Mesa (master): vc4: Fix vc4_nir_lower_io for non-vec4 I/O.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 3c1ea6e65122197b9ef67e16ca8f5758ac9d6800
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=3c1ea6e65122197b9ef67e16ca8f5758ac9d6800

Author: Eric Anholt <eric at anholt.net>
Date:   Tue May 17 13:46:51 2016 -0700

vc4: Fix vc4_nir_lower_io for non-vec4 I/O.

To support GLSL-to-NIR, we need to be able to support actual
float/vec2/vec3 varyings.

---

 src/gallium/drivers/vc4/vc4_nir_lower_io.c | 34 +++++++++++-------------------
 1 file changed, 12 insertions(+), 22 deletions(-)

diff --git a/src/gallium/drivers/vc4/vc4_nir_lower_io.c b/src/gallium/drivers/vc4/vc4_nir_lower_io.c
index d61c95a..4a795f8 100644
--- a/src/gallium/drivers/vc4/vc4_nir_lower_io.c
+++ b/src/gallium/drivers/vc4/vc4_nir_lower_io.c
@@ -26,8 +26,8 @@
 #include "util/u_format.h"
 
 /**
- * Walks the NIR generated by TGSI-to-NIR to lower its io intrinsics into
- * something amenable to the VC4 architecture.
+ * Walks the NIR generated by TGSI-to-NIR or GLSL-to-NIR to lower its io
+ * intrinsics into something amenable to the VC4 architecture.
  *
  * Currently, it splits VS inputs and uniforms into scalars, drops any
  * non-position outputs in coordinate shaders, and fixes up the addressing on
@@ -36,17 +36,17 @@
  */
 
 static void
-replace_intrinsic_with_vec4(nir_builder *b, nir_intrinsic_instr *intr,
-                            nir_ssa_def **comps)
+replace_intrinsic_with_vec(nir_builder *b, nir_intrinsic_instr *intr,
+                           nir_ssa_def **comps)
 {
 
-        /* Batch things back together into a vec4.  This will get split by the
-         * later ALU scalarization pass.
+        /* Batch things back together into a vector.  This will get split by
+         * the later ALU scalarization pass.
          */
-        nir_ssa_def *vec = nir_vec4(b, comps[0], comps[1], comps[2], comps[3]);
+        nir_ssa_def *vec = nir_vec(b, comps, intr->num_components);
 
         /* Replace the old intrinsic with a reference to our reconstructed
-         * vec4.
+         * vector.
          */
         nir_ssa_def_rewrite_uses(&intr->dest.ssa, nir_src_for_ssa(vec));
         nir_instr_remove(&intr->instr);
@@ -177,9 +177,6 @@ vc4_nir_lower_vertex_attr(struct vc4_compile *c, nir_builder *b,
         enum pipe_format format = c->vs_key->attr_formats[attr];
         uint32_t attr_size = util_format_get_blocksize(format);
 
-        /* All TGSI-to-NIR inputs are vec4. */
-        assert(intr->num_components == 4);
-
         /* We only accept direct outputs and TGSI only ever gives them to us
          * with an offset value of 0.
          */
@@ -210,7 +207,7 @@ vc4_nir_lower_vertex_attr(struct vc4_compile *c, nir_builder *b,
                 util_format_description(format);
 
         nir_ssa_def *dests[4];
-        for (int i = 0; i < 4; i++) {
+        for (int i = 0; i < intr->num_components; i++) {
                 uint8_t swiz = desc->swizzle[i];
                 dests[i] = vc4_nir_get_vattr_channel_vpm(c, b, vpm_reads, swiz,
                                                          desc);
@@ -226,7 +223,7 @@ vc4_nir_lower_vertex_attr(struct vc4_compile *c, nir_builder *b,
                 }
         }
 
-        replace_intrinsic_with_vec4(b, intr, dests);
+        replace_intrinsic_with_vec(b, intr, dests);
 }
 
 static bool
@@ -325,16 +322,9 @@ static void
 vc4_nir_lower_uniform(struct vc4_compile *c, nir_builder *b,
                       nir_intrinsic_instr *intr)
 {
-        /* All TGSI-to-NIR uniform loads are vec4, but we need byte offsets
-         * in the backend.
-         */
-        if (intr->num_components == 1)
-                return;
-        assert(intr->num_components == 4);
-
         b->cursor = nir_before_instr(&intr->instr);
 
-        /* Generate scalar loads equivalent to the original VEC4. */
+        /* Generate scalar loads equivalent to the original vector. */
         nir_ssa_def *dests[4];
         for (unsigned i = 0; i < intr->num_components; i++) {
                 nir_intrinsic_instr *intr_comp =
@@ -359,7 +349,7 @@ vc4_nir_lower_uniform(struct vc4_compile *c, nir_builder *b,
                 nir_builder_instr_insert(b, &intr_comp->instr);
         }
 
-        replace_intrinsic_with_vec4(b, intr, dests);
+        replace_intrinsic_with_vec(b, intr, dests);
 }
 
 static void