From: Richard Biener Date: Fri, 25 Nov 2016 10:22:57 +0000 (+0000) Subject: re PR tree-optimization/78343 (Loop is not eliminated) X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=59ec925b1199f9777d0d10be46251516f774b214;p=gcc.git re PR tree-optimization/78343 (Loop is not eliminated) 2016-11-24 Richard Biener PR tree-optimization/78343 * passes.def: Add CD-DCE pass after loop splitting. * tree-ssa-dce.c (find_obviously_necessary_stmts): Move SCEV init/finalize ... (perform_tree_ssa_dce): ... here. Deal with being executed inside the loop pipeline in aggressive mode. * gcc.dg/tree-ssa/sccp-2.c: New testcase. * gcc.dg/autopar/uns-outer-6.c: Adjust. * gcc.dg/tree-ssa/20030808-1.c: Likewise. * gcc.dg/tree-ssa/20040305-1.c: Likewise. * gcc.dg/vect/pr38529.c: Likewise. From-SVN: r242872 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9e2c4ff0550..9681566de99 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,12 @@ +2016-11-24 Richard Biener + + PR tree-optimization/78343 + * passes.def: Add CD-DCE pass after loop splitting. + * tree-ssa-dce.c (find_obviously_necessary_stmts): Move + SCEV init/finalize ... + (perform_tree_ssa_dce): ... here. Deal with being + executed inside the loop pipeline in aggressive mode. + 2016-11-25 Thomas Preud'homme * tree-ssa-math-opts.c (struct symbolic_number): Improve comment. diff --git a/gcc/passes.def b/gcc/passes.def index b73000923b6..1117b8b112b 100644 --- a/gcc/passes.def +++ b/gcc/passes.def @@ -272,6 +272,9 @@ along with GCC; see the file COPYING3. If not see NEXT_PASS (pass_tree_unswitch); NEXT_PASS (pass_scev_cprop); NEXT_PASS (pass_loop_split); + /* All unswitching, final value replacement and splitting can expose + empty loops. Remove them now. */ + NEXT_PASS (pass_cd_dce); NEXT_PASS (pass_record_bounds); NEXT_PASS (pass_loop_distribution); NEXT_PASS (pass_copy_prop); diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 7e1aace6837..7072950f236 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,12 @@ +2016-11-24 Richard Biener + + PR tree-optimization/78343 + * gcc.dg/tree-ssa/sccp-2.c: New testcase. + * gcc.dg/autopar/uns-outer-6.c: Adjust. + * gcc.dg/tree-ssa/20030808-1.c: Likewise. + * gcc.dg/tree-ssa/20040305-1.c: Likewise. + * gcc.dg/vect/pr38529.c: Likewise. + 2016-11-25 Thomas Preud'homme PR tree-optimization/77673 diff --git a/gcc/testsuite/gcc.dg/autopar/uns-outer-6.c b/gcc/testsuite/gcc.dg/autopar/uns-outer-6.c index dc2870be8d4..12bd3979202 100644 --- a/gcc/testsuite/gcc.dg/autopar/uns-outer-6.c +++ b/gcc/testsuite/gcc.dg/autopar/uns-outer-6.c @@ -25,7 +25,7 @@ parloop (int N) for (i = 0; i < N; i++) { for (j = 0; j < N; j++) - y[i]=x[i][j]; + y[i] += x[i][j]; sum += y[i]; } g_sum = sum; diff --git a/gcc/testsuite/gcc.dg/tree-ssa/20030808-1.c b/gcc/testsuite/gcc.dg/tree-ssa/20030808-1.c index 7cc5404561c..cda86a7bbf1 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/20030808-1.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/20030808-1.c @@ -33,8 +33,8 @@ delete_dead_jumptables () /* There should be no loads of ->code. If any exist, then we failed to optimize away all the IF statements and the statements feeding their conditions. */ -/* { dg-final { scan-tree-dump-times "->code" 0 "cddce2"} } */ +/* { dg-final { scan-tree-dump-times "->code" 0 "cddce3"} } */ /* There should be no IF statements. */ -/* { dg-final { scan-tree-dump-times "if " 0 "cddce2"} } */ +/* { dg-final { scan-tree-dump-times "if " 0 "cddce3"} } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/20040305-1.c b/gcc/testsuite/gcc.dg/tree-ssa/20040305-1.c index 501e28cff54..d1a9af83348 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/20040305-1.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/20040305-1.c @@ -27,4 +27,4 @@ void foo(int edx, int eax) /* After cddce we should have two IF statements remaining as the other two tests can be threaded. */ -/* { dg-final { scan-tree-dump-times "if " 2 "cddce2"} } */ +/* { dg-final { scan-tree-dump-times "if " 2 "cddce3"} } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/sccp-2.c b/gcc/testsuite/gcc.dg/tree-ssa/sccp-2.c new file mode 100644 index 00000000000..099b2810a0c --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/sccp-2.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ + +unsigned int +test(unsigned int quant) +{ + unsigned int sum = 0; + for (unsigned int i = 0; i < quant; ++i) + sum += quant; + return sum; +} + +/* A single basic-block should remain (computing and + returning quant * quant). */ +/* { dg-final { scan-tree-dump-times "bb" 1 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/vect/pr38529.c b/gcc/testsuite/gcc.dg/vect/pr38529.c index 171adebfa20..9b5919d6704 100644 --- a/gcc/testsuite/gcc.dg/vect/pr38529.c +++ b/gcc/testsuite/gcc.dg/vect/pr38529.c @@ -11,7 +11,3 @@ void foo() for (j = 0; j < 17; ++j) a[i] = 0; } - -/* { dg-final { scan-tree-dump-times "OUTER LOOP VECTORIZED" 1 "vect" } } */ - - diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c index 7b9814e1aa7..50b5eefc1fc 100644 --- a/gcc/tree-ssa-dce.c +++ b/gcc/tree-ssa-dce.c @@ -400,7 +400,6 @@ find_obviously_necessary_stmts (bool aggressive) if (aggressive) { struct loop *loop; - scev_initialize (); if (mark_irreducible_loops ()) FOR_EACH_BB_FN (bb, cfun) { @@ -423,7 +422,6 @@ find_obviously_necessary_stmts (bool aggressive) fprintf (dump_file, "can not prove finiteness of loop %i\n", loop->num); mark_control_dependent_edges_necessary (loop->latch, false); } - scev_finalize (); } } @@ -1567,9 +1565,13 @@ perform_tree_ssa_dce (bool aggressive) /* Preheaders are needed for SCEV to work. Simple lateches and recorded exits improve chances that loop will proved to be finite in testcases such as in loop-15.c and loop-24.c */ - if (aggressive) - loop_optimizer_init (LOOPS_NORMAL - | LOOPS_HAVE_RECORDED_EXITS); + bool in_loop_pipeline = scev_initialized_p (); + if (aggressive && ! in_loop_pipeline) + { + scev_initialize (); + loop_optimizer_init (LOOPS_NORMAL + | LOOPS_HAVE_RECORDED_EXITS); + } tree_dce_init (aggressive); @@ -1588,8 +1590,11 @@ perform_tree_ssa_dce (bool aggressive) find_obviously_necessary_stmts (aggressive); - if (aggressive) - loop_optimizer_finalize (); + if (aggressive && ! in_loop_pipeline) + { + loop_optimizer_finalize (); + scev_finalize (); + } longest_chain = 0; total_chain = 0; @@ -1623,7 +1628,7 @@ perform_tree_ssa_dce (bool aggressive) if (something_changed) { free_numbers_of_iterations_estimates (cfun); - if (scev_initialized_p ()) + if (in_loop_pipeline) scev_reset (); return TODO_update_ssa | TODO_cleanup_cfg; }