>- _5 = __atomic_fetch_or_8 (&set_work_pending_p, 1, 0);
>- # DEBUG old => (long int) _5
>+ _6 = .ATOMIC_BIT_TEST_AND_SET (&set_work_pending_p, 0, 1, 0,
>__atomic_fetch_or_8);
>+ # DEBUG old => NULL
> # DEBUG BEGIN_STMT
>- # DEBUG D#2 => _5 & 1
>+ # DEBUG D#2 => NULL
>...
>- _10 = ~_5;
>- _8 = (_Bool) _10;
>- # DEBUG ret => _8
>+ _8 = _6 == 0;
>+ # DEBUG ret => (_Bool) _10
>
>confirmed. convert_atomic_bit_not does this, it checks for single_use
>and removes the def, failing to release the name (which would fix this up
>IIRC).
>
>Note the function removes stmts in "wrong" order (before uses of LHS
>are removed), so it requires larger surgery. And it leaks SSA names.
Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}.
Ok for trunk?
gcc/ChangeLog:
PR target/115872
* tree-ssa-ccp.cc (convert_atomic_bit_not): Remove use_stmt after
use_nop_stmt is removed.
(optimize_atomic_bit_test_and): Ditto.
gcc/testsuite/ChangeLog:
* gcc.target/i386/pr115872.c: New test.
---
gcc/testsuite/gcc.target/i386/pr115872.c | 16 ++++++++++++++++
gcc/tree-ssa-ccp.cc | 12 ++++++++----
2 files changed, 24 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr115872.c
diff --git a/gcc/testsuite/gcc.target/i386/pr115872.c
b/gcc/testsuite/gcc.target/i386/pr115872.c
new file mode 100644
index 00000000000..937004456d3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr115872.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -g" } */
+
+long set_work_pending_p;
+_Bool set_work_pending() {
+ _Bool __trans_tmp_1;
+ long mask = 1, old = __atomic_fetch_or(&set_work_pending_p, mask, 0);
+ __trans_tmp_1 = old & mask;
+ return !__trans_tmp_1;
+}
+void __queue_work() {
+ _Bool ret = set_work_pending();
+ if (ret)
+ __queue_work();
+}
+
diff --git a/gcc/tree-ssa-ccp.cc b/gcc/tree-ssa-ccp.cc
index 3749126b5f7..de83d26d311 100644
--- a/gcc/tree-ssa-ccp.cc
+++ b/gcc/tree-ssa-ccp.cc
@@ -3332,9 +3332,10 @@ convert_atomic_bit_not (enum internal_fn fn, gimple
*use_stmt,
return nullptr;
gimple_stmt_iterator gsi;
- gsi = gsi_for_stmt (use_stmt);
- gsi_remove (&gsi, true);
tree var = make_ssa_name (TREE_TYPE (lhs));
+ /* use_stmt need to be removed after use_nop_stmt,
+ so use_lhs can be released. */
+ gimple *use_stmt_removal = use_stmt;
use_stmt = gimple_build_assign (var, BIT_AND_EXPR, lhs, and_mask);
gsi = gsi_for_stmt (use_not_stmt);
gsi_insert_before (&gsi, use_stmt, GSI_NEW_STMT);
@@ -3344,6 +3345,8 @@ convert_atomic_bit_not (enum internal_fn fn, gimple
*use_stmt,
gsi_insert_after (&gsi, g, GSI_NEW_STMT);
gsi = gsi_for_stmt (use_not_stmt);
gsi_remove (&gsi, true);
+ gsi = gsi_for_stmt (use_stmt_removal);
+ gsi_remove (&gsi, true);
return use_stmt;
}
@@ -3646,8 +3649,7 @@ optimize_atomic_bit_test_and (gimple_stmt_iterator *gsip,
*/
}
var = make_ssa_name (TREE_TYPE (use_rhs));
- gsi = gsi_for_stmt (use_stmt);
- gsi_remove (&gsi, true);
+ gimple* use_stmt_removal = use_stmt;
g = gimple_build_assign (var, BIT_AND_EXPR, use_rhs,
and_mask);
gsi = gsi_for_stmt (use_nop_stmt);
@@ -3664,6 +3666,8 @@ optimize_atomic_bit_test_and (gimple_stmt_iterator *gsip,
gsi_insert_after (&gsi, g, GSI_NEW_STMT);
gsi = gsi_for_stmt (use_nop_stmt);
gsi_remove (&gsi, true);
+ gsi = gsi_for_stmt (use_stmt_removal);
+ gsi_remove (&gsi, true);
}
}
else
--
2.31.1
