diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 52c5cc64854..3ab942eec92 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2005-04-12 Mostafa Hagog + + * postreload-gcse.c (eliminate_partially_redundant_load): Don't + split critical edges when not possible/profitable. + 2005-04-12 Richard Sandiford * config/ns32k/ns32k.h (target_flags, MASK_32081, MASK_RTD) diff --git a/gcc/postreload-gcse.c b/gcc/postreload-gcse.c index 79b11eebf61..daacb538b62 100644 --- a/gcc/postreload-gcse.c +++ b/gcc/postreload-gcse.c @@ -1008,6 +1008,7 @@ eliminate_partially_redundant_load (basic_block bb, rtx insn, gcov_type ok_count = 0; /* Redundant load execution count. */ gcov_type critical_count = 0; /* Execution count of critical edges. */ edge_iterator ei; + bool critical_edge_split = false; /* The execution count of the loads to be added to make the load fully redundant. */ @@ -1028,6 +1029,7 @@ eliminate_partially_redundant_load (basic_block bb, rtx insn, rtx next_pred_bb_end; avail_insn = NULL_RTX; + avail_reg = NULL_RTX; pred_bb = pred->src; next_pred_bb_end = NEXT_INSN (BB_END (pred_bb)); for (a_occr = get_bb_avail_insn (pred_bb, expr->avail_occr); a_occr; @@ -1064,6 +1066,15 @@ eliminate_partially_redundant_load (basic_block bb, rtx insn, { npred_ok++; ok_count += pred->count; + if (! set_noop_p (PATTERN (gen_move_insn (copy_rtx (dest), + copy_rtx (avail_reg))))) + { + /* Check if there is going to be a split. */ + if (EDGE_CRITICAL_P (pred)) + critical_edge_split = true; + } + else /* Its a dead move no need to generate. */ + continue; occr = (struct unoccr *) obstack_alloc (&unoccr_obstack, sizeof (struct occr)); occr->insn = avail_insn; @@ -1075,6 +1086,9 @@ eliminate_partially_redundant_load (basic_block bb, rtx insn, } else { + /* Adding a load on a critical edge will cuase a split. */ + if (EDGE_CRITICAL_P (pred)) + critical_edge_split = true; not_ok_count += pred->count; unoccr = (struct unoccr *) obstack_alloc (&unoccr_obstack, sizeof (struct unoccr)); @@ -1090,7 +1104,12 @@ eliminate_partially_redundant_load (basic_block bb, rtx insn, if (/* No load can be replaced by copy. */ npred_ok == 0 /* Prevent exploding the code. */ - || (optimize_size && npred_ok > 1)) + || (optimize_size && npred_ok > 1) + /* If we don't have profile information we cannot tell if splitting + a critical edge is profitable or not so don't do it. */ + || ((! profile_info || ! flag_branch_probabilities + || targetm.cannot_modify_jumps_p ()) + && critical_edge_split)) goto cleanup; /* Check if it's worth applying the partial redundancy elimination. */ @@ -1150,7 +1169,17 @@ eliminate_partially_redundant_load (basic_block bb, rtx insn, a_occr = get_bb_avail_insn (bb, a_occr->next)); if (!a_occr) - delete_insn (insn); + { + stats.insns_deleted++; + + if (dump_file) + { + fprintf (dump_file, "deleting insn:\n"); + print_rtl_single (dump_file, insn); + fprintf (dump_file, "\n"); + } + delete_insn (insn); + } else a_occr->deleted_p = 1; @@ -1276,9 +1305,6 @@ void gcse_after_reload_main (rtx f ATTRIBUTE_UNUSED) { - if (targetm.cannot_modify_jumps_p ()) - return; - memset (&stats, 0, sizeof (stats)); /* Allocate ememory for this pass.