1 files changed, 26 insertions, 35 deletions

diff --git a/ast_to_hir.cpp b/ast_to_hir.cpp
index 1d9df36143..740adb9f43 100644
--- a/ast_to_hir.cpp
+++ b/ast_to_hir.cpp
@@ -151,10 +151,7 @@ arithmetic_result_type(const struct glsl_type *type_a,
     *      vector."
     */
    if (type_a->is_vector() && type_b->is_vector()) {
-      if (type_a->vector_elements == type_b->vector_elements)
-	 return type_a;
-      else
-	 return glsl_error_type;
+      return (type_a == type_b) ? type_a : glsl_error_type;
    }
 
    /* All of the combinations of <scalar, scalar>, <vector, scalar>,
@@ -183,48 +180,42 @@ arithmetic_result_type(const struct glsl_type *type_a,
     *      more detail how vectors and matrices are operated on."
     */
    if (! multiply) {
-      if (type_a->is_matrix() && type_b->is_matrix()
-	  && (type_a->vector_elements == type_b->vector_elements)
-	  && (type_a->matrix_rows == type_b->matrix_rows))
-	 return type_a;
-      else
-	 return glsl_error_type;
+      return (type_a == type_b) ? type_a : glsl_error_type;
    } else {
       if (type_a->is_matrix() && type_b->is_matrix()) {
-	 if (type_a->vector_elements == type_b->matrix_rows) {
-	    char type_name[7];
-	    const struct glsl_type *t;
-
-	    type_name[0] = 'm';
-	    type_name[1] = 'a';
-	    type_name[2] = 't';
-
-	    if (type_a->matrix_rows == type_b->vector_elements) {
-	       type_name[3] = '0' + type_a->matrix_rows;
-	       type_name[4] = '\0';
-	    } else {
-	       type_name[3] = '0' + type_a->matrix_rows;
-	       type_name[4] = 'x';
-	       type_name[5] = '0' + type_b->vector_elements;
-	       type_name[6] = '\0';
-	    }
-
-	    t = state->symbols->get_type(type_name);
-	    return (t != NULL) ? t : glsl_error_type;
+	 /* Matrix multiply.  The columns of A must match the rows of B.  Given
+	  * the other previously tested constraints, this means the vector type
+	  * of a row from A must be the same as the vector type of a column from
+	  * B.
+	  */
+	 if (type_a->row_type() == type_b->column_type()) {
+	    /* The resulting matrix has the number of columns of matrix B and
+	     * the number of rows of matrix A.  We get the row count of A by
+	     * looking at the size of a vector that makes up a column.  The
+	     * transpose (size of a row) is done for B.
+	     */
+	    return
+	       glsl_type::get_instance(type_a->base_type,
+				       type_a->column_type()->vector_elements,
+				       type_b->row_type()->vector_elements);
 	 }
       } else if (type_a->is_matrix()) {
 	 /* A is a matrix and B is a column vector.  Columns of A must match
-	  * rows of B.
+	  * rows of B.  Given the other previously tested constraints, this
+	  * means the vector type of a row from A must be the same as the
+	  * vector the type of B.
 	  */
-	 if (type_a->vector_elements == type_b->vector_elements)
+	 if (type_a->row_type() == type_b)
 	    return type_b;
       } else {
 	 assert(type_b->is_matrix());
 
-	 /* A is a row vector and B is a matrix.  Columns of A must match
-	  * rows of B.
+	 /* A is a row vector and B is a matrix.  Columns of A must match rows
+	  * of B.  Given the other previously tested constraints, this means
+	  * the type of A must be the same as the vector type of a column from
+	  * B.
 	  */
-	 if (type_a->vector_elements == type_b->matrix_rows)
+	 if (type_a == type_b->column_type())
 	    return type_a;
       }
    }