[Mesa-dev] [PATCH v3 3/7] nir: lower 64bit subgroup shuffle intrinsics

[Daniel Schürmann]

---
 src/compiler/nir/nir.h                 |  1 +
 src/compiler/nir/nir_lower_subgroups.c | 68 +++++++++++++++++++++++++++-------
 2 files changed, 56 insertions(+), 13 deletions(-)

diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index f33049d713..f3326e6df9 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -2609,6 +2609,7 @@ typedef struct nir_lower_subgroups_options {
    bool lower_vote_eq_to_ballot:1;
    bool lower_subgroup_masks:1;
    bool lower_shuffle:1;
+   bool lower_shuffle_to_32bit:1;
    bool lower_quad:1;
 } nir_lower_subgroups_options;
 
diff --git a/src/compiler/nir/nir_lower_subgroups.c b/src/compiler/nir/nir_lower_subgroups.c
index 9dc7be7947..8e59861f35 100644
--- a/src/compiler/nir/nir_lower_subgroups.c
+++ b/src/compiler/nir/nir_lower_subgroups.c
@@ -28,6 +28,38 @@
  * \file nir_opt_intrinsics.c
  */
 
+static nir_intrinsic_instr *
+lower_subgroups_64bit_split_intrinsic(nir_builder *b, nir_intrinsic_instr *intrin,
+                                      unsigned int component)
+{
+   nir_ssa_def *comp;
+   if (component == 0)
+      comp = nir_unpack_64_2x32_split_x(b, intrin->src[0].ssa);
+   else
+      comp = nir_unpack_64_2x32_split_y(b, intrin->src[0].ssa);
+
+   nir_intrinsic_instr *intr = nir_intrinsic_instr_create(b->shader, intrin->intrinsic);
+   nir_ssa_dest_init(&intr->instr, &intr->dest, 1, 32, NULL);
+   intr->const_index[0] = intrin->const_index[0];
+   intr->const_index[1] = intrin->const_index[1];
+   intr->src[0] = nir_src_for_ssa(comp);
+   if (nir_intrinsic_infos[intrin->intrinsic].num_srcs == 2)
+      nir_src_copy(&intr->src[1], &intrin->src[1], intr);
+
+   intr->num_components = 1;
+   nir_builder_instr_insert(b, &intr->instr);
+   return intr;
+}
+
+static nir_ssa_def *
+lower_subgroup_op_to_32bit(nir_builder *b, nir_intrinsic_instr *intrin)
+{
+   assert(intrin->src[0].ssa->bit_size == 64);
+   nir_intrinsic_instr *intr_x = lower_subgroups_64bit_split_intrinsic(b, intrin, 0);
+   nir_intrinsic_instr *intr_y = lower_subgroups_64bit_split_intrinsic(b, intrin, 1);
+   return nir_pack_64_2x32_split(b, &intr_x->dest.ssa, &intr_y->dest.ssa);
+}
+
 static nir_ssa_def *
 ballot_type_to_uint(nir_builder *b, nir_ssa_def *value, unsigned bit_size)
 {
@@ -80,7 +112,8 @@ uint_to_ballot_type(nir_builder *b, nir_ssa_def *value,
 }
 
 static nir_ssa_def *
-lower_subgroup_op_to_scalar(nir_builder *b, nir_intrinsic_instr *intrin)
+lower_subgroup_op_to_scalar(nir_builder *b, nir_intrinsic_instr *intrin,
+                            bool lower_to_32bit)
 {
    /* This is safe to call on scalar things but it would be silly */
    assert(intrin->dest.ssa.num_components > 1);
@@ -107,9 +140,12 @@ lower_subgroup_op_to_scalar(nir_builder *b, nir_intrinsic_instr *intrin)
       chan_intrin->const_index[0] = intrin->const_index[0];
       chan_intrin->const_index[1] = intrin->const_index[1];
 
-      nir_builder_instr_insert(b, &chan_intrin->instr);
-
-      reads[i] = &chan_intrin->dest.ssa;
+      if (lower_to_32bit && chan_intrin->src[0].ssa->bit_size == 64) {
+         reads[i] = lower_subgroup_op_to_32bit(b, chan_intrin);
+      } else {
+         nir_builder_instr_insert(b, &chan_intrin->instr);
+         reads[i] = &chan_intrin->dest.ssa;
+      }
    }
 
    return nir_vec(b, reads, intrin->num_components);
@@ -188,7 +224,7 @@ lower_vote_eq_to_ballot(nir_builder *b, nir_intrinsic_instr *intrin,
 
 static nir_ssa_def *
 lower_shuffle(nir_builder *b, nir_intrinsic_instr *intrin,
-              bool lower_to_scalar)
+              bool lower_to_scalar, bool lower_to_32bit)
 {
    nir_ssa_def *index = nir_load_subgroup_invocation(b);
    switch (intrin->intrinsic) {
@@ -241,7 +277,9 @@ lower_shuffle(nir_builder *b, nir_intrinsic_instr *intrin,
                      intrin->dest.ssa.bit_size, NULL);
 
    if (lower_to_scalar && shuffle->num_components > 1) {
-      return lower_subgroup_op_to_scalar(b, shuffle);
+      return lower_subgroup_op_to_scalar(b, shuffle, lower_to_32bit);
+   } else if (lower_to_32bit && shuffle->src[0].ssa->bit_size == 64) {
+      return lower_subgroup_op_to_32bit(b, shuffle);
    } else {
       nir_builder_instr_insert(b, &shuffle->instr);
       return &shuffle->dest.ssa;
@@ -279,7 +317,7 @@ lower_subgroups_intrin(nir_builder *b, nir_intrinsic_instr *intrin,
    case nir_intrinsic_read_invocation:
    case nir_intrinsic_read_first_invocation:
       if (options->lower_to_scalar && intrin->num_components > 1)
-         return lower_subgroup_op_to_scalar(b, intrin);
+         return lower_subgroup_op_to_scalar(b, intrin, false);
       break;
 
    case nir_intrinsic_load_subgroup_eq_mask:
@@ -400,16 +438,20 @@ lower_subgroups_intrin(nir_builder *b, nir_intrinsic_instr *intrin,
 
    case nir_intrinsic_shuffle:
       if (options->lower_to_scalar && intrin->num_components > 1)
-         return lower_subgroup_op_to_scalar(b, intrin);
+         return lower_subgroup_op_to_scalar(b, intrin, options->lower_shuffle_to_32bit);
+      else if (options->lower_shuffle_to_32bit && intrin->src[0].ssa->bit_size == 64)
+         return lower_subgroup_op_to_32bit(b, intrin);
       break;
 
    case nir_intrinsic_shuffle_xor:
    case nir_intrinsic_shuffle_up:
    case nir_intrinsic_shuffle_down:
       if (options->lower_shuffle)
-         return lower_shuffle(b, intrin, options->lower_to_scalar);
+         return lower_shuffle(b, intrin, options->lower_to_scalar, options->lower_shuffle_to_32bit);
       else if (options->lower_to_scalar && intrin->num_components > 1)
-         return lower_subgroup_op_to_scalar(b, intrin);
+         return lower_subgroup_op_to_scalar(b, intrin, options->lower_shuffle_to_32bit);
+      else if (options->lower_shuffle_to_32bit && intrin->src[0].ssa->bit_size == 64)
+         return lower_subgroup_op_to_32bit(b, intrin);
       break;
 
    case nir_intrinsic_quad_broadcast:
@@ -417,16 +459,16 @@ lower_subgroups_intrin(nir_builder *b, nir_intrinsic_instr *intrin,
    case nir_intrinsic_quad_swap_vertical:
    case nir_intrinsic_quad_swap_diagonal:
       if (options->lower_quad)
-         return lower_shuffle(b, intrin, options->lower_to_scalar);
+         return lower_shuffle(b, intrin, options->lower_to_scalar, false);
       else if (options->lower_to_scalar && intrin->num_components > 1)
-         return lower_subgroup_op_to_scalar(b, intrin);
+         return lower_subgroup_op_to_scalar(b, intrin, false);
       break;
 
    case nir_intrinsic_reduce:
    case nir_intrinsic_inclusive_scan:
    case nir_intrinsic_exclusive_scan:
       if (options->lower_to_scalar && intrin->num_components > 1)
-         return lower_subgroup_op_to_scalar(b, intrin);
+         return lower_subgroup_op_to_scalar(b, intrin, false);
       break;
 
    default:
-- 
2.14.1