Find the place of the data-ref in STMT_INFO in the interleaving chain that starts from FIRST_STMT_INFO. Return -1 if the data-ref is not a part of the chain. */ @@ -2694,6 +2707,39 @@ vect_slp_analyze_node_operations_1 (vec_info *vinfo, slp_tree node, return vect_analyze_stmt (stmt_info, &dummy, node, node_instance, cost_vec); } +/* Try to build NODE from scalars, returning true on success. + NODE_INSTANCE is the SLP instance that contains NODE. */ + +static bool +vect_slp_convert_to_external (vec_info *vinfo, slp_tree node, + slp_instance node_instance) +{ + stmt_vec_info stmt_info; + unsigned int i; + + if (!is_a (vinfo) + || node == SLP_INSTANCE_TREE (node_instance) + || vect_contains_pattern_stmt_p (SLP_TREE_SCALAR_STMTS (node))) + return false; + + if (dump_enabled_p ()) + dump_printf_loc (MSG_NOTE, vect_location, + "Building vector operands from scalars instead\n"); + + /* Don't remove and free the child nodes here, since they could be + referenced by other structures. The analysis and scheduling phases + (need to) ignore child nodes of anything that isn't vect_internal_def. */ + unsigned int group_size = SLP_TREE_SCALAR_STMTS (node).length (); + SLP_TREE_DEF_TYPE (node) = vect_external_def; + SLP_TREE_SCALAR_OPS (node).safe_grow (group_size); + FOR_EACH_VEC_ELT (SLP_TREE_SCALAR_STMTS (node), i, stmt_info) + { + tree lhs = gimple_get_lhs (vect_orig_stmt (stmt_info)->stmt); + SLP_TREE_SCALAR_OPS (node)[i] = lhs; + } + return true; +} + /* Analyze statements contained in SLP tree NODE after recursively analyzing the subtree. NODE_INSTANCE contains NODE and VINFO contains INSTANCE. @@ -2720,6 +2766,13 @@ vect_slp_analyze_node_operations (vec_info *vinfo, slp_tree node, { SLP_TREE_NUMBER_OF_VEC_STMTS (node) = SLP_TREE_NUMBER_OF_VEC_STMTS (*leader); + /* Cope with cases in which we made a late decision to build the + node from scalars. */ + if (SLP_TREE_DEF_TYPE (*leader) == vect_external_def + && vect_slp_convert_to_external (vinfo, node, node_instance)) + ; + else + gcc_assert (SLP_TREE_DEF_TYPE (node) == SLP_TREE_DEF_TYPE (*leader)); return true; } @@ -2779,6 +2832,11 @@ vect_slp_analyze_node_operations (vec_info *vinfo, slp_tree node, if (SLP_TREE_SCALAR_STMTS (child).length () != 0) STMT_VINFO_DEF_TYPE (SLP_TREE_SCALAR_STMTS (child)[0]) = dt[j]; + /* If this node can't be vectorized, try pruning the tree here rather + than felling the whole thing. */ + if (!res && vect_slp_convert_to_external (vinfo, node, node_instance)) + res = true; + return res; } -- 2.30.2