lib/igt_matrix: Unroll and inline igt_matrix_transform()

Using the current igt_matrix for NV12 conversion ends up being
about 4x as slow as the current non-igt_matrix based code. Unrolling
and inlining igt_matrix_transform() improves that factor to ~1.5x.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 41 insertions, 2 deletions

diff --git a/lib/igt_matrix.h b/lib/igt_matrix.h
index 33acb815..7a2b9ad8 100644
--- a/lib/igt_matrix.h
+++ b/lib/igt_matrix.h
@@ -44,13 +44,52 @@ struct igt_mat4 {
 	float d[16];
 };
 
+#define m(row, col) ((col) * 4 + (row))
+
 void igt_matrix_print(const struct igt_mat4 *m);
 struct igt_mat4 igt_matrix_identity(void);
 struct igt_mat4 igt_matrix_scale(float x, float y, float z);
 struct igt_mat4 igt_matrix_translate(float x, float y, float z);
-struct igt_vec4 igt_matrix_transform(const struct igt_mat4 *m,
-				     const struct igt_vec4 *v);
 struct igt_mat4 igt_matrix_multiply(const struct igt_mat4 *a,
 				    const struct igt_mat4 *b);
 
+/**
+ * igt_matrix_transform:
+ *
+ * Transform the vector @v by the matrix @m. @m is on the left,
+ * @v on the right.
+ *
+ * Returns:
+ * The transformed vector.
+ */
+static inline struct igt_vec4
+igt_matrix_transform(const struct igt_mat4 *m,
+		     const struct igt_vec4 *v)
+{
+	struct igt_vec4 ret = {
+		.d = { m->d[m(0, 0)] * v->d[0] +
+		       m->d[m(0, 1)] * v->d[1] +
+		       m->d[m(0, 2)] * v->d[2] +
+		       m->d[m(0, 3)] * v->d[3],
+
+		       m->d[m(1, 0)] * v->d[0] +
+		       m->d[m(1, 1)] * v->d[1] +
+		       m->d[m(1, 2)] * v->d[2] +
+		       m->d[m(1, 3)] * v->d[3],
+
+		       m->d[m(2, 0)] * v->d[0] +
+		       m->d[m(2, 1)] * v->d[1] +
+		       m->d[m(2, 2)] * v->d[2] +
+		       m->d[m(2, 3)] * v->d[3],
+
+		       m->d[m(3, 0)] * v->d[0] +
+		       m->d[m(3, 1)] * v->d[1] +
+		       m->d[m(3, 2)] * v->d[2] +
+		       m->d[m(3, 3)] * v->d[3],
+		},
+	};
+
+	return ret;
+}
+
 #endif /* __IGT_MATRIX_H__ */