This makes the dumps easier to follow. Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard. 2014-05-20 Richard Biener <rguent...@suse.de> * tree-ssa-sccvn.c (process_scc): Dump SCC here, when iterating, (extract_and_process_scc_for_name): not here. (cond_dom_walker::before_dom_children): Only process stmts that end the BB in interesting ways. (run_scc_vn): Mark param uses as visited. Index: gcc/tree-ssa-sccvn.c =================================================================== --- gcc/tree-ssa-sccvn.c (revision 210635) +++ gcc/tree-ssa-sccvn.c (working copy) @@ -3833,6 +3833,9 @@ process_scc (vec<tree> scc) } } + if (dump_file && (dump_flags & TDF_DETAILS)) + print_scc (dump_file, scc); + /* Iterate over the SCC with the optimistic table until it stops changing. */ current_info = optimistic_info; @@ -3858,6 +3861,8 @@ process_scc (vec<tree> scc) changed |= visit_use (var); } + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "Processing SCC needed %d iterations\n", iterations); statistics_histogram_event (cfun, "SCC iterations", iterations); /* Finally, copy the contents of the no longer used optimistic @@ -3909,9 +3914,6 @@ extract_and_process_scc_for_name (tree n if (scc.length () > 1) sort_scc (scc); - if (dump_file && (dump_flags & TDF_DETAILS)) - print_scc (dump_file, scc); - process_scc (scc); return true; @@ -4221,6 +4223,19 @@ cond_dom_walker::before_dom_children (ba if (!stmt) return; + enum gimple_code code = gimple_code (stmt); + if (code != GIMPLE_COND + && code != GIMPLE_SWITCH + && code != GIMPLE_GOTO) + return; + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Value-numbering operands of stmt ending BB %d: ", + bb->index); + print_gimple_stmt (dump_file, stmt, 0, 0); + } + /* Value-number the last stmts SSA uses. */ ssa_op_iter i; tree op; @@ -4236,7 +4251,7 @@ cond_dom_walker::before_dom_children (ba if value-numbering can prove they are not reachable. Handling computed gotos is also possible. */ tree val; - switch (gimple_code (stmt)) + switch (code) { case GIMPLE_COND: { @@ -4259,8 +4274,7 @@ cond_dom_walker::before_dom_children (ba val = gimple_goto_dest (stmt); break; default: - val = NULL_TREE; - break; + gcc_unreachable (); } if (!val) return; @@ -4300,7 +4314,10 @@ run_scc_vn (vn_lookup_kind default_vn_wa { tree def = ssa_default_def (cfun, param); if (def) - VN_INFO (def)->valnum = def; + { + VN_INFO (def)->visited = true; + VN_INFO (def)->valnum = def; + } } /* Mark all edges as possibly executable. */