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| author | Marc Glisse <marc.glisse@inria.fr> | 2013-10-09 15:03:13 +0200 |
|---|---|---|
| committer | Marc Glisse <glisse@gcc.gnu.org> | 2013-10-09 13:03:13 +0000 |
| commit | 826cacfe24c4643799d85f07b25d15a0d3b76bc0 (patch) | |
| tree | ca712605143da33b695da4c91076aa641b7f23d3 /gcc/tree-vrp.c | |
| parent | 378f8976f26a17a53c5c306f7277971e8e7a6aa7 (diff) | |
| download | gcc-826cacfe24c4643799d85f07b25d15a0d3b76bc0.zip gcc-826cacfe24c4643799d85f07b25d15a0d3b76bc0.tar.gz gcc-826cacfe24c4643799d85f07b25d15a0d3b76bc0.tar.bz2 | |
re PR c/20318 (RFE: add attribute to specify that a function never returns NULL)
2013-10-09 Marc Glisse <marc.glisse@inria.fr>
PR tree-optimization/20318
gcc/c-family/
* c-common.c (handle_returns_nonnull_attribute): New function.
(c_common_attribute_table): Add returns_nonnull.
gcc/
* doc/extend.texi (returns_nonnull): New function attribute.
* fold-const.c (tree_expr_nonzero_warnv_p): Look for returns_nonnull
attribute.
* tree-vrp.c (gimple_stmt_nonzero_warnv_p): Likewise.
(stmt_interesting_for_vrp): Accept all GIMPLE_CALL.
gcc/testsuite/
* c-c++-common/pr20318.c: New file.
* gcc.dg/tree-ssa/pr20318.c: New file.
From-SVN: r203316
Diffstat (limited to 'gcc/tree-vrp.c')
| -rw-r--r-- | gcc/tree-vrp.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 156a58f..4cd2f2a 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -1038,7 +1038,7 @@ gimple_assign_nonzero_warnv_p (gimple stmt, bool *strict_overflow_p) } } -/* Return true if STMT is know to to compute a non-zero value. +/* Return true if STMT is known to compute a non-zero value. If the return value is based on the assumption that signed overflow is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change *STRICT_OVERFLOW_P.*/ @@ -1058,6 +1058,10 @@ gimple_stmt_nonzero_warnv_p (gimple stmt, bool *strict_overflow_p) && DECL_IS_OPERATOR_NEW (fndecl) && !TREE_NOTHROW (fndecl)) return true; + if (flag_delete_null_pointer_checks && + lookup_attribute ("returns_nonnull", + TYPE_ATTRIBUTES (gimple_call_fntype (stmt)))) + return true; return gimple_alloca_call_p (stmt); } default: @@ -6536,10 +6540,7 @@ stmt_interesting_for_vrp (gimple stmt) if (lhs && TREE_CODE (lhs) == SSA_NAME && (INTEGRAL_TYPE_P (TREE_TYPE (lhs)) || POINTER_TYPE_P (TREE_TYPE (lhs))) - && ((is_gimple_call (stmt) - && gimple_call_fndecl (stmt) != NULL_TREE - && (DECL_BUILT_IN (gimple_call_fndecl (stmt)) - || DECL_IS_OPERATOR_NEW (gimple_call_fndecl (stmt)))) + && (is_gimple_call (stmt) || !gimple_vuse (stmt))) return true; } |