On Thu, 3 Aug 2023 at 18:46, Richard Sandiford
<richard.sandif...@arm.com> wrote:
>
> Richard Sandiford <richard.sandif...@arm.com> writes:
> > Prathamesh Kulkarni <prathamesh.kulka...@linaro.org> writes:
> >> On Tue, 25 Jul 2023 at 18:25, Richard Sandiford
> >> <richard.sandif...@arm.com> wrote:
> >>>
> >>> Hi,
> >>>
> >>> Thanks for the rework and sorry for the slow review.
> >> Hi Richard,
> >> Thanks for the suggestions! Please find my responses inline below.
> >>>
> >>> Prathamesh Kulkarni <prathamesh.kulka...@linaro.org> writes:
> >>> > Hi Richard,
> >>> > This is reworking of patch to extend fold_vec_perm to handle VLA
> >>> > vectors.
> >>> > The attached patch unifies handling of VLS and VLA vector_csts, while
> >>> > using fallback code
> >>> > for ctors.
> >>> >
> >>> > For VLS vector, the patch ignores underlying encoding, and
> >>> > uses npatterns = nelts, and nelts_per_pattern = 1.
> >>> >
> >>> > For VLA patterns, if sel has a stepped sequence, then it
> >>> > only chooses elements from a particular pattern of a particular
> >>> > input vector.
> >>> >
> >>> > To make things simpler, the patch imposes following constraints:
> >>> > (a) op0_npatterns, op1_npatterns and sel_npatterns are powers of 2.
> >>> > (b) The step size for a stepped sequence is a power of 2, and
> >>> > multiple of npatterns of chosen input vector.
> >>> > (c) Runtime vector length of sel is a multiple of sel_npatterns.
> >>> > So, we don't handle sel.length = 2 + 2x and npatterns = 4.
> >>> >
> >>> > Eg:
> >>> > op0, op1: npatterns = 2, nelts_per_pattern = 3
> >>> > op0_len = op1_len = 16 + 16x.
> >>> > sel = { 0, 0, 2, 0, 4, 0, ... }
> >>> > npatterns = 2, nelts_per_pattern = 3.
> >>> >
> >>> > For pattern {0, 2, 4, ...}
> >>> > Let,
> >>> > a1 = 2
> >>> > S = step size = 2
> >>> >
> >>> > Let Esel denote number of elements per pattern in sel at runtime.
> >>> > Esel = (16 + 16x) / npatterns_sel
> >>> > = (16 + 16x) / 2
> >>> > = (8 + 8x)
> >>> >
> >>> > So, last element of pattern:
> >>> > ae = a1 + (Esel - 2) * S
> >>> > = 2 + (8 + 8x - 2) * 2
> >>> > = 14 + 16x
> >>> >
> >>> > a1 /trunc arg0_len = 2 / (16 + 16x) = 0
> >>> > ae /trunc arg0_len = (14 + 16x) / (16 + 16x) = 0
> >>> > Since both are equal with quotient = 0, we select elements from op0.
> >>> >
> >>> > Since step size (S) is a multiple of npatterns(op0), we select
> >>> > all elements from same pattern of op0.
> >>> >
> >>> > res_npatterns = max (op0_npatterns, max (op1_npatterns, sel_npatterns))
> >>> > = max (2, max (2, 2)
> >>> > = 2
> >>> >
> >>> > res_nelts_per_pattern = max (op0_nelts_per_pattern,
> >>> > max
> >>> > (op1_nelts_per_pattern,
> >>> >
> >>> > sel_nelts_per_pattern))
> >>> > = max (3, max (3, 3))
> >>> > = 3
> >>> >
> >>> > So res has encoding with npatterns = 2, nelts_per_pattern = 3.
> >>> > res: { op0[0], op0[0], op0[2], op0[0], op0[4], op0[0], ... }
> >>> >
> >>> > Unfortunately, this results in an issue for poly_int_cst index:
> >>> > For example,
> >>> > op0, op1: npatterns = 1, nelts_per_pattern = 3
> >>> > op0_len = op1_len = 4 + 4x
> >>> >
> >>> > sel: { 4 + 4x, 5 + 4x, 6 + 4x, ... } // should choose op1
> >>> >
> >>> > In this case,
> >>> > a1 = 5 + 4x
> >>> > S = (6 + 4x) - (5 + 4x) = 1
> >>> > Esel = 4 + 4x
> >>> >
> >>> > ae = a1 + (esel - 2) * S
> >>> > = (5 + 4x) + (4 + 4x - 2) * 1
> >>> > = 7 + 8x
> >>> >
> >>> > IIUC, 7 + 8x will always be index for last element of op1 ?
> >>> > if x = 0, len = 4, 7 + 8x = 7
> >>> > if x = 1, len = 8, 7 + 8x = 15, etc.
> >>> > So the stepped sequence will always choose elements
> >>> > from op1 regardless of vector length for above case ?
> >>> >
> >>> > However,
> >>> > ae /trunc op0_len
> >>> > = (7 + 8x) / (4 + 4x)
> >>> > which is not defined because 7/4 != 8/4
> >>> > and we return NULL_TREE, but I suppose the expected result would be:
> >>> > res: { op1[0], op1[1], op1[2], ... } ?
> >>> >
> >>> > The patch passes bootstrap+test on aarch64-linux-gnu with and without
> >>> > sve,
> >>> > and on x86_64-unknown-linux-gnu.
> >>> > I would be grateful for suggestions on how to proceed.
> >>> >
> >>> > Thanks,
> >>> > Prathamesh
> >>> >
> >>> > diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
> >>> > index a02ede79fed..8028b3e8e9a 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>
> >>> > +#include "tree-pretty-print.h"
> >>> > +#include "gimple-pretty-print.h"
> >>> > +#include "print-tree.h"
> >>> >
> >>> > /* Nonzero if we are folding constants inside an initializer or a C++
> >>> > manifestly-constant-evaluated context; zero otherwise.
> >>> > @@ -10493,15 +10497,9 @@ 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;
> >>> >
> >>> > @@ -10519,6 +10517,230 @@ vec_cst_ctor_to_array (tree arg, unsigned int
> >>> > nelts, tree *elts)
> >>> > return true;
> >>> > }
> >>> >
> >>> > +/* Return a vector with (NPATTERNS, NELTS_PER_PATTERN) encoding. */
> >>> > +
> >>> > +static tree
> >>> > +vector_cst_reshape (tree vec, unsigned npatterns, unsigned
> >>> > nelts_per_pattern)
> >>> > +{
> >>> > + gcc_assert (pow2p_hwi (npatterns));
> >>> > +
> >>> > + if (VECTOR_CST_NPATTERNS (vec) == npatterns
> >>> > + && VECTOR_CST_NELTS_PER_PATTERN (vec) == nelts_per_pattern)
> >>> > + return vec;
> >>> > +
> >>> > + tree v = make_vector (exact_log2 (npatterns), nelts_per_pattern);
> >>> > + TREE_TYPE (v) = TREE_TYPE (vec);
> >>> > +
> >>> > + unsigned nelts = npatterns * nelts_per_pattern;
> >>> > + for (unsigned i = 0; i < nelts; i++)
> >>> > + VECTOR_CST_ENCODED_ELT(v, i) = vector_cst_elt (vec, i);
> >>> > + return v;
> >>> > +}
> >>> > +
> >>> > +/* Helper routine for fold_vec_perm_vla to check if ARG is a suitable
> >>> > + operand for VLA vec_perm folding. If arg is VLS, then set
> >>> > + NPATTERNS = nelts and NELTS_PER_PATTERN = 1. */
> >>> > +
> >>> > +static tree
> >>> > +valid_operand_for_fold_vec_perm_cst_p (tree arg)
> >>> > +{
> >>> > + if (TREE_CODE (arg) != VECTOR_CST)
> >>> > + return NULL_TREE;
> >>> > +
> >>> > + unsigned HOST_WIDE_INT nelts;
> >>> > + unsigned npatterns, nelts_per_pattern;
> >>> > + if (TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg)).is_constant (&nelts))
> >>> > + {
> >>> > + npatterns = nelts;
> >>> > + nelts_per_pattern = 1;
> >>> > + }
> >>> > + else
> >>> > + {
> >>> > + npatterns = VECTOR_CST_NPATTERNS (arg);
> >>> > + nelts_per_pattern = VECTOR_CST_NELTS_PER_PATTERN (arg);
> >>> > + }
> >>> > +
> >>> > + if (!pow2p_hwi (npatterns))
> >>> > + return NULL_TREE;
> >>> > +
> >>> > + return vector_cst_reshape (arg, npatterns, nelts_per_pattern);
> >>> > +}
> >>>
> >>> I don't think we should reshape the vectors for VLS, since it would
> >>> create more nodes for GC to clean up later. Also, the "compact" encoding
> >>> is canonical even for VLS, so the reshaping would effectively create
> >>> noncanonical constants (even if only temporarily).
> >> Removed in the attached patch.
> >>>
> >>> Instead, I think we should change the later:
> >>>
> >>> > + if (!valid_mask_for_fold_vec_perm_cst_p (arg0, arg1, sel,
> >>> > sel_npatterns,
> >>> > + sel_nelts_per_pattern, reason,
> >>> > verbose))
> >>> > + return NULL_TREE;
> >>>
> >>> so that it comes after the computation of res_npatterns and
> >>> res_nelts_per_pattern. Then, if valid_mask_for_fold_vec_perm_cst_p
> >>> returns false, and if the result type has a constant number of elements,
> >>> we should:
> >>>
> >>> * set res_npatterns to that number of elements
> >>> * set res_nelts_per_pattern to 1
> >>> * continue instead of returning null
> >> Assuming we don't enforce only VLA or only VLS for input vectors and sel,
> >> won't that be still an issue if res (and sel) is VLS, and input
> >> vectors are VLA ?
> >> For eg:
> >> arg0, arg1 are type VNx4SI with npatterns = 2, nelts_per_pattern = 3, step
> >> = 2
> >> sel is V4SI constant with encoding { 0, 2, 4, ... }
> >> and res_type is V4SI.
> >> In this case, when it comes to index 4, the vector selection becomes
> >> ambiguous,
> >> since it can be arg1 for len = 4 + 4x, and arg0 for lengths > 4 + 4x ?
> >
> > Ah, right. So the condition is whether the result type and the data
> > input type have a constant number of elements, rather than just the result.
>
> Actually, I take that back. The reason:
>
> >>> The loop that follows will then do the correct thing for each element.
>
> is true is that:
>
> + if (!can_div_trunc_p (sel[i], len, &q, &r))
> + {
> + if (reason)
> + strcpy (reason, "cannot divide selector element by arg len");
> + return NULL_TREE;
> + }
>
> will return false if q isn't computable at compile time (that is,
> if we can't decide at compile time which input the element comes from).
>
> So I think checking the result is enough.
Ah yes, thanks for pointing it out! I verified that's indeed the case
(test 4 in test_fold_vec_perm_cst::test_mixed in attached patch).
Does the attached patch look OK ?
Bootstrapped+tested on aarch64-linux-gnu with and without SVE, and on
x86_64-linux-gnu.
Thanks,
Prathamesh
>
> Thanks,
> Richard
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>
+#include "tree-pretty-print.h"
+#include "gimple-pretty-print.h"
+#include "print-tree.h"
/* 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)
+{
+ 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;
+ 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. */
+ 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;
+ }
+
+ 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.
+ res_nelts_per_pattern = 1.
+ This exception is made so that VLS ARG0, ARG1 and SEL work as before.
*/
+
+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;
+
+ 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;
+ }
+
+ /* 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))));
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,
+ tree vectype = NULL_TREE)
+{
+ if (!vectype)
+ vectype = get_preferred_vectype (inner_type);
+ 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);
+
+ for (unsigned i = 0; i < vector_cst_encoded_nelts (res); i++)
+ 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. */
+ {
+ 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]);
+
+ 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. */
+ {
+ 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"));
+ }
+
+ /* 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]);
+
+ 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. */
+ {
+ 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
+ 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
