OpenE2K
/
gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

re PR c++/71537 (GCC rejects consetxpr boolean conversions and comparisons on the result of pointer arithmetic.) 

2016-12-06  Jakub Jelinek  <jakub@redhat.com>

	PR c++/71537
	* fold-const-call.c (fold_const_call_1): Remove memchr handling here.
	(fold_const_call) <case CFN_BUILT_IN_STRNCMP,
	case CFN_BUILT_IN_STRNCASECMP>: Formatting improvements.
	(fold_const_call) <case CFN_BUILT_IN_MEMCMP>: Likewise.  If s2 is 0
	and arguments have no side-effects, return 0.
	(fold_const_call): Handle CFN_BUILT_IN_MEMCHR.

	* g++.dg/cpp0x/constexpr-memchr.C: New test.

From-SVN: r243285
This commit is contained in:
Jakub Jelinek 2016-12-06 10:23:51 +01:00 committed by Jakub Jelinek
parent bf2d0849a3
commit 66972191ee
4 changed files with 81 additions and 54 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
gcc/ChangeLog
View File

@ -1,5 +1,13 @@
2016-12-06 Jakub Jelinek <jakub@redhat.com>
PR c++/71537
* fold-const-call.c (fold_const_call_1): Remove memchr handling here.
(fold_const_call) <case CFN_BUILT_IN_STRNCMP,
case CFN_BUILT_IN_STRNCASECMP>: Formatting improvements.
(fold_const_call) <case CFN_BUILT_IN_MEMCMP>: Likewise. If s2 is 0
and arguments have no side-effects, return 0.
(fold_const_call): Handle CFN_BUILT_IN_MEMCHR.
PR c++/71537
* fold-const-call.c (fold_const_call): Handle
CFN_BUILT_IN_{INDEX,STRCHR,RINDEX,STRRCHR}.

100
gcc/fold-const-call.c
View File

@ -1491,36 +1491,6 @@ fold_const_call_1 (combined_fn fn, tree type, tree arg0, tree arg1, tree arg2)
return NULL_TREE;
}
switch (fn)
{
case CFN_BUILT_IN_MEMCHR:
{
char c;
if (integer_zerop (arg2)
&& !TREE_SIDE_EFFECTS (arg0)
&& !TREE_SIDE_EFFECTS (arg1))
return build_int_cst (type, 0);
if (!tree_fits_uhwi_p (arg2) || !target_char_cst_p (arg1, &c))
return NULL_TREE;
unsigned HOST_WIDE_INT length = tree_to_uhwi (arg2);
unsigned HOST_WIDE_INT string_length;
const char *p1 = c_getstr (arg0, &string_length);
if (p1)
{
const char *r
= (const char *)memchr (p1, c, MIN (length, string_length));
if (r == NULL && length <= string_length)
return build_int_cst (type, 0);
}
break;
}
default:
break;
}
return NULL_TREE;
}
@ -1531,47 +1501,69 @@ tree
fold_const_call (combined_fn fn, tree type, tree arg0, tree arg1, tree arg2)
{
const char *p0, *p1;
char c;
unsigned HOST_WIDE_INT s0, s1;
size_t s2 = 0;
switch (fn)
{
case CFN_BUILT_IN_STRNCMP:
{
bool const_size_p = host_size_t_cst_p (arg2, &s2);
if (const_size_p && s2 == 0
&& !TREE_SIDE_EFFECTS (arg0)
&& !TREE_SIDE_EFFECTS (arg1))
return build_int_cst (type, 0);
else if (const_size_p
&& (p0 = c_getstr (arg0))
&& (p1 = c_getstr (arg1)))
return build_int_cst (type, strncmp (p0, p1, s2));
if (!host_size_t_cst_p (arg2, &s2))
return NULL_TREE;
}
if (s2 == 0
&& !TREE_SIDE_EFFECTS (arg0)
&& !TREE_SIDE_EFFECTS (arg1))
return build_int_cst (type, 0);
else if ((p0 = c_getstr (arg0)) && (p1 = c_getstr (arg1)))
return build_int_cst (type, strncmp (p0, p1, s2));
return NULL_TREE;
case CFN_BUILT_IN_STRNCASECMP:
{
bool const_size_p = host_size_t_cst_p (arg2, &s2);
if (const_size_p && s2 == 0
&& !TREE_SIDE_EFFECTS (arg0)
&& !TREE_SIDE_EFFECTS (arg1))
return build_int_cst (type, 0);
else if (const_size_p
&& (p0 = c_getstr (arg0))
&& (p1 = c_getstr (arg1))
&& strncmp (p0, p1, s2) == 0)
return build_int_cst (type, 0);
if (!host_size_t_cst_p (arg2, &s2))
return NULL_TREE;
}
if (s2 == 0
&& !TREE_SIDE_EFFECTS (arg0)
&& !TREE_SIDE_EFFECTS (arg1))
return build_int_cst (type, 0);
else if ((p0 = c_getstr (arg0))
&& (p1 = c_getstr (arg1))
&& strncmp (p0, p1, s2) == 0)
return build_int_cst (type, 0);
return NULL_TREE;
case CFN_BUILT_IN_BCMP:
case CFN_BUILT_IN_MEMCMP:
if (!host_size_t_cst_p (arg2, &s2))
return NULL_TREE;
if (s2 == 0
&& !TREE_SIDE_EFFECTS (arg0)
&& !TREE_SIDE_EFFECTS (arg1))
return build_int_cst (type, 0);
if ((p0 = c_getstr (arg0, &s0))
&& (p1 = c_getstr (arg1, &s1))
&& host_size_t_cst_p (arg2, &s2)
&& s2 <= s0
&& s2 <= s1)
return build_cmp_result (type, memcmp (p0, p1, s2));
return NULL_TREE;
case CFN_BUILT_IN_MEMCHR:
if (!host_size_t_cst_p (arg2, &s2))
return NULL_TREE;
if (s2 == 0
&& !TREE_SIDE_EFFECTS (arg0)
&& !TREE_SIDE_EFFECTS (arg1))
return build_int_cst (type, 0);
if ((p0 = c_getstr (arg0, &s0))
&& s2 <= s0
&& target_char_cst_p (arg1, &c))
{
const char *r = (const char *) memchr (p0, c, s2);
if (r == NULL)
return build_int_cst (type, 0);
return fold_convert (type,
fold_build_pointer_plus_hwi (arg0, r - p0));
}
return NULL_TREE;
default:
return fold_const_call_1 (fn, type, arg0, arg1, arg2);
}

3
gcc/testsuite/ChangeLog
View File

@ -1,5 +1,8 @@
2016-12-06 Jakub Jelinek <jakub@redhat.com>
PR c++/71537
* g++.dg/cpp0x/constexpr-memchr.C: New test.
PR c++/71537
* g++.dg/cpp0x/constexpr-strchr.C: New test.

24
gcc/testsuite/g++.dg/cpp0x/constexpr-memchr.C Normal file
View File

@ -0,0 +1,24 @@
// { dg-do compile { target c++11 } }
typedef decltype (sizeof (0)) size_t;
constexpr const void *f1 (const char *p, int q) { return __builtin_memchr (p, q, __builtin_strlen (p) + 1); }
constexpr const void *f2 (const char *p, int q, size_t r) { return __builtin_memchr (p, q, r); }
constexpr const char a[] = "abcdefedcba";
static_assert (f1 ("abcde", 'f') == nullptr, "");
static_assert (f1 (a, 'g') == nullptr, "");
static_assert (f1 (a, 'f') == a + 5, "");
static_assert (f1 (a, 'c') == a + 2, "");
static_assert (f1 (a, '\0') == a + 11, "");
static_assert (f2 ("abcde", 'f', 6) == nullptr, "");
static_assert (f2 ("abcde", 'f', 1) == nullptr, "");
static_assert (f2 ("abcde", 'f', 0) == nullptr, "");
static_assert (f2 (a, 'g', 7) == nullptr, "");
static_assert (f2 (a, 'g', 0) == nullptr, "");
static_assert (f2 (a, 'f', 6) == a + 5, "");
static_assert (f2 (a, 'f', 5) == nullptr, "");
static_assert (f2 (a, 'c', 12) == a + 2, "");
static_assert (f2 (a, 'c', 3) == a + 2, "");
static_assert (f2 (a, 'c', 2) == nullptr, "");
static_assert (f2 (a, '\0', 12) == a + 11, "");
static_assert (f2 (a, '\0', 11) == nullptr, "");
static_assert (f2 (a, '\0', 0) == nullptr, "");