return target;
}
+static rtx
+aarch64_expand_sve_const_pred_1 (rtx, rtx_vector_builder &, bool);
+
+/* BUILDER is a constant predicate in which the index of every set bit
+ is a multiple of ELT_SIZE (which is <= 8). Try to load the constant
+ by inverting every element at a multiple of ELT_SIZE and EORing the
+ result with an ELT_SIZE PTRUE.
+
+ Return a register that contains the constant on success, otherwise
+ return null. Use TARGET as the register if it is nonnull and
+ convenient. */
+
+static rtx
+aarch64_expand_sve_const_pred_eor (rtx target, rtx_vector_builder &builder,
+ unsigned int elt_size)
+{
+ /* Invert every element at a multiple of ELT_SIZE, keeping the
+ other bits zero. */
+ rtx_vector_builder inv_builder (VNx16BImode, builder.npatterns (),
+ builder.nelts_per_pattern ());
+ for (unsigned int i = 0; i < builder.encoded_nelts (); ++i)
+ if ((i & (elt_size - 1)) == 0 && INTVAL (builder.elt (i)) == 0)
+ inv_builder.quick_push (const1_rtx);
+ else
+ inv_builder.quick_push (const0_rtx);
+ inv_builder.finalize ();
+
+ /* See if we can load the constant cheaply. */
+ rtx inv = aarch64_expand_sve_const_pred_1 (NULL_RTX, inv_builder, false);
+ if (!inv)
+ return NULL_RTX;
+
+ /* EOR the result with an ELT_SIZE PTRUE. */
+ rtx mask = aarch64_ptrue_all (elt_size);
+ mask = force_reg (VNx16BImode, mask);
+ target = aarch64_target_reg (target, VNx16BImode);
+ emit_insn (gen_aarch64_pred_z (XOR, VNx16BImode, target, mask, inv, mask));
+ return target;
+}
+
+/* BUILDER is a constant predicate in which the index of every set bit
+ is a multiple of ELT_SIZE (which is <= 8). Try to load the constant
+ using a TRN1 of size PERMUTE_SIZE, which is >= ELT_SIZE. Return the
+ register on success, otherwise return null. Use TARGET as the register
+ if nonnull and convenient. */
+
+static rtx
+aarch64_expand_sve_const_pred_trn (rtx target, rtx_vector_builder &builder,
+ unsigned int elt_size,
+ unsigned int permute_size)
+{
+ /* We're going to split the constant into two new constants A and B,
+ with element I of BUILDER going into A if (I & PERMUTE_SIZE) == 0
+ and into B otherwise. E.g. for PERMUTE_SIZE == 4 && ELT_SIZE == 1:
+
+ A: { 0, 1, 2, 3, _, _, _, _, 8, 9, 10, 11, _, _, _, _ }
+ B: { 4, 5, 6, 7, _, _, _, _, 12, 13, 14, 15, _, _, _, _ }
+
+ where _ indicates elements that will be discarded by the permute.
+
+ First calculate the ELT_SIZEs for A and B. */
+ unsigned int a_elt_size = GET_MODE_SIZE (DImode);
+ unsigned int b_elt_size = GET_MODE_SIZE (DImode);
+ for (unsigned int i = 0; i < builder.encoded_nelts (); i += elt_size)
+ if (INTVAL (builder.elt (i)) != 0)
+ {
+ if (i & permute_size)
+ b_elt_size |= i - permute_size;
+ else
+ a_elt_size |= i;
+ }
+ a_elt_size &= -a_elt_size;
+ b_elt_size &= -b_elt_size;
+
+ /* Now construct the vectors themselves. */
+ rtx_vector_builder a_builder (VNx16BImode, builder.npatterns (),
+ builder.nelts_per_pattern ());
+ rtx_vector_builder b_builder (VNx16BImode, builder.npatterns (),
+ builder.nelts_per_pattern ());
+ unsigned int nelts = builder.encoded_nelts ();
+ for (unsigned int i = 0; i < nelts; ++i)
+ if (i & (elt_size - 1))
+ {
+ a_builder.quick_push (const0_rtx);
+ b_builder.quick_push (const0_rtx);
+ }
+ else if ((i & permute_size) == 0)
+ {
+ /* The A and B elements are significant. */
+ a_builder.quick_push (builder.elt (i));
+ b_builder.quick_push (builder.elt (i + permute_size));
+ }
+ else
+ {
+ /* The A and B elements are going to be discarded, so pick whatever
+ is likely to give a nice constant. We are targeting element
+ sizes A_ELT_SIZE and B_ELT_SIZE for A and B respectively,
+ with the aim of each being a sequence of ones followed by
+ a sequence of zeros. So:
+
+ * if X_ELT_SIZE <= PERMUTE_SIZE, the best approach is to
+ duplicate the last X_ELT_SIZE element, to extend the
+ current sequence of ones or zeros.
+
+ * if X_ELT_SIZE > PERMUTE_SIZE, the best approach is to add a
+ zero, so that the constant really does have X_ELT_SIZE and
+ not a smaller size. */
+ if (a_elt_size > permute_size)
+ a_builder.quick_push (const0_rtx);
+ else
+ a_builder.quick_push (a_builder.elt (i - a_elt_size));
+ if (b_elt_size > permute_size)
+ b_builder.quick_push (const0_rtx);
+ else
+ b_builder.quick_push (b_builder.elt (i - b_elt_size));
+ }
+ a_builder.finalize ();
+ b_builder.finalize ();
+
+ /* Try loading A into a register. */
+ rtx_insn *last = get_last_insn ();
+ rtx a = aarch64_expand_sve_const_pred_1 (NULL_RTX, a_builder, false);
+ if (!a)
+ return NULL_RTX;
+
+ /* Try loading B into a register. */
+ rtx b = a;
+ if (a_builder != b_builder)
+ {
+ b = aarch64_expand_sve_const_pred_1 (NULL_RTX, b_builder, false);
+ if (!b)
+ {
+ delete_insns_since (last);
+ return NULL_RTX;
+ }
+ }
+
+ /* Emit the TRN1 itself. */
+ machine_mode mode = aarch64_sve_pred_mode (permute_size).require ();
+ target = aarch64_target_reg (target, mode);
+ emit_insn (gen_aarch64_sve (UNSPEC_TRN1, mode, target,
+ gen_lowpart (mode, a),
+ gen_lowpart (mode, b)));
+ return target;
+}
+
/* Subroutine of aarch64_expand_sve_const_pred. Try to load the VNx16BI
constant in BUILDER into an SVE predicate register. Return the register
on success, otherwise return null. Use TARGET for the register if
- nonnull and convenient. */
+ nonnull and convenient.
+
+ ALLOW_RECURSE_P is true if we can use methods that would call this
+ function recursively. */
static rtx
-aarch64_expand_sve_const_pred_1 (rtx target, rtx_vector_builder &builder)
+aarch64_expand_sve_const_pred_1 (rtx target, rtx_vector_builder &builder,
+ bool allow_recurse_p)
{
if (builder.encoded_nelts () == 1)
/* A PFALSE or a PTRUE .B ALL. */
return aarch64_sve_move_pred_via_while (target, mode, vl);
}
+ if (!allow_recurse_p)
+ return NULL_RTX;
+
+ /* Try inverting the vector in element size ELT_SIZE and then EORing
+ the result with an ELT_SIZE PTRUE. */
+ if (INTVAL (builder.elt (0)) == 0)
+ if (rtx res = aarch64_expand_sve_const_pred_eor (target, builder,
+ elt_size))
+ return res;
+
+ /* Try using TRN1 to permute two simpler constants. */
+ for (unsigned int i = elt_size; i <= 8; i *= 2)
+ if (rtx res = aarch64_expand_sve_const_pred_trn (target, builder,
+ elt_size, i))
+ return res;
+
return NULL_RTX;
}
aarch64_expand_sve_const_pred (rtx target, rtx_vector_builder &builder)
{
/* Try loading the constant using pure predicate operations. */
- if (rtx res = aarch64_expand_sve_const_pred_1 (target, builder))
+ if (rtx res = aarch64_expand_sve_const_pred_1 (target, builder, true))
return res;
/* Try forcing the constant to memory. */
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