From c04f07f4cfe0621ab2b707ae7691b52747b9ce44 Mon Sep 17 00:00:00 2001 From: Diego Novillo Date: Wed, 22 Sep 2004 23:33:20 +0000 Subject: [PATCH] re PR tree-optimization/16721 (Accesses to volatile objects optimized away) PR tree-optimization/16721 * tree-dfa.c (dump_variable): Show TREE_THIS_VOLATILE. * tree-ssa-alias.c (create_memory_tag): Move setting of TREE_THIS_VOLATILE ... (get_tmt_for): ... here. testsuite/ChangeLog PR tree-optimization/16721 * testsuite/gcc.dg/tree-ssa/pr16721.c: New test. From-SVN: r87895 --- gcc/ChangeLog | 8 ++++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/tree-ssa/pr16721.c | 15 +++++++++++++++ gcc/tree-dfa.c | 3 +++ gcc/tree-ssa-alias.c | 6 +++--- 5 files changed, 34 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr16721.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 3680fead8be..9feec2ead0b 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2004-09-22 Diego Novillo + + PR tree-optimization/16721 + * tree-dfa.c (dump_variable): Show TREE_THIS_VOLATILE. + * tree-ssa-alias.c (create_memory_tag): Move setting of + TREE_THIS_VOLATILE ... + (get_tmt_for): ... here. + 2004-09-22 Eric Botcazou * config/sparc/sparc.md (cmove splitter): Fix formatting. diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 0d7aa425772..5c6e8958fd9 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2004-09-22 Diego Novillo + + PR tree-optimization/16721 + * testsuite/gcc.dg/tree-ssa/pr16721.c: New test. + 2004-09-23 Ulrich Weigand * gcc.dg/20030123-1.c: Add prototypes for builtin functions. diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr16721.c b/gcc/testsuite/gcc.dg/tree-ssa/pr16721.c new file mode 100644 index 00000000000..869ab96497e --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr16721.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fno-strict-aliasing -fdump-tree-optimized" } */ + +struct data { + volatile unsigned long *addr; +} *p; + +int test() +{ + *p->addr; + return 0; +} + +/* The load from p->addr should not disappear. */ +/* { dg-final { scan-tree-dump-times "\->addr" 1 "optimized"} } */ diff --git a/gcc/tree-dfa.c b/gcc/tree-dfa.c index 4e65c5dffc8..9db0cbb243a 100644 --- a/gcc/tree-dfa.c +++ b/gcc/tree-dfa.c @@ -552,6 +552,9 @@ dump_variable (FILE *file, tree var) if (is_global_var (var)) fprintf (file, ", is global"); + if (TREE_THIS_VOLATILE (var)) + fprintf (file, ", is volatile"); + if (is_call_clobbered (var)) fprintf (file, ", call clobbered"); diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index baf5ff27696..3d99d94e92e 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -2025,9 +2025,6 @@ create_memory_tag (tree type, bool is_type_tag) determine whether they should be considered globals. */ DECL_CONTEXT (tag) = current_function_decl; - /* If the pointed-to type is volatile, so is the tag. */ - TREE_THIS_VOLATILE (tag) = TREE_THIS_VOLATILE (type); - /* Memory tags are by definition addressable. This also prevents is_gimple_ref frome confusing memory tags with optimizable variables. */ @@ -2126,6 +2123,9 @@ get_tmt_for (tree ptr, struct alias_info *ai) ai->pointers[ai->num_pointers++] = alias_map; } + /* If the pointed-to type is volatile, so is the tag. */ + TREE_THIS_VOLATILE (tag) = TREE_THIS_VOLATILE (tag_type); + /* Make sure that the type tag has the same alias set as the pointed-to type. */ gcc_assert (tag_set == get_alias_set (tag)); -- 2.30.2