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comparison gcc/tree-ssa-uncprop.c @ 131:84e7813d76e9

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gcc-8.2
author mir3636
date Thu, 25 Oct 2018 07:37:49 +0900
parents 04ced10e8804
children 1830386684a0
comparison
equal deleted inserted replaced
111:04ced10e8804 131:84e7813d76e9
1 /* Routines for discovering and unpropagating edge equivalences. 1 /* Routines for discovering and unpropagating edge equivalences.
2 Copyright (C) 2005-2017 Free Software Foundation, Inc. 2 Copyright (C) 2005-2018 Free Software Foundation, Inc.
3 3
4 This file is part of GCC. 4 This file is part of GCC.
5 5
6 GCC is free software; you can redistribute it and/or modify 6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by 7 it under the terms of the GNU General Public License as published by
182 which are reached by a single case label which represents 182 which are reached by a single case label which represents
183 a single value. */ 183 a single value. */
184 for (i = 0; i < n_labels; i++) 184 for (i = 0; i < n_labels; i++)
185 { 185 {
186 tree label = gimple_switch_label (switch_stmt, i); 186 tree label = gimple_switch_label (switch_stmt, i);
187 basic_block bb = label_to_block (CASE_LABEL (label)); 187 basic_block bb = label_to_block (cfun, CASE_LABEL (label));
188 188
189 if (CASE_HIGH (label) 189 if (CASE_HIGH (label)
190 || !CASE_LOW (label) 190 || !CASE_LOW (label)
191 || info[bb->index]) 191 || info[bb->index])
192 info[bb->index] = error_mark_node; 192 info[bb->index] = error_mark_node;
406 remove_equivalence (equiv->rhs); 406 remove_equivalence (equiv->rhs);
407 } 407 }
408 } 408 }
409 } 409 }
410 410
411 /* Ignoring loop backedges, if BB has precisely one incoming edge then
412 return that edge. Otherwise return NULL. */
413 static edge
414 single_incoming_edge_ignoring_loop_edges (basic_block bb)
415 {
416 edge retval = NULL;
417 edge e;
418 edge_iterator ei;
419
420 FOR_EACH_EDGE (e, ei, bb->preds)
421 {
422 /* A loop back edge can be identified by the destination of
423 the edge dominating the source of the edge. */
424 if (dominated_by_p (CDI_DOMINATORS, e->src, e->dest))
425 continue;
426
427 /* If we have already seen a non-loop edge, then we must have
428 multiple incoming non-loop edges and thus we return NULL. */
429 if (retval)
430 return NULL;
431
432 /* This is the first non-loop incoming edge we have found. Record
433 it. */
434 retval = e;
435 }
436
437 return retval;
438 }
439
440 edge 411 edge
441 uncprop_dom_walker::before_dom_children (basic_block bb) 412 uncprop_dom_walker::before_dom_children (basic_block bb)
442 { 413 {
443 basic_block parent; 414 basic_block parent;
444 edge e;
445 bool recorded = false; 415 bool recorded = false;
446 416
447 /* If this block is dominated by a single incoming edge and that edge 417 /* If this block is dominated by a single incoming edge and that edge
448 has an equivalency, then record the equivalency and push the 418 has an equivalency, then record the equivalency and push the
449 VALUE onto EQUIV_STACK. Else push a NULL entry on EQUIV_STACK. */ 419 VALUE onto EQUIV_STACK. Else push a NULL entry on EQUIV_STACK. */
450 parent = get_immediate_dominator (CDI_DOMINATORS, bb); 420 parent = get_immediate_dominator (CDI_DOMINATORS, bb);
451 if (parent) 421 if (parent)
452 { 422 {
453 e = single_incoming_edge_ignoring_loop_edges (bb); 423 edge e = single_pred_edge_ignoring_loop_edges (bb, false);
454 424
455 if (e && e->src == parent && e->aux) 425 if (e && e->src == parent && e->aux)
456 { 426 {
457 struct edge_equivalency *equiv = (struct edge_equivalency *) e->aux; 427 struct edge_equivalency *equiv = (struct edge_equivalency *) e->aux;
458 428