We fail to verify the constraints under which we allow handled
components to wrap registers. The gcc.dg/pr70022.c testcase shows
that we happily end up with
_2 = VIEW_CONVERT_EXPR<int[4]>(v_1(D))
as produced by SSA rewrite and update_address_taken. But the intent
was that we wrap registers with at most a single level of handled
components and specifically only allow __real, __imag, BIT_FIELD_REF
and VIEW_CONVERT_EXPR on them, but not ARRAY_REF or COMPONENT_REF.
Together with the improved gimple_load predicate taking advantage
of the above and ASAN this eventually ICEd.
The following fixes update_address_taken as to this constraint.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/109594
* tree-ssa.cc (non_rewritable_mem_ref_base): Constrain
what we rewrite to a register based on the above.
---
gcc/tree-ssa.cc | 35 ++++++++++++++++++++++++++++-------
1 file changed, 28 insertions(+), 7 deletions(-)
diff --git a/gcc/tree-ssa.cc b/gcc/tree-ssa.cc
index 4ca1f5f3104..70828355c2b 100644
--- a/gcc/tree-ssa.cc
+++ b/gcc/tree-ssa.cc
@@ -1572,14 +1572,30 @@ non_rewritable_mem_ref_base (tree ref)
if (DECL_P (ref))
return NULL_TREE;
- if (! (base = CONST_CAST_TREE (strip_invariant_refs (ref))))
+ switch (TREE_CODE (ref))
{
- base = get_base_address (ref);
- if (DECL_P (base))
- return base;
- return NULL_TREE;
+ case REALPART_EXPR:
+ case IMAGPART_EXPR:
+ case BIT_FIELD_REF:
+ if (DECL_P (TREE_OPERAND (ref, 0)))
+ return NULL_TREE;
+ break;
+ case VIEW_CONVERT_EXPR:
+ if (DECL_P (TREE_OPERAND (ref, 0)))
+ {
+ if (TYPE_SIZE (TREE_TYPE (ref))
+ != TYPE_SIZE (TREE_TYPE (TREE_OPERAND (ref, 0))))
+ return TREE_OPERAND (ref, 0);
+ return NULL_TREE;
+ }
+ break;
+ /* We would need to rewrite ARRAY_REFs or COMPONENT_REFs and even
+ more so multiple levels of handled components. */
+ default:;
}
+ base = ref;
+
/* But watch out for MEM_REFs we cannot lower to a
VIEW_CONVERT_EXPR or a BIT_FIELD_REF. */
if (TREE_CODE (base) == MEM_REF
@@ -1630,9 +1646,14 @@ non_rewritable_mem_ref_base (tree ref)
return decl;
}
+ /* We cannot rewrite a decl in the base. */
+ base = get_base_address (ref);
+ if (DECL_P (base))
+ return base;
+
/* We cannot rewrite TARGET_MEM_REFs. */
- if (TREE_CODE (base) == TARGET_MEM_REF
- && TREE_CODE (TREE_OPERAND (base, 0)) == ADDR_EXPR)
+ else if (TREE_CODE (base) == TARGET_MEM_REF
+ && TREE_CODE (TREE_OPERAND (base, 0)) == ADDR_EXPR)
{
tree decl = TREE_OPERAND (TREE_OPERAND (base, 0), 0);
if (! DECL_P (decl))
--
2.35.3
