On 1/13/2026 11:39 AM, Pengxuan Zheng wrote:
>
> +/* Fold (X >> C) != 0 into X < 0 if C is one less than the width
> + of X. Similarly fold (X >> C) == 0 into X >= 0. */
> +(for neeq (ne eq)
> + ltge (lt ge)
> + (simplify
> + (neeq
> + (rshift@2 @0 INTEGER_CST@1)
> + integer_zerop)
> + (with { tree itype = signed_type_for (TREE_TYPE (@0)); }
> + /* Make sure to transform vector compares only to supported
> + ones or from unsupported ones and check that only after
> + IPA so offloaded code is handled correctly in this
regard. */
> + (if (wi::to_wide (@1) == element_precision (itype) - 1
> + && (!VECTOR_TYPE_P (itype)
> + || (cfun
> + && cfun->after_inlining
> + && VECTOR_BOOLEAN_TYPE_P (type)
> + && (expand_vec_cmp_expr_p (itype, type, ltge)
> + || !expand_vec_cmp_expr_p (TREE_TYPE (@2),
> + type, neeq)))))
> + (ltge (convert:itype @0) { build_zero_cst (itype); })))))
> +
So in the PR Richi said the condition ought to be
canonicalize_math_after_vectorization_p; this seems to check
something
meaningfully different (after_inlining). Can you explain why you
ended
up using the after_inlining test rather than the
after_vectorization test?
Yes, Jeff, Richard initially suggested to use
canonicalize_math_after_vectorization_p,
but in his latest patch he changed the checks to after_inlining instead
(https://gcc.gnu.org/cgit/gcc/commit/?id=ae0cdb01b08fb4929ef17c534f86cd9fae78e799).
Therefore, I updated the checks here to align with Richard's latest
implementation.
Ah, perfect. In that case this is OK for the trunk, go ahead and push it.
Thanks!
jeff
