diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 9 | ||||
| -rw-r--r-- | gcc/gimple-fold.c | 37 | ||||
| -rw-r--r-- | gcc/gimple-fold.h | 1 | ||||
| -rw-r--r-- | gcc/tree-ssa-propagate.c | 2 |
4 files changed, 48 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 64ed03b87b2..00708ed6d5e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,12 @@ +2014-10-28 Richard Biener <rguenther@suse.de> + + * gimple-fold.h (follow_single_use_edges): Declare. + * gimple-fold.c (follow_single_use_edges): New function. + (gimple_fold_stmt_to_constant_1): Dispatch to gimple_simplify. + * tree-ssa-propagate.c + (substitute_and_fold_dom_walker::before_dom_children): Allow + following single-use edges when folding stmts we propagated into. + 2014-10-28 Alexander Ivchenko <alexander.ivchenko@intel.com> Maxim Kuznetsov <maxim.kuznetsov@intel.com> Anna Tikhonova <anna.tikhonova@intel.com> diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 8c889303277..d0554f4e54f 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -65,6 +65,8 @@ along with GCC; see the file COPYING3. If not see #include "output.h" #include "tree-eh.h" #include "gimple-match.h" +#include "tree-phinodes.h" +#include "ssa-iterators.h" /* Return true when DECL can be referenced from current unit. FROM_DECL (if non-null) specify constructor of variable DECL was taken from. @@ -3241,6 +3243,17 @@ no_follow_ssa_edges (tree) return NULL_TREE; } +/* Valueization callback that ends up following single-use SSA edges only. */ + +tree +follow_single_use_edges (tree val) +{ + if (TREE_CODE (val) == SSA_NAME + && !has_single_use (val)) + return NULL_TREE; + return val; +} + /* Fold the statement pointed to by GSI. In some cases, this function may replace the whole statement with a new one. Returns true iff folding makes any changes. @@ -4371,6 +4384,30 @@ maybe_fold_or_comparisons (enum tree_code code1, tree op1a, tree op1b, tree gimple_fold_stmt_to_constant_1 (gimple stmt, tree (*valueize) (tree)) { + code_helper rcode; + tree ops[3] = {}; + /* ??? The SSA propagators do not correctly deal with following SSA use-def + edges if there are intermediate VARYING defs. For this reason + do not follow SSA edges here even though SCCVN can technically + just deal fine with that. */ + if (gimple_simplify (stmt, &rcode, ops, NULL, no_follow_ssa_edges) + && rcode.is_tree_code () + && (TREE_CODE_LENGTH ((tree_code) rcode) == 0 + || ((tree_code) rcode) == ADDR_EXPR) + && is_gimple_val (ops[0])) + { + tree res = ops[0]; + if (dump_file && dump_flags & TDF_DETAILS) + { + fprintf (dump_file, "Match-and-simplified "); + print_gimple_expr (dump_file, stmt, 0, TDF_SLIM); + fprintf (dump_file, " to "); + print_generic_expr (dump_file, res, 0); + fprintf (dump_file, "\n"); + } + return res; + } + location_t loc = gimple_location (stmt); switch (gimple_code (stmt)) { diff --git a/gcc/gimple-fold.h b/gcc/gimple-fold.h index 39c53ff3916..0cd2899494e 100644 --- a/gcc/gimple-fold.h +++ b/gcc/gimple-fold.h @@ -33,6 +33,7 @@ extern tree maybe_fold_and_comparisons (enum tree_code, tree, tree, extern tree maybe_fold_or_comparisons (enum tree_code, tree, tree, enum tree_code, tree, tree); extern tree no_follow_ssa_edges (tree); +extern tree follow_single_use_edges (tree); extern tree gimple_fold_stmt_to_constant_1 (gimple, tree (*) (tree)); extern tree gimple_fold_stmt_to_constant (gimple, tree (*) (tree)); extern tree fold_const_aggregate_ref_1 (tree, tree (*) (tree)); diff --git a/gcc/tree-ssa-propagate.c b/gcc/tree-ssa-propagate.c index e5e682629da..9f4d3811f28 100644 --- a/gcc/tree-ssa-propagate.c +++ b/gcc/tree-ssa-propagate.c @@ -1150,7 +1150,7 @@ substitute_and_fold_dom_walker::before_dom_children (basic_block bb) /* If we made a replacement, fold the statement. */ if (did_replace) - fold_stmt (&i); + fold_stmt (&i, follow_single_use_edges); /* Now cleanup. */ if (did_replace) |