From 404938eda1ea3f5dcbca089aa7b23dc04f75b9e0 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Mon, 21 Aug 2017 13:18:35 +0000 Subject: [PATCH] re PR tree-optimization/81900 (GCC trunk miscompiles Perl / __sigsetjmp issue) 2017-08-21 Richard Biener PR tree-optimization/81900 * tree-ssa-pre.c (compute_antic_aux): Properly compute changed for blocks with abnormal predecessors. (compute_antic): Do not set visited flag prematurely. * gcc.dg/torture/pr81900.c: New testcase. From-SVN: r251226 --- gcc/ChangeLog | 7 +++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/torture/pr81900.c | 19 +++++++++++++++++++ gcc/tree-ssa-pre.c | 10 +++------- 4 files changed, 34 insertions(+), 7 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr81900.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index e0dae1503dc..25b745208a7 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2017-08-21 Richard Biener + + PR tree-optimization/81900 + * tree-ssa-pre.c (compute_antic_aux): Properly compute changed + for blocks with abnormal predecessors. + (compute_antic): Do not set visited flag prematurely. + 2017-08-21 Georg-Johann Lay PR target/79883 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 731c812826a..53505ef21f4 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-08-21 Richard Biener + + PR tree-optimization/81900 + * gcc.dg/torture/pr81900.c: New testcase. + 2017-08-21 Richard Biener * c-c++-common/asan/global-overflow-1.c: Adjust diagnostic location diff --git a/gcc/testsuite/gcc.dg/torture/pr81900.c b/gcc/testsuite/gcc.dg/torture/pr81900.c new file mode 100644 index 00000000000..9e4e8f4a7ca --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr81900.c @@ -0,0 +1,19 @@ +/* PR/81900 */ +/* { dg-do compile } */ +/* { dg-skip-if "" { *-*-* } { "-flto" } { "" } } */ +/* { dg-options "-fdump-tree-optimized" } */ + +void Perl_croak() __attribute__((noreturn)); +char *Perl_sv_gets(); +void __attribute__((returns_twice)) __sigsetjmp (); +void a() { + __sigsetjmp(); + char *b; + if ((b = Perl_sv_gets()) == 0) + Perl_croak("No Perl script found in input\n"); + if (*b == '#') + __asm__("" : : ""("badbad")); +} + +/* Do not elide the test against zero. */ +/* { dg-final { scan-tree-dump " == 0B" "optimized" } } */ diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c index a6a68cf8372..7243cf808f5 100644 --- a/gcc/tree-ssa-pre.c +++ b/gcc/tree-ssa-pre.c @@ -2119,16 +2119,15 @@ static sbitmap has_abnormal_preds; static bool compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge) { - bool changed = false; bitmap_set_t S, old, ANTIC_OUT; bitmap_iterator bi; unsigned int bii; edge e; edge_iterator ei; - bool was_visited = BB_VISITED (block); - old = ANTIC_OUT = S = NULL; + bool changed = ! BB_VISITED (block); BB_VISITED (block) = 1; + old = ANTIC_OUT = S = NULL; /* If any edges from predecessors are abnormal, antic_in is empty, so do nothing. */ @@ -2217,7 +2216,7 @@ compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge) /* clean (ANTIC_IN (block)) is defered to after the iteration converged because it can cause non-convergence, see for example PR81181. */ - if (!was_visited || !bitmap_set_equal (old, ANTIC_IN (block))) + if (!bitmap_set_equal (old, ANTIC_IN (block))) changed = true; maybe_dump_sets: @@ -2396,9 +2395,6 @@ compute_antic (void) if (e->flags & EDGE_ABNORMAL) { bitmap_set_bit (has_abnormal_preds, block->index); - - /* We also anticipate nothing. */ - BB_VISITED (block) = 1; break; } -- 2.30.2