This patch reworks the VEC_PERM_EXPR folding so that more of it
works for variable-length vectors. E.g. it means that we can
now recognise variable-length permutes that reduce to a single
vector, or cases in which a variable-length permute only needs
one input. There should be no functional change for fixed-length
vectors.
2018-01-02 Richard Sandiford <richard.sandiford@linaro.org>
gcc/
* selftest.h (selftest::vec_perm_indices_c_tests): Declare.
* selftest-run-tests.c (selftest::run_tests): Call it.
* vector-builder.h (vector_builder::operator ==): New function.
(vector_builder::operator !=): Likewise.
* vec-perm-indices.h (vec_perm_indices::series_p): Declare.
(vec_perm_indices::all_from_input_p): New function.
* vec-perm-indices.c (vec_perm_indices::series_p): Likewise.
(test_vec_perm_12, selftest::vec_perm_indices_c_tests): Likewise.
* fold-const.c (fold_ternary_loc): Use tree_to_vec_perm_builder
instead of reading the VECTOR_CST directly. Detect whether both
vector inputs are the same before constructing the vec_perm_indices,
and update the number of inputs argument accordingly. Use the
utility functions added above. Only construct sel2 if we need to.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@256098
138bc75d-0d04-0410-961f-
82ee72b054a4
+2018-01-02 Richard Sandiford <richard.sandiford@linaro.org>
+
+ * selftest.h (selftest::vec_perm_indices_c_tests): Declare.
+ * selftest-run-tests.c (selftest::run_tests): Call it.
+ * vector-builder.h (vector_builder::operator ==): New function.
+ (vector_builder::operator !=): Likewise.
+ * vec-perm-indices.h (vec_perm_indices::series_p): Declare.
+ (vec_perm_indices::all_from_input_p): New function.
+ * vec-perm-indices.c (vec_perm_indices::series_p): Likewise.
+ (test_vec_perm_12, selftest::vec_perm_indices_c_tests): Likewise.
+ * fold-const.c (fold_ternary_loc): Use tree_to_vec_perm_builder
+ instead of reading the VECTOR_CST directly. Detect whether both
+ vector inputs are the same before constructing the vec_perm_indices,
+ and update the number of inputs argument accordingly. Use the
+ utility functions added above. Only construct sel2 if we need to.
+
2018-01-02 Richard Sandiford <richard.sandiford@linaro.org>
* optabs.c (expand_vec_perm_var): Use an explicit encoding for
case VEC_PERM_EXPR:
if (TREE_CODE (arg2) == VECTOR_CST)
{
- unsigned int nelts = VECTOR_CST_NELTS (arg2), i, mask, mask2;
- bool need_mask_canon = false;
- bool need_mask_canon2 = false;
- bool all_in_vec0 = true;
- bool all_in_vec1 = true;
- bool maybe_identity = true;
- bool single_arg = (op0 == op1);
- bool changed = false;
-
- mask2 = 2 * nelts - 1;
- mask = single_arg ? (nelts - 1) : mask2;
- gcc_assert (nelts == TYPE_VECTOR_SUBPARTS (type));
- vec_perm_builder sel (nelts, nelts, 1);
- vec_perm_builder sel2 (nelts, nelts, 1);
- for (i = 0; i < nelts; i++)
- {
- tree val = VECTOR_CST_ELT (arg2, i);
- if (TREE_CODE (val) != INTEGER_CST)
- return NULL_TREE;
-
- /* Make sure that the perm value is in an acceptable
- range. */
- wi::tree_to_wide_ref t = wi::to_wide (val);
- need_mask_canon |= wi::gtu_p (t, mask);
- need_mask_canon2 |= wi::gtu_p (t, mask2);
- unsigned int elt = t.to_uhwi () & mask;
- unsigned int elt2 = t.to_uhwi () & mask2;
-
- if (elt < nelts)
- all_in_vec1 = false;
- else
- all_in_vec0 = false;
-
- if ((elt & (nelts - 1)) != i)
- maybe_identity = false;
+ /* Build a vector of integers from the tree mask. */
+ vec_perm_builder builder;
+ if (!tree_to_vec_perm_builder (&builder, arg2))
+ return NULL_TREE;
- sel.quick_push (elt);
- sel2.quick_push (elt2);
- }
+ /* Create a vec_perm_indices for the integer vector. */
+ unsigned int nelts = TYPE_VECTOR_SUBPARTS (type);
+ bool single_arg = (op0 == op1);
+ vec_perm_indices sel (builder, single_arg ? 1 : 2, nelts);
- if (maybe_identity)
- {
- if (all_in_vec0)
- return op0;
- if (all_in_vec1)
- return op1;
- }
+ /* Check for cases that fold to OP0 or OP1 in their original
+ element order. */
+ if (sel.series_p (0, 1, 0, 1))
+ return op0;
+ if (sel.series_p (0, 1, nelts, 1))
+ return op1;
- if (all_in_vec0)
- op1 = op0;
- else if (all_in_vec1)
+ if (!single_arg)
{
- op0 = op1;
- for (i = 0; i < nelts; i++)
- sel[i] -= nelts;
- need_mask_canon = true;
+ if (sel.all_from_input_p (0))
+ op1 = op0;
+ else if (sel.all_from_input_p (1))
+ {
+ op0 = op1;
+ sel.rotate_inputs (1);
+ }
}
- vec_perm_indices indices (sel, 2, nelts);
if ((TREE_CODE (op0) == VECTOR_CST
|| TREE_CODE (op0) == CONSTRUCTOR)
&& (TREE_CODE (op1) == VECTOR_CST
|| TREE_CODE (op1) == CONSTRUCTOR))
{
- tree t = fold_vec_perm (type, op0, op1, indices);
+ tree t = fold_vec_perm (type, op0, op1, sel);
if (t != NULL_TREE)
return t;
}
- if (op0 == op1 && !single_arg)
- changed = true;
-
- /* Some targets are deficient and fail to expand a single
- argument permutation while still allowing an equivalent
- 2-argument version. */
- if (need_mask_canon && arg2 == op2
- && !can_vec_perm_const_p (TYPE_MODE (type), indices, false)
- && can_vec_perm_const_p (TYPE_MODE (type),
- vec_perm_indices (sel2, 2, nelts),
- false))
- {
- need_mask_canon = need_mask_canon2;
- sel.truncate (0);
- sel.splice (sel2);
- }
+ bool changed = (op0 == op1 && !single_arg);
- if (need_mask_canon && arg2 == op2)
+ /* Generate a canonical form of the selector. */
+ if (arg2 == op2 && sel.encoding () != builder)
{
- tree eltype = TREE_TYPE (TREE_TYPE (arg2));
- tree_vector_builder tsel (TREE_TYPE (arg2), nelts, 1);
- for (i = 0; i < nelts; i++)
- tsel.quick_push (build_int_cst (eltype, sel[i]));
- op2 = tsel.build ();
+ /* Some targets are deficient and fail to expand a single
+ argument permutation while still allowing an equivalent
+ 2-argument version. */
+ if (sel.ninputs () == 2
+ || can_vec_perm_const_p (TYPE_MODE (type), sel, false))
+ op2 = vec_perm_indices_to_tree (TREE_TYPE (arg2), sel);
+ else
+ {
+ vec_perm_indices sel2 (builder, 2, nelts);
+ if (can_vec_perm_const_p (TYPE_MODE (type), sel2, false))
+ op2 = vec_perm_indices_to_tree (TREE_TYPE (arg2), sel2);
+ else
+ /* Not directly supported with either encoding,
+ so use the preferred form. */
+ op2 = vec_perm_indices_to_tree (TREE_TYPE (arg2), sel);
+ }
changed = true;
}
/* Mid-level data structures. */
input_c_tests ();
+ vec_perm_indices_c_tests ();
tree_c_tests ();
gimple_c_tests ();
rtl_tests_c_tests ();
extern void wide_int_cc_tests ();
extern void predict_c_tests ();
extern void simplify_rtx_c_tests ();
+extern void vec_perm_indices_c_tests ();
extern int num_passes;
#include "rtl.h"
#include "memmodel.h"
#include "emit-rtl.h"
+#include "selftest.h"
/* Switch to a new permutation vector that selects between NINPUTS vector
inputs that have NELTS_PER_INPUT elements each. Take the elements of the
m_encoding[i] = clamp (m_encoding[i] + element_delta);
}
+/* Return true if index OUT_BASE + I * OUT_STEP selects input
+ element IN_BASE + I * IN_STEP. */
+
+bool
+vec_perm_indices::series_p (unsigned int out_base, unsigned int out_step,
+ element_type in_base, element_type in_step) const
+{
+ /* Check the base value. */
+ if (clamp (m_encoding.elt (out_base)) != clamp (in_base))
+ return false;
+
+ unsigned int full_nelts = m_encoding.full_nelts ();
+ unsigned int npatterns = m_encoding.npatterns ();
+
+ /* Calculate which multiple of OUT_STEP elements we need to get
+ back to the same pattern. */
+ unsigned int cycle_length = least_common_multiple (out_step, npatterns);
+
+ /* Check the steps. */
+ in_step = clamp (in_step);
+ out_base += out_step;
+ unsigned int limit = 0;
+ for (;;)
+ {
+ /* Succeed if we've checked all the elements in the vector. */
+ if (out_base >= full_nelts)
+ return true;
+
+ if (out_base >= npatterns)
+ {
+ /* We've got to the end of the "foreground" values. Check
+ 2 elements from each pattern in the "background" values. */
+ if (limit == 0)
+ limit = out_base + cycle_length * 2;
+ else if (out_base >= limit)
+ return true;
+ }
+
+ element_type v0 = m_encoding.elt (out_base - out_step);
+ element_type v1 = m_encoding.elt (out_base);
+ if (clamp (v1 - v0) != in_step)
+ return false;
+
+ out_base += out_step;
+ }
+ return true;
+}
+
/* Return true if all elements of the permutation vector are in the range
[START, START + SIZE). */
RTVEC_ELT (v, i) = gen_int_mode (indices[i], GET_MODE_INNER (mode));
return gen_rtx_CONST_VECTOR (mode, v);
}
+
+#if CHECKING_P
+
+namespace selftest {
+
+/* Test a 12-element vector. */
+
+static void
+test_vec_perm_12 (void)
+{
+ vec_perm_builder builder (12, 12, 1);
+ for (unsigned int i = 0; i < 4; ++i)
+ {
+ builder.quick_push (i * 5);
+ builder.quick_push (3 + i);
+ builder.quick_push (2 + 3 * i);
+ }
+ vec_perm_indices indices (builder, 1, 12);
+ ASSERT_TRUE (indices.series_p (0, 3, 0, 5));
+ ASSERT_FALSE (indices.series_p (0, 3, 3, 5));
+ ASSERT_FALSE (indices.series_p (0, 3, 0, 8));
+ ASSERT_TRUE (indices.series_p (1, 3, 3, 1));
+ ASSERT_TRUE (indices.series_p (2, 3, 2, 3));
+
+ ASSERT_TRUE (indices.series_p (0, 4, 0, 4));
+ ASSERT_FALSE (indices.series_p (1, 4, 3, 4));
+
+ ASSERT_TRUE (indices.series_p (0, 6, 0, 10));
+ ASSERT_FALSE (indices.series_p (0, 6, 0, 100));
+
+ ASSERT_FALSE (indices.series_p (1, 10, 3, 7));
+ ASSERT_TRUE (indices.series_p (1, 10, 3, 8));
+
+ ASSERT_TRUE (indices.series_p (0, 12, 0, 10));
+ ASSERT_TRUE (indices.series_p (0, 12, 0, 11));
+ ASSERT_TRUE (indices.series_p (0, 12, 0, 100));
+}
+
+/* Run selftests for this file. */
+
+void
+vec_perm_indices_c_tests ()
+{
+ test_vec_perm_12 ();
+}
+
+} // namespace selftest
+
+#endif
element_type clamp (element_type) const;
element_type operator[] (unsigned int i) const;
+ bool series_p (unsigned int, unsigned int, element_type, element_type) const;
bool all_in_range_p (element_type, element_type) const;
+ bool all_from_input_p (unsigned int) const;
private:
vec_perm_indices (const vec_perm_indices &);
return clamp (m_encoding.elt (i));
}
+/* Return true if the permutation vector only selects elements from
+ input I. */
+
+inline bool
+vec_perm_indices::all_from_input_p (unsigned int i) const
+{
+ return all_in_range_p (i * m_nelts_per_input, m_nelts_per_input);
+}
+
#endif
bool encoded_full_vector_p () const;
T elt (unsigned int) const;
+ bool operator == (const Derived &) const;
+ bool operator != (const Derived &x) const { return !operator == (x); }
+
void finalize ();
protected:
this->truncate (0);
}
+/* Return true if this vector and OTHER have the same elements and
+ are encoded in the same way. */
+
+template<typename T, typename Derived>
+bool
+vector_builder<T, Derived>::operator == (const Derived &other) const
+{
+ if (m_full_nelts != other.m_full_nelts
+ || m_npatterns != other.m_npatterns
+ || m_nelts_per_pattern != other.m_nelts_per_pattern)
+ return false;
+
+ unsigned int nelts = encoded_nelts ();
+ for (unsigned int i = 0; i < nelts; ++i)
+ if (!derived ()->equal_p ((*this)[i], other[i]))
+ return false;
+
+ return true;
+}
+
/* Return the value of vector element I, which might or might not be
encoded explicitly. */
projects / thirdparty / gcc.git / commitdiff
