From: Richard Biener Date: Tue, 23 Jul 2019 10:00:24 +0000 (+0000) Subject: re PR tree-optimization/83518 (Missing optimization: useless instructions should... X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=62e3e66f130fc280eac0bbb6b69e9adca328c03b;p=gcc.git re PR tree-optimization/83518 (Missing optimization: useless instructions should be dropped) 2019-07-23 Richard Biener PR tree-optimization/83518 * tree-ssa-sccvn.c (vn_reference_lookup_3): Handle aggregate init from a constant even when partial defs are already recorded. c/ * gimple-parser.c (c_parser_parse_gimple_body): When we have a CFG also rebuild cgraph edges. * gcc.dg/tree-ssa/ssa-fre-79.c: New testcase. From-SVN: r273732 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index fb9b0ff8db2..1add332e0fe 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2019-07-23 Richard Biener + + PR tree-optimization/83518 + * tree-ssa-sccvn.c (vn_reference_lookup_3): Handle aggregate + init from a constant even when partial defs are already recorded. + 2019-07-23 Jan Hubicka * i386-common.c: Use PROCESSOR_ZNVER2 scheduler for znver2. diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog index a75f0d80955..0bb1d4c1c32 100644 --- a/gcc/c/ChangeLog +++ b/gcc/c/ChangeLog @@ -1,3 +1,9 @@ +2019-07-23 Richard Biener + + PR tree-optimization/83518 + * gimple-parser.c (c_parser_parse_gimple_body): When we have + a CFG also rebuild cgraph edges. + 2019-07-20 Jakub Jelinek * c-parser.c (c_parser_omp_clause_name): Handle bind clause. diff --git a/gcc/c/gimple-parser.c b/gcc/c/gimple-parser.c index 4970ae1e9e0..3f575992d32 100644 --- a/gcc/c/gimple-parser.c +++ b/gcc/c/gimple-parser.c @@ -356,6 +356,8 @@ c_parser_parse_gimple_body (c_parser *cparser, char *gimple_pass, gcov_type t = PARAM_VALUE (PARAM_GIMPLE_FE_COMPUTED_HOT_BB_THRESHOLD); set_hot_bb_threshold (t); update_max_bb_count (); + cgraph_node::get_create (cfun->decl); + cgraph_edge::rebuild_edges (); } dump_function (TDI_gimple, current_function_decl); } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index d5efd503cb8..8e6b02668fb 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2019-07-23 Richard Biener + + PR tree-optimization/83518 + * gcc.dg/tree-ssa/ssa-fre-79.c: New testcase. + 2019-07-23 Ed Schonberg * gnat.dg/task4.adb: New testcase. diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-79.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-79.c new file mode 100644 index 00000000000..83aef9ad0f3 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-79.c @@ -0,0 +1,29 @@ +/* { dg-do run } */ +/* { dg-options "-O -fgimple -fdump-tree-fre1" } */ + +struct S { char a[4]; }; +const struct S cs = { 1, 2, 3, 4 }; + +int __GIMPLE(ssa,startwith("fre")) +main () +{ + struct S s; + short _1; + + __BB(2): + s = cs; + s.a[1] = _Literal (char) 3; + _1 = __MEM (&s + 1); + if (_1 != _Literal (short) 0x303) + goto __BB3; + else + goto __BB4; + + __BB(3): + __builtin_abort (); + + __BB(4): + return 0; +} + +/* { dg-final { scan-tree-dump-not "abort" "fre1" } } */ diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index cab2460a308..9369c36f50e 100644 --- a/gcc/tree-ssa-sccvn.c +++ b/gcc/tree-ssa-sccvn.c @@ -2702,9 +2702,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_, && gimple_assign_single_p (def_stmt) && (DECL_P (gimple_assign_rhs1 (def_stmt)) || TREE_CODE (gimple_assign_rhs1 (def_stmt)) == MEM_REF - || handled_component_p (gimple_assign_rhs1 (def_stmt))) - /* Handling this is more complicated, give up for now. */ - && data->partial_defs.is_empty ()) + || handled_component_p (gimple_assign_rhs1 (def_stmt)))) { tree base2; int i, j, k; @@ -2808,8 +2806,30 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_, /* Try folding the new reference to a constant. */ tree val = fully_constant_vn_reference_p (vr); if (val) - return vn_reference_lookup_or_insert_for_pieces - (vuse, vr->set, vr->type, vr->operands, val); + { + if (data->partial_defs.is_empty ()) + return vn_reference_lookup_or_insert_for_pieces + (vuse, vr->set, vr->type, vr->operands, val); + /* This is the only interesting case for partial-def handling + coming from targets that like to gimplify init-ctors as + aggregate copies from constant data like aarch64 for + PR83518. */ + if (maxsize.is_constant (&maxsizei) + && known_eq (ref->size, maxsize)) + { + pd_data pd; + pd.rhs = val; + pd.offset = 0; + pd.size = maxsizei / BITS_PER_UNIT; + return data->push_partial_def (pd, vuse, maxsizei); + } + } + + /* Continuing with partial defs isn't easily possible here, we + have to find a full def from further lookups from here. Probably + not worth the special-casing everywhere. */ + if (!data->partial_defs.is_empty ()) + return (void *)-1; /* Adjust *ref from the new operands. */ if (!ao_ref_init_from_vn_reference (&r, vr->set, vr->type, vr->operands))