On Fri, 4 Aug 2023 at 20:36, Richard Sandiford
<[email protected]> wrote:
>
> Full review this time, sorry for the skipping the tests earlier.
Thanks for the detailed review! Please find my responses inline below.
>
> Prathamesh Kulkarni <[email protected]> writes:
> > diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
> > index 7e5494dfd39..680d0e54fd4 100644
> > --- a/gcc/fold-const.cc
> > +++ b/gcc/fold-const.cc
> > @@ -85,6 +85,10 @@ along with GCC; see the file COPYING3. If not see
> > #include "vec-perm-indices.h"
> > #include "asan.h"
> > #include "gimple-range.h"
> > +#include <algorithm>
>
> This should be included by defining INCLUDE_ALGORITHM instead.
Done. Just curious, why do we use this macro instead of directly
including <algorithm> ?
>
> > +#include "tree-pretty-print.h"
> > +#include "gimple-pretty-print.h"
> > +#include "print-tree.h"
>
> Are these still needed, or were they for debugging?
Just for debugging, removed.
>
> >
> > /* Nonzero if we are folding constants inside an initializer or a C++
> > manifestly-constant-evaluated context; zero otherwise.
> > @@ -10494,15 +10498,9 @@ fold_mult_zconjz (location_t loc, tree type, tree
> > expr)
> > static bool
> > vec_cst_ctor_to_array (tree arg, unsigned int nelts, tree *elts)
> > {
> > - unsigned HOST_WIDE_INT i, nunits;
> > + unsigned HOST_WIDE_INT i;
> >
> > - if (TREE_CODE (arg) == VECTOR_CST
> > - && VECTOR_CST_NELTS (arg).is_constant (&nunits))
> > - {
> > - for (i = 0; i < nunits; ++i)
> > - elts[i] = VECTOR_CST_ELT (arg, i);
> > - }
> > - else if (TREE_CODE (arg) == CONSTRUCTOR)
> > + if (TREE_CODE (arg) == CONSTRUCTOR)
> > {
> > constructor_elt *elt;
> >
> > @@ -10520,6 +10518,192 @@ vec_cst_ctor_to_array (tree arg, unsigned int
> > nelts, tree *elts)
> > return true;
> > }
> >
> > +/* Helper routine for fold_vec_perm_cst to check if SEL is a suitable
> > + mask for VLA vec_perm folding.
> > + REASON if specified, will contain the reason why SEL is not suitable.
> > + Used only for debugging and unit-testing.
> > + VERBOSE if enabled is used for debugging output. */
> > +
> > +static bool
> > +valid_mask_for_fold_vec_perm_cst_p (tree arg0, tree arg1,
> > + const vec_perm_indices &sel,
> > + const char **reason = NULL,
> > + ATTRIBUTE_UNUSED bool verbose = false)
>
> Since verbose is no longer needed (good!), I think we should just remove it.
Done.
>
> > +{
> > + unsigned sel_npatterns = sel.encoding ().npatterns ();
> > + unsigned sel_nelts_per_pattern = sel.encoding ().nelts_per_pattern ();
> > +
> > + if (!(pow2p_hwi (sel_npatterns)
> > + && pow2p_hwi (VECTOR_CST_NPATTERNS (arg0))
> > + && pow2p_hwi (VECTOR_CST_NPATTERNS (arg1))))
> > + {
> > + if (reason)
> > + *reason = "npatterns is not power of 2";
> > + return false;
> > + }
> > +
> > + /* We want to avoid cases where sel.length is not a multiple of
> > npatterns.
> > + For eg: sel.length = 2 + 2x, and sel npatterns = 4. */
> > + poly_uint64 esel;
> > + if (!multiple_p (sel.length (), sel_npatterns, &esel))
> > + {
> > + if (reason)
> > + *reason = "sel.length is not multiple of sel_npatterns";
> > + return false;
> > + }
> > +
> > + if (sel_nelts_per_pattern < 3)
> > + return true;
> > +
> > + for (unsigned pattern = 0; pattern < sel_npatterns; pattern++)
> > + {
> > + poly_uint64 a1 = sel[pattern + sel_npatterns];
> > + poly_uint64 a2 = sel[pattern + 2 * sel_npatterns];
> > + HOST_WIDE_INT S;
>
> Trailing whitespace. The convention is to use lowercase variable
> names, so please call this "step".
Fixed, thanks.
>
> > + if (!poly_int64 (a2 - a1).is_constant (&S))
> > + {
> > + if (reason)
> > + *reason = "step is not constant";
> > + return false;
> > + }
> > + // FIXME: Punt on S < 0 for now, revisit later.
> > + if (S < 0)
> > + return false;
> > + if (S == 0)
> > + continue;
> > +
> > + if (!pow2p_hwi (S))
> > + {
> > + if (reason)
> > + *reason = "step is not power of 2";
> > + return false;
> > + }
> > +
> > + /* Ensure that stepped sequence of the pattern selects elements
> > + only from the same input vector if it's VLA. */
>
> s/ if it's VLA//
Oops sorry, that was a relic of something else I was trying :)
Fixed, thanks.
>
> > + uint64_t q1, qe;
> > + poly_uint64 r1, re;
> > + poly_uint64 ae = a1 + (esel - 2) * S;
> > + poly_uint64 arg_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + if (!(can_div_trunc_p (a1, arg_len, &q1, &r1)
> > + && can_div_trunc_p (ae, arg_len, &qe, &re)
> > + && q1 == qe))
> > + {
> > + if (reason)
> > + *reason = "crossed input vectors";
> > + return false;
> > + }
> > +
>
> Probably worth a comment above the following code too:
>
> /* Ensure that the stepped sequence always selects from the same
> input pattern. */
Done.
>
> > + unsigned arg_npatterns
> > + = ((q1 & 0) == 0) ? VECTOR_CST_NPATTERNS (arg0)
> > + : VECTOR_CST_NPATTERNS (arg1);
> > +
> > + if (!multiple_p (S, arg_npatterns))
> > + {
> > + if (reason)
> > + *reason = "S is not multiple of npatterns";
> > + return false;
> > + }
> > + }
> > +
> > + return true;
> > +}
> > +
> > +/* Try to fold permutation of ARG0 and ARG1 with SEL selector when
> > + the input vectors are VECTOR_CST. Return NULL_TREE otherwise.
> > + REASON and VERBOSE have same purpose as described in
> > + valid_mask_for_fold_vec_perm_cst_p.
> > +
> > + (1) If SEL is a suitable mask as determined by
> > + valid_mask_for_fold_vec_perm_cst_p, then:
> > + res_npatterns = max of npatterns between ARG0, ARG1, and SEL
> > + res_nelts_per_pattern = max of nelts_per_pattern between
> > + ARG0, ARG1 and SEL.
> > + (2) If SEL is not a suitable mask, and ARG0, ARG1 are VLS,
> > + then:
> > + res_npatterns = nelts in input vector.
>
> s/input vector/result vector/
Fixed, thanks.
>
> > + res_nelts_per_pattern = 1.
> > + This exception is made so that VLS ARG0, ARG1 and SEL work as
> > before. */
>
> Guess this is personal preference, but (1) and (2) seem more like
> implementation details, so I think they belong...
>
> > +
> > +static tree
> > +fold_vec_perm_cst (tree type, tree arg0, tree arg1, const vec_perm_indices
> > &sel,
> > + const char **reason = NULL, bool verbose = false)
> > +{
> > + unsigned res_npatterns, res_nelts_per_pattern;
> > + unsigned HOST_WIDE_INT res_nelts;
> > +
>
> ...here instead.
Done.
>
> > + if (valid_mask_for_fold_vec_perm_cst_p (arg0, arg1, sel, reason,
> > verbose))
> > + {
> > + res_npatterns
> > + = std::max (VECTOR_CST_NPATTERNS (arg0),
> > + std::max (VECTOR_CST_NPATTERNS (arg1),
> > + sel.encoding ().npatterns ()));
> > +
> > + res_nelts_per_pattern
> > + = std::max (VECTOR_CST_NELTS_PER_PATTERN (arg0),
> > + std::max (VECTOR_CST_NELTS_PER_PATTERN (arg1),
> > + sel.encoding ().nelts_per_pattern ()));
> > +
> > + res_nelts = res_npatterns * res_nelts_per_pattern;
> > + }
> > + else if (TYPE_VECTOR_SUBPARTS (type).is_constant (&res_nelts))
> > + {
> > + res_npatterns = res_nelts;
> > + res_nelts_per_pattern = 1;
> > + }
> > + else
> > + return NULL_TREE;
> > +
> > + tree_vector_builder out_elts (type, res_npatterns,
> > res_nelts_per_pattern);
> > + for (unsigned i = 0; i < res_nelts; i++)
> > + {
> > + poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > + uint64_t q;
> > + poly_uint64 r;
> > + unsigned HOST_WIDE_INT index;
> > +
> > + unsigned HOST_WIDE_INT arg_nelts;
> > + if (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)).is_constant (&arg_nelts)
> > + && known_ge (sel[i], poly_int64 (2 * arg_nelts)))
> > + {
> > + if (reason)
> > + *reason = "out of bounds access";
> > + return NULL_TREE;
> > + }
>
> I don't think this is needed. The selector indices wrap, and the code
> below should handle the wrapping correctly.
Removed, thanks.
>
> > +
> > + /* Punt if sel[i] /trunc_div len cannot be determined,
> > + because the input vector to be chosen will depend on
> > + runtime vector length.
> > + For example if len == 4 + 4x, and sel[i] == 4,
> > + If len at runtime equals 4, we choose arg1[0].
> > + For any other value of len > 4 at runtime, we choose arg0[4].
> > + which makes the element choice dependent on runtime vector length.
> > */
> > + if (!can_div_trunc_p (sel[i], len, &q, &r))
> > + {
> > + if (reason)
> > + *reason = "cannot divide selector element by arg len";
> > + return NULL_TREE;
> > + }
> > +
> > + /* sel[i] % len will give the index of element in the chosen input
> > + vector. For example if sel[i] == 5 + 4x and len == 4 + 4x,
> > + we will choose arg1[1] since (5 + 4x) % (4 + 4x) == 1. */
> > + if (!r.is_constant (&index))
> > + {
> > + if (reason)
> > + *reason = "remainder is not constant";
> > + return NULL_TREE;
> > + }
> > +
> > + tree arg = ((q & 1) == 0) ? arg0 : arg1;
> > + tree elem = vector_cst_elt (arg, index);
> > + out_elts.quick_push (elem);
> > + }
> > +
> > + return out_elts.build ();
> > +}
> > +
> > /* Attempt to fold vector permutation of ARG0 and ARG1 vectors using SEL
> > selector. Return the folded VECTOR_CST or CONSTRUCTOR if successful,
> > NULL_TREE otherwise. */
> > @@ -10529,43 +10713,40 @@ fold_vec_perm (tree type, tree arg0, tree arg1,
> > const vec_perm_indices &sel)
> > {
> > unsigned int i;
> > unsigned HOST_WIDE_INT nelts;
> > - bool need_ctor = false;
> >
> > - if (!sel.length ().is_constant (&nelts))
> > - return NULL_TREE;
> > - gcc_assert (known_eq (TYPE_VECTOR_SUBPARTS (type), nelts)
> > - && known_eq (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)), nelts)
> > - && known_eq (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg1)), nelts));
> > + gcc_assert (known_eq (TYPE_VECTOR_SUBPARTS (type), sel.length ())
> > + && known_eq (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)),
> > + TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg1))));
> > +
> > if (TREE_TYPE (TREE_TYPE (arg0)) != TREE_TYPE (type)
> > || TREE_TYPE (TREE_TYPE (arg1)) != TREE_TYPE (type))
> > return NULL_TREE;
> >
> > + if (TREE_CODE (arg0) == VECTOR_CST
> > + && TREE_CODE (arg1) == VECTOR_CST)
> > + return fold_vec_perm_cst (type, arg0, arg1, sel);
> > +
> > + /* For fall back case, we want to ensure we have VLS vectors
> > + with equal length. */
> > + if (!sel.length ().is_constant (&nelts))
> > + return NULL_TREE;
> > +
> > + gcc_assert (known_eq (sel.length (), TYPE_VECTOR_SUBPARTS (TREE_TYPE
> > (arg0))));
>
> Nit: long line.
Fixed, thanks.
>
> > tree *in_elts = XALLOCAVEC (tree, nelts * 2);
> > if (!vec_cst_ctor_to_array (arg0, nelts, in_elts)
> > || !vec_cst_ctor_to_array (arg1, nelts, in_elts + nelts))
> > return NULL_TREE;
> >
> > - tree_vector_builder out_elts (type, nelts, 1);
> > + vec<constructor_elt, va_gc> *v;
> > + vec_alloc (v, nelts);
> > for (i = 0; i < nelts; i++)
> > {
> > HOST_WIDE_INT index;
> > if (!sel[i].is_constant (&index))
> > return NULL_TREE;
> > - if (!CONSTANT_CLASS_P (in_elts[index]))
> > - need_ctor = true;
> > - out_elts.quick_push (unshare_expr (in_elts[index]));
> > - }
> > -
> > - if (need_ctor)
> > - {
> > - vec<constructor_elt, va_gc> *v;
> > - vec_alloc (v, nelts);
> > - for (i = 0; i < nelts; i++)
> > - CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, out_elts[i]);
> > - return build_constructor (type, v);
> > + CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, in_elts[index]);
> > }
> > - else
> > - return out_elts.build ();
> > + return build_constructor (type, v);
> > }
> >
> > /* Try to fold a pointer difference of type TYPE two address expressions of
> > @@ -16892,6 +17073,508 @@ test_arithmetic_folding ()
> > x);
> > }
> >
> > +namespace test_fold_vec_perm_cst {
> > +
> > +static tree
> > +get_preferred_vectype (tree inner_type)
> > +{
> > + scalar_int_mode int_mode = SCALAR_INT_TYPE_MODE (inner_type);
> > + machine_mode vmode = targetm.vectorize.preferred_simd_mode (int_mode);
> > + poly_uint64 nunits = GET_MODE_NUNITS (vmode);
> > + return build_vector_type (inner_type, nunits);
> > +}
> > +
> > +static tree
> > +build_vec_cst_rand (tree inner_type, unsigned npatterns,
> > + unsigned nelts_per_pattern, int S = 0,
>
> Similar comment about lowercase variable names here.
>
> > + tree vectype = NULL_TREE)
> > +{
> > + if (!vectype)
> > + vectype = get_preferred_vectype (inner_type);
>
> I'm not sure how portable this is. It looks like the tests rely on
> the integer_type_node vectors being 4 + 4x, but that isn't necessarily
> true on all VLA targets.
>
> Perhaps instead the tests could be classified based on the vector
> lengths that they assume. Then we can iterate through the vector
> modes and call the appropriate function based on GET_MODE_NUNITS
> and GET_MODE_INNER.
I tried this approach in the attached patch.
Does it look OK ?
>
> > + tree_vector_builder builder (vectype, npatterns, nelts_per_pattern);
> > +
> > + // Fill a0 for each pattern
> > + for (unsigned i = 0; i < npatterns; i++)
> > + builder.quick_push (build_int_cst (inner_type, rand () % 100));
> > +
> > + if (nelts_per_pattern == 1)
> > + return builder.build ();
> > +
> > + // Fill a1 for each pattern
> > + for (unsigned i = 0; i < npatterns; i++)
> > + builder.quick_push (build_int_cst (inner_type, rand () % 100));
> > +
> > + if (nelts_per_pattern == 2)
> > + return builder.build ();
> > +
> > + for (unsigned i = npatterns * 2; i < npatterns * nelts_per_pattern; i++)
> > + {
> > + tree prev_elem = builder[i - npatterns];
> > + int prev_elem_val = TREE_INT_CST_LOW (prev_elem);
> > + int val = prev_elem_val + S;
> > + builder.quick_push (build_int_cst (inner_type, val));
> > + }
> > +
> > + return builder.build ();
> > +}
> > +
> > +static void
> > +validate_res (unsigned npatterns, unsigned nelts_per_pattern,
> > + tree res, tree *expected_res)
> > +{
> > + ASSERT_TRUE (VECTOR_CST_NPATTERNS (res) == npatterns);
> > + ASSERT_TRUE (VECTOR_CST_NELTS_PER_PATTERN (res) == nelts_per_pattern);
>
> I don't think this is safe when the inputs are randomised. E.g. we
> could by chance end up with a vector of all zeros, which would have
> a single pattern and a single element per pattern, regardless of the
> shapes of the inputs.
>
> Given the way that vector_builder<T, Shape, Derived>::finalize
> canonicalises the encoding, it should be safe to use:
>
> * VECTOR_CST_NPATTERNS (res) <= npatterns
> * vector_cst_encoded_nelts (res) <= npatterns * nelts_per_pattern
>
> If we do that then...
>
> > +
> > + for (unsigned i = 0; i < vector_cst_encoded_nelts (res); i++)
>
> ...this loop bound should be npatterns * nelts_per_pattern instead.
Ah indeed. Fixed, thanks.
>
> > + ASSERT_TRUE (operand_equal_p (VECTOR_CST_ELT (res, i),
> > expected_res[i], 0));
> > +}
> > +
> > +static void
> > +validate_res_vls (tree res, tree *expected_res, unsigned expected_nelts)
> > +{
> > + ASSERT_TRUE (known_eq (VECTOR_CST_NELTS (res), expected_nelts));
> > + for (unsigned i = 0; i < expected_nelts; i++)
> > + ASSERT_TRUE (operand_equal_p (VECTOR_CST_ELT (res, i),
> > expected_res[i], 0));
> > +}
> > +
> > +/* Verify VLA vec_perm folding. */
> > +
> > +static void
> > +test_stepped ()
> > +{
> > + /* Case 1: sel = {0, 1, 2, ...}
> > + npatterns = 1, nelts_per_pattern = 3
> > + expected res: { arg0[0], arg0[1], arg0[2], ... } */
> > + {
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 1, 3, 2);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 1, 3, 2);
> > + poly_uint64 arg0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + vec_perm_builder builder (arg0_len, 1, 3);
> > + builder.quick_push (0);
> > + builder.quick_push (1);
> > + builder.quick_push (2);
> > +
> > + vec_perm_indices sel (builder, 2, arg0_len);
> > + tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
> > + tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt
> > (arg0, 1),
> > + vector_cst_elt (arg0, 2) };
> > + validate_res (1, 3, res, expected_res);
> > + }
> > +
> > + /* Case 2: sel = {len, len + 1, len + 2, ... }
> > + npatterns = 1, nelts_per_pattern = 3
> > + FIXME: This should return
> > + expected res: { op1[0], op1[1], op1[2], ... }
> > + however it returns NULL_TREE. */
>
> Looks like the comment is out of date.
Fixed, thanks.
>
> > + {
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 1, 3, 2);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 1, 3, 2);
> > + poly_uint64 arg0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + vec_perm_builder builder (arg0_len, 1, 3);
> > + builder.quick_push (arg0_len);
> > + builder.quick_push (arg0_len + 1);
> > + builder.quick_push (arg0_len + 2);
> > +
> > + vec_perm_indices sel (builder, 2, arg0_len);
> > + tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel, NULL,
> > true);
> > + tree expected_res[] = { vector_cst_elt (arg1, 0), vector_cst_elt
> > (arg1, 1),
> > + vector_cst_elt (arg1, 2) };
> > + validate_res (1, 3, res, expected_res);
> > + }
> > +
> > + /* Case 3: Leading element of arg1, stepped sequence: pattern 0 of arg0.
> > + sel = {len, 0, 0, 0, 2, 0, ...}
> > + npatterns = 2, nelts_per_pattern = 3.
> > + Use extra pattern {0, ...} to lower number of elements per pattern.
> > */
> > + {
> > + tree arg0 = build_vec_cst_rand (char_type_node, 1, 3, 2);
> > + tree arg1 = build_vec_cst_rand (char_type_node, 1, 3, 2);
> > + poly_uint64 arg0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + vec_perm_builder builder (arg0_len, 2, 3);
> > + builder.quick_push (arg0_len);
> > + int mask_elems[] = { 0, 0, 0, 2, 0 };
> > + for (int i = 0; i < 5; i++)
> > + builder.quick_push (mask_elems[i]);
>
> This leaves one of the elements unspecified.
Sorry, I didn't understand.
It first pushes len in:
builder.quick_push (arg0_len)
and then pushes the remaining indices in the loop:
for (int i = 0; i < 5; i++)
builder.quick_push (mask_elems[i])
So overall, builder will have 6 elements: {len, 0, 0, 0, 2, 0}
>
> > +
> > + vec_perm_indices sel (builder, 2, arg0_len);
> > + const char *reason;
> > + tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel,
> > &reason);
> > +
> > + tree expected_res[] = { vector_cst_elt (arg1, 0), vector_cst_elt
> > (arg0, 0),
> > + vector_cst_elt (arg0, 0), vector_cst_elt (arg0,
> > 0),
> > + vector_cst_elt (arg0, 2), vector_cst_elt (arg0, 0)
> > + };
> > + validate_res (2, 3, res, expected_res);
> > + }
> > +
> > + /* Case 4:
> > + sel = { len, 0, 2, ... } npatterns = 1, nelts_per_pattern = 3.
> > + This should return NULL because we cross the input vectors.
> > + Because,
> > + arg0_len = 16 + 16x
> > + a1 = 0
> > + S = 2
> > + esel = arg0_len / npatterns_sel = 16+16x/1 = 16 + 16x
> > + ae = 0 + (esel - 2) * S
> > + = 0 + (16 + 16x - 2) * 2
> > + = 28 + 32x
> > + a1 / arg0_len = 0 /trunc (16 + 16x) = 0
> > + ae / arg0_len = (28 + 32x) /trunc (16 + 16x), which is not defined,
> > + since 28/16 != 32/16.
> > + So return NULL_TREE. */
>
> The division should succeed now, so as the test says, the reason should
> instead be that ae is in the second input.
Fixed, thanks.
>
> > + {
> > + tree arg0 = build_vec_cst_rand (char_type_node, 1, 3, 2);
> > + tree arg1 = build_vec_cst_rand (char_type_node, 1, 3, 2);
> > + poly_uint64 arg0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + vec_perm_builder builder (arg0_len, 1, 3);
> > + builder.quick_push (arg0_len);
> > + builder.quick_push (0);
> > + builder.quick_push (2);
> > +
> > + vec_perm_indices sel (builder, 2, arg0_len);
> > + const char *reason;
> > + tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel,
> > &reason, false);
> > + gcc_assert (res == NULL_TREE);
> > + gcc_assert (!strcmp (reason, "crossed input vectors"));
>
> The tests should use ASSERT_* macros rather than gcc_assert.
Fixed, thanks.
>
> > + }
> > +
> > + /* Case 5: Select elements from different patterns.
> > + Should return NULL. */
> > + {
> > + tree op0 = build_vec_cst_rand (char_type_node, 2, 3, 2);
> > + tree op1 = build_vec_cst_rand (char_type_node, 2, 3, 2);
> > + poly_uint64 op0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (op0));
> > +
> > + vec_perm_builder builder (op0_len, 2, 3);
> > + builder.quick_push (op0_len);
> > + int mask_elems[] = { 0, 0, 0, 1, 0 };
> > + for (int i = 0; i < 5; i++)
> > + builder.quick_push (mask_elems[i]);
>
> Should be 6 elements here too.
>
> > +
> > + vec_perm_indices sel (builder, 2, op0_len);
> > + const char *reason;
> > + tree res = fold_vec_perm_cst (TREE_TYPE (op0), op0, op1, sel, &reason,
> > false);
> > + gcc_assert (res == NULL_TREE);
> > + gcc_assert (!strcmp (reason, "S is not multiple of npatterns"));
> > + }
> > +
> > + /* Case 6: Select pattern 0 of op0 and dup of op0[0]
> > + op0, op1, sel: npatterns = 2, nelts_per_pattern = 3
> > + sel = { 0, 0, 2, 0, 4, 0, ... }.
> > +
> > + For pattern {0, 2, 4, ...}:
> > + a1 = 2
> > + len = 16 + 16x
> > + S = 2
> > + esel = len / npatterns_sel = (16 + 16x) / 2 = (8 + 8x)
> > + ae = a1 + (esel - 2) * S
> > + = 2 + (8 + 8x - 2) * 2
> > + = 14 + 16x
> > + a1 / arg0_len = 2 / (16 + 16x) = 0
> > + ae / arg0_len = (14 + 16x) / (16 + 16x) = 0
> > + So a1/arg0_len = ae/arg0_len = 0
> > + Hence we select from first vector op0
> > + S = 2, npatterns = 2.
> > + Since S is multiple of npatterns(op0), we are selecting from
> > + same pattern of op0.
> > +
> > + For pattern {0, ...}, we are choosing { op0[0] ... }
> > + So res will be combination of above patterns:
> > + res: { op0[0], op0[0], op0[2], op0[0], op0[4], op0[0], ... }
> > + with npatterns = 2, nelts_per_pattern = 3. */
> > + {
> > + tree op0 = build_vec_cst_rand (char_type_node, 2, 3, 2);
> > + tree op1 = build_vec_cst_rand (char_type_node, 2, 3, 2);
> > + poly_uint64 op0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (op0));
> > +
> > + vec_perm_builder builder (op0_len, 2, 3);
> > + int mask_elems[] = { 0, 0, 2, 0, 4, 0 };
> > + for (int i = 0; i < 6; i++)
> > + builder.quick_push (mask_elems[i]);
> > +
> > + vec_perm_indices sel (builder, 2, op0_len);
> > + tree res = fold_vec_perm_cst (TREE_TYPE (op0), op0, op1, sel);
> > + tree expected_res[] = { vector_cst_elt (op0, 0), vector_cst_elt (op0,
> > 0),
> > + vector_cst_elt (op0, 2), vector_cst_elt (op0, 0),
> > + vector_cst_elt (op0, 4), vector_cst_elt (op0, 0)
> > };
> > + validate_res (2, 3, res, expected_res);
> > + }
> > +
> > + /* Case 7: sel_npatterns > op_npatterns;
> > + op0, op1: npatterns = 2, nelts_per_pattern = 3
> > + sel: { 0, 0, 1, len, 2, 0, 3, len, 4, 0, 5, len, ...},
> > + with npatterns = 4, nelts_per_pattern = 3. */
> > + {
> > + tree op0 = build_vec_cst_rand (char_type_node, 2, 3, 2);
> > + tree op1 = build_vec_cst_rand (char_type_node, 2, 3, 2);
> > + poly_uint64 op0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (op0));
> > +
> > + vec_perm_builder builder(op0_len, 4, 3);
> > + // -1 is used as place holder for poly_int_cst
> > + int mask_elems[] = { 0, 0, 1, -1, 2, 0, 3, -1, 4, 0, 5, -1 };
> > + for (int i = 0; i < 12; i++)
> > + builder.quick_push ((mask_elems[i] == -1) ? op0_len : mask_elems[i]);
> > +
> > + vec_perm_indices sel (builder, 2, op0_len);
> > + tree res = fold_vec_perm_cst (TREE_TYPE (op0), op0, op1, sel);
> > + tree expected_res[] = { vector_cst_elt (op0, 0), vector_cst_elt (op0,
> > 0),
> > + vector_cst_elt (op0, 1), vector_cst_elt (op1, 0),
> > + vector_cst_elt (op0, 2), vector_cst_elt (op0, 0),
> > + vector_cst_elt (op0, 3), vector_cst_elt (op1, 0),
> > + vector_cst_elt (op0, 4), vector_cst_elt (op0, 0),
> > + vector_cst_elt (op0, 5), vector_cst_elt (op1, 0)
> > };
> > + validate_res (4, 3, res, expected_res);
> > + }
> > +}
> > +
> > +static void
> > +test_dup ()
> > +{
> > + /* Case 1: mask = {0, ...} */
> > + {
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + vec_perm_builder builder (len, 1, 1);
> > + builder.quick_push (0);
> > + vec_perm_indices sel (builder, 2, len);
> > + tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
> > +
> > + tree expected_res[] = { vector_cst_elt (res, 0) };
> > + validate_res (1, 1, res, expected_res);
> > + }
> > +
> > + /* Case 2: mask = {len, ...} */
> > + {
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + vec_perm_builder builder (len, 1, 1);
> > + builder.quick_push (len);
> > + vec_perm_indices sel (builder, 2, len);
> > + tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
> > +
> > + tree expected_res[] = { vector_cst_elt (arg1, 0) };
> > + validate_res (1, 1, res, expected_res);
> > + }
> > +
> > + /* Case 3: mask = { 0, len, ... } */
> > + {
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + vec_perm_builder builder (len, 2, 1);
> > + builder.quick_push (0);
> > + builder.quick_push (len);
> > + vec_perm_indices sel (builder, 2, len);
> > + tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
> > +
> > + tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt
> > (arg1, 0) };
> > + validate_res (2, 1, res, expected_res);
> > + }
> > +
> > + /* Case 4: mask = { 0, len, 1, len+1, ... } */
> > + {
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + vec_perm_builder builder (len, 2, 2);
> > + builder.quick_push (0);
> > + builder.quick_push (len);
> > + builder.quick_push (1);
> > + builder.quick_push (len + 1);
> > + vec_perm_indices sel (builder, 2, len);
> > + tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
> > +
> > + tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt
> > (arg1, 0),
> > + vector_cst_elt (arg0, 1), vector_cst_elt (arg1, 1)
> > + };
> > + validate_res (2, 2, res, expected_res);
> > + }
> > +
> > + /* Case 5: mask = { 0, len, 1, len+1, .... }
> > + npatterns = 4, nelts_per_pattern = 1 */
> > + {
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + vec_perm_builder builder (len, 4, 1);
> > + builder.quick_push (0);
> > + builder.quick_push (len);
> > + builder.quick_push (1);
> > + builder.quick_push (len + 1);
> > + vec_perm_indices sel (builder, 2, len);
> > + tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
> > +
> > + tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt
> > (arg1, 0),
> > + vector_cst_elt (arg0, 1), vector_cst_elt (arg1, 1)
> > + };
> > + validate_res (4, 1, res, expected_res);
> > + }
> > +
> > + /* Case 6: mask = {0, 4, ...}
> > + npatterns = 1, nelts_per_pattern = 2.
> > + This should return NULL_TREE because the index 4 may choose
> > + from either arg0 or arg1 depending on vector length. */
> > + {
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + vec_perm_builder builder (len, 1, 2);
> > + builder.quick_push (0);
> > + builder.quick_push (4);
> > + vec_perm_indices sel (builder, 2, len);
> > + tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
> > + ASSERT_TRUE (res == NULL_TREE);
> > + }
> > +
> > + /* Case 7: npatterns(arg0) = 4 > npatterns(sel) = 2
> > + mask = {0, len, 1, len + 1, ...}
> > + sel_npatterns = 2, sel_nelts_per_pattern = 2. */
>
> This is a good test to have, but it doesn't seem to match the
> name of the containing function (test_dup).
Well since the selector has nelts_per_pattern = 2, ie, dup of a1, I
chose to put it in test_dup.
Anyway, the functions are now re-classified based on vector length in the patch.
>
> > + {
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 2, 3, 1);
> > + poly_uint64 arg0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> > +
> > + vec_perm_builder builder (arg0_len, 2, 2);
> > + builder.quick_push (0);
> > + builder.quick_push (arg0_len);
> > + builder.quick_push (1);
> > + builder.quick_push (arg0_len + 1);
> > + vec_perm_indices sel (builder, 2, arg0_len);
> > + tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
> > +
> > + tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt
> > (arg1, 0),
> > + vector_cst_elt (arg0, 1), vector_cst_elt (arg1, 1)
> > + };
> > + validate_res (2, 2, res, expected_res);
> > + }
> > +}
> > +
> > +static void
> > +test_mixed ()
> > +{
> > + /* Case 1: op0, op1 -> VLS, sel -> VLA and selects from both input
> > vectors.
> > + In this case, we treat res_npatterns = nelts in input vector
> > + and res_nelts_per_pattern = 1, and create a dup pattern.
> > + sel = { 0, 4, 1, 5, ... }
> > + res = { op0[0], op1[0], op0[1], op1[1], ...} // (4, 1)
> > + res_npatterns = 4, res_nelts_per_pattern = 1. */
> > + {
> > + tree arg_vectype = build_vector_type (integer_type_node, 4);
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 4, 1, 0,
> > arg_vectype);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 4, 1, 0,
> > arg_vectype);
> > +
> > + tree res_type = get_preferred_vectype (integer_type_node);
> > + poly_uint64 res_len = TYPE_VECTOR_SUBPARTS (res_type);
> > + vec_perm_builder builder (res_len, 4, 1);
> > + builder.quick_push (0);
> > + builder.quick_push (4);
> > + builder.quick_push (1);
> > + builder.quick_push (5);
> > +
> > + vec_perm_indices sel (builder, 2, res_len);
> > + tree res = fold_vec_perm_cst (res_type, arg0, arg1, sel);
> > + tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt
> > (arg1, 0),
> > + vector_cst_elt (arg0, 1), vector_cst_elt (arg1, 1)
> > + };
> > + validate_res (4, 1, res, expected_res);
> > + }
> > +
> > + /* Case 2: Same as Case 1, but sel contains an out of bounds index.
> > + result should be NULL_TREE. */
> > + {
> > + tree arg_vectype = build_vector_type (integer_type_node, 4);
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 4, 1, 0,
> > arg_vectype);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 4, 1, 0,
> > arg_vectype);
> > +
> > + tree res_type = get_preferred_vectype (integer_type_node);
> > + poly_uint64 res_len = TYPE_VECTOR_SUBPARTS (res_type);
> > + vec_perm_builder builder (res_len, 4, 1);
> > + builder.quick_push (0);
> > + builder.quick_push (8);
> > + builder.quick_push (1);
> > + builder.quick_push (5);
> > +
> > + vec_perm_indices sel (builder, 2, res_len);
> > + const char *reason;
> > + tree res = fold_vec_perm_cst (res_type, arg0, arg1, sel, &reason);
> > + gcc_assert (res == NULL_TREE);
> > + gcc_assert (!strcmp (reason, "out of bounds access"));
> > + }
> > +
> > + /* Case 3: op0, op1 are VLA and sel is VLS.
> > + op0, op1: VNx16QI with shape (2, 3)
> > + sel = V4SI with values {0, 2, 4, 6}
> > + res: V4SI with values { op0[0], op0[2], op0[4], op0[6] }. */
> > + {
> > + tree arg0 = build_vec_cst_rand (char_type_node, 2, 3, 2);
> > + tree arg1 = build_vec_cst_rand (char_type_node, 2, 3, 2);
> > +
> > + poly_uint64 res_len = 4;
> > + tree res_type = build_vector_type (char_type_node, res_len);
> > + vec_perm_builder builder (res_len, 4, 1);
> > + builder.quick_push (0);
> > + builder.quick_push (2);
> > + builder.quick_push (4);
> > + builder.quick_push (6);
> > +
> > + vec_perm_indices sel (builder, 2, res_len);
> > + tree res = fold_vec_perm_cst (res_type, arg0, arg1, sel);
> > +
> > + tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt
> > (arg0, 2),
> > + vector_cst_elt (arg0, 4), vector_cst_elt (arg0, 6)
> > + };
> > + validate_res_vls (res, expected_res, 4);
> > + }
> > +
> > + /* Case 4: Same as case 4, but op0, op1 are VNx4SI with shape (2, 3) and
> > step = 2
>
> Same as case 3?
Oops sorry, fixed.
The attached patch passes bootstrap+test on aarch64-linux-gnu with and
without SVE, and on x86_64-linux-gnu.
Thanks,
Prathamesh
>
> Thanks,
> Richard
>
> > + sel = V4SI with values {0, 2, 4, 6}
> > + In this case result should be NULL_TREE because we cross input vector
> > + boundary at index 4. */
> > + {
> > + tree arg0 = build_vec_cst_rand (integer_type_node, 2, 3, 2);
> > + tree arg1 = build_vec_cst_rand (integer_type_node, 2, 3, 2);
> > +
> > + poly_uint64 res_len = 4;
> > + tree res_type = build_vector_type (char_type_node, res_len);
> > + vec_perm_builder builder (res_len, 4, 1);
> > + builder.quick_push (0);
> > + builder.quick_push (2);
> > + builder.quick_push (4);
> > + builder.quick_push (6);
> > +
> > + vec_perm_indices sel (builder, 2, res_len);
> > + const char *reason;
> > + tree res = fold_vec_perm_cst (res_type, arg0, arg1, sel, &reason);
> > + gcc_assert (res == NULL_TREE);
> > + gcc_assert (!strcmp (reason, "cannot divide selector element by arg
> > len"));
> > + }
> > +}
> > +
> > +static void
> > +test ()
> > +{
> > + tree vectype = get_preferred_vectype (integer_type_node);
> > + if (TYPE_VECTOR_SUBPARTS (vectype).is_constant ())
> > + return;
> > +
> > + test_dup ();
> > + test_stepped ();
> > + test_mixed ();
> > +}
> > +};
> > +
> > /* Verify that various binary operations on vectors are folded
> > correctly. */
> >
> > @@ -16943,6 +17626,7 @@ fold_const_cc_tests ()
> > test_arithmetic_folding ();
> > test_vector_folding ();
> > test_vec_duplicate_folding ();
> > + test_fold_vec_perm_cst::test ();
> > }
> >
> > } // namespace selftest
diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
index 7e5494dfd39..648ef5c647e 100644
--- a/gcc/fold-const.cc
+++ b/gcc/fold-const.cc
@@ -40,6 +40,7 @@ along with GCC; see the file COPYING3. If not see
gimple code, we need to handle GIMPLE tuples as well as their
corresponding tree equivalents. */
+#define INCLUDE_ALGORITHM
#include "config.h"
#include "system.h"
#include "coretypes.h"
@@ -10494,15 +10495,9 @@ fold_mult_zconjz (location_t loc, tree type, tree expr)
static bool
vec_cst_ctor_to_array (tree arg, unsigned int nelts, tree *elts)
{
- unsigned HOST_WIDE_INT i, nunits;
+ unsigned HOST_WIDE_INT i;
- if (TREE_CODE (arg) == VECTOR_CST
- && VECTOR_CST_NELTS (arg).is_constant (&nunits))
- {
- for (i = 0; i < nunits; ++i)
- elts[i] = VECTOR_CST_ELT (arg, i);
- }
- else if (TREE_CODE (arg) == CONSTRUCTOR)
+ if (TREE_CODE (arg) == CONSTRUCTOR)
{
constructor_elt *elt;
@@ -10520,6 +10515,182 @@ vec_cst_ctor_to_array (tree arg, unsigned int nelts,
tree *elts)
return true;
}
+/* Helper routine for fold_vec_perm_cst to check if SEL is a suitable
+ mask for VLA vec_perm folding.
+ REASON if specified, will contain the reason why SEL is not suitable.
+ Used only for debugging and unit-testing. */
+
+static bool
+valid_mask_for_fold_vec_perm_cst_p (tree arg0, tree arg1,
+ const vec_perm_indices &sel,
+ const char **reason = NULL)
+{
+ unsigned sel_npatterns = sel.encoding ().npatterns ();
+ unsigned sel_nelts_per_pattern = sel.encoding ().nelts_per_pattern ();
+
+ if (!(pow2p_hwi (sel_npatterns)
+ && pow2p_hwi (VECTOR_CST_NPATTERNS (arg0))
+ && pow2p_hwi (VECTOR_CST_NPATTERNS (arg1))))
+ {
+ if (reason)
+ *reason = "npatterns is not power of 2";
+ return false;
+ }
+
+ /* We want to avoid cases where sel.length is not a multiple of npatterns.
+ For eg: sel.length = 2 + 2x, and sel npatterns = 4. */
+ poly_uint64 esel;
+ if (!multiple_p (sel.length (), sel_npatterns, &esel))
+ {
+ if (reason)
+ *reason = "sel.length is not multiple of sel_npatterns";
+ return false;
+ }
+
+ if (sel_nelts_per_pattern < 3)
+ return true;
+
+ for (unsigned pattern = 0; pattern < sel_npatterns; pattern++)
+ {
+ poly_uint64 a1 = sel[pattern + sel_npatterns];
+ poly_uint64 a2 = sel[pattern + 2 * sel_npatterns];
+ HOST_WIDE_INT step;
+ if (!poly_int64 (a2 - a1).is_constant (&step))
+ {
+ if (reason)
+ *reason = "step is not constant";
+ return false;
+ }
+ // FIXME: Punt on step < 0 for now, revisit later.
+ if (step < 0)
+ return false;
+ if (step == 0)
+ continue;
+
+ if (!pow2p_hwi (step))
+ {
+ if (reason)
+ *reason = "step is not power of 2";
+ return false;
+ }
+
+ /* Ensure that stepped sequence of the pattern selects elements
+ only from the same input vector. */
+ uint64_t q1, qe;
+ poly_uint64 r1, re;
+ poly_uint64 ae = a1 + (esel - 2) * step;
+ poly_uint64 arg_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ if (!(can_div_trunc_p (a1, arg_len, &q1, &r1)
+ && can_div_trunc_p (ae, arg_len, &qe, &re)
+ && q1 == qe))
+ {
+ if (reason)
+ *reason = "crossed input vectors";
+ return false;
+ }
+
+ /* Ensure that the stepped sequence always selects from the same
+ input pattern. */
+ unsigned arg_npatterns
+ = ((q1 & 0) == 0) ? VECTOR_CST_NPATTERNS (arg0)
+ : VECTOR_CST_NPATTERNS (arg1);
+
+ if (!multiple_p (step, arg_npatterns))
+ {
+ if (reason)
+ *reason = "step is not multiple of npatterns";
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/* Try to fold permutation of ARG0 and ARG1 with SEL selector when
+ the input vectors are VECTOR_CST. Return NULL_TREE otherwise.
+ REASON has same purpose as described in
+ valid_mask_for_fold_vec_perm_cst_p. */
+
+
+static tree
+fold_vec_perm_cst (tree type, tree arg0, tree arg1, const vec_perm_indices
&sel,
+ const char **reason = NULL)
+{
+ unsigned res_npatterns, res_nelts_per_pattern;
+ unsigned HOST_WIDE_INT res_nelts;
+
+ /* (1) If SEL is a suitable mask as determined by
+ valid_mask_for_fold_vec_perm_cst_p, then:
+ res_npatterns = max of npatterns between ARG0, ARG1, and SEL
+ res_nelts_per_pattern = max of nelts_per_pattern between
+ ARG0, ARG1 and SEL.
+ (2) If SEL is not a suitable mask, and TYPE is VLS then:
+ res_npatterns = nelts in result vector.
+ res_nelts_per_pattern = 1.
+ This exception is made so that VLS ARG0, ARG1 and SEL work as before. */
+ if (valid_mask_for_fold_vec_perm_cst_p (arg0, arg1, sel, reason))
+ {
+ res_npatterns
+ = std::max (VECTOR_CST_NPATTERNS (arg0),
+ std::max (VECTOR_CST_NPATTERNS (arg1),
+ sel.encoding ().npatterns ()));
+
+ res_nelts_per_pattern
+ = std::max (VECTOR_CST_NELTS_PER_PATTERN (arg0),
+ std::max (VECTOR_CST_NELTS_PER_PATTERN (arg1),
+ sel.encoding ().nelts_per_pattern ()));
+
+ res_nelts = res_npatterns * res_nelts_per_pattern;
+ }
+ else if (TYPE_VECTOR_SUBPARTS (type).is_constant (&res_nelts))
+ {
+ res_npatterns = res_nelts;
+ res_nelts_per_pattern = 1;
+ }
+ else
+ return NULL_TREE;
+
+ tree_vector_builder out_elts (type, res_npatterns, res_nelts_per_pattern);
+ for (unsigned i = 0; i < res_nelts; i++)
+ {
+ poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+ uint64_t q;
+ poly_uint64 r;
+ unsigned HOST_WIDE_INT index;
+
+ /* Punt if sel[i] /trunc_div len cannot be determined,
+ because the input vector to be chosen will depend on
+ runtime vector length.
+ For example if len == 4 + 4x, and sel[i] == 4,
+ If len at runtime equals 4, we choose arg1[0].
+ For any other value of len > 4 at runtime, we choose arg0[4].
+ which makes the element choice dependent on runtime vector length. */
+ if (!can_div_trunc_p (sel[i], len, &q, &r))
+ {
+ if (reason)
+ *reason = "cannot divide selector element by arg len";
+ return NULL_TREE;
+ }
+
+ /* sel[i] % len will give the index of element in the chosen input
+ vector. For example if sel[i] == 5 + 4x and len == 4 + 4x,
+ we will choose arg1[1] since (5 + 4x) % (4 + 4x) == 1. */
+ if (!r.is_constant (&index))
+ {
+ if (reason)
+ *reason = "remainder is not constant";
+ return NULL_TREE;
+ }
+
+ tree arg = ((q & 1) == 0) ? arg0 : arg1;
+ tree elem = vector_cst_elt (arg, index);
+ out_elts.quick_push (elem);
+ }
+
+ return out_elts.build ();
+}
+
/* Attempt to fold vector permutation of ARG0 and ARG1 vectors using SEL
selector. Return the folded VECTOR_CST or CONSTRUCTOR if successful,
NULL_TREE otherwise. */
@@ -10529,43 +10700,41 @@ fold_vec_perm (tree type, tree arg0, tree arg1, const
vec_perm_indices &sel)
{
unsigned int i;
unsigned HOST_WIDE_INT nelts;
- bool need_ctor = false;
- if (!sel.length ().is_constant (&nelts))
- return NULL_TREE;
- gcc_assert (known_eq (TYPE_VECTOR_SUBPARTS (type), nelts)
- && known_eq (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)), nelts)
- && known_eq (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg1)), nelts));
+ gcc_assert (known_eq (TYPE_VECTOR_SUBPARTS (type), sel.length ())
+ && known_eq (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)),
+ TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg1))));
+
if (TREE_TYPE (TREE_TYPE (arg0)) != TREE_TYPE (type)
|| TREE_TYPE (TREE_TYPE (arg1)) != TREE_TYPE (type))
return NULL_TREE;
+ if (TREE_CODE (arg0) == VECTOR_CST
+ && TREE_CODE (arg1) == VECTOR_CST)
+ return fold_vec_perm_cst (type, arg0, arg1, sel);
+
+ /* For fall back case, we want to ensure we have VLS vectors
+ with equal length. */
+ if (!sel.length ().is_constant (&nelts))
+ return NULL_TREE;
+
+ gcc_assert (known_eq (sel.length (),
+ TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0))));
tree *in_elts = XALLOCAVEC (tree, nelts * 2);
if (!vec_cst_ctor_to_array (arg0, nelts, in_elts)
|| !vec_cst_ctor_to_array (arg1, nelts, in_elts + nelts))
return NULL_TREE;
- tree_vector_builder out_elts (type, nelts, 1);
+ vec<constructor_elt, va_gc> *v;
+ vec_alloc (v, nelts);
for (i = 0; i < nelts; i++)
{
HOST_WIDE_INT index;
if (!sel[i].is_constant (&index))
return NULL_TREE;
- if (!CONSTANT_CLASS_P (in_elts[index]))
- need_ctor = true;
- out_elts.quick_push (unshare_expr (in_elts[index]));
- }
-
- if (need_ctor)
- {
- vec<constructor_elt, va_gc> *v;
- vec_alloc (v, nelts);
- for (i = 0; i < nelts; i++)
- CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, out_elts[i]);
- return build_constructor (type, v);
+ CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, in_elts[index]);
}
- else
- return out_elts.build ();
+ return build_constructor (type, v);
}
/* Try to fold a pointer difference of type TYPE two address expressions of
@@ -16892,6 +17061,554 @@ test_arithmetic_folding ()
x);
}
+namespace test_fold_vec_perm_cst {
+
+/* Build a VECTOR_CST corresponding to VMODE, and has
+ encoding given by NPATTERNS, NELTS_PER_PATTERN and STEP.
+ Fill it with randomized elements, using rand() % THRESHOLD. */
+
+static tree
+build_vec_cst_rand (machine_mode vmode, unsigned npatterns,
+ unsigned nelts_per_pattern,
+ int step = 0, int threshold = 100)
+{
+ tree inner_type = lang_hooks.types.type_for_mode (GET_MODE_INNER (vmode), 1);
+ tree vectype = build_vector_type_for_mode (inner_type, vmode);
+ tree_vector_builder builder (vectype, npatterns, nelts_per_pattern);
+
+ // Fill a0 for each pattern
+ for (unsigned i = 0; i < npatterns; i++)
+ builder.quick_push (build_int_cst (inner_type, rand () % threshold));
+
+ if (nelts_per_pattern == 1)
+ return builder.build ();
+
+ // Fill a1 for each pattern
+ for (unsigned i = 0; i < npatterns; i++)
+ builder.quick_push (build_int_cst (inner_type, rand () % threshold));
+
+ if (nelts_per_pattern == 2)
+ return builder.build ();
+
+ for (unsigned i = npatterns * 2; i < npatterns * nelts_per_pattern; i++)
+ {
+ tree prev_elem = builder[i - npatterns];
+ int prev_elem_val = TREE_INT_CST_LOW (prev_elem);
+ int val = prev_elem_val + step;
+ builder.quick_push (build_int_cst (inner_type, val));
+ }
+
+ return builder.build ();
+}
+
+/* Validate result of VEC_PERM_EXPR folding for the unit-tests below,
+ when result is VLA. */
+
+static void
+validate_res (unsigned npatterns, unsigned nelts_per_pattern,
+ tree res, tree *expected_res)
+{
+ /* Actual npatterns / nelts_per_pattern in res may be less than expected due
+ to canonicalization. */
+ ASSERT_TRUE (VECTOR_CST_NPATTERNS (res) <= npatterns);
+ ASSERT_TRUE (VECTOR_CST_NELTS_PER_PATTERN (res) <= nelts_per_pattern);
+
+ for (unsigned i = 0; i < npatterns * nelts_per_pattern; i++)
+ ASSERT_TRUE (operand_equal_p (VECTOR_CST_ELT (res, i), expected_res[i],
0));
+}
+
+/* Validate result of VEC_PERM_EXPR folding for the unit-tests below,
+ when the result is VLS. */
+
+static void
+validate_res_vls (tree res, tree *expected_res, unsigned expected_nelts)
+{
+ ASSERT_TRUE (known_eq (VECTOR_CST_NELTS (res), expected_nelts));
+ for (unsigned i = 0; i < expected_nelts; i++)
+ ASSERT_TRUE (operand_equal_p (VECTOR_CST_ELT (res, i), expected_res[i],
0));
+}
+
+/* Test cases where result and input vectors are VNx4SI */
+
+static void
+test_vnx4si (machine_mode vmode)
+{
+ /* Case 1: mask = {0, ...} */
+ {
+ tree arg0 = build_vec_cst_rand (vmode, 2, 3, 1);
+ tree arg1 = build_vec_cst_rand (vmode, 2, 3, 1);
+ poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ vec_perm_builder builder (len, 1, 1);
+ builder.quick_push (0);
+ vec_perm_indices sel (builder, 2, len);
+ tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
+
+ tree expected_res[] = { vector_cst_elt (res, 0) };
+ validate_res (1, 1, res, expected_res);
+ }
+
+ /* Case 2: mask = {len, ...} */
+ {
+ tree arg0 = build_vec_cst_rand (vmode, 2, 3, 1);
+ tree arg1 = build_vec_cst_rand (vmode, 2, 3, 1);
+ poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ vec_perm_builder builder (len, 1, 1);
+ builder.quick_push (len);
+ vec_perm_indices sel (builder, 2, len);
+ tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
+
+ tree expected_res[] = { vector_cst_elt (arg1, 0) };
+ validate_res (1, 1, res, expected_res);
+ }
+
+ /* Case 3: mask = { 0, len, ... } */
+ {
+ tree arg0 = build_vec_cst_rand (vmode, 2, 3, 1);
+ tree arg1 = build_vec_cst_rand (vmode, 2, 3, 1);
+ poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ vec_perm_builder builder (len, 2, 1);
+ builder.quick_push (0);
+ builder.quick_push (len);
+ vec_perm_indices sel (builder, 2, len);
+ tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
+
+ tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt (arg1, 0)
};
+ validate_res (2, 1, res, expected_res);
+ }
+
+ /* Case 4: mask = { 0, len, 1, len+1, ... } */
+ {
+ tree arg0 = build_vec_cst_rand (vmode, 2, 3, 1);
+ tree arg1 = build_vec_cst_rand (vmode, 2, 3, 1);
+ poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ vec_perm_builder builder (len, 2, 2);
+ builder.quick_push (0);
+ builder.quick_push (len);
+ builder.quick_push (1);
+ builder.quick_push (len + 1);
+ vec_perm_indices sel (builder, 2, len);
+ tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
+
+ tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt (arg1, 0),
+ vector_cst_elt (arg0, 1), vector_cst_elt (arg1, 1)
+ };
+ validate_res (2, 2, res, expected_res);
+ }
+
+ /* Case 5: mask = { 0, len, 1, len+1, .... }
+ npatterns = 4, nelts_per_pattern = 1 */
+ {
+ tree arg0 = build_vec_cst_rand (vmode, 2, 3, 1);
+ tree arg1 = build_vec_cst_rand (vmode, 2, 3, 1);
+ poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ vec_perm_builder builder (len, 4, 1);
+ builder.quick_push (0);
+ builder.quick_push (len);
+ builder.quick_push (1);
+ builder.quick_push (len + 1);
+ vec_perm_indices sel (builder, 2, len);
+ tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
+
+ tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt (arg1, 0),
+ vector_cst_elt (arg0, 1), vector_cst_elt (arg1, 1)
+ };
+ validate_res (4, 1, res, expected_res);
+ }
+
+ /* Case 6: mask = {0, 4, ...}
+ npatterns = 1, nelts_per_pattern = 2.
+ This should return NULL_TREE because the index 4 may choose
+ from either arg0 or arg1 depending on vector length. */
+ {
+ tree arg0 = build_vec_cst_rand (vmode, 2, 3, 1);
+ tree arg1 = build_vec_cst_rand (vmode, 2, 3, 1);
+ poly_uint64 len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ vec_perm_builder builder (len, 1, 2);
+ builder.quick_push (0);
+ builder.quick_push (4);
+ vec_perm_indices sel (builder, 2, len);
+ tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
+ ASSERT_TRUE (res == NULL_TREE);
+ }
+
+ /* Case 7: npatterns(arg0) = 4 > npatterns(sel) = 2
+ mask = {0, len, 1, len + 1, ...}
+ sel_npatterns = 2, sel_nelts_per_pattern = 2. */
+ {
+ tree arg0 = build_vec_cst_rand (vmode, 2, 3, 1);
+ tree arg1 = build_vec_cst_rand (vmode, 2, 3, 1);
+ poly_uint64 arg0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ vec_perm_builder builder (arg0_len, 2, 2);
+ builder.quick_push (0);
+ builder.quick_push (arg0_len);
+ builder.quick_push (1);
+ builder.quick_push (arg0_len + 1);
+ vec_perm_indices sel (builder, 2, arg0_len);
+ tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
+
+ tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt (arg1, 0),
+ vector_cst_elt (arg0, 1), vector_cst_elt (arg1, 1)
+ };
+ validate_res (2, 2, res, expected_res);
+ }
+
+ /* Case 8: sel = {0, 1, 2, ...}
+ npatterns = 1, nelts_per_pattern = 3
+ expected res: { arg0[0], arg0[1], arg0[2], ... } */
+ {
+ tree arg0 = build_vec_cst_rand (vmode, 1, 3, 2);
+ tree arg1 = build_vec_cst_rand (vmode, 1, 3, 2);
+ poly_uint64 arg0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ vec_perm_builder builder (arg0_len, 1, 3);
+ builder.quick_push (0);
+ builder.quick_push (1);
+ builder.quick_push (2);
+
+ vec_perm_indices sel (builder, 2, arg0_len);
+ tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel);
+ tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt (arg0, 1),
+ vector_cst_elt (arg0, 2) };
+ validate_res (1, 3, res, expected_res);
+ }
+
+ /* Case 9: sel = {len, len + 1, len + 2, ... }
+ npatterns = 1, nelts_per_pattern = 3
+ expected res: { op1[0], op1[1], op1[2], ... } */
+ {
+ tree arg0 = build_vec_cst_rand (vmode, 1, 3, 2);
+ tree arg1 = build_vec_cst_rand (vmode, 1, 3, 2);
+ poly_uint64 arg0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ vec_perm_builder builder (arg0_len, 1, 3);
+ builder.quick_push (arg0_len);
+ builder.quick_push (arg0_len + 1);
+ builder.quick_push (arg0_len + 2);
+
+ vec_perm_indices sel (builder, 2, arg0_len);
+ tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel, NULL);
+ tree expected_res[] = { vector_cst_elt (arg1, 0), vector_cst_elt (arg1, 1),
+ vector_cst_elt (arg1, 2) };
+ validate_res (1, 3, res, expected_res);
+ }
+}
+
+/* Test cases where result and input vectors are VNx16QI */
+
+static void
+test_vnx16qi (machine_mode vmode)
+{
+ /* Case 1: Leading element of arg1, stepped sequence: pattern 0 of arg0.
+ sel = {len, 0, 0, 0, 2, 0, ...}
+ npatterns = 2, nelts_per_pattern = 3.
+ Use extra pattern {0, ...} to lower number of elements per pattern. */
+ {
+ tree arg0 = build_vec_cst_rand (vmode, 1, 3, 2);
+ tree arg1 = build_vec_cst_rand (vmode, 1, 3, 2);
+ poly_uint64 arg0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ vec_perm_builder builder (arg0_len, 2, 3);
+ builder.quick_push (arg0_len);
+ int mask_elems[] = { 0, 0, 0, 2, 0 };
+ for (int i = 0; i < 5; i++)
+ builder.quick_push (mask_elems[i]);
+
+ vec_perm_indices sel (builder, 2, arg0_len);
+ const char *reason;
+ tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel, &reason);
+
+ tree expected_res[] = { vector_cst_elt (arg1, 0), vector_cst_elt (arg0, 0),
+ vector_cst_elt (arg0, 0), vector_cst_elt (arg0, 0),
+ vector_cst_elt (arg0, 2), vector_cst_elt (arg0, 0)
+ };
+ validate_res (2, 3, res, expected_res);
+ }
+
+ /* Case 2:
+ sel = { len, 0, 2, ... } npatterns = 1, nelts_per_pattern = 3.
+ This should return NULL because we cross the input vectors.
+ Because,
+ arg0_len = 16 + 16x
+ a1 = 0
+ S = 2
+ esel = arg0_len / npatterns_sel = 16+16x/1 = 16 + 16x
+ ae = 0 + (esel - 2) * S
+ = 0 + (16 + 16x - 2) * 2
+ = 28 + 32x
+ Let q1 = a1 / arg0_len = 0 /trunc (16 + 16x) = 0
+ Let qe = ae / arg0_len = (28 + 32x) /trunc (16 + 16x) = 1.
+ Since q1 != qe, we cross input vectors.
+ So return NULL_TREE. */
+ {
+ tree arg0 = build_vec_cst_rand (vmode, 1, 3, 2);
+ tree arg1 = build_vec_cst_rand (vmode, 1, 3, 2);
+ poly_uint64 arg0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
+
+ vec_perm_builder builder (arg0_len, 1, 3);
+ builder.quick_push (arg0_len);
+ builder.quick_push (0);
+ builder.quick_push (2);
+
+ vec_perm_indices sel (builder, 2, arg0_len);
+ const char *reason;
+ tree res = fold_vec_perm_cst (TREE_TYPE (arg0), arg0, arg1, sel, &reason);
+ ASSERT_TRUE (res == NULL_TREE);
+ ASSERT_TRUE (!strcmp (reason, "crossed input vectors"));
+ }
+
+ /* Case 3: Select elements from different patterns.
+ Should return NULL. */
+ {
+ tree op0 = build_vec_cst_rand (vmode, 2, 3, 2);
+ tree op1 = build_vec_cst_rand (vmode, 2, 3, 2);
+ poly_uint64 op0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (op0));
+
+ vec_perm_builder builder (op0_len, 2, 3);
+ builder.quick_push (op0_len);
+ int mask_elems[] = { 0, 0, 0, 1, 0 };
+ for (int i = 0; i < 5; i++)
+ builder.quick_push (mask_elems[i]);
+
+ vec_perm_indices sel (builder, 2, op0_len);
+ const char *reason;
+ tree res = fold_vec_perm_cst (TREE_TYPE (op0), op0, op1, sel, &reason);
+ ASSERT_TRUE (res == NULL_TREE);
+ ASSERT_TRUE (!strcmp (reason, "step is not multiple of npatterns"));
+ }
+
+ /* Case 4: Select pattern 0 of op0 and dup of op0[0]
+ op0, op1, sel: npatterns = 2, nelts_per_pattern = 3
+ sel = { 0, 0, 2, 0, 4, 0, ... }.
+
+ For pattern {0, 2, 4, ...}:
+ a1 = 2
+ len = 16 + 16x
+ S = 2
+ esel = len / npatterns_sel = (16 + 16x) / 2 = (8 + 8x)
+ ae = a1 + (esel - 2) * S
+ = 2 + (8 + 8x - 2) * 2
+ = 14 + 16x
+ a1 / arg0_len = 2 / (16 + 16x) = 0
+ ae / arg0_len = (14 + 16x) / (16 + 16x) = 0
+ So a1/arg0_len = ae/arg0_len = 0
+ Hence we select from first vector op0
+ S = 2, npatterns = 2.
+ Since S is multiple of npatterns(op0), we are selecting from
+ same pattern of op0.
+
+ For pattern {0, ...}, we are choosing { op0[0] ... }
+ So res will be combination of above patterns:
+ res: { op0[0], op0[0], op0[2], op0[0], op0[4], op0[0], ... }
+ with npatterns = 2, nelts_per_pattern = 3. */
+ {
+ tree op0 = build_vec_cst_rand (vmode, 2, 3, 2);
+ tree op1 = build_vec_cst_rand (vmode, 2, 3, 2);
+ poly_uint64 op0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (op0));
+
+ vec_perm_builder builder (op0_len, 2, 3);
+ int mask_elems[] = { 0, 0, 2, 0, 4, 0 };
+ for (int i = 0; i < 6; i++)
+ builder.quick_push (mask_elems[i]);
+
+ vec_perm_indices sel (builder, 2, op0_len);
+ tree res = fold_vec_perm_cst (TREE_TYPE (op0), op0, op1, sel);
+ tree expected_res[] = { vector_cst_elt (op0, 0), vector_cst_elt (op0, 0),
+ vector_cst_elt (op0, 2), vector_cst_elt (op0, 0),
+ vector_cst_elt (op0, 4), vector_cst_elt (op0, 0) };
+ validate_res (2, 3, res, expected_res);
+ }
+
+ /* Case 7: sel_npatterns > op_npatterns;
+ op0, op1: npatterns = 2, nelts_per_pattern = 3
+ sel: { 0, 0, 1, len, 2, 0, 3, len, 4, 0, 5, len, ...},
+ with npatterns = 4, nelts_per_pattern = 3. */
+ {
+ tree op0 = build_vec_cst_rand (vmode, 2, 3, 2);
+ tree op1 = build_vec_cst_rand (vmode, 2, 3, 2);
+ poly_uint64 op0_len = TYPE_VECTOR_SUBPARTS (TREE_TYPE (op0));
+
+ vec_perm_builder builder(op0_len, 4, 3);
+ // -1 is used as place holder for poly_int_cst
+ int mask_elems[] = { 0, 0, 1, -1, 2, 0, 3, -1, 4, 0, 5, -1 };
+ for (int i = 0; i < 12; i++)
+ builder.quick_push ((mask_elems[i] == -1) ? op0_len : mask_elems[i]);
+
+ vec_perm_indices sel (builder, 2, op0_len);
+ tree res = fold_vec_perm_cst (TREE_TYPE (op0), op0, op1, sel);
+ tree expected_res[] = { vector_cst_elt (op0, 0), vector_cst_elt (op0, 0),
+ vector_cst_elt (op0, 1), vector_cst_elt (op1, 0),
+ vector_cst_elt (op0, 2), vector_cst_elt (op0, 0),
+ vector_cst_elt (op0, 3), vector_cst_elt (op1, 0),
+ vector_cst_elt (op0, 4), vector_cst_elt (op0, 0),
+ vector_cst_elt (op0, 5), vector_cst_elt (op1, 0) };
+ validate_res (4, 3, res, expected_res);
+ }
+}
+
+/* Test cases where result is VNx4SI and input vectors are V4SI. */
+
+static void
+test_vnx4si_v4si (machine_mode vnx4si_mode, machine_mode v4si_mode)
+{
+ /* Case 1:
+ sel = { 0, 4, 1, 5, ... }
+ res = { op0[0], op1[0], op0[1], op1[1], ...} // (4, 1) */
+ {
+ tree arg0 = build_vec_cst_rand (v4si_mode, 4, 1, 0);
+ tree arg1 = build_vec_cst_rand (v4si_mode, 4, 1, 0);
+
+ tree inner_type
+ = lang_hooks.types.type_for_mode (GET_MODE_INNER (vnx4si_mode), 1);
+ tree res_type = build_vector_type_for_mode (inner_type, vnx4si_mode);
+
+ poly_uint64 res_len = TYPE_VECTOR_SUBPARTS (res_type);
+ vec_perm_builder builder (res_len, 4, 1);
+ builder.quick_push (0);
+ builder.quick_push (4);
+ builder.quick_push (1);
+ builder.quick_push (5);
+
+ vec_perm_indices sel (builder, 2, res_len);
+ tree res = fold_vec_perm_cst (res_type, arg0, arg1, sel);
+ tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt (arg1, 0),
+ vector_cst_elt (arg0, 1), vector_cst_elt (arg1, 1)
+ };
+ validate_res (4, 1, res, expected_res);
+ }
+
+ /* Case 2: Same as case 1, but contains an out of bounds access which
+ should wrap around.
+ sel = {0, 8, 4, 12, ...} (4, 1)
+ res = { op0[0], op0[0], op1[0], op1[0], ... } (4, 1). */
+ {
+ tree arg0 = build_vec_cst_rand (v4si_mode, 4, 1, 0);
+ tree arg1 = build_vec_cst_rand (v4si_mode, 4, 1, 0);
+
+ tree inner_type
+ = lang_hooks.types.type_for_mode (GET_MODE_INNER (vnx4si_mode), 1);
+ tree res_type = build_vector_type_for_mode (inner_type, vnx4si_mode);
+
+ poly_uint64 res_len = TYPE_VECTOR_SUBPARTS (res_type);
+ vec_perm_builder builder (res_len, 4, 1);
+ builder.quick_push (0);
+ builder.quick_push (8);
+ builder.quick_push (4);
+ builder.quick_push (12);
+
+ vec_perm_indices sel (builder, 2, res_len);
+ tree res = fold_vec_perm_cst (res_type, arg0, arg1, sel);
+ tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt (arg0, 0),
+ vector_cst_elt (arg1, 0), vector_cst_elt (arg1, 0)
+ };
+ validate_res (4, 1, res, expected_res);
+ }
+}
+
+/* Test cases where result is V4SI and input vectors are VNx4SI. */
+
+static void
+test_v4si_vnx4si (machine_mode v4si_mode, machine_mode vnx4si_mode)
+{
+ /* Case 1:
+ sel = { 0, 1, 2, 3}
+ res = { op0[0], op0[1], op0[2], op0[3] }. */
+ {
+ tree arg0 = build_vec_cst_rand (vnx4si_mode, 4, 1);
+ tree arg1 = build_vec_cst_rand (vnx4si_mode, 4, 1);
+
+ tree inner_type
+ = lang_hooks.types.type_for_mode (GET_MODE_INNER (v4si_mode), 1);
+ tree res_type = build_vector_type_for_mode (inner_type, v4si_mode);
+
+ poly_uint64 res_len = TYPE_VECTOR_SUBPARTS (res_type);
+ vec_perm_builder builder (res_len, 4, 1);
+ for (int i = 0; i < 4; i++)
+ builder.quick_push (i);
+
+ vec_perm_indices sel (builder, 2, res_len);
+ tree res = fold_vec_perm_cst (res_type, arg0, arg1, sel);
+ tree expected_res[] = { vector_cst_elt (arg0, 0), vector_cst_elt (arg0, 1),
+ vector_cst_elt (arg0, 2), vector_cst_elt (arg0, 3)
};
+ validate_res_vls (res, expected_res, 4);
+ }
+
+ /* Case 2: Same as Case 1, but crossing input vector.
+ sel = {0, 2, 4, 6}
+ In this case,the index 4 is ambiguous since len = 4 + 4x.
+ If x = 0 at runtime, we choose op1[0]
+ For x > 0 at runtime, we choose op0[4]
+ Since we cannot determine, which vector to choose from during compile
time,
+ should return NULL_TREE. */
+ {
+ tree arg0 = build_vec_cst_rand (vnx4si_mode, 4, 1);
+ tree arg1 = build_vec_cst_rand (vnx4si_mode, 4, 1);
+
+ tree inner_type
+ = lang_hooks.types.type_for_mode (GET_MODE_INNER (v4si_mode), 1);
+ tree res_type = build_vector_type_for_mode (inner_type, v4si_mode);
+
+ poly_uint64 res_len = TYPE_VECTOR_SUBPARTS (res_type);
+ vec_perm_builder builder (res_len, 4, 1);
+ for (int i = 0; i < 8; i += 2)
+ builder.quick_push (i);
+
+ vec_perm_indices sel (builder, 2, res_len);
+ const char *reason;
+ tree res = fold_vec_perm_cst (res_type, arg0, arg1, sel, &reason);
+ ASSERT_TRUE (res == NULL_TREE);
+ ASSERT_TRUE (!strcmp (reason, "cannot divide selector element by arg
len"));
+ }
+}
+
+/* Helper function to get a vector mode that has element
+ mode as INNER_MODE and GET_MODE_NUNITS equal to len. */
+
+static machine_mode
+get_vmode (machine_mode inner_mode, poly_uint64 len)
+{
+ machine_mode vmode;
+ FOR_EACH_MODE_IN_CLASS (vmode, MODE_VECTOR_INT)
+ if (GET_MODE_INNER (vmode) == inner_mode
+ && known_eq (GET_MODE_NUNITS (vmode), len))
+ return vmode;
+ return E_VOIDmode;
+}
+
+/* Invoke tests for fold_vec_perm_cst. */
+
+static void
+test ()
+{
+ /* Conditionally execute fold_vec_perm_cst tests, if target supports
+ VLA vectors. Use a compile time check so we avoid instantiating
+ poly_uint64 with N > 1 on targets that do not support VLA vectors. */
+ if constexpr (poly_int_traits<poly_uint64>::num_coeffs > 1)
+ {
+ machine_mode vnx4si_mode = get_vmode (SImode, poly_uint64 (4, 4));
+ if (vnx4si_mode == E_VOIDmode)
+ return;
+ machine_mode vnx16qi_mode = get_vmode (QImode, poly_uint64 (16, 16));
+ if (vnx16qi_mode == E_VOIDmode)
+ return;
+ machine_mode v4si_mode = get_vmode (SImode, 4);
+ if (v4si_mode == E_VOIDmode)
+ return;
+
+ test_vnx4si (vnx4si_mode);
+ test_vnx16qi (vnx16qi_mode);
+ test_vnx4si_v4si (vnx4si_mode, v4si_mode);
+ test_v4si_vnx4si (v4si_mode, vnx4si_mode);
+ }
+}
+}; // end of test_fold_vec_perm_cst namespace
+
/* Verify that various binary operations on vectors are folded
correctly. */
@@ -16943,6 +17660,7 @@ fold_const_cc_tests ()
test_arithmetic_folding ();
test_vector_folding ();
test_vec_duplicate_folding ();
+ test_fold_vec_perm_cst::test ();
}
} // namespace selftest
