When processing a &ANYTHING = X constraint we treat it as *ANYTHING = X
during constraint processing but then end up recording it as
&ANYTHING = X anyway, breaking constraint graph building. This is
because we only update the local copy of the LHS and not the constraint
itself.
Bootstrap and regtest running on x86_64-unknown-linux-gnu.
PR tree-optimization/115199
* tree-ssa-structalias.cc (process_constraint): Also
record &ANYTHING = X as *ANYTING = X in the end.
* gcc.dg/torture/pr115199.c: New testcase.
---
gcc/testsuite/gcc.dg/torture/pr115199.c | 24 ++++++++++++++++++++++++
gcc/tree-ssa-structalias.cc | 2 +-
2 files changed, 25 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr115199.c
diff --git a/gcc/testsuite/gcc.dg/torture/pr115199.c
b/gcc/testsuite/gcc.dg/torture/pr115199.c
new file mode 100644
index 00000000000..981a7330b32
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr115199.c
@@ -0,0 +1,24 @@
+/* { dg-do run } */
+
+struct b {
+ char *volatile c;
+};
+struct b * __attribute__((noipa))
+d()
+{
+ char *e;
+ struct b *b = __builtin_malloc(sizeof(b));
+ void *f = __builtin_malloc(1);
+
+ e = __builtin_memcpy(f, "z", 1);
+ b->c = e;
+ return b;
+}
+
+int main()
+{
+ struct b b = *d();
+ if (b.c[0] != 'z')
+ __builtin_abort();
+ return 0;
+}
diff --git a/gcc/tree-ssa-structalias.cc b/gcc/tree-ssa-structalias.cc
index 0e9423a78ec..a39b36c146e 100644
--- a/gcc/tree-ssa-structalias.cc
+++ b/gcc/tree-ssa-structalias.cc
@@ -3104,7 +3104,7 @@ process_constraint (constraint_t t)
it here by turning it into *ANYTHING. */
if (lhs.type == ADDRESSOF
&& lhs.var == anything_id)
- lhs.type = DEREF;
+ t->lhs.type = lhs.type = DEREF;
/* ADDRESSOF on the lhs is invalid. */
gcc_assert (lhs.type != ADDRESSOF);
--
2.35.3
