Hi! After lengthy IRC discussions, here is an updated patch, which should also fix the problem that variably_modified_type_p on a REAL_TYPE returns true even when it has constant maximum and minimum.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2018-01-16 Jakub Jelinek <ja...@redhat.com> Richard Biener <rgue...@suse.de> PR libgomp/83590 * gimplify.c (gimplify_one_sizepos): For is_gimple_constant (expr) return early, inline manually is_gimple_sizepos. Make sure if we call gimplify_expr we don't end up with a gimple constant. * tree.c (variably_modified_type_p): Don't return true for is_gimple_constant (_t). Inline manually is_gimple_sizepos. * gimplify.h (is_gimple_sizepos): Remove. --- gcc/gimplify.c.jj 2018-01-12 16:38:50.705238254 +0100 +++ gcc/gimplify.c 2018-01-16 12:21:15.895859416 +0100 @@ -12562,7 +12562,10 @@ gimplify_one_sizepos (tree *expr_p, gimp a VAR_DECL. If it's a VAR_DECL from another function, the gimplifier will want to replace it with a new variable, but that will cause problems if this type is from outside the function. It's OK to have that here. */ - if (is_gimple_sizepos (expr)) + if (expr == NULL_TREE + || is_gimple_constant (expr) + || TREE_CODE (expr) == VAR_DECL + || CONTAINS_PLACEHOLDER_P (expr)) return; *expr_p = unshare_expr (expr); @@ -12570,6 +12573,12 @@ gimplify_one_sizepos (tree *expr_p, gimp /* SSA names in decl/type fields are a bad idea - they'll get reclaimed if the def vanishes. */ gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue, false); + + /* If expr wasn't already is_gimple_sizepos or is_gimple_constant from the + FE, ensure that it is a VAR_DECL, otherwise we might handle some decls + as gimplify_vla_decl even when they would have all sizes INTEGER_CSTs. */ + if (is_gimple_constant (*expr_p)) + *expr_p = get_initialized_tmp_var (*expr_p, stmt_p, NULL, false); } /* Gimplify the body of statements of FNDECL and return a GIMPLE_BIND node --- gcc/tree.c.jj 2018-01-15 10:01:40.830186474 +0100 +++ gcc/tree.c 2018-01-16 12:24:11.254821615 +0100 @@ -8825,11 +8825,12 @@ variably_modified_type_p (tree type, tre do { tree _t = (T); \ if (_t != NULL_TREE \ && _t != error_mark_node \ - && TREE_CODE (_t) != INTEGER_CST \ + && !CONSTANT_CLASS_P (_t) \ && TREE_CODE (_t) != PLACEHOLDER_EXPR \ && (!fn \ || (!TYPE_SIZES_GIMPLIFIED (type) \ - && !is_gimple_sizepos (_t)) \ + && (TREE_CODE (_t) != VAR_DECL \ + && !CONTAINS_PLACEHOLDER_P (_t))) \ || walk_tree (&_t, find_var_from_fn, fn, NULL))) \ return true; } while (0) --- gcc/gimplify.h.jj 2018-01-03 10:19:53.757533721 +0100 +++ gcc/gimplify.h 2018-01-16 12:24:51.995812831 +0100 @@ -85,23 +85,4 @@ extern enum gimplify_status gimplify_va_ gimple_seq *); gimple *gimplify_assign (tree, tree, gimple_seq *); -/* Return true if gimplify_one_sizepos doesn't need to gimplify - expr (when in TYPE_SIZE{,_UNIT} and similar type/decl size/bitsize - fields). */ - -static inline bool -is_gimple_sizepos (tree expr) -{ - /* gimplify_one_sizepos doesn't need to do anything if the value isn't there, - is constant, or contains A PLACEHOLDER_EXPR. We also don't want to do - anything if it's already a VAR_DECL. If it's a VAR_DECL from another - function, the gimplifier will want to replace it with a new variable, - but that will cause problems if this type is from outside the function. - It's OK to have that here. */ - return (expr == NULL_TREE - || TREE_CODE (expr) == INTEGER_CST - || TREE_CODE (expr) == VAR_DECL - || CONTAINS_PLACEHOLDER_P (expr)); -} - #endif /* GCC_GIMPLIFY_H */ Jakub