diff options
Diffstat (limited to 'gcc/tree-if-conv.c')
| -rw-r--r-- | gcc/tree-if-conv.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c index 822aae5b83f..af49813b0d1 100644 --- a/gcc/tree-if-conv.c +++ b/gcc/tree-if-conv.c @@ -120,6 +120,7 @@ along with GCC; see the file COPYING3. If not see #include "fold-const.h" #include "tree-ssa-sccvn.h" #include "tree-cfgcleanup.h" +#include "tree-ssa-dse.h" /* Only handle PHIs with no more arguments unless we are asked to by simd pragma. */ @@ -2873,7 +2874,7 @@ ifcvt_split_critical_edges (class loop *loop, bool aggressive_if_conv) loop vectorization. */ static void -ifcvt_local_dce (basic_block bb) +ifcvt_local_dce (class loop *loop) { gimple *stmt; gimple *stmt1; @@ -2890,6 +2891,10 @@ ifcvt_local_dce (basic_block bb) replace_uses_by (name_pair->first, name_pair->second); redundant_ssa_names.release (); + /* The loop has a single BB only. */ + basic_block bb = loop->header; + tree latch_vdef = NULL_TREE; + worklist.create (64); /* Consider all phi as live statements. */ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) @@ -2897,6 +2902,8 @@ ifcvt_local_dce (basic_block bb) phi = gsi_stmt (gsi); gimple_set_plf (phi, GF_PLF_2, true); worklist.safe_push (phi); + if (virtual_operand_p (gimple_phi_result (phi))) + latch_vdef = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (loop)); } /* Consider load/store statements, CALL and COND as live. */ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) @@ -2960,6 +2967,19 @@ ifcvt_local_dce (basic_block bb) while (!gsi_end_p (gsi)) { stmt = gsi_stmt (gsi); + if (gimple_store_p (stmt)) + { + tree lhs = gimple_get_lhs (stmt); + ao_ref write; + ao_ref_init (&write, lhs); + + if (dse_classify_store (&write, stmt, false, NULL, NULL, latch_vdef) + == DSE_STORE_DEAD) + delete_dead_or_redundant_assignment (&gsi, "dead"); + gsi_next (&gsi); + continue; + } + if (gimple_plf (stmt, GF_PLF_2)) { gsi_next (&gsi); @@ -3070,7 +3090,7 @@ tree_if_conversion (class loop *loop, vec<gimple *> *preds) todo |= do_rpo_vn (cfun, loop_preheader_edge (loop), exit_bbs); /* Delete dead predicate computations. */ - ifcvt_local_dce (loop->header); + ifcvt_local_dce (loop); BITMAP_FREE (exit_bbs); todo |= TODO_cleanup_cfg; |