On Thu, Nov 27, 2025 at 09:05:26AM +0100, Jakub Jelinek wrote:
> Hi!
>
> The bitint_extended changes in limb_access broke bitint_big_endian.
> As we sometimes (for bitint_extended) access the MEM_REFs using
> atype rather than m_limb_type, for big-endian we need to adjust
> the MEM_REFs offset if atype has smaller TYPE_SIZE_UNIT than m_limb_size.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
> ok for trunk if Stefan's testing on s390x-linux succeeds?
Bootstrap+regtest finished successfully for targets z16,z14,z13,z10.
Tests gcc.dg/torture/bitint-{10,15,16,19,20,32,35,5,6,7,8}.c are green,
now. Thanks for fixing this so quickly :)
Cheers,
Stefan
>
> 2025-11-27 Jakub Jelinek <[email protected]>
>
> PR target/122714
> * gimple-lower-bitint.cc (bitint_large_huge::limb_access): Adjust
> MEM_REFs offset for bitint_big_endian if ltype doesn't have the
> same byte size as m_limb_type.
>
> --- gcc/gimple-lower-bitint.cc.jj 2025-09-30 13:37:48.364854566 +0200
> +++ gcc/gimple-lower-bitint.cc 2025-11-26 17:03:51.815649841 +0100
> @@ -630,6 +630,8 @@ bitint_large_huge::limb_access (tree typ
> | ENCODE_QUAL_ADDR_SPACE (as));
> tree ptype = build_pointer_type (strip_array_types (TREE_TYPE (var)));
> unsigned HOST_WIDE_INT off = tree_to_uhwi (idx) * m_limb_size;
> + if (bitint_big_endian)
> + off += m_limb_size - tree_to_uhwi (TYPE_SIZE_UNIT (ltype));
> ret = build2 (MEM_REF, ltype,
> build_fold_addr_expr (var),
> build_int_cst (ptype, off));
> @@ -641,12 +643,14 @@ bitint_large_huge::limb_access (tree typ
> if (as != TYPE_ADDR_SPACE (ltype))
> ltype = build_qualified_type (ltype, TYPE_QUALS (ltype)
> | ENCODE_QUAL_ADDR_SPACE (as));
> + unsigned HOST_WIDE_INT off = tree_to_uhwi (idx) * m_limb_size;
> + if (bitint_big_endian)
> + off += m_limb_size - tree_to_uhwi (TYPE_SIZE_UNIT (ltype));
> ret
> = build2 (MEM_REF, ltype, unshare_expr (TREE_OPERAND (var, 0)),
> size_binop (PLUS_EXPR, TREE_OPERAND (var, 1),
> build_int_cst (TREE_TYPE (TREE_OPERAND (var, 1)),
> - tree_to_uhwi (idx)
> - * m_limb_size)));
> + off)));
> TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (var);
> TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (var);
> TREE_THIS_NOTRAP (ret) = TREE_THIS_NOTRAP (var);
>
> Jakub
>
