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| author | Jan Hubicka <hubicka@ucw.cz> | 2014-07-14 00:12:54 +0200 |
|---|---|---|
| committer | Jan Hubicka <hubicka@gcc.gnu.org> | 2014-07-13 22:12:54 +0000 |
| commit | 893306188659dafdd4fe386235039b0ec4b8c4c8 (patch) | |
| tree | 205f9c439effd6b0b1d8538404e92216504a3f4c /gcc/fold-const.c | |
| parent | 69dc8208ee905dbc2a6d04faa4cec7211874745e (diff) | |
| download | gcc-893306188659dafdd4fe386235039b0ec4b8c4c8.zip gcc-893306188659dafdd4fe386235039b0ec4b8c4c8.tar.gz gcc-893306188659dafdd4fe386235039b0ec4b8c4c8.tar.bz2 | |
cgraph.h (symtab_node): Add nonzero_address.
* cgraph.h (symtab_node): Add nonzero_address.
(decl_in_symtab_p): Break out from ...
(symtab_get_node): ... here.
* fold-const.c: Include cgraph.h
(tree_single_nonzero_warnv_p): Use symtab to determine
if symbol is non-zero.
* symtab.c (symtab_node::nonzero_address): New method.
* gcc.dg/pr36901.h: Simplify because non-zero symbol folding no
longer happens during parsing.
* gcc.dg/pr44024.c: Update template.
* g++.dg/tree-ssa/nonzero-2.C: New testcase.
* g++.dg/tree-ssa/nonzero-1.C: New testcase.
* gcc.dg/tree-ssa/nonzero-1.c: New testcase.
From-SVN: r212499
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index d51bda7..6a1c502 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -69,6 +69,7 @@ along with GCC; see the file COPYING3. If not see #include "tree-dfa.h" #include "hash-table.h" /* Required for ENABLE_FOLD_CHECKING. */ #include "builtins.h" +#include "cgraph.h" /* Nonzero if we are folding constants inside an initializer; zero otherwise. */ @@ -16020,21 +16021,33 @@ tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p) case ADDR_EXPR: { tree base = TREE_OPERAND (t, 0); + if (!DECL_P (base)) base = get_base_address (base); if (!base) return false; - /* Weak declarations may link to NULL. Other things may also be NULL - so protect with -fdelete-null-pointer-checks; but not variables - allocated on the stack. */ + /* For objects in symbol table check if we know they are non-zero. + Don't do anything for variables and functions before symtab is built; + it is quite possible that they will be declared weak later. */ + if (DECL_P (base) && decl_in_symtab_p (base)) + { + struct symtab_node *symbol; + + symbol = symtab_get_node (base); + if (symbol) + return symbol->nonzero_address (); + else + return false; + } + + /* Function local objects are never NULL. */ if (DECL_P (base) - && (flag_delete_null_pointer_checks - || (DECL_CONTEXT (base) - && TREE_CODE (DECL_CONTEXT (base)) == FUNCTION_DECL - && auto_var_in_fn_p (base, DECL_CONTEXT (base))))) - return !VAR_OR_FUNCTION_DECL_P (base) || !DECL_WEAK (base); + && (DECL_CONTEXT (base) + && TREE_CODE (DECL_CONTEXT (base)) == FUNCTION_DECL + && auto_var_in_fn_p (base, DECL_CONTEXT (base)))) + return true; /* Constants are never weak. */ if (CONSTANT_CLASS_P (base)) |