On Wed, Jun 2, 2021 at 12:47 PM Julian Brown <jul...@codesourcery.com> wrote: > > 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).
But the two code paths clearly do sth different. The base_ref case allows (*p)[i] while the !base_ref does not because TREE_CODE (base) != COMPONENT_REF. And the !base_ref case for INDIRECT_REF is quite odd, only allowing *(x.p) where x.p is of REFERENCE_TYPE. Whatever this code is supposed to do ... maybe the "prologue" should be inlined at the two callers instead. Richard. > 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. > > 2021-06-02 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 a38cd502aa5..255a2a648c1 100644 > --- a/gcc/gimplify.c > +++ b/gcc/gimplify.c > @@ -8527,31 +8527,21 @@ 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 >
