On Mon, 21 Oct 2024, Tamar Christina wrote:
> Hi All,
>
> For boolean mask handling we have to lower BIT_NOT_EXPR for correctness into
> BIT_XOR_EXPR. Normally this is done through vect_recog_bool_pattern by
> following the defs of the gimple_assign.
>
> In the PR we ICE because early exits have the comparison inside the gcond
> itself and so vect_recog_bool_pattern does not get a chance to lower it.
>
> This patch changes it so vect_recog_gcond_pattern also does the lowering.
>
> The reason we ICE with SLP but not non-SLP is because for non-SLP the
> vectorization is driven from the gcond, where vectorizable_comparison_1
> rejects the operation. For SLP the body is vectorized before the root.
>
> My initial attempt was to try to re-use vect_recog_bool_pattern but this
> didn't
> work for the same reasons we didn't change vect_recog_bool_pattern to handle
> gconds.
>
> I also tried introducing an explicit assign for the conditional and having
> vect_recog_bool_pattern see the conditional. However this fails because
> vect_recog_bool_pattern and helpers only handle COND_EXPR, converts and
> operands that are being loaded from memory.
>
> Since I believe BIT_NOT_EXPR is the only one needing to be lowered for
> correctness, I just manually do so like we do in other places.
So how does it work for BIT_IOR_EXPR/BIT_AND_EXPR and their feeding
stmts? How do those get transformed for the mask use? I'd have expected
the same mechanism to handle the BIT_NOT_EXPR case.
Richard.
> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
>
> Ok for master?
>
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> PR tree-optimization/117176
> * tree-vect-patterns.cc (vect_recog_gcond_pattern): Lower BIT_NOT_EXPR.
>
> gcc/testsuite/ChangeLog:
>
> PR tree-optimization/117176
> * gcc.dg/vect/vect-early-break_130-pr117176.c: New test.
>
> ---
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_130-pr117176.c
> b/gcc/testsuite/gcc.dg/vect/vect-early-break_130-pr117176.c
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..841dcce284dd7cff0c4f0648e6dc57082c8756c1
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_130-pr117176.c
> @@ -0,0 +1,21 @@
> +/* { dg-do compile } */
> +/* { dg-add-options vect_early_break } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +struct ColorSpace {
> + int componentCt;
> +};
> +
> +struct Psnr {
> + double psnr[3];
> +};
> +
> +int f(struct Psnr psnr, struct ColorSpace colorSpace) {
> + int i, hitsTarget = 1;
> +
> + for (i = 1; i < colorSpace.componentCt && hitsTarget; ++i)
> + hitsTarget = !(psnr.psnr[i] < 1);
> +
> + return hitsTarget;
> +}
> diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
> index
> 746f100a0842090953571b535ff05375f46033c0..b7cb6cf1308590e2723ca2872cf917edb4036c57
> 100644
> --- a/gcc/tree-vect-patterns.cc
> +++ b/gcc/tree-vect-patterns.cc
> @@ -5946,8 +5946,45 @@ vect_recog_gcond_pattern (vec_info *vinfo,
>
> if (code == NE_EXPR
> && zerop (rhs)
> + && TREE_CODE (lhs) == SSA_NAME
> && VECT_SCALAR_BOOLEAN_TYPE_P (scalar_type))
> - return NULL;
> + {
> + stmt_vec_info def_stmt_info = vect_get_internal_def (vinfo, lhs);
> + if (!def_stmt_info)
> + return NULL;
> +
> + gimple *lhs_stmt = STMT_VINFO_STMT (def_stmt_info);
> + if (!is_gimple_assign (lhs_stmt))
> + return NULL;
> +
> + /* This is normally handled by adjust_bool_pattern, however this is
> + driven from a gimple assign normally and cannot handle gcond.
> + BIT_NOT_EXPR are the only ones needing to be lowered for correctness,
> + the rest are more optimizations. */
> + switch (gimple_assign_rhs_code (lhs_stmt))
> + {
> + case BIT_NOT_EXPR:
> + {
> + tree rhs1 = gimple_assign_rhs1 (lhs_stmt);
> + tree itype = TREE_TYPE (rhs1);
> + tree ilhs = vect_recog_temp_ssa_var (boolean_type_node, NULL);
> + gimple *pattern_stmt
> + = gimple_build_assign (ilhs, BIT_XOR_EXPR, rhs1,
> + build_int_cst (itype, 1));
> +
> + tree lhs_vtype = get_mask_type_for_scalar_type (vinfo, itype);
> + if (lhs_vtype == NULL_TREE)
> + return NULL;
> +
> + append_pattern_def_seq (vinfo, stmt_vinfo, pattern_stmt, lhs_vtype,
> + itype);
> + lhs = ilhs;
> + break;
> + }
> + default:
> + return NULL;
> + }
> + }
>
> tree vecitype = get_vectype_for_scalar_type (vinfo, scalar_type);
> if (vecitype == NULL_TREE)
> @@ -6208,7 +6245,6 @@ vect_recog_bool_pattern (vec_info *vinfo,
> return NULL;
> }
>
> -
> /* A helper for vect_recog_mask_conversion_pattern. Build
> conversion of MASK to a type suitable for masking VECTYPE.
> Built statement gets required vectype and is appended to
>
>
>
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
