nir: Separate texture from sampler in nir_tex_instr

This commit adds the capability to NIR to support separate textures and
samplers.  As it currently stands, glsl_to_nir only sets the texture deref
and leaves the sampler deref alone as it did before and nir_lower_samplers
assumes this.  Backends can still assume that they are combined and only
look at only at the texture index.  Or, if they wish, they can assume that
they are separate because nir_lower_samplers, tgsi_to_nir, and prog_to_nir
all set both texture and sampler index whenever a sampler is required (the
two indices are the same in this case).

Reviewed-by: Kenneth Graunke <[email protected]>

14 files changed, 102 insertions, 18 deletions

diff --git a/src/compiler/nir/nir.c b/src/compiler/nir/nir.c
index 6a070f530b2..df40a554714 100644
--- a/src/compiler/nir/nir.c
+++ b/src/compiler/nir/nir.c
@@ -489,6 +489,8 @@ nir_tex_instr_create(nir_shader *shader, unsigned num_srcs)
    instr->texture_index = 0;
    instr->texture_array_size = 0;
    instr->texture = NULL;
+   instr->sampler_index = 0;
+   instr->sampler = NULL;
 
    return instr;
 }
@@ -1012,6 +1014,11 @@ visit_tex_src(nir_tex_instr *instr, nir_foreach_src_cb cb, void *state)
          return false;
    }
 
+   if (instr->sampler != NULL) {
+      if (!visit_deref_src(instr->sampler, cb, state))
+         return false;
+   }
+
    return true;
 }
 
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index 48dda99a949..8085341b552 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -966,6 +966,7 @@ typedef enum {
    nir_tex_src_ddx,
    nir_tex_src_ddy,
    nir_tex_src_texture_offset, /* < dynamically uniform indirect offset */
+   nir_tex_src_sampler_offset, /* < dynamically uniform indirect offset */
    nir_num_tex_src_types
 } nir_tex_src_type;
 
@@ -1025,7 +1026,35 @@ typedef struct {
    /** The size of the texture array or 0 if it's not an array */
    unsigned texture_array_size;
 
-   nir_deref_var *texture; /* if this is NULL, use texture_index instead */
+   /** The texture deref
+    *
+    * If this is null, use texture_index instead.
+    */
+   nir_deref_var *texture;
+
+   /** The sampler index
+    *
+    * The following operations do not require a sampler and, as such, this
+    * field should be ignored:
+    *    - nir_texop_txf
+    *    - nir_texop_txf_ms
+    *    - nir_texop_txs
+    *    - nir_texop_lod
+    *    - nir_texop_tg4
+    *    - nir_texop_query_levels
+    *    - nir_texop_texture_samples
+    *    - nir_texop_samples_identical
+    *
+    * If this texture instruction has a nir_tex_src_sampler_offset source,
+    * then the sampler index is given by sampler_index + sampler_offset.
+    */
+   unsigned sampler_index;
+
+   /** The sampler deref
+    *
+    * If this is null, use sampler_index instead.
+    */
+   nir_deref_var *sampler;
 } nir_tex_instr;
 
 static inline unsigned
diff --git a/src/compiler/nir/nir_clone.c b/src/compiler/nir/nir_clone.c
index d9c190d35e9..a666d8ee451 100644
--- a/src/compiler/nir/nir_clone.c
+++ b/src/compiler/nir/nir_clone.c
@@ -357,10 +357,15 @@ clone_tex(clone_state *state, const nir_tex_instr *tex)
    ntex->is_new_style_shadow = tex->is_new_style_shadow;
    memcpy(ntex->const_offset, tex->const_offset, sizeof(ntex->const_offset));
    ntex->component = tex->component;
+
    ntex->texture_index = tex->texture_index;
-   ntex->texture_array_size = tex->texture_array_size;
    if (tex->texture)
       ntex->texture = clone_deref_var(state, tex->texture, &ntex->instr);
+   ntex->texture_array_size = tex->texture_array_size;
+
+   ntex->sampler_index = tex->sampler_index;
+   if (tex->sampler)
+      ntex->sampler = clone_deref_var(state, tex->sampler, &ntex->instr);
 
    return ntex;
 }
diff --git a/src/compiler/nir/nir_instr_set.c b/src/compiler/nir/nir_instr_set.c
index 4489a881905..c3cf2579be7 100644
--- a/src/compiler/nir/nir_instr_set.c
+++ b/src/compiler/nir/nir_instr_set.c
@@ -157,8 +157,9 @@ hash_tex(uint32_t hash, const nir_tex_instr *instr)
    hash = HASH(hash, component);
    hash = HASH(hash, instr->texture_index);
    hash = HASH(hash, instr->texture_array_size);
+   hash = HASH(hash, instr->sampler_index);
 
-   assert(!instr->texture);
+   assert(!instr->texture && !instr->sampler);
 
    return hash;
 }
@@ -306,12 +307,14 @@ nir_instrs_equal(const nir_instr *instr1, const nir_instr *instr2)
                  sizeof(tex1->const_offset)) != 0 ||
           tex1->component != tex2->component ||
          tex1->texture_index != tex2->texture_index ||
-         tex1->texture_array_size != tex2->texture_array_size) {
+         tex1->texture_array_size != tex2->texture_array_size ||
+         tex1->sampler_index != tex2->sampler_index) {
          return false;
       }
 
-      /* Don't support un-lowered texture derefs currently. */
-      assert(!tex1->texture && !tex2->texture);
+      /* Don't support un-lowered sampler derefs currently. */
+      assert(!tex1->texture && !tex1->sampler &&
+             !tex2->texture && !tex2->sampler);
 
       return true;
    }
@@ -421,8 +424,8 @@ instr_can_rewrite(nir_instr *instr)
    case nir_instr_type_tex: {
       nir_tex_instr *tex = nir_instr_as_tex(instr);
 
-      /* Don't support un-lowered texture derefs currently. */
-      if (tex->texture)
+      /* Don't support un-lowered sampler derefs currently. */
+      if (tex->texture || tex->sampler)
          return false;
 
       return true;
diff --git a/src/compiler/nir/nir_lower_samplers.c b/src/compiler/nir/nir_lower_samplers.c
index bccb544dc91..f5d3e596c20 100644
--- a/src/compiler/nir/nir_lower_samplers.c
+++ b/src/compiler/nir/nir_lower_samplers.c
@@ -94,6 +94,9 @@ lower_sampler(nir_tex_instr *instr, const struct gl_shader_program *shader_progr
    if (instr->texture == NULL)
       return;
 
+   /* In GLSL, we only fill out the texture field.  The sampler is inferred */
+   assert(instr->sampler == NULL);
+
    instr->texture_index = 0;
    unsigned location = instr->texture->var->data.location;
    unsigned array_elements = 1;
@@ -106,7 +109,7 @@ lower_sampler(nir_tex_instr *instr, const struct gl_shader_program *shader_progr
    if (indirect) {
       /* First, we have to resize the array of texture sources */
       nir_tex_src *new_srcs = rzalloc_array(instr, nir_tex_src,
-                                            instr->num_srcs + 1);
+                                            instr->num_srcs + 2);
 
       for (unsigned i = 0; i < instr->num_srcs; i++) {
          new_srcs[i].src_type = instr->src[i].src_type;
@@ -126,6 +129,12 @@ lower_sampler(nir_tex_instr *instr, const struct gl_shader_program *shader_progr
                             &instr->src[instr->num_srcs - 1].src,
                             nir_src_for_ssa(indirect));
 
+      instr->src[instr->num_srcs].src_type = nir_tex_src_sampler_offset;
+      instr->num_srcs++;
+      nir_instr_rewrite_src(&instr->instr,
+                            &instr->src[instr->num_srcs - 1].src,
+                            nir_src_for_ssa(indirect));
+
       instr->texture_array_size = array_elements;
    }
 
@@ -138,6 +147,8 @@ lower_sampler(nir_tex_instr *instr, const struct gl_shader_program *shader_progr
    instr->texture_index +=
       shader_program->UniformStorage[location].opaque[stage].index;
 
+   instr->sampler_index = instr->texture_index;
+
    instr->texture = NULL;
 }
 
diff --git a/src/compiler/nir/nir_lower_tex.c b/src/compiler/nir/nir_lower_tex.c
index 4c0759b8788..806acd8333c 100644
--- a/src/compiler/nir/nir_lower_tex.c
+++ b/src/compiler/nir/nir_lower_tex.c
@@ -291,11 +291,11 @@ nir_lower_tex_block(nir_block *block, void *void_state)
       /* mask of src coords to saturate (clamp): */
       unsigned sat_mask = 0;
 
-      if ((1 << tex->texture_index) & state->options->saturate_r)
+      if ((1 << tex->sampler_index) & state->options->saturate_r)
          sat_mask |= (1 << 2);    /* .z */
-      if ((1 << tex->texture_index) & state->options->saturate_t)
+      if ((1 << tex->sampler_index) & state->options->saturate_t)
          sat_mask |= (1 << 1);    /* .y */
-      if ((1 << tex->texture_index) & state->options->saturate_s)
+      if ((1 << tex->sampler_index) & state->options->saturate_s)
          sat_mask |= (1 << 0);    /* .x */
 
       /* If we are clamping any coords, we must lower projector first
diff --git a/src/compiler/nir/nir_opt_constant_folding.c b/src/compiler/nir/nir_opt_constant_folding.c
index 20b31a8110c..04876a42fd7 100644
--- a/src/compiler/nir/nir_opt_constant_folding.c
+++ b/src/compiler/nir/nir_opt_constant_folding.c
@@ -136,10 +136,15 @@ constant_fold_intrinsic_instr(nir_intrinsic_instr *instr)
 static bool
 constant_fold_tex_instr(nir_tex_instr *instr)
 {
+   bool progress = false;
+
    if (instr->texture)
-      return constant_fold_deref(&instr->instr, instr->texture);
-   else
-      return false;
+      progress |= constant_fold_deref(&instr->instr, instr->texture);
+
+   if (instr->sampler)
+      progress |= constant_fold_deref(&instr->instr, instr->sampler);
+
+   return progress;
 }
 
 static bool
diff --git a/src/compiler/nir/nir_print.c b/src/compiler/nir/nir_print.c
index 5e7ae820968..d9d75c2e8df 100644
--- a/src/compiler/nir/nir_print.c
+++ b/src/compiler/nir/nir_print.c
@@ -625,6 +625,9 @@ print_tex_instr(nir_tex_instr *instr, print_state *state)
       case nir_tex_src_texture_offset:
          fprintf(fp, "(texture_offset)");
          break;
+      case nir_tex_src_sampler_offset:
+         fprintf(fp, "(sampler_offset)");
+         break;
 
       default:
          unreachable("Invalid texture source type");
@@ -654,11 +657,16 @@ print_tex_instr(nir_tex_instr *instr, print_state *state)
 
    if (instr->texture) {
       print_deref(instr->texture, state);
+      fprintf(fp, " (texture)");
+      if (instr->sampler) {
+         print_deref(instr->sampler, state);
+         fprintf(fp, " (sampler)");
+      }
    } else {
-      fprintf(fp, "%u", instr->texture_index);
+      assert(instr->sampler == NULL);
+      fprintf(fp, "%u (texture) %u (sampler)",
+              instr->texture_index, instr->sampler_index);
    }
-
-   fprintf(fp, " (texture)");
 }
 
 static void
diff --git a/src/compiler/nir/nir_remove_dead_variables.c b/src/compiler/nir/nir_remove_dead_variables.c
index 24bae46c7fc..65192682d3c 100644
--- a/src/compiler/nir/nir_remove_dead_variables.c
+++ b/src/compiler/nir/nir_remove_dead_variables.c
@@ -58,6 +58,11 @@ add_var_use_tex(nir_tex_instr *instr, struct set *live)
       nir_variable *var = instr->texture->var;
       _mesa_set_add(live, var);
    }
+
+   if (instr->sampler != NULL) {
+      nir_variable *var = instr->sampler->var;
+      _mesa_set_add(live, var);
+   }
 }
 
 static bool
diff --git a/src/compiler/nir/nir_validate.c b/src/compiler/nir/nir_validate.c
index 2fadff7869e..d1a90485e7e 100644
--- a/src/compiler/nir/nir_validate.c
+++ b/src/compiler/nir/nir_validate.c
@@ -448,6 +448,9 @@ validate_tex_instr(nir_tex_instr *instr, validate_state *state)
    if (instr->texture != NULL)
       validate_deref_var(instr, instr->texture, state);
 
+   if (instr->sampler != NULL)
+      validate_deref_var(instr, instr->sampler, state);
+
    validate_dest(&instr->dest, state);
 }
 
diff --git a/src/gallium/auxiliary/nir/tgsi_to_nir.c b/src/gallium/auxiliary/nir/tgsi_to_nir.c
index 8cd8ea4cb66..b71917618c1 100644
--- a/src/gallium/auxiliary/nir/tgsi_to_nir.c
+++ b/src/gallium/auxiliary/nir/tgsi_to_nir.c
@@ -1310,6 +1310,7 @@ ttn_tex(struct ttn_compile *c, nir_alu_dest dest, nir_ssa_def **src)
 
    assert(tgsi_inst->Src[samp].Register.File == TGSI_FILE_SAMPLER);
    instr->texture_index = tgsi_inst->Src[samp].Register.Index;
+   instr->sampler_index = tgsi_inst->Src[samp].Register.Index;
 
    /* TODO if we supported any opc's which take an explicit SVIEW
     * src, we would use that here instead.  But for the "legacy"
diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
index ecca3ef7183..1a2c39f4b35 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
@@ -3024,6 +3024,9 @@ fs_visitor::nir_emit_texture(const fs_builder &bld, nir_tex_instr *instr)
          break;
       }
 
+      case nir_tex_src_sampler_offset:
+         break; /* Ignored for now */
+
       default:
          unreachable("unknown texture source");
       }
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
index 40a7530d940..41d20ff0d13 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
@@ -1738,6 +1738,9 @@ vec4_visitor::nir_emit_texture(nir_tex_instr *instr)
          break;
       }
 
+      case nir_tex_src_sampler_offset:
+         break; /* Ignored for now */
+
       case nir_tex_src_projector:
          unreachable("Should be lowered by do_lower_texture_projection");
 
diff --git a/src/mesa/program/prog_to_nir.c b/src/mesa/program/prog_to_nir.c
index 93a167e0aa1..74cbbfb1cc6 100644
--- a/src/mesa/program/prog_to_nir.c
+++ b/src/mesa/program/prog_to_nir.c
@@ -610,6 +610,7 @@ ptn_tex(nir_builder *b, nir_alu_dest dest, nir_ssa_def **src,
    instr->dest_type = nir_type_float;
    instr->is_shadow = prog_inst->TexShadow;
    instr->texture_index = prog_inst->TexSrcUnit;
+   instr->sampler_index = prog_inst->TexSrcUnit;
 
    switch (prog_inst->TexSrcTarget) {
    case TEXTURE_1D_INDEX: