diff options
Diffstat (limited to 'gcc/tree-if-conv.c')
| -rw-r--r-- | gcc/tree-if-conv.c | 112 |
1 files changed, 101 insertions, 11 deletions
diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c index e88ddc9..d0ca046 100644 --- a/gcc/tree-if-conv.c +++ b/gcc/tree-if-conv.c @@ -121,6 +121,7 @@ along with GCC; see the file COPYING3. If not see #include "tree-cfgcleanup.h" #include "tree-ssa-dse.h" #include "tree-vectorizer.h" +#include "tree-eh.h" /* Only handle PHIs with no more arguments unless we are asked to by simd pragma. */ @@ -2496,7 +2497,7 @@ predicate_rhs_code (gassign *stmt, tree mask, tree cond, */ static void -predicate_statements (loop_p loop, edge pe) +predicate_statements (loop_p loop) { unsigned int i, orig_loop_num_nodes = loop->num_nodes; auto_vec<int, 1> vect_sizes; @@ -2597,13 +2598,7 @@ predicate_statements (loop_p loop, edge pe) { gassign *stmt2 = as_a <gassign *> (gsi_stmt (gsi2)); gsi_remove (&gsi2, false); - /* Make sure to move invariant conversions out of the - loop. */ - if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt2)) - && expr_invariant_in_loop_p (loop, - gimple_assign_rhs1 (stmt2))) - gsi_insert_on_edge_immediate (pe, stmt2); - else if (first) + if (first) { gsi_insert_before (&gsi, stmt2, GSI_NEW_STMT); first = false; @@ -2684,7 +2679,7 @@ remove_conditions_and_labels (loop_p loop) blocks. Replace PHI nodes with conditional modify expressions. */ static void -combine_blocks (class loop *loop, edge pe) +combine_blocks (class loop *loop) { basic_block bb, exit_bb, merge_target_bb; unsigned int orig_loop_num_nodes = loop->num_nodes; @@ -2697,7 +2692,7 @@ combine_blocks (class loop *loop, edge pe) predicate_all_scalar_phis (loop); if (need_to_predicate || need_to_rewrite_undefined) - predicate_statements (loop, pe); + predicate_statements (loop); /* Merge basic blocks. */ exit_bb = NULL; @@ -3181,6 +3176,99 @@ ifcvt_local_dce (class loop *loop) } } +/* Return true if VALUE is already available on edge PE. */ + +static bool +ifcvt_available_on_edge_p (edge pe, tree value) +{ + if (is_gimple_min_invariant (value)) + return true; + + if (TREE_CODE (value) == SSA_NAME) + { + basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (value)); + if (!def_bb || dominated_by_p (CDI_DOMINATORS, pe->dest, def_bb)) + return true; + } + + return false; +} + +/* Return true if STMT can be hoisted from if-converted loop LOOP to + edge PE. */ + +static bool +ifcvt_can_hoist (class loop *loop, edge pe, gimple *stmt) +{ + if (auto *call = dyn_cast<gcall *> (stmt)) + { + if (gimple_call_internal_p (call) + && internal_fn_mask_index (gimple_call_internal_fn (call)) >= 0) + return false; + } + else if (auto *assign = dyn_cast<gassign *> (stmt)) + { + if (gimple_assign_rhs_code (assign) == COND_EXPR) + return false; + } + else + return false; + + if (gimple_has_side_effects (stmt) + || gimple_could_trap_p (stmt) + || stmt_could_throw_p (cfun, stmt) + || gimple_vdef (stmt) + || gimple_vuse (stmt)) + return false; + + int num_args = gimple_num_args (stmt); + if (pe != loop_preheader_edge (loop)) + { + for (int i = 0; i < num_args; ++i) + if (!ifcvt_available_on_edge_p (pe, gimple_arg (stmt, i))) + return false; + } + else + { + for (int i = 0; i < num_args; ++i) + if (!expr_invariant_in_loop_p (loop, gimple_arg (stmt, i))) + return false; + } + + return true; +} + +/* Hoist invariant statements from LOOP to edge PE. */ + +static void +ifcvt_hoist_invariants (class loop *loop, edge pe) +{ + gimple_stmt_iterator hoist_gsi = {}; + unsigned int num_blocks = loop->num_nodes; + basic_block *body = get_loop_body (loop); + for (unsigned int i = 0; i < num_blocks; ++i) + for (gimple_stmt_iterator gsi = gsi_start_bb (body[i]); !gsi_end_p (gsi);) + { + gimple *stmt = gsi_stmt (gsi); + if (ifcvt_can_hoist (loop, pe, stmt)) + { + /* Once we've hoisted one statement, insert other statements + after it. */ + gsi_remove (&gsi, false); + if (hoist_gsi.ptr) + gsi_insert_after (&hoist_gsi, stmt, GSI_NEW_STMT); + else + { + gsi_insert_on_edge_immediate (pe, stmt); + hoist_gsi = gsi_for_stmt (stmt); + } + continue; + } + gsi_next (&gsi); + } + free (body); +} + /* If-convert LOOP when it is legal. For the moment this pass has no profitability analysis. Returns non-zero todo flags when something changed. */ @@ -3275,7 +3363,7 @@ tree_if_conversion (class loop *loop, vec<gimple *> *preds) /* Now all statements are if-convertible. Combine all the basic blocks into one huge basic block doing the if-conversion on-the-fly. */ - combine_blocks (loop, pe); + combine_blocks (loop); /* Perform local CSE, this esp. helps the vectorizer analysis if loads and stores are involved. CSE only the loop body, not the entry @@ -3297,6 +3385,8 @@ tree_if_conversion (class loop *loop, vec<gimple *> *preds) ifcvt_local_dce (loop); BITMAP_FREE (exit_bbs); + ifcvt_hoist_invariants (loop, pe); + todo |= TODO_cleanup_cfg; cleanup: |