Currently, we are not saving the strlen() call we inserted for possible
future common subexpression elimination. Also, it's possible that we can
further fold that strlen() call. So, refactor handle_builtin_strlen()
so that it can be called from fold_strstr_to_strncmp().
gcc/ChangeLog:
* tree-ssa-strlen.cc (strlen_pass::handle_builtin_strlen):
Remove from class and mark as static.
(handle_builtin_strlen): Add parameter
"gimple_stmt_iterator gsi" and replace references of m_gsi
with gsi.
(fold_strstr_to_strncmp): Call handle_builtin_strlen().
(strlen_pass::check_and_optimize_call): Add m_gsi to the
handle_builtin_strlen() call.
gcc/testsuite/ChangeLog:
* gcc.dg/strlenopt-30.c: Add a test.
Signed-off-by: Hamza Mahfooz <some...@effective-light.com>
---
v2: bump up the number of strncmp()s from 6 to 7 in strlenopt-30.c
---
gcc/testsuite/gcc.dg/strlenopt-30.c | 9 ++++++++-
gcc/tree-ssa-strlen.cc | 23 ++++++++++++-----------
2 files changed, 20 insertions(+), 12 deletions(-)
diff --git a/gcc/testsuite/gcc.dg/strlenopt-30.c
b/gcc/testsuite/gcc.dg/strlenopt-30.c
index 1ee814048c1..d89fe83ca98 100644
--- a/gcc/testsuite/gcc.dg/strlenopt-30.c
+++ b/gcc/testsuite/gcc.dg/strlenopt-30.c
@@ -44,6 +44,12 @@ _Bool f6(char *s, char *t)
return __builtin_strstr (s, t) == s;
}
+__attribute__((no_icf))
+_Bool f6plus(char *s, char *t)
+{
+ return __builtin_strstr (s, t) == s && __builtin_strlen(t) > 10;
+}
+
/* Do not perform transform in this case, since
t1 doesn't have single use. */
@@ -57,4 +63,5 @@ _Bool f7(char *s)
return (t1 == s);
}
-/* { dg-final { scan-tree-dump-times "__builtin_strncmp" 6 "strlen1" } } */
+/* { dg-final { scan-tree-dump-times "__builtin_strlen" 2 "strlen1" } } */
+/* { dg-final { scan-tree-dump-times "__builtin_strncmp" 7 "strlen1" } } */
diff --git a/gcc/tree-ssa-strlen.cc b/gcc/tree-ssa-strlen.cc
index b0ebbb0db62..8ec6ddbc7c0 100644
--- a/gcc/tree-ssa-strlen.cc
+++ b/gcc/tree-ssa-strlen.cc
@@ -252,7 +252,6 @@ public:
bool handle_assign (tree lhs, bool *zero_write);
bool handle_store (bool *zero_write);
void handle_pointer_plus ();
- void handle_builtin_strlen ();
void handle_builtin_strchr ();
void handle_builtin_strcpy (built_in_function);
void handle_integral_assign (bool *cleanup_eh);
@@ -2211,10 +2210,10 @@ strlen_pass::maybe_warn_overflow (gimple *stmt, bool
call_lhs,
the strlen call with the known value, otherwise remember that strlen
of the argument is stored in the lhs SSA_NAME. */
-void
-strlen_pass::handle_builtin_strlen ()
+static void
+handle_builtin_strlen (gimple_stmt_iterator gsi)
{
- gimple *stmt = gsi_stmt (m_gsi);
+ gimple *stmt = gsi_stmt (gsi);
tree lhs = gimple_call_lhs (stmt);
if (lhs == NULL_TREE)
@@ -2268,8 +2267,8 @@ strlen_pass::handle_builtin_strlen ()
if (bound)
rhs = fold_build2_loc (loc, MIN_EXPR, TREE_TYPE (rhs), rhs, bound);
- gimplify_and_update_call_from_tree (&m_gsi, rhs);
- stmt = gsi_stmt (m_gsi);
+ gimplify_and_update_call_from_tree (&gsi, rhs);
+ stmt = gsi_stmt (gsi);
update_stmt (stmt);
if (dump_file && (dump_flags & TDF_DETAILS) != 0)
{
@@ -2367,8 +2366,8 @@ strlen_pass::handle_builtin_strlen ()
}
if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (ret)))
ret = fold_convert_loc (loc, TREE_TYPE (lhs), ret);
- gimplify_and_update_call_from_tree (&m_gsi, ret);
- stmt = gsi_stmt (m_gsi);
+ gimplify_and_update_call_from_tree (&gsi, ret);
+ stmt = gsi_stmt (gsi);
update_stmt (stmt);
if (dump_file && (dump_flags & TDF_DETAILS) != 0)
{
@@ -5272,8 +5271,9 @@ fold_strstr_to_strncmp (tree rhs1, tree rhs2, gimple
*stmt)
{
tree arg1 = gimple_call_arg (call_stmt, 1);
tree arg1_len = NULL_TREE;
- int idx = get_stridx (arg1, call_stmt);
gimple_stmt_iterator gsi = gsi_for_stmt (call_stmt);
+again:
+ int idx = get_stridx (arg1, call_stmt);
if (idx)
{
@@ -5296,7 +5296,8 @@ fold_strstr_to_strncmp (tree rhs1, tree rhs2, gimple
*stmt)
gimple_call_set_lhs (strlen_call, strlen_lhs);
gimple_set_vuse (strlen_call, gimple_vuse (call_stmt));
gsi_insert_before (&gsi, strlen_call, GSI_SAME_STMT);
- arg1_len = strlen_lhs;
+ handle_builtin_strlen (gsi_for_stmt (strlen_call));
+ goto again;
}
else if (!is_gimple_val (arg1_len))
{
@@ -5393,7 +5394,7 @@ strlen_pass::check_and_optimize_call (bool *zero_write)
{
case BUILT_IN_STRLEN:
case BUILT_IN_STRNLEN:
- handle_builtin_strlen ();
+ handle_builtin_strlen (m_gsi);
break;
case BUILT_IN_STRCHR:
handle_builtin_strchr ();
--
2.42.0
