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| author | Jun Ma <JunMa@linux.alibaba.com> | 2019-06-27 09:50:35 +0000 |
|---|---|---|
| committer | Jun Ma <junma@gcc.gnu.org> | 2019-06-27 09:50:35 +0000 |
| commit | 5fd336bbd7b273408018dfbb7a170e1d54facb8e (patch) | |
| tree | 22f6406d9cbec125a110e719d1d92089c273176e | |
| parent | e11c48711128a8aff3938cf28954acf1b1cc0b62 (diff) | |
| download | gcc-5fd336bbd7b273408018dfbb7a170e1d54facb8e.zip gcc-5fd336bbd7b273408018dfbb7a170e1d54facb8e.tar.gz gcc-5fd336bbd7b273408018dfbb7a170e1d54facb8e.tar.bz2 | |
re PR tree-optimization/89772 (memchr for a character not in constant nul-padded string not folded)
PR tree-optimization/89772
* gimple-fold.c (gimple_fold_builtin_memchr): consider trailing nuls in
out-of-bound accesses checking.
gcc/testsuite
* gcc.dg/builtin-memchr-4.c: New test.
From-SVN: r272740
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/gimple-fold.c | 10 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/builtin-memchr-4.c | 40 |
4 files changed, 60 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a1bd798..44f9850 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2019-06-27 Jun Ma <JunMa@linux.alibaba.com> + + PR tree-optimization/89772 + * gimple-fold.c (gimple_fold_builtin_memchr): consider trailing nuls in + out-of-bound accesses checking. + 2019-06-27 Martin Liska <mliska@suse.cz> PR tree-optimization/91014 diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index dfb31a0..118718a 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -2543,7 +2543,15 @@ gimple_fold_builtin_memchr (gimple_stmt_iterator *gsi) const char *r = (const char *)memchr (p1, c, MIN (length, string_length)); if (r == NULL) { - if (length <= string_length) + tree mem_size, offset_node; + string_constant (arg1, &offset_node, &mem_size, NULL); + unsigned HOST_WIDE_INT offset = (offset_node == NULL_TREE) + ? 0 : tree_to_uhwi (offset_node); + /* MEM_SIZE is the size of the array the string literal + is stored in. */ + unsigned HOST_WIDE_INT string_size = tree_to_uhwi (mem_size) - offset; + gcc_checking_assert (string_length <= string_size); + if (length <= string_size) { replace_call_with_value (gsi, build_int_cst (ptr_type_node, 0)); return true; diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index c48ceef..3c459a4 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2019-06-27 Jun Ma <JunMa@linux.alibaba.com> + + PR tree-optimization/89772 + * gcc.dg/builtin-memchr-4.c: New test. + 2019-06-27 Martin Liska <mliska@suse.cz> PR tree-optimization/91014 diff --git a/gcc/testsuite/gcc.dg/builtin-memchr-4.c b/gcc/testsuite/gcc.dg/builtin-memchr-4.c new file mode 100644 index 0000000..58a3b44 --- /dev/null +++ b/gcc/testsuite/gcc.dg/builtin-memchr-4.c @@ -0,0 +1,40 @@ +/* PR tree-optimization/89772 + Verify that memchr calls with a pointer to a constant character + are folded as expected. + { dg-do compile } + { dg-options "-O1 -Wall -fdump-tree-release_ssa" } */ + +typedef __SIZE_TYPE__ size_t; +typedef __WCHAR_TYPE__ wchar_t; + +extern void* memchr (const void*, int, size_t); +extern int printf (const char*, ...); +extern void abort (void); + +#define A(expr) \ + ((expr) \ + ? (void)0 \ + : (printf ("assertion failed on line %i: %s\n", \ + __LINE__, #expr), \ + abort ())) + +const char a[8] = {'a',0,'b'}; +const char b[3] = {'a','b'}; +const char c[8] = {'a','b','c'}; + +void test_memchr_cst_char (void) +{ + A (!memchr (a, 'c', 2)); + A (!memchr (a, 'c', 5)); + A (!memchr (a, 'c', sizeof a)); + A (&a[1] == memchr (a, 0, sizeof a)); + + A (!memchr (b, 0, 2)); + A (&b[2] == memchr (b, 0, sizeof b)); + + A (!memchr (c, 0, 2)); + A (&c[3] == memchr (c, 0, 4)); + A (&c[3] == memchr (c, 0, sizeof a)); +} + +/* { dg-final { scan-tree-dump-not "abort" "release_ssa" } } */ |