For historical reasons, it seems that extract_base_bit_offset unnecessarily used two different ways to strip ARRAY_REF/INDIRECT_REF nodes from component accesses. I verified that the two ways of performing the operation gave the same results across the whole testsuite (and several additional benchmarks).
The code was like this since an earlier "mechanical" refactoring by me, first posted here: https://gcc.gnu.org/pipermail/gcc-patches/2018-November/510503.html It was never clear to me if there was an important semantic difference between the two ways of stripping the base before calling get_inner_reference, but it appears that there is not, so one can go away. 2021-05-11 Julian Brown <jul...@codesourcery.com> gcc/ * gimplify.c (extract_base_bit_offset): Unify ARRAY_REF/INDIRECT_REF stripping code in first call/subsequent call cases. --- gcc/gimplify.c | 32 +++++++++++--------------------- 1 file changed, 11 insertions(+), 21 deletions(-) diff --git a/gcc/gimplify.c b/gcc/gimplify.c index ba071e8ae68..b36b961bf26 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -8340,31 +8340,21 @@ extract_base_bit_offset (tree base, tree *base_ref, poly_int64 *bitposp, poly_offset_int poffset; if (base_ref) - { - *base_ref = NULL_TREE; - - while (TREE_CODE (base) == ARRAY_REF) - base = TREE_OPERAND (base, 0); + *base_ref = NULL_TREE; - if (TREE_CODE (base) == INDIRECT_REF) - base = TREE_OPERAND (base, 0); - } - else + if (TREE_CODE (base) == ARRAY_REF) { - if (TREE_CODE (base) == ARRAY_REF) - { - while (TREE_CODE (base) == ARRAY_REF) - base = TREE_OPERAND (base, 0); - if (TREE_CODE (base) != COMPONENT_REF - || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE) - return NULL_TREE; - } - else if (TREE_CODE (base) == INDIRECT_REF - && TREE_CODE (TREE_OPERAND (base, 0)) == COMPONENT_REF - && (TREE_CODE (TREE_TYPE (TREE_OPERAND (base, 0))) - == REFERENCE_TYPE)) + while (TREE_CODE (base) == ARRAY_REF) base = TREE_OPERAND (base, 0); + if (TREE_CODE (base) != COMPONENT_REF + || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE) + return NULL_TREE; } + else if (TREE_CODE (base) == INDIRECT_REF + && TREE_CODE (TREE_OPERAND (base, 0)) == COMPONENT_REF + && (TREE_CODE (TREE_TYPE (TREE_OPERAND (base, 0))) + == REFERENCE_TYPE)) + base = TREE_OPERAND (base, 0); base = get_inner_reference (base, &bitsize, &bitpos, &offset, &mode, &unsignedp, &reversep, &volatilep); -- 2.29.2
