On Fri, Nov 29, 2019 at 11:12 AM Richard Sandiford
<richard.sandif...@arm.com> wrote:
>
> vect_recog_bool_pattern assumed that a comparison between two booleans
> should always become a comparison of vector mask types (implemented as an
> XOR_EXPR). But if the booleans in question are generated as data values
> (e.g. because they're loaded directly from memory), we should treat them
> like ordinary integers instead, just as we do for boolean logic ops whose
> operands are loaded from memory. vect_get_mask_type_for_stmt already
> handled this case:
>
> /* We may compare boolean value loaded as vector of integers.
> Fix mask_type in such case. */
> if (mask_type
> && !VECTOR_BOOLEAN_TYPE_P (mask_type)
> && gimple_code (stmt) == GIMPLE_ASSIGN
> && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)) ==
> tcc_comparison)
> mask_type = truth_type_for (mask_type);
>
> and not handling it here complicated later patches.
>
> The initial list of targets for vect_bool_cmp is deliberately conservative.
OK.
Richard.
>
> 2019-11-30 Richard Sandiford <richard.sandif...@arm.com>
>
> gcc/
> * doc/sourcebuild.texi (vect_bool_cmp): Document.
> * tree-vect-patterns.c (search_type_for_mask_1): If neither
> operand to a boolean comparison is a natural vector mask,
> handle both operands like normal integers instead.
>
> gcc/testsuite/
> * gcc.dg/vect/vect-bool-cmp-2.c: New test.
> * lib/target-supports.exp (check_effective_target_vect_bool_cmp): New
> effective target procedure.
>
> Index: gcc/doc/sourcebuild.texi
> ===================================================================
> --- gcc/doc/sourcebuild.texi 2019-11-20 21:11:59.065472803 +0000
> +++ gcc/doc/sourcebuild.texi 2019-11-29 09:11:21.365130870 +0000
> @@ -1522,6 +1522,10 @@ Target does not support a vector add ins
> @item vect_no_bitwise
> Target does not support vector bitwise instructions.
>
> +@item vect_bool_cmp
> +Target supports comparison of @code{bool} vectors for at least one
> +vector length.
> +
> @item vect_char_add
> Target supports addition of @code{char} vectors for at least one
> vector length.
> Index: gcc/tree-vect-patterns.c
> ===================================================================
> --- gcc/tree-vect-patterns.c 2019-11-16 10:29:21.207212217 +0000
> +++ gcc/tree-vect-patterns.c 2019-11-29 09:11:21.389130702 +0000
> @@ -3944,7 +3944,8 @@ search_type_for_mask_1 (tree var, vec_in
> vinfo, cache);
> if (!res || (res2 && TYPE_PRECISION (res) > TYPE_PRECISION
> (res2)))
> res = res2;
> - break;
> + if (res)
> + break;
> }
>
> comp_vectype = get_vectype_for_scalar_type (vinfo, TREE_TYPE
> (rhs1));
> Index: gcc/testsuite/gcc.dg/vect/vect-bool-cmp-2.c
> ===================================================================
> --- /dev/null 2019-09-17 11:41:18.176664108 +0100
> +++ gcc/testsuite/gcc.dg/vect/vect-bool-cmp-2.c 2019-11-29 09:11:21.373130815
> +0000
> @@ -0,0 +1,10 @@
> +/* { dg-do compile } */
> +
> +void
> +f (_Bool *restrict x, _Bool *restrict y)
> +{
> + for (int i = 0; i < 128; ++i)
> + x[i] = x[i] == y[i];
> +}
> +
> +/* { dg-final { scan-tree-dump "loop vectorized" "vect" { target
> vect_bool_cmp } } } */
> Index: gcc/testsuite/lib/target-supports.exp
> ===================================================================
> --- gcc/testsuite/lib/target-supports.exp 2019-11-26 22:11:24.494545152
> +0000
> +++ gcc/testsuite/lib/target-supports.exp 2019-11-29 09:11:21.373130815
> +0000
> @@ -5749,6 +5749,16 @@ proc check_effective_target_vect_bswap {
> || [istarget amdgcn-*-*] }}]
> }
>
> +# Return 1 if the target supports comparison of bool vectors for at
> +# least one vector length.
> +
> +proc check_effective_target_vect_bool_cmp { } {
> + return [check_cached_effective_target_indexed vect_bool_cmp {
> + expr { [istarget i?86-*-*] || [istarget x86_64-*-*]
> + || [istarget aarch64*-*-*]
> + || [is-effective-target arm_neon] }}]
> +}
> +
> # Return 1 if the target supports addition of char vectors for at least
> # one vector length.
>
