From 108fdd6d848eb083021de4a43f3e682fa7babbf3 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Mon, 23 Jan 2017 22:29:17 +0000 Subject: [PATCH] re PR tree-optimization/79088 (wrong code at -O2 on x86_64-linux-gnu) 2017-01-23 Richard Biener PR tree-optimization/79088 PR tree-optimization/79188 * tree-ssa-threadupdate.c (mark_threaded_blocks): Move code resetting loop bounds after last path deletion. Reset loop bounds of the target loop, make code match the comments. * tree-ssa-threadbackwards.c (pass_early_thread_jumps::execute): Make sure loops need no fixups. * gcc.dg/torture/pr79088.c: New testcase. * gcc.dg/torture/pr79188.c: Likewise. From-SVN: r244837 --- gcc/ChangeLog | 10 ++++ gcc/testsuite/ChangeLog | 7 +++ gcc/testsuite/gcc.dg/torture/pr79088.c | 23 ++++++++ gcc/testsuite/gcc.dg/torture/pr79188.c | 44 +++++++++++++++ gcc/tree-ssa-threadbackward.c | 4 ++ gcc/tree-ssa-threadupdate.c | 76 ++++++++++++++------------ 6 files changed, 128 insertions(+), 36 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr79088.c create mode 100644 gcc/testsuite/gcc.dg/torture/pr79188.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 468e012b14e..8df91c72f4d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,13 @@ +2017-01-23 Richard Biener + + PR tree-optimization/79088 + PR tree-optimization/79188 + * tree-ssa-threadupdate.c (mark_threaded_blocks): Move code + resetting loop bounds after last path deletion. Reset loop + bounds of the target loop, make code match the comments. + * tree-ssa-threadbackwards.c (pass_early_thread_jumps::execute): + Make sure loops need no fixups. + 2017-01-23 Kelvin Nilsen * config/rs6000/rs6000-builtin.def (VSIEDPF): Add scalar insert diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 004bff932bb..c05ea54fe74 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,10 @@ +2017-01-23 Richard Biener + + PR tree-optimization/79088 + PR tree-optimization/79188 + * gcc.dg/torture/pr79088.c: New testcase. + * gcc.dg/torture/pr79188.c: Likewise. + 2017-01-23 Kelvin Nilsen * gcc.target/powerpc/bfp/scalar-insert-exp-3.c: New test. diff --git a/gcc/testsuite/gcc.dg/torture/pr79088.c b/gcc/testsuite/gcc.dg/torture/pr79088.c new file mode 100644 index 00000000000..7c78f15e3da --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr79088.c @@ -0,0 +1,23 @@ +/* { dg-do run } */ + +int a, b, c, d, e = 1; + +int main () +{ + int f; + if (a) + goto L; + for (f = 0; f < e; e++) + { +L: + if (d) + continue; + if (c) + goto L; + for (a = 0; a < 6; a++) + for (f = 0; f < 3; f++) + while (b) + c++; + } + return 0; +} diff --git a/gcc/testsuite/gcc.dg/torture/pr79188.c b/gcc/testsuite/gcc.dg/torture/pr79188.c new file mode 100644 index 00000000000..fc3208c4032 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr79188.c @@ -0,0 +1,44 @@ +/* { dg-do run } */ + +int a, b, c, d, e, f, h, j, k; + +static void fn1 () +{ + int g = 1, i; + if (!f) + { + for (; d < 1; d++) + for (i = 0, j = 1; i < 1; i = j) + a = 2; + for (; e < 1; e++) + { + for (; k; k++) + L: + ; + for (c = 0; c < 2; c++) + { + for (i = 0; i < 4; i++) + { + for (; h; h++) + g = 0; + b = 0; + } + if (b) + goto L; + } + a = 0; + } + if (g < 0) + goto L; + } +} + +int main () +{ + fn1 (); + + if (a != 0) + __builtin_abort (); + + return 0; +} diff --git a/gcc/tree-ssa-threadbackward.c b/gcc/tree-ssa-threadbackward.c index e09ecb8906a..51f30a7639c 100644 --- a/gcc/tree-ssa-threadbackward.c +++ b/gcc/tree-ssa-threadbackward.c @@ -865,6 +865,8 @@ pass_early_thread_jumps::gate (function *fun ATTRIBUTE_UNUSED) unsigned int pass_early_thread_jumps::execute (function *fun) { + loop_optimizer_init (AVOID_CFG_MODIFICATIONS); + /* Try to thread each block with more than one successor. */ basic_block bb; FOR_EACH_BB_FN (bb, fun) @@ -873,6 +875,8 @@ pass_early_thread_jumps::execute (function *fun) find_jump_threads_backwards (bb, false); } thread_through_all_blocks (true); + + loop_optimizer_finalize (); return 0; } diff --git a/gcc/tree-ssa-threadupdate.c b/gcc/tree-ssa-threadupdate.c index f85fed314f0..8e08ae29e03 100644 --- a/gcc/tree-ssa-threadupdate.c +++ b/gcc/tree-ssa-threadupdate.c @@ -2086,42 +2086,6 @@ mark_threaded_blocks (bitmap threaded_blocks) else bitmap_copy (threaded_blocks, tmp); - /* Look for jump threading paths which cross multiple loop headers. - - The code to thread through loop headers will change the CFG in ways - that invalidate the cached loop iteration information. So we must - detect that case and wipe the cached information. */ - EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi) - { - basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i); - FOR_EACH_EDGE (e, ei, bb->preds) - { - if (e->aux) - { - vec *path = THREAD_PATH (e); - - for (unsigned int i = 0, crossed_headers = 0; - i < path->length (); - i++) - { - basic_block dest = (*path)[i]->e->dest; - basic_block src = (*path)[i]->e->src; - crossed_headers += (dest == dest->loop_father->header); - /* If we step from a block outside an irreducible region - to a block inside an irreducible region, then we have - crossed into a loop. */ - crossed_headers += ((src->flags & BB_IRREDUCIBLE_LOOP) - != (dest->flags & BB_IRREDUCIBLE_LOOP)); - if (crossed_headers > 1) - { - vect_free_loop_info_assumptions (dest->loop_father); - break; - } - } - } - } - } - /* If we have a joiner block (J) which has two successors S1 and S2 and we are threading though S1 and the final destination of the thread is S2, then we must verify that any PHI nodes in S2 have the same @@ -2166,6 +2130,46 @@ mark_threaded_blocks (bitmap threaded_blocks) } } + /* Look for jump threading paths which cross multiple loop headers. + + The code to thread through loop headers will change the CFG in ways + that invalidate the cached loop iteration information. So we must + detect that case and wipe the cached information. */ + EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, bi) + { + basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i); + FOR_EACH_EDGE (e, ei, bb->preds) + { + if (e->aux) + { + vec *path = THREAD_PATH (e); + + for (unsigned int i = 0, crossed_headers = 0; + i < path->length (); + i++) + { + basic_block dest = (*path)[i]->e->dest; + basic_block src = (*path)[i]->e->src; + /* If we enter a loop. */ + if (flow_loop_nested_p (src->loop_father, dest->loop_father)) + ++crossed_headers; + /* If we step from a block outside an irreducible region + to a block inside an irreducible region, then we have + crossed into a loop. */ + else if (! (src->flags & BB_IRREDUCIBLE_LOOP) + && (dest->flags & BB_IRREDUCIBLE_LOOP)) + ++crossed_headers; + if (crossed_headers > 1) + { + vect_free_loop_info_assumptions + ((*path)[path->length () - 1]->e->dest->loop_father); + break; + } + } + } + } + } + BITMAP_FREE (tmp); } -- 2.30.2