nir/builder: add a nir_fdot() convenience function

diff --git a/src/glsl/nir/nir_builder.h b/src/glsl/nir/nir_builder.h
index 08b40f8ea7cf71a332ad4521f15b2fa01f17344d..3aa0efded3c90817bce9fad806e23847922dc34a 100644 (file)
--- a/src/glsl/nir/nir_builder.h
+++ b/src/glsl/nir/nir_builder.h
@@ -217,6 +217,23 @@ nir_swizzle(nir_builder *build, nir_ssa_def *src, unsigned swiz[4],
                      nir_imov_alu(build, alu_src, num_components);
 }
 
+/* Selects the right fdot given the number of components in each source. */
+static inline nir_ssa_def *
+nir_fdot(nir_builder *build, nir_ssa_def *src0, nir_ssa_def *src1)
+{
+   assert(src0->num_components == src1->num_components);
+   switch (src0->num_components) {
+   case 1: return nir_fmul(build, src0, src1);
+   case 2: return nir_fdot2(build, src0, src1);
+   case 3: return nir_fdot3(build, src0, src1);
+   case 4: return nir_fdot4(build, src0, src1);
+   default:
+      unreachable("bad component size");
+   }
+
+   return NULL;
+}
+
 /**
  * Turns a nir_src into a nir_ssa_def * so it can be passed to
  * nir_build_alu()-based builder calls.