https://gcc.gnu.org/g:45a36dc994b3a6157111570b2601e8f632af7d5d
commit r17-1687-g45a36dc994b3a6157111570b2601e8f632af7d5d Author: Xin Wang <[email protected]> Date: Wed May 20 16:17:15 2026 +0800 tree-optimization: Clarify LIM memory ref equality Restructure mem_ref_hasher::equal so the non-decomposed fallback and the decomposed comparison path are explicit. The non-decomposed lookup still compares the original refs with operand_equal_p, while the decomposed path keeps the same base, offset, size, max_size, volatile, alias-set, and type checks as before. This matches the split in gather_mem_refs_stmt, where non-decomposed references are marked with an unknown max_size and decomposed references are hashed from base, offset, and size. * tree-ssa-loop-im.cc (mem_ref_hasher::equal): Refactor for clarity. Signed-off-by: Xin Wang <[email protected]> Diff: --- gcc/tree-ssa-loop-im.cc | 64 +++++++++++++++++++++++++++---------------------- 1 file changed, 36 insertions(+), 28 deletions(-) diff --git a/gcc/tree-ssa-loop-im.cc b/gcc/tree-ssa-loop-im.cc index c207a96f5c39..592a37da5dc7 100644 --- a/gcc/tree-ssa-loop-im.cc +++ b/gcc/tree-ssa-loop-im.cc @@ -202,34 +202,43 @@ mem_ref_hasher::hash (const im_mem_ref *mem) inline bool mem_ref_hasher::equal (const im_mem_ref *mem1, const ao_ref *obj2) { - if (obj2->max_size_known_p ()) - return (mem1->ref_decomposed - && ((TREE_CODE (mem1->mem.base) == MEM_REF - && TREE_CODE (obj2->base) == MEM_REF - && operand_equal_p (TREE_OPERAND (mem1->mem.base, 0), - TREE_OPERAND (obj2->base, 0), 0) - && known_eq (mem_ref_offset (mem1->mem.base) * BITS_PER_UNIT + mem1->mem.offset, - mem_ref_offset (obj2->base) * BITS_PER_UNIT + obj2->offset)) - || (operand_equal_p (mem1->mem.base, obj2->base, 0) - && known_eq (mem1->mem.offset, obj2->offset))) - && known_eq (mem1->mem.size, obj2->size) - && known_eq (mem1->mem.max_size, obj2->max_size) - && mem1->mem.volatile_p == obj2->volatile_p - && (mem1->mem.ref_alias_set == obj2->ref_alias_set - /* We are not canonicalizing alias-sets but for the - special-case we didn't canonicalize yet and the - incoming ref is a alias-set zero MEM we pick - the correct one already. */ - || (!mem1->ref_canonical - && (TREE_CODE (obj2->ref) == MEM_REF - || TREE_CODE (obj2->ref) == TARGET_MEM_REF) - && obj2->ref_alias_set == 0) - /* Likewise if there's a canonical ref with alias-set zero. */ - || (mem1->ref_canonical && mem1->mem.ref_alias_set == 0)) - && types_compatible_p (TREE_TYPE (mem1->mem.ref), - TREE_TYPE (obj2->ref))); - else + if (!obj2->max_size_known_p ()) return operand_equal_p (mem1->mem.ref, obj2->ref, 0); + + if (!mem1->ref_decomposed) + return false; + + /* obj2 is now known decomposable and the hash is based on offset, + size and base, matching gather_mem_refs_stmt. */ + bool refs_equal + = ((TREE_CODE (mem1->mem.base) == MEM_REF + && TREE_CODE (obj2->base) == MEM_REF + && operand_equal_p (TREE_OPERAND (mem1->mem.base, 0), + TREE_OPERAND (obj2->base, 0), 0) + && known_eq (mem_ref_offset (mem1->mem.base) * BITS_PER_UNIT + + mem1->mem.offset, + mem_ref_offset (obj2->base) * BITS_PER_UNIT + + obj2->offset)) + || (operand_equal_p (mem1->mem.base, obj2->base, 0) + && known_eq (mem1->mem.offset, obj2->offset))); + + return (refs_equal + && known_eq (mem1->mem.size, obj2->size) + && known_eq (mem1->mem.max_size, obj2->max_size) + && mem1->mem.volatile_p == obj2->volatile_p + && (mem1->mem.ref_alias_set == obj2->ref_alias_set + /* We are not canonicalizing alias-sets but for the + special-case we didn't canonicalize yet and the + incoming ref is a alias-set zero MEM we pick + the correct one already. */ + || (!mem1->ref_canonical + && (TREE_CODE (obj2->ref) == MEM_REF + || TREE_CODE (obj2->ref) == TARGET_MEM_REF) + && obj2->ref_alias_set == 0) + /* Likewise if there's a canonical ref with alias-set zero. */ + || (mem1->ref_canonical && mem1->mem.ref_alias_set == 0)) + && types_compatible_p (TREE_TYPE (mem1->mem.ref), + TREE_TYPE (obj2->ref))); } @@ -3866,4 +3875,3 @@ make_pass_lim (gcc::context *ctxt) return new pass_lim (ctxt); } -
