nir/build: add nir_vec() helper

Signed-off-by: Rob Clark <robclark@freedesktop.org>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>

src/glsl/nir/nir_builder.h

@@ -173,6 +173,24 @@ nir_##op(nir_builder *build, nir_ssa_def *src0,                           \
 
 #include "nir_builder_opcodes.h"
 
+static inline nir_ssa_def *
+nir_vec(nir_builder *build, nir_ssa_def **comp, unsigned num_components)
+{
+   switch (num_components) {
+   case 4:
+      return nir_vec4(build, comp[0], comp[1], comp[2], comp[3]);
+   case 3:
+      return nir_vec3(build, comp[0], comp[1], comp[2]);
+   case 2:
+      return nir_vec2(build, comp[0], comp[1]);
+   case 1:
+      return comp[0];
+   default:
+      unreachable("bad component count");
+      return NULL;
+   }
+}
+
 /**
  * Similar to nir_fmov, but takes a nir_alu_src instead of a nir_ssa_def.
  */

src/glsl/nir/nir_lower_load_const_to_scalar.c

@@ -55,20 +55,7 @@ lower_load_const_instr_scalar(nir_load_const_instr *lower)
    }
 
    /* Batch things back together into a vector. */
-   nir_ssa_def *vec;
-   switch (lower->def.num_components) {
-   case 2:
-      vec = nir_vec2(&b, loads[0], loads[1]);
-      break;
-   case 3:
-      vec = nir_vec3(&b, loads[0], loads[1], loads[2]);
-      break;
-   case 4:
-      vec = nir_vec4(&b, loads[0], loads[1], loads[2], loads[3]);
-      break;
-   default:
-      unreachable("Unknown load_const component count.");
-   }
+   nir_ssa_def *vec = nir_vec(&b, loads, lower->def.num_components);
 
    /* Replace the old load with a reference to our reconstructed vector. */
    nir_ssa_def_rewrite_uses(&lower->def, nir_src_for_ssa(vec));

src/glsl/nir/nir_lower_tex.c

@@ -205,23 +205,7 @@ saturate_src(nir_builder *b, nir_tex_instr *tex, unsigned sat_mask)
       }
 
       /* and move the result back into a single vecN: */
-      switch (tex->coord_components) {
-      case 4:
-         src = nir_vec4(b, comp[0], comp[1], comp[2], comp[3]);
-         break;
-      case 3:
-         src = nir_vec3(b, comp[0], comp[1], comp[2]);
-         break;
-      case 2:
-         src = nir_vec2(b, comp[0], comp[1]);
-         break;
-      case 1:
-         src = comp[0];
-         break;
-      default:
-         unreachable("bad texture coord count");
-         break;
-      }
+      src = nir_vec(b, comp, tex->coord_components);
 
       nir_instr_rewrite_src(&tex->instr,
                             &tex->src[i].src,