v3d: Implement noperspective varyings on V3D 4.x.

Fixes a bunch of piglit interpolation tests, and reduces my concern about
some MSAA blit shaders with noperspective varyings.

3 files changed, 8 insertions, 3 deletions

diff --git a/src/broadcom/compiler/nir_to_vir.c b/src/broadcom/compiler/nir_to_vir.c
index 89e4bc9fafa..426b41e2be8 100644
--- a/src/broadcom/compiler/nir_to_vir.c
+++ b/src/broadcom/compiler/nir_to_vir.c
@@ -443,9 +443,7 @@ emit_fragment_varying(struct v3d_compile *c, nir_variable *var,
                         return vir_FADD(c, vir_FMUL(c, vary, c->payload_w), r5);
                 }
         case INTERP_MODE_NOPERSPECTIVE:
-                /* C appears after the mov from the varying.
-                   XXX: improve ldvary setup.
-                */
+                BITSET_SET(c->noperspective_flags, i);
                 return vir_FADD(c, vir_MOV(c, vary), r5);
         case INTERP_MODE_FLAT:
                 BITSET_SET(c->flat_shade_flags, i);
diff --git a/src/broadcom/compiler/v3d_compiler.h b/src/broadcom/compiler/v3d_compiler.h
index 24af18e8f9e..f3e3875c87c 100644
--- a/src/broadcom/compiler/v3d_compiler.h
+++ b/src/broadcom/compiler/v3d_compiler.h
@@ -476,6 +476,8 @@ struct v3d_compile {
          */
         uint32_t flat_shade_flags[BITSET_WORDS(V3D_MAX_FS_INPUTS)];
 
+        uint32_t noperspective_flags[BITSET_WORDS(V3D_MAX_FS_INPUTS)];
+
         uint32_t centroid_flags[BITSET_WORDS(V3D_MAX_FS_INPUTS)];
 
         bool uses_center_w;
@@ -659,6 +661,8 @@ struct v3d_fs_prog_data {
          */
         uint32_t flat_shade_flags[((V3D_MAX_FS_INPUTS - 1) / 24) + 1];
 
+        uint32_t noperspective_flags[((V3D_MAX_FS_INPUTS - 1) / 24) + 1];
+
         uint32_t centroid_flags[((V3D_MAX_FS_INPUTS - 1) / 24) + 1];
 
         bool writes_z;
diff --git a/src/broadcom/compiler/vir.c b/src/broadcom/compiler/vir.c
index 2754924e6c1..ee0f329040e 100644
--- a/src/broadcom/compiler/vir.c
+++ b/src/broadcom/compiler/vir.c
@@ -759,6 +759,9 @@ v3d_set_fs_prog_data_inputs(struct v3d_compile *c,
                 if (BITSET_TEST(c->flat_shade_flags, i))
                         prog_data->flat_shade_flags[i / 24] |= 1 << (i % 24);
 
+                if (BITSET_TEST(c->noperspective_flags, i))
+                        prog_data->noperspective_flags[i / 24] |= 1 << (i % 24);
+
                 if (BITSET_TEST(c->centroid_flags, i))
                         prog_data->centroid_flags[i / 24] |= 1 << (i % 24);
         }