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acf7028b79
The following testcase is miscompiled since my r12-6382 change, because
it doesn't play well with the gimple_fold_indirect_ref function which uses
STRIP_NOPS and then has
/* *(foo *)fooarrptr => (*fooarrptr)[0] */
if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
&& TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (subtype)))) == INTEGER_CST
&& useless_type_conversion_p (type, TREE_TYPE (TREE_TYPE (subtype))))
{
tree type_domain;
tree min_val = size_zero_node;
tree osub = sub;
sub = gimple_fold_indirect_ref (sub);
if (! sub)
sub = build1 (INDIRECT_REF, TREE_TYPE (subtype), osub);
type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
if (type_domain && TYPE_MIN_VALUE (type_domain))
min_val = TYPE_MIN_VALUE (type_domain);
if (TREE_CODE (min_val) == INTEGER_CST)
return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
}
Without the GENERIC
#if GENERIC
(simplify
(pointer_plus (convert:s (pointer_plus:s @0 @1)) @3)
(convert:type (pointer_plus @0 (plus @1 @3))))
#endif
we have INDIRECT_REF of POINTER_PLUS_EXPR with int * type of NOP_EXPR
to that type of POINTER_PLUS_EXPR with pointer to int[4] ARRAY_TYPE, so
gimple_fold_indirect_ref doesn't create the ARRAY_REF.
But with it, it is simplified to NOP_EXPR to int * type from
POINTER_PLUS_EXPR with pointer to int[4] ARRAY_TYPE, the NOP_EXPR is
skipped over by STRIP_NOPS and the above code triggers.
The following patch fixes it by swapping the order, do NOP_EXPR
inside of POINTER_PLUS_EXPR first argument instead of NOP_EXPR with
POINTER_PLUS_EXPR.
2026-03-06 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/124358
* match.pd ((ptr) (x p+ y) p+ z -> (ptr) (x p+ (y + z))): Simplify
into (ptr) x p+ (y + z) instead.
* gcc.c-torture/execute/pr124358.c: New test.
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