nir: Add a flag to lower_io to force "sample" interpolation

Signed-off-by: Jason Ekstrand <[email protected]>
Reviewed-by: Anuj Phogat <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

7 files changed, 38 insertions, 21 deletions

diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index 94eae6d3037..6f0597200e9 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -2397,9 +2397,17 @@ void nir_assign_var_locations(struct exec_list *var_list, unsigned *size,
                               unsigned base_offset,
                               int (*type_size)(const struct glsl_type *));
 
+typedef enum {
+   /* If set, this forces all non-flat fragment shader inputs to be
+    * interpolated as if with the "sample" qualifier.  This requires
+    * nir_shader_compiler_options::use_interpolated_input_intrinsics.
+    */
+   nir_lower_io_force_sample_interpolation = (1 << 1),
+} nir_lower_io_options;
 void nir_lower_io(nir_shader *shader,
                   nir_variable_mode modes,
-                  int (*type_size)(const struct glsl_type *));
+                  int (*type_size)(const struct glsl_type *),
+                  nir_lower_io_options);
 nir_src *nir_get_io_offset_src(nir_intrinsic_instr *instr);
 nir_src *nir_get_io_vertex_index_src(nir_intrinsic_instr *instr);
 
diff --git a/src/compiler/nir/nir_lower_io.c b/src/compiler/nir/nir_lower_io.c
index b36836f6f76..d469b6180f8 100644
--- a/src/compiler/nir/nir_lower_io.c
+++ b/src/compiler/nir/nir_lower_io.c
@@ -39,6 +39,7 @@ struct lower_io_state {
    void *mem_ctx;
    int (*type_size)(const struct glsl_type *type);
    nir_variable_mode modes;
+   nir_lower_io_options options;
 };
 
 void
@@ -205,7 +206,8 @@ lower_load(nir_intrinsic_instr *intrin, struct lower_io_state *state,
          assert(vertex_index == NULL);
 
          nir_intrinsic_op bary_op;
-         if (var->data.sample)
+         if (var->data.sample ||
+             (state->options & nir_lower_io_force_sample_interpolation))
             bary_op = nir_intrinsic_load_barycentric_sample;
          else if (var->data.centroid)
             bary_op = nir_intrinsic_load_barycentric_centroid;
@@ -347,7 +349,9 @@ lower_interpolate_at(nir_intrinsic_instr *intrin, struct lower_io_state *state,
    nir_intrinsic_op bary_op;
    switch (intrin->intrinsic) {
    case nir_intrinsic_interp_var_at_centroid:
-      bary_op = nir_intrinsic_load_barycentric_centroid;
+      bary_op = (state->options & nir_lower_io_force_sample_interpolation) ?
+                nir_intrinsic_load_barycentric_sample :
+                nir_intrinsic_load_barycentric_centroid;
       break;
    case nir_intrinsic_interp_var_at_sample:
       bary_op = nir_intrinsic_load_barycentric_at_sample;
@@ -505,7 +509,8 @@ nir_lower_io_block(nir_block *block,
 static void
 nir_lower_io_impl(nir_function_impl *impl,
                   nir_variable_mode modes,
-                  int (*type_size)(const struct glsl_type *))
+                  int (*type_size)(const struct glsl_type *),
+                  nir_lower_io_options options)
 {
    struct lower_io_state state;
 
@@ -513,6 +518,7 @@ nir_lower_io_impl(nir_function_impl *impl,
    state.mem_ctx = ralloc_parent(impl);
    state.modes = modes;
    state.type_size = type_size;
+   state.options = options;
 
    nir_foreach_block(block, impl) {
       nir_lower_io_block(block, &state);
@@ -524,11 +530,13 @@ nir_lower_io_impl(nir_function_impl *impl,
 
 void
 nir_lower_io(nir_shader *shader, nir_variable_mode modes,
-             int (*type_size)(const struct glsl_type *))
+             int (*type_size)(const struct glsl_type *),
+             nir_lower_io_options options)
 {
    nir_foreach_function(function, shader) {
-      if (function->impl)
-         nir_lower_io_impl(function->impl, modes, type_size);
+      if (function->impl) {
+         nir_lower_io_impl(function->impl, modes, type_size, options);
+      }
    }
 }
 
diff --git a/src/gallium/drivers/freedreno/ir3/ir3_cmdline.c b/src/gallium/drivers/freedreno/ir3/ir3_cmdline.c
index 41532fc4fb1..d749bfad817 100644
--- a/src/gallium/drivers/freedreno/ir3/ir3_cmdline.c
+++ b/src/gallium/drivers/freedreno/ir3/ir3_cmdline.c
@@ -93,7 +93,7 @@ load_glsl(unsigned num_files, char* const* files, gl_shader_stage stage)
 	// TODO nir_assign_var_locations??
 
 	NIR_PASS_V(nir, nir_lower_system_values);
-	NIR_PASS_V(nir, nir_lower_io, nir_var_all, st_glsl_type_size);
+	NIR_PASS_V(nir, nir_lower_io, nir_var_all, st_glsl_type_size, 0);
 	NIR_PASS_V(nir, nir_lower_samplers, prog);
 
 	return nir;
diff --git a/src/intel/blorp/blorp.c b/src/intel/blorp/blorp.c
index 955e543a315..1c8fd550af6 100644
--- a/src/intel/blorp/blorp.c
+++ b/src/intel/blorp/blorp.c
@@ -204,7 +204,7 @@ brw_blorp_compile_nir_shader(struct blorp_context *blorp, struct nir_shader *nir
       unsigned end = var->data.location + nir_uniform_type_size(var->type);
       nir->num_uniforms = MAX2(nir->num_uniforms, end);
    }
-   nir_lower_io(nir, nir_var_uniform, nir_uniform_type_size);
+   nir_lower_io(nir, nir_var_uniform, nir_uniform_type_size, 0);
 
    const unsigned *program =
       brw_compile_fs(compiler, blorp->driver_ctx, mem_ctx,
diff --git a/src/mesa/drivers/dri/i965/brw_nir.c b/src/mesa/drivers/dri/i965/brw_nir.c
index 5b2130fa688..b4c1cf1a214 100644
--- a/src/mesa/drivers/dri/i965/brw_nir.c
+++ b/src/mesa/drivers/dri/i965/brw_nir.c
@@ -205,7 +205,7 @@ brw_nir_lower_vs_inputs(nir_shader *nir,
     * loaded as one vec4 or dvec4 per element (or matrix column), depending on
     * whether it is a double-precision type or not.
     */
-   nir_lower_io(nir, nir_var_shader_in, type_size_vs_input);
+   nir_lower_io(nir, nir_var_shader_in, type_size_vs_input, 0);
 
    /* This pass needs actual constants */
    nir_opt_constant_folding(nir);
@@ -237,7 +237,7 @@ brw_nir_lower_vue_inputs(nir_shader *nir, bool is_scalar,
    }
 
    /* Inputs are stored in vec4 slots, so use type_size_vec4(). */
-   nir_lower_io(nir, nir_var_shader_in, type_size_vec4);
+   nir_lower_io(nir, nir_var_shader_in, type_size_vec4, 0);
 
    if (is_scalar || nir->stage != MESA_SHADER_GEOMETRY) {
       /* This pass needs actual constants */
@@ -262,7 +262,7 @@ brw_nir_lower_tes_inputs(nir_shader *nir, const struct brw_vue_map *vue_map)
       var->data.driver_location = var->data.location;
    }
 
-   nir_lower_io(nir, nir_var_shader_in, type_size_vec4);
+   nir_lower_io(nir, nir_var_shader_in, type_size_vec4, 0);
 
    /* This pass needs actual constants */
    nir_opt_constant_folding(nir);
@@ -287,7 +287,7 @@ brw_nir_lower_fs_inputs(nir_shader *nir)
       var->data.driver_location = var->data.location;
    }
 
-   nir_lower_io(nir, nir_var_shader_in, type_size_vec4);
+   nir_lower_io(nir, nir_var_shader_in, type_size_vec4, 0);
 
    /* This pass needs actual constants */
    nir_opt_constant_folding(nir);
@@ -303,11 +303,11 @@ brw_nir_lower_vue_outputs(nir_shader *nir,
       nir_assign_var_locations(&nir->outputs, &nir->num_outputs,
                                VARYING_SLOT_VAR0,
                                type_size_vec4_times_4);
-      nir_lower_io(nir, nir_var_shader_out, type_size_vec4_times_4);
+      nir_lower_io(nir, nir_var_shader_out, type_size_vec4_times_4, 0);
    } else {
       nir_foreach_variable(var, &nir->outputs)
          var->data.driver_location = var->data.location;
-      nir_lower_io(nir, nir_var_shader_out, type_size_vec4);
+      nir_lower_io(nir, nir_var_shader_out, type_size_vec4, 0);
    }
 }
 
@@ -318,7 +318,7 @@ brw_nir_lower_tcs_outputs(nir_shader *nir, const struct brw_vue_map *vue_map)
       var->data.driver_location = var->data.location;
    }
 
-   nir_lower_io(nir, nir_var_shader_out, type_size_vec4);
+   nir_lower_io(nir, nir_var_shader_out, type_size_vec4, 0);
 
    /* This pass needs actual constants */
    nir_opt_constant_folding(nir);
@@ -345,7 +345,7 @@ brw_nir_lower_fs_outputs(nir_shader *nir)
          SET_FIELD(var->data.location, BRW_NIR_FRAG_OUTPUT_LOCATION);
    }
 
-   nir_lower_io(nir, nir_var_shader_out, type_size_dvec4);
+   nir_lower_io(nir, nir_var_shader_out, type_size_dvec4, 0);
 }
 
 void
@@ -353,7 +353,7 @@ brw_nir_lower_cs_shared(nir_shader *nir)
 {
    nir_assign_var_locations(&nir->shared, &nir->num_shared, 0,
                             type_size_scalar_bytes);
-   nir_lower_io(nir, nir_var_shared, type_size_scalar_bytes);
+   nir_lower_io(nir, nir_var_shared, type_size_scalar_bytes, 0);
 }
 
 #define OPT(pass, ...) ({                                  \
diff --git a/src/mesa/drivers/dri/i965/brw_program.c b/src/mesa/drivers/dri/i965/brw_program.c
index 9d32dd3c3ff..b39b90fdc46 100644
--- a/src/mesa/drivers/dri/i965/brw_program.c
+++ b/src/mesa/drivers/dri/i965/brw_program.c
@@ -53,11 +53,11 @@ brw_nir_lower_uniforms(nir_shader *nir, bool is_scalar)
    if (is_scalar) {
       nir_assign_var_locations(&nir->uniforms, &nir->num_uniforms, 0,
                                type_size_scalar_bytes);
-      nir_lower_io(nir, nir_var_uniform, type_size_scalar_bytes);
+      nir_lower_io(nir, nir_var_uniform, type_size_scalar_bytes, 0);
    } else {
       nir_assign_var_locations(&nir->uniforms, &nir->num_uniforms, 0,
                                type_size_vec4_bytes);
-      nir_lower_io(nir, nir_var_uniform, type_size_vec4_bytes);
+      nir_lower_io(nir, nir_var_uniform, type_size_vec4_bytes, 0);
    }
 }
 
diff --git a/src/mesa/state_tracker/st_glsl_to_nir.cpp b/src/mesa/state_tracker/st_glsl_to_nir.cpp
index e6e6bb953f4..5b5fad44f18 100644
--- a/src/mesa/state_tracker/st_glsl_to_nir.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_nir.cpp
@@ -359,7 +359,8 @@ st_finalize_nir(struct st_context *st, struct gl_program *prog, nir_shader *nir)
                                    &nir->uniforms, &nir->num_uniforms);
 
    NIR_PASS_V(nir, nir_lower_system_values);
-   NIR_PASS_V(nir, nir_lower_io, nir_var_all, st_glsl_type_size);
+   NIR_PASS_V(nir, nir_lower_io, nir_var_all, st_glsl_type_size,
+              (nir_lower_io_options)0);
    NIR_PASS_V(nir, nir_lower_samplers, shader_program);
 }