middle-end/107115 - avoid bogus redundant store removal during RTL expansion
Commit Message
The following preserves the (premature) redundant store removal
done in store_expr by appropriately guarding it with
mems_same_for_tbaa_p. The testcase added needs scheduling disabled
for now since there's a similar bug there still present.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR middle-end/107115
* expr.cc (store_expr): Check mems_same_for_tbaa_p before
eliding a seemingly redundant store.
* gcc.dg/torture/pr107115.c: New testcase.
---
gcc/expr.cc | 4 ++-
gcc/testsuite/gcc.dg/torture/pr107115.c | 37 +++++++++++++++++++++++++
2 files changed, 40 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr107115.c
@@ -6207,7 +6207,9 @@ store_expr (tree exp, rtx target, int call_param_p,
if ((! rtx_equal_p (temp, target)
|| (temp != target && (side_effects_p (temp)
- || side_effects_p (target))))
+ || side_effects_p (target)
+ || (MEM_P (temp)
+ && !mems_same_for_tbaa_p (temp, target)))))
&& TREE_CODE (exp) != ERROR_MARK
/* If store_expr stores a DECL whose DECL_RTL(exp) == TARGET,
but TARGET is not valid memory reference, TEMP will differ
new file mode 100644
@@ -0,0 +1,37 @@
+/* { dg-do run } */
+/* PR/107115 */
+/* { dg-additional-options "-fno-schedule-insns -fno-schedule-insns2" } */
+
+#include <stdlib.h>
+
+void test1(long *p1)
+{
+ p1[0] = 1;
+}
+long test2(long long *p2, int index1, int index2)
+{
+ p2[index1] = 2;
+ return p2[index2];
+}
+long test3(long *p3, int index2, long value)
+{
+ p3[index2] = 3;
+ p3[index2] = value;
+ return p3[0];
+}
+long test4(void *p4, int index1, int index2)
+{
+ test1(p4);
+ long temp = test2(p4, index1, index2);
+ return test3(p4, index2, temp);
+}
+long (*volatile vtest)(void *, int, int) = test4;
+int main(void)
+{
+ void *pp = malloc(sizeof (long) + sizeof(long long));
+ if (!pp) abort();
+ long result = vtest(pp, 0, 0);
+ if (*(long *)pp != 2 || result != 2)
+ __builtin_abort ();
+ return 0;
+}