diff --git a/configure.ac b/configure.ac
index 33bc9101..850e771f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,6 +18,12 @@ AC_ARG_ENABLE([debug],
   [enable_debug=no]
 )
 
+AC_ARG_ENABLE([debug-generated],
+  [AS_HELP_STRING([--enable-debug-generated], [enable this to abstain from generating #line @<:@no@:>@])],
+  [],
+  [enable_debug_generated=no]
+)
+
 AC_ARG_ENABLE([memcheck],
   [AS_HELP_STRING([--enable-memcheck], [check memory allocations when debugging @<:@yes@:>@])],
   [],
@@ -156,7 +162,7 @@ test -z "$M4"	 && AC_MSG_ERROR([M4 is missing.])
 AC_MSG_CHECKING([bison version])
 BIRD_CHECK_BISON_VERSION(BISON_VERSION)
 AC_MSG_RESULT([$BISON_VERSION])
-if test "$bird_bison_synclines" = yes; then
+if test "$bird_bison_synclines" = yes && test "$enable_debug_generated" = no; then
   M4FLAGS="$M4FLAGS -s"
 fi
 
diff --git a/filter/Makefile b/filter/Makefile
index 15f2c3d0..f5f50045 100644
--- a/filter/Makefile
+++ b/filter/Makefile
@@ -1,13 +1,10 @@
-src := filter.c f-util.c tree.c trie.c f-inst-new.c
+src := filter.c f-util.c tree.c trie.c
 obj := $(src-o-files)
 $(all-daemon)
 $(cf-local)
 
 M4FLAGS_FILTERS=$(filter-out -s,$(M4FLAGS))
 
-$(o)f-inst-line-size.c: $(s)line-size.m4 $(s)f-inst.c $(objdir)/.dir-stamp
-	$(M4) $(M4FLAGS_FILTERS) -P $^ >$@
-
 $(o)f-inst-postfixify.c: $(s)postfixify.m4 $(s)f-inst.c $(objdir)/.dir-stamp
 	$(M4) $(M4FLAGS_FILTERS) -P $^ >$@
 
@@ -17,16 +14,13 @@ $(o)f-inst-interpret.c: $(s)interpret.m4 $(s)f-inst.c $(objdir)/.dir-stamp
 $(o)f-inst-same.c: $(s)same.m4 $(s)f-inst.c $(objdir)/.dir-stamp
 	$(M4) $(M4FLAGS_FILTERS) -P $^ >$@
 
-$(o)f-inst-struct.h: $(s)struct.m4 $(s)f-inst.c $(objdir)/.dir-stamp
-	$(M4) $(M4FLAGS_FILTERS) -P $^ >$@
-
-$(o)f-inst-new.c: $(s)new.m4 $(s)f-inst.c $(objdir)/.dir-stamp
+$(o)f-inst-decl.h: $(s)decl.m4 $(s)f-inst.c $(objdir)/.dir-stamp
 	$(M4) $(M4FLAGS_FILTERS) -P $^ >$@
 
 $(o)f-inst-dump.c: $(s)dump.m4 $(s)f-inst.c $(objdir)/.dir-stamp
 	$(M4) $(M4FLAGS_FILTERS) -P $^ >$@
 
-$(o)filter.o: $(o)f-inst-interpret.c $(o)f-inst-line-size.c $(o)f-inst-postfixify.c $(o)f-inst-same.c $(o)f-inst-dump.c $(o)f-inst-struct.h
+$(o)filter.o: $(o)f-inst-interpret.c $(o)f-inst-postfixify.c $(o)f-inst-same.c $(o)f-inst-dump.c $(o)f-inst-decl.h
 
 tests_src := tree_test.c filter_test.c trie_test.c
 tests_targets := $(tests_targets) $(tests-target-files)
diff --git a/filter/config.Y b/filter/config.Y
index 31ceb3f5..42624f44 100644
--- a/filter/config.Y
+++ b/filter/config.Y
@@ -11,7 +11,7 @@
 CF_HDR
 
 #include "filter/f-inst.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 
 CF_DEFINES
 
@@ -418,7 +418,7 @@ assert_assign(struct f_lval *lval, struct f_inst *expr, const char *start, const
   }
 
   checker = f_new_inst(FI_EQ, expr, getter);
-  f_inst_next(setter, checker);
+  setter->next = checker;
   
   return assert_done(setter, start, end);
 }
@@ -550,7 +550,7 @@ one_decl:
 decls: /* EMPTY */ { $$ = NULL; }
  | one_decl ';' decls {
      $$ = $1;
-     f_inst_next($$, $3);
+     $$->next = $3;
    }
  ;
 
@@ -559,7 +559,7 @@ declsn: one_decl { $$.inst = $1; $$.count = 1; }
  | one_decl ';' declsn {
      $$ = $3;
      $$.count++;
-     f_inst_next($$.inst, $1);
+     $$.inst->next = $1;
    }
  ;
 
@@ -640,7 +640,7 @@ cmds: /* EMPTY */ { $$ = NULL; }
  ;
 
 cmds_int: cmd { $$[0] = $$[1] = $1; }
- | cmds_int cmd { $$[1] = $2; f_inst_next($1[1], $2); $$[0] = $1[0]; }
+ | cmds_int cmd { $$[1] = $2; $1[1]->next = $2; $$[0] = $1[0]; }
  ;
 
 block:
@@ -803,11 +803,11 @@ bgp_path:
  ;
 
 bgp_path_tail:
-   NUM bgp_path_tail		{ $$ = f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_PATH_MASK_ITEM, .val.pmi = { .asn = $1, .kind = PM_ASN, }, }); f_inst_next($$, $2);  }
- | NUM DDOT NUM bgp_path_tail	{ $$ = f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_PATH_MASK_ITEM, .val.pmi = { .from = $1, .to = $3, .kind = PM_ASN_RANGE }, }); f_inst_next($$, $4); }
- | '*' bgp_path_tail		{ $$ = f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_PATH_MASK_ITEM, .val.pmi = { .kind = PM_ASTERISK }, }); f_inst_next($$, $2); }
- | '?' bgp_path_tail		{ $$ = f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_PATH_MASK_ITEM, .val.pmi = { .kind = PM_QUESTION }, }); f_inst_next($$, $2); }
- | bgp_path_expr bgp_path_tail	{ $$ = $1; f_inst_next($$, $2); }
+   NUM bgp_path_tail		{ $$ = f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_PATH_MASK_ITEM, .val.pmi = { .asn = $1, .kind = PM_ASN, }, }); $$->next = $2;  }
+ | NUM DDOT NUM bgp_path_tail	{ $$ = f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_PATH_MASK_ITEM, .val.pmi = { .from = $1, .to = $3, .kind = PM_ASN_RANGE }, }); $$->next = $4; }
+ | '*' bgp_path_tail		{ $$ = f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_PATH_MASK_ITEM, .val.pmi = { .kind = PM_ASTERISK }, }); $$->next = $2; }
+ | '?' bgp_path_tail		{ $$ = f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_PATH_MASK_ITEM, .val.pmi = { .kind = PM_QUESTION }, }); $$->next = $2; }
+ | bgp_path_expr bgp_path_tail	{ $$ = $1; $$->next = $2; }
  | 				{ $$ = NULL; }
  ;
 
@@ -946,7 +946,7 @@ print_list: /* EMPTY */ { $$ = NULL; }
  | print_one { $$ = $1; }
  | print_one ',' print_list {
      if ($1) {
-       f_inst_next($1, $3);
+       $1->next = $3;
        $$ = $1;
      } else $$ = $3;
    }
@@ -957,7 +957,7 @@ var_listn: term {
    }
  | term ',' var_listn {
      $$ = $1;
-     f_inst_next($$, $3);
+     $$->next = $3;
    }
  ;
 
diff --git a/filter/f-util.h b/filter/data.h
similarity index 89%
rename from filter/f-util.h
rename to filter/data.h
index a7d77bbd..58db3e44 100644
--- a/filter/f-util.h
+++ b/filter/data.h
@@ -1,5 +1,5 @@
 /*
- *	BIRD Internet Routing Daemon -- Filter utils
+ *	BIRD Internet Routing Daemon -- Dynamic data structures
  *
  *	(c) 1999 Pavel Machek <pavel@ucw.cz>
  *	(c) 2018--2019 Maria Matejka <mq@jmq.cz>
@@ -7,14 +7,10 @@
  *	Can be freely distributed and used under the terms of the GNU GPL.
  */
 
-#ifndef _BIRD_F_UTIL_H_
-#define _BIRD_F_UTIL_H_
+#ifndef _BIRD_FILTER_DATA_H_
+#define _BIRD_FILTER_DATA_H_
 
-/* IP prefix range structure */
-struct f_prefix {
-  net_addr net;		/* The matching prefix must match this net */
-  u8 lo, hi;		/* And its length must fit between lo and hi */
-};
+#include "nest/bird.h"
 
 /* Type numbers must be in 0..0xff range */
 #define T_MASK 0xff
@@ -84,8 +80,6 @@ struct f_val {
   } val;
 };
 
-#define NEW_F_VAL struct f_val * val; val = cfg_alloc(sizeof(struct f_val));
-
 /* Dynamic attribute definition (eattrs) */
 struct f_dynamic_attr {
   u8 type;		/* EA type (EAF_*) */
@@ -113,6 +107,30 @@ struct f_static_attr {
   int readonly:1;			/* Don't allow writing */
 };
 
+/* Filter l-value type */
+enum f_lval_type {
+  F_LVAL_VARIABLE,
+  F_LVAL_PREFERENCE,
+  F_LVAL_SA,
+  F_LVAL_EA,
+};
+
+/* Filter l-value */
+struct f_lval {
+  enum f_lval_type type;
+  union {
+    const struct symbol *sym;
+    struct f_dynamic_attr da;
+    struct f_static_attr sa;
+  };
+};
+
+/* IP prefix range structure */
+struct f_prefix {
+  net_addr net;		/* The matching prefix must match this net */
+  u8 lo, hi;		/* And its length must fit between lo and hi */
+};
+
 struct f_tree {
   struct f_tree *left, *right;
   struct f_val from, to;
diff --git a/filter/decl.m4 b/filter/decl.m4
new file mode 100644
index 00000000..bdbb3e27
--- /dev/null
+++ b/filter/decl.m4
@@ -0,0 +1,128 @@
+m4_divert(-1)m4_dnl
+#
+#	BIRD -- Construction of per-instruction structures
+#
+#	(c) 2018 Maria Matejka <mq@jmq.cz>
+#
+#	Can be freely distributed and used under the terms of the GNU GPL.
+#
+#
+#	Global Diversions:
+#	4	enum fi_code
+#	1	struct f_inst_FI_...
+#	2	union in struct f_inst
+#	3	constructors
+#
+#	Per-inst Diversions:
+#	11	content of struct f_inst_FI_...
+#	12	constructor arguments
+#	13	constructor body
+
+# Flush the completed instruction
+
+m4_define(FID_END, `m4_divert(-1)')
+
+m4_define(FID_ZONE, `m4_divert($1) /* $2 for INST_NAME() */')
+m4_define(FID_STRUCT, `FID_ZONE(1, Per-instruction structure)')
+m4_define(FID_UNION, `FID_ZONE(2, Union member)')
+m4_define(FID_NEW, `FID_ZONE(3, Constructor)')
+m4_define(FID_ENUM, `FID_ZONE(4, Code enum)')
+
+m4_define(FID_STRUCT_IN, `m4_divert(101)')
+m4_define(FID_NEW_ARGS, `m4_divert(102)')
+m4_define(FID_NEW_BODY, `m4_divert(103)')
+
+m4_define(INST_FLUSH, `m4_ifdef([[INST_NAME]], [[
+FID_ENUM
+INST_NAME(),
+FID_STRUCT
+struct f_inst_[[]]INST_NAME() {
+m4_undivert(101)
+};
+FID_UNION
+struct f_inst_[[]]INST_NAME() i_[[]]INST_NAME();
+FID_NEW
+static inline struct f_inst *f_new_inst_]]INST_NAME()[[(enum f_instruction_code fi_code
+m4_undivert(102)
+) {
+  struct f_inst *what_ = cfg_allocz(sizeof(struct f_inst));
+  what_->fi_code = fi_code;
+  what_->lineno = ifs->lino;
+  what_->size = 1;
+  struct f_inst_[[]]INST_NAME() *what UNUSED = &(what_->i_[[]]INST_NAME());
+m4_undivert(103)
+  return what_;
+}
+FID_END
+]])')
+
+m4_define(INST, `INST_FLUSH()m4_define([[INST_NAME]], [[$1]])')
+
+m4_define(FID_MEMBER, `m4_dnl
+FID_STRUCT_IN
+$1 $2;
+FID_NEW_ARGS
+, $1 $2
+FID_NEW_BODY
+what->$2 = $2;
+FID_END')
+
+m4_define(ARG, `FID_MEMBER(const struct f_inst *, f$1)
+FID_NEW_BODY
+for (const struct f_inst *child = f$1; child; child = child->next) what_->size += child->size;
+FID_END')
+m4_define(ARG_ANY, `FID_MEMBER(const struct f_inst *, f$1)
+FID_NEW_BODY
+for (const struct f_inst *child = f$1; child; child = child->next) what_->size += child->size;
+FID_END')
+m4_define(LINE, `FID_MEMBER(const struct f_inst *, f$1)')
+m4_define(LINEP, `FID_STRUCT_IN
+const struct f_line *fl$1;
+FID_END')
+m4_define(SYMBOL, `FID_MEMBER(const struct symbol *, sym)')
+m4_define(VALI, `FID_MEMBER(struct f_val, vali)')
+m4_define(VALP, `FID_MEMBER(const struct f_val *, valp)')
+m4_define(VAR, `m4_dnl
+FID_STRUCT_IN
+const struct f_val *valp;
+const struct symbol *sym;
+FID_NEW_ARGS
+, const struct symbol *sym
+FID_NEW_BODY
+what->valp = (what->sym = sym)->def;
+FID_END')
+m4_define(FRET, `FID_MEMBER(enum filter_return, fret)')
+m4_define(ECS, `FID_MEMBER(enum ec_subtype, ecs)')
+m4_define(RTC, `FID_MEMBER(const struct rtable_config *, rtc)')
+m4_define(STATIC_ATTR, `FID_MEMBER(struct f_static_attr, sa)')
+m4_define(DYNAMIC_ATTR, `FID_MEMBER(struct f_dynamic_attr, da)')
+m4_define(COUNT, `FID_MEMBER(uint, count)')
+m4_define(TREE, `FID_MEMBER(const struct f_tree *, tree)')
+m4_define(STRING, `FID_MEMBER(const char *, s)')
+
+m4_m4wrap(`
+INST_FLUSH()
+m4_divert(0)
+/* Filter instruction codes */
+enum f_instruction_code {
+m4_undivert(4)
+};
+
+/* Per-instruction structures */
+m4_undivert(1)
+
+struct f_inst {
+  const struct f_inst *next;		/* Next instruction */
+  enum f_instruction_code fi_code;	/* Instruction code */
+  int size;				/* How many instructions are underneath */
+  int lineno;				/* Line number */
+  union {
+    m4_undivert(2)
+  };
+};
+
+/* Instruction constructors */
+m4_undivert(3)
+')
+
+m4_changequote([[,]])
diff --git a/filter/f-inst.c b/filter/f-inst.c
index 0dd9f9f6..afb895c5 100644
--- a/filter/f-inst.c
+++ b/filter/f-inst.c
@@ -109,15 +109,15 @@
     ARG_ANY(1);
     COUNT(2);
 
-    NEW(, [[
-	uint len = 0;
-	uint dyn = 0;
-	for (const struct f_inst *tt = f1; tt; tt = tt->next, len++)
-	  if (tt->fi_code != FI_CONSTANT)
-	    dyn++;
+    FID_NEW_BODY
+      uint len = 0;
+      uint dyn = 0;
+      for (const struct f_inst *tt = f1; tt; tt = tt->next, len++)
+	if (tt->fi_code != FI_CONSTANT)
+	  dyn++;
 
-	WHAT().count = len;
-	]]);
+      what->count = len;
+    FID_END
 
     if (vstk.cnt < what->count) /* TODO: make this check systematic */
       runtime("Construction of BGP path mask from %u elements must have at least that number of elements", what->count);
@@ -719,17 +719,17 @@
     /* Then push the arguments */
     LINE(1,1);
 
-    NEW(, [[
-	if (sym->class != SYM_FUNCTION)
-	  cf_error("You can't call something which is not a function. Really.");
+    FID_NEW_BODY
+      if (sym->class != SYM_FUNCTION)
+	cf_error("You can't call something which is not a function. Really.");
 
-	uint count = 0;
-	for (const struct f_inst *inst = f1; inst; inst = inst->next)
-	  count++;
-	
-	if (count != sym->aux2)
-	  cf_error("Function %s takes %u arguments, got %u.", sym->name, sym->aux2, count);
-    ]]);
+      uint count = 0;
+      for (const struct f_inst *inst = f1; inst; inst = inst->next)
+	count++;
+
+      if (count != sym->aux2)
+	cf_error("Function %s takes %u arguments, got %u.", sym->name, sym->aux2, count);
+    FID_END
   }
 
   INST(FI_DROP_RESULT, 1, 0) {
diff --git a/filter/f-inst.h b/filter/f-inst.h
index 63124aa1..1423e685 100644
--- a/filter/f-inst.h
+++ b/filter/f-inst.h
@@ -10,137 +10,21 @@
 #ifndef _BIRD_F_INST_H_
 #define _BIRD_F_INST_H_
 
+#include "nest/bird.h"
+#include "conf/conf.h"
 #include "filter/filter.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 
-/* Filter l-value type */
-enum f_lval_type {
-  F_LVAL_VARIABLE,
-  F_LVAL_PREFERENCE,
-  F_LVAL_SA,
-  F_LVAL_EA,
-};
+/* Include generated filter instruction declarations */
+#include "filter/f-inst-decl.h"
 
-/* Filter l-value */
-struct f_lval {
-  enum f_lval_type type;
-  union {
-    const struct symbol *sym;
-    struct f_dynamic_attr da;
-    struct f_static_attr sa;
-  };
-};
-
-/* Filter instruction declarations */
-#define FI__LIST \
-  F(FI_NOP) \
-  F(FI_ADD, ARG, ARG) \
-  F(FI_SUBTRACT, ARG, ARG) \
-  F(FI_MULTIPLY, ARG, ARG) \
-  F(FI_DIVIDE, ARG, ARG) \
-  F(FI_AND, ARG, LINE) \
-  F(FI_OR, ARG, LINE) \
-  F(FI_PAIR_CONSTRUCT, ARG, ARG) \
-  F(FI_EC_CONSTRUCT, ARG, ARG, ECS) \
-  F(FI_LC_CONSTRUCT, ARG, ARG, ARG) \
-  F(FI_PATHMASK_CONSTRUCT, ARG, COUNT) \
-  F(FI_NEQ, ARG, ARG) \
-  F(FI_EQ, ARG, ARG) \
-  F(FI_LT, ARG, ARG) \
-  F(FI_LTE, ARG, ARG) \
-  F(FI_NOT, ARG) \
-  F(FI_MATCH, ARG, ARG) \
-  F(FI_NOT_MATCH, ARG, ARG) \
-  F(FI_DEFINED, ARG) \
-  F(FI_TYPE, ARG) \
-  F(FI_IS_V4, ARG) \
-  F(FI_SET, ARG, SYMBOL) \
-  F(FI_CONSTANT, VALI) \
-  F(FI_VARIABLE, SYMBOL) \
-  F(FI_CONSTANT_INDIRECT, VALP) \
-  F(FI_PRINT, ARG) \
-  F(FI_CONDITION, ARG, LINE, LINE) \
-  F(FI_PRINT_AND_DIE, ARG, FRET) \
-  F(FI_RTA_GET, SA) \
-  F(FI_RTA_SET, ARG, SA) \
-  F(FI_EA_GET, EA) \
-  F(FI_EA_SET, ARG, EA) \
-  F(FI_EA_UNSET, EA) \
-  F(FI_PREF_GET) \
-  F(FI_PREF_SET, ARG) \
-  F(FI_LENGTH, ARG) \
-  F(FI_ROA_MAXLEN, ARG) \
-  F(FI_ROA_ASN, ARG) \
-  F(FI_SADR_SRC, ARG) \
-  F(FI_IP, ARG) \
-  F(FI_ROUTE_DISTINGUISHER, ARG) \
-  F(FI_AS_PATH_FIRST, ARG) \
-  F(FI_AS_PATH_LAST, ARG) \
-  F(FI_AS_PATH_LAST_NAG, ARG) \
-  F(FI_RETURN, ARG) \
-  F(FI_CALL, SYMBOL, LINE) \
-  F(FI_DROP_RESULT, ARG) \
-  F(FI_SWITCH, ARG, TREE) \
-  F(FI_IP_MASK, ARG, ARG) \
-  F(FI_PATH_PREPEND, ARG, ARG) \
-  F(FI_CLIST_ADD, ARG, ARG) \
-  F(FI_CLIST_DEL, ARG, ARG) \
-  F(FI_CLIST_FILTER, ARG, ARG) \
-  F(FI_ROA_CHECK_IMPLICIT, RTC) \
-  F(FI_ROA_CHECK_EXPLICIT, ARG, ARG, RTC) \
-  F(FI_FORMAT, ARG) \
-  F(FI_ASSERT, ARG, STRING)
-
-/* The enum itself */
-enum f_instruction_code {
-#define F(c, ...) c,
-FI__LIST
-#undef F
-  FI__MAX,
-} PACKED;
+#define f_new_inst(...) MACRO_CONCAT_AFTER(f_new_inst_, MACRO_FIRST(__VA_ARGS__))(__VA_ARGS__)
 
 /* Convert the instruction back to the enum name */
 const char *f_instruction_name(enum f_instruction_code fi);
 
-struct f_inst;
-void f_inst_next(struct f_inst *first, const struct f_inst *append);
 struct f_inst *f_clear_local_vars(struct f_inst *decls);
 
-#define FIA(x)	, FIA_##x
-#define FIA_ARG	const struct f_inst *
-#define FIA_LINE const struct f_inst *
-#define FIA_COUNT uint
-#define FIA_SYMBOL const struct symbol *
-#define FIA_VALI struct f_val
-#define FIA_VALP const struct f_val *
-#define FIA_FRET enum filter_return
-#define FIA_ECS enum ec_subtype
-#define FIA_SA struct f_static_attr
-#define FIA_EA struct f_dynamic_attr
-#define FIA_RTC const struct rtable_config *
-#define FIA_TREE const struct f_tree *
-#define FIA_STRING const char *
-#define F(c, ...) \
-  struct f_inst *f_new_inst_##c(enum f_instruction_code MACRO_IFELSE(MACRO_ISLAST(__VA_ARGS__))()(MACRO_FOREACH(FIA, __VA_ARGS__)));
-FI__LIST
-#undef F
-#undef FIA_ARG
-#undef FIA_LINE
-#undef FIA_LINEP
-#undef FIA_COUNT
-#undef FIA_SYMBOL
-#undef FIA_VALI
-#undef FIA_VALP
-#undef FIA_FRET
-#undef FIA_ECS
-#undef FIA_SA
-#undef FIA_EA
-#undef FIA_RTC
-#undef FIA_STRING
-#undef FIA
-
-#define f_new_inst(...) MACRO_CONCAT_AFTER(f_new_inst_, MACRO_FIRST(__VA_ARGS__))(__VA_ARGS__)
-
 /* Flags for instructions */
 enum f_instruction_flags {
   FIF_PRINTED = 1,		/* FI_PRINT_AND_DIE: message put in buffer */
@@ -202,7 +86,4 @@ struct f_bt_test_suite {
   const char *dsc;		/* Description */
 };
 
-/* Include the auto-generated structures */
-#include "filter/f-inst-struct.h"
-
 #endif
diff --git a/filter/f-util.c b/filter/f-util.c
index eb948fa0..82aaa385 100644
--- a/filter/f-util.c
+++ b/filter/f-util.c
@@ -17,22 +17,6 @@
 
 #define P(a,b) ((a<<8) | b)
 
-static const char * const f_instruction_name_str[] = {
-#define F(c,...) \
-  [c] = #c,
-FI__LIST
-#undef F
-};
-
-const char *
-f_instruction_name(enum f_instruction_code fi)
-{
-  if (fi < FI__MAX)
-    return f_instruction_name_str[fi];
-  else
-    bug("Got unknown instruction code: %d", fi);
-}
-
 char *
 filter_name(struct filter *filter)
 {
@@ -56,18 +40,21 @@ struct filter *f_new_where(const struct f_inst *where)
   struct f_inst acc = {
     .fi_code = FI_PRINT_AND_DIE,
     .lineno = ifs->lino,
+    .size = 1,
     .i_FI_PRINT_AND_DIE = { .fret = F_ACCEPT, },
   };
 
   struct f_inst rej = {
     .fi_code = FI_PRINT_AND_DIE,
     .lineno = ifs->lino,
+    .size = 1,
     .i_FI_PRINT_AND_DIE = { .fret = F_REJECT, },
   };
 
   struct f_inst i = {
     .fi_code = FI_CONDITION,
     .lineno = ifs->lino,
+    .size = 3,
     .i_FI_CONDITION = {
       .f1 = where,
       .f2 = &acc,
diff --git a/filter/filter.c b/filter/filter.c
index ff702f2b..0cb56fe4 100644
--- a/filter/filter.c
+++ b/filter/filter.c
@@ -48,7 +48,7 @@
 #include "conf/conf.h"
 #include "filter/filter.h"
 #include "filter/f-inst.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 
 #define CMP_ERROR 999
 
@@ -64,6 +64,75 @@ struct filter_state {
 
 void (*bt_assert_hook)(int result, const struct f_line_item *assert);
 
+static const char * const f_instruction_name_str[] = {
+  /* TODO: Make this better */
+  [FI_ADD] = "FI_ADD",
+  [FI_SUBTRACT] = "FI_SUBTRACT",
+  [FI_MULTIPLY] = "FI_MULTIPLY",
+  [FI_DIVIDE] = "FI_DIVIDE",
+  [FI_AND] = "FI_AND",
+  [FI_OR] = "FI_OR",
+  [FI_PAIR_CONSTRUCT] = "FI_PAIR_CONSTRUCT",
+  [FI_EC_CONSTRUCT] = "FI_EC_CONSTRUCT",
+  [FI_LC_CONSTRUCT] = "FI_LC_CONSTRUCT",
+  [FI_PATHMASK_CONSTRUCT] = "FI_PATHMASK_CONSTRUCT",
+  [FI_NEQ] = "FI_NEQ",
+  [FI_EQ] = "FI_EQ",
+  [FI_LT] = "FI_LT",
+  [FI_LTE] = "FI_LTE",
+  [FI_NOT] = "FI_NOT",
+  [FI_MATCH] = "FI_MATCH",
+  [FI_NOT_MATCH] = "FI_NOT_MATCH",
+  [FI_DEFINED] = "FI_DEFINED",
+  [FI_TYPE] = "FI_TYPE",
+  [FI_IS_V4] = "FI_IS_V4",
+  [FI_SET] = "FI_SET",
+  [FI_CONSTANT] = "FI_CONSTANT",
+  [FI_VARIABLE] = "FI_VARIABLE",
+  [FI_CONSTANT_INDIRECT] = "FI_CONSTANT_INDIRECT",
+  [FI_PRINT] = "FI_PRINT",
+  [FI_CONDITION] = "FI_CONDITION",
+  [FI_PRINT_AND_DIE] = "FI_PRINT_AND_DIE",
+  [FI_RTA_GET] = "FI_RTA_GET",
+  [FI_RTA_SET] = "FI_RTA_SET",
+  [FI_EA_GET] = "FI_EA_GET",
+  [FI_EA_SET] = "FI_EA_SET",
+  [FI_EA_UNSET] = "FI_EA_UNSET",
+  [FI_PREF_GET] = "FI_PREF_GET",
+  [FI_PREF_SET] = "FI_PREF_SET",
+  [FI_LENGTH] = "FI_LENGTH",
+  [FI_SADR_SRC] = "FI_SADR_SRC",
+  [FI_ROA_MAXLEN] = "FI_ROA_MAXLEN",
+  [FI_ROA_ASN] = "FI_ROA_ASN",
+  [FI_IP] = "FI_IP",
+  [FI_ROUTE_DISTINGUISHER] = "FI_ROUTE_DISTINGUISHER",
+  [FI_AS_PATH_FIRST] = "FI_AS_PATH_FIRST",
+  [FI_AS_PATH_LAST] = "FI_AS_PATH_LAST",
+  [FI_AS_PATH_LAST_NAG] = "FI_AS_PATH_LAST_NAG",
+  [FI_RETURN] = "FI_RETURN",
+  [FI_CALL] = "FI_CALL",
+  [FI_DROP_RESULT] = "FI_DROP_RESULT",
+  [FI_SWITCH] = "FI_SWITCH",
+  [FI_IP_MASK] = "FI_IP_MASK",
+  [FI_PATH_PREPEND] = "FI_PATH_PREPEND",
+  [FI_CLIST_ADD] = "FI_CLIST_ADD",
+  [FI_CLIST_DEL] = "FI_CLIST_DEL",
+  [FI_CLIST_FILTER] = "FI_CLIST_FILTER",
+  [FI_ROA_CHECK_IMPLICIT] = "FI_ROA_CHECK_IMPLICIT",
+  [FI_ROA_CHECK_EXPLICIT] = "FI_ROA_CHECK_EXPLICIT",
+  [FI_FORMAT] = "FI_FORMAT",
+  [FI_ASSERT] = "FI_ASSERT",
+};
+
+const char *
+f_instruction_name(enum f_instruction_code fi)
+{
+  if (fi < (sizeof(f_instruction_name_str) / sizeof(f_instruction_name_str[0])))
+    return f_instruction_name_str[fi];
+  else
+    bug("Got unknown instruction code: %d", fi);
+}
+
 /* Special undef value for paths and clists */
 static inline int
 undef_value(struct f_val v)
@@ -615,18 +684,6 @@ val_format_str(struct filter_state *fs, struct f_val *v) {
 
 static struct tbf rl_runtime_err = TBF_DEFAULT_LOG_LIMITS;
 
-static uint
-inst_line_size(const struct f_inst *what_)
-{
-  uint cnt = 0;
-  for ( ; what_; what_ = what_->next) {
-    switch (what_->fi_code) {
-#include "filter/f-inst-line-size.c"
-    }
-  }
-  return cnt;
-}
-
 #define INDENT (((const char *) f_dump_line_indent_str) + sizeof(f_dump_line_indent_str) - (indent) - 1)
 static const char f_dump_line_indent_str[] = "                                ";
 
@@ -685,7 +742,8 @@ f_postfixify_concat(const struct f_inst * const inst[], uint count)
 {
   uint len = 0;
   for (uint i=0; i<count; i++)
-    len += inst_line_size(inst[i]);
+    for (const struct f_inst *what = inst[i]; what; what = what->next)
+      len += what->size;
 
   struct f_line *out = cfg_allocz(sizeof(struct f_line) + sizeof(struct f_line_item)*len);
 
diff --git a/filter/filter_test.c b/filter/filter_test.c
index a02f0832..edd73ac8 100644
--- a/filter/filter_test.c
+++ b/filter/filter_test.c
@@ -17,7 +17,7 @@
 #include "test/bt-utils.h"
 
 #include "filter/filter.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 #include "filter/f-inst.h"
 #include "conf/conf.h"
 
diff --git a/filter/interpret.m4 b/filter/interpret.m4
index dfd5c6a7..e32b3a76 100644
--- a/filter/interpret.m4
+++ b/filter/interpret.m4
@@ -63,10 +63,11 @@ m4_define(TREE, `')
 m4_define(STRING, `')
 m4_define(COUNT, `')
 m4_define(POSTFIXIFY, `')
-m4_define(LINE_SIZE, `')
 m4_define(SAME, `')
-m4_define(STRUCT, `')
-m4_define(NEW, `')
+m4_define(FID_STRUCT_IN, `m4_divert(-1)')
+m4_define(FID_NEW_ARGS, `m4_divert(-1)')
+m4_define(FID_NEW_BODY, `m4_divert(-1)')
+m4_define(FID_END, `m4_divert(2)')
 
 m4_m4wrap(`
 INST_FLUSH()
diff --git a/filter/line-size.m4 b/filter/line-size.m4
deleted file mode 100644
index 051d3b90..00000000
--- a/filter/line-size.m4
+++ /dev/null
@@ -1,41 +0,0 @@
-m4_divert(-1)m4_dnl
-#
-#	BIRD -- Line size counting
-#
-#	(c) 2018 Maria Matejka <mq@jmq.cz>
-#
-#	Can be freely distributed and used under the terms of the GNU GPL.
-#
-
-# Common aliases
-m4_define(DNL, `m4_dnl')
-
-m4_define(INST_FLUSH, `m4_ifdef([[INST_NAME]], [[
-m4_divert(1)
-case INST_NAME():
-cnt += 1;
-#define what ((const struct f_inst_]]INST_NAME()[[ *) &(what_->i_]]INST_NAME()[[))
-m4_undivert(2)
-#undef what
-break;
-m4_divert(-1)
-]])')
-m4_define(INST, `INST_FLUSH()m4_define([[INST_NAME]], [[$1]])')
-
-m4_define(ARG, `m4_divert(2)cnt += inst_line_size(what->f$1);
-m4_divert(-1)')
-m4_define(ARG_T, `m4_divert(2)cnt += inst_line_size(what->f$1);
-m4_divert(-1)')
-m4_define(ARG_ANY, `m4_divert(2)cnt += inst_line_size(what->f$1);
-m4_divert(-1)')
-m4_define(LINE_SIZE, `m4_divert(2)$1m4_divert(-1)')
-
-m4_m4wrap(`
-INST_FLUSH()
-m4_divert(0)DNL
-m4_undivert(1)
-
-default: bug( "Unknown instruction %d (%c)", what_->fi_code, what_->fi_code & 0xff);
-')
-
-m4_changequote([[,]])
diff --git a/filter/new.m4 b/filter/new.m4
deleted file mode 100644
index 38295e5c..00000000
--- a/filter/new.m4
+++ /dev/null
@@ -1,78 +0,0 @@
-m4_divert(-1)m4_dnl
-#
-#	BIRD -- Construction of per-instruction structures
-#
-#	(c) 2018 Maria Matejka <mq@jmq.cz>
-#
-#	Can be freely distributed and used under the terms of the GNU GPL.
-#
-#
-#	Diversions:
-#	1	for prepared output
-#	2	for function arguments
-#	3	for function body
-
-# Common aliases
-m4_define(DNL, `m4_dnl')
-
-m4_define(FNSTOP, `m4_divert(-1)')
-m4_define(FNOUT, `m4_divert(1)')
-m4_define(FNARG, `m4_divert(2)')
-m4_define(FNBODY, `m4_divert(3)')
-
-m4_define(INST_FLUSH,  `m4_ifdef([[INST_NAME]], [[
-FNOUT()DNL
-struct f_inst *f_new_inst_]]INST_NAME()[[(enum f_instruction_code fi_code
-m4_undivert(2)
-) {
-  struct f_inst *what = cfg_allocz(sizeof(struct f_inst));
-  what->fi_code = fi_code;
-  what->lineno = ifs->lino;
-m4_undivert(3)
-  return what;
-}
-FNSTOP()
-]]DNL
-)')
-
-m4_define(INST, `INST_FLUSH()m4_define([[INST_NAME]], [[$1]])')
-
-m4_define(WHAT, `what->i_[[]]INST_NAME()')
-
-m4_define(FNMETAARG, `FNARG(), $1 $2
-FNBODY()  WHAT().$2 = $2;
-FNSTOP()')
-m4_define(ARG, `FNMETAARG(const struct f_inst *, f$1)')
-m4_define(ARG_ANY, `FNMETAARG(const struct f_inst *, f$1)')
-m4_define(LINE, `FNMETAARG(const struct f_inst *, f$1)')
-m4_define(SYMBOL, `FNMETAARG(const struct symbol *, sym)')
-m4_define(VALI, `FNMETAARG(struct f_val, vali)')
-m4_define(VALP, `FNMETAARG(const struct f_val *, valp)')
-m4_define(VAR, `FNARG(), const struct symbol * sym
-FNBODY() WHAT().valp = (WHAT().sym = sym)->def;
-FNSTOP()')
-m4_define(FRET, `FNMETAARG(enum filter_return, fret)')
-m4_define(ECS, `FNMETAARG(enum ec_subtype, ecs)')
-m4_define(RTC, `FNMETAARG(const struct rtable_config *, rtc)')
-m4_define(STATIC_ATTR, `FNMETAARG(struct f_static_attr, sa)')
-m4_define(DYNAMIC_ATTR, `FNMETAARG(struct f_dynamic_attr, da)')
-m4_define(COUNT, `FNMETAARG(uint, count)')
-m4_define(TREE, `FNMETAARG(const struct f_tree *, tree)')
-m4_define(STRING, `FNMETAARG(const char *, s)')
-m4_define(NEW, `FNARG()$1
-FNBODY()$2
-FNSTOP()')
-
-m4_m4wrap(`
-INST_FLUSH()
-m4_divert(0)
-#include "nest/bird.h"
-#include "conf/conf.h"
-#include "filter/filter.h"
-#include "filter/f-inst.h"
-
-m4_undivert(1)
-
-')
-
-m4_changequote([[,]])
diff --git a/filter/struct.m4 b/filter/struct.m4
deleted file mode 100644
index 7af28cfd..00000000
--- a/filter/struct.m4
+++ /dev/null
@@ -1,73 +0,0 @@
-m4_divert(-1)m4_dnl
-#
-#	BIRD -- Definition of per-instruction structures
-#
-#	(c) 2018 Maria Matejka <mq@jmq.cz>
-#
-#	Can be freely distributed and used under the terms of the GNU GPL.
-#
-
-# Common aliases
-m4_define(DNL, `m4_dnl')
-
-m4_define(INST_FLUSH, `m4_ifdef([[INST_NAME]], [[
-m4_divert(1)
-struct f_inst_[[]]INST_NAME() {
-m4_undivert(2)
-};
-m4_divert(3)
-struct f_inst_[[]]INST_NAME() i_[[]]INST_NAME();
-m4_divert(-1)
-]])')
-m4_define(INST, `INST_FLUSH()m4_define([[INST_NAME]], [[$1]])')
-
-m4_define(ARG, `m4_divert(2)const struct f_inst *f$1;
-m4_divert(-1)')
-m4_define(ARG_ANY, `m4_divert(2)const struct f_inst *f$1;
-m4_divert(-1)')
-m4_define(LINE, `m4_divert(2)const struct f_inst *f$1;
-m4_divert(-1)')
-m4_define(LINEP, `m4_divert(2)const struct f_line *fl$1;
-m4_divert(-1)')
-m4_define(SYMBOL, `m4_divert(2)const struct symbol *sym;
-m4_divert(-1)')
-m4_define(VALI, `m4_divert(2)struct f_val vali;
-m4_divert(-1)')
-m4_define(VALP, `m4_divert(2)const struct f_val *valp;
-m4_divert(-1)')
-m4_define(VAR, `VALP()SYMBOL()')
-m4_define(FRET, `m4_divert(2)enum filter_return fret;
-m4_divert(-1)')
-m4_define(ECS, `m4_divert(2)enum ec_subtype ecs;
-m4_divert(-1)')
-m4_define(RTC, `m4_divert(2)const struct rtable_config *rtc;
-m4_divert(-1)')
-m4_define(STATIC_ATTR, `m4_divert(2)struct f_static_attr sa;
-m4_divert(-1)')
-m4_define(DYNAMIC_ATTR, `m4_divert(2)struct f_dynamic_attr da;
-m4_divert(-1)')
-m4_define(COUNT, `m4_divert(2)uint count;
-m4_divert(-1)')
-m4_define(TREE, `m4_divert(2)const struct f_tree *tree;
-m4_divert(-1)')
-m4_define(STRING, `m4_divert(2)const char *s;
-m4_divert(-1)')
-m4_define(STRUCT, `m4_divert(2)$1
-m4_divert(-1)')
-
-m4_m4wrap(`
-INST_FLUSH()
-m4_divert(0)DNL
-m4_undivert(1)
-
-struct f_inst {
-  const struct f_inst *next;		/* Next instruction */
-  enum f_instruction_code fi_code;	/* Instruction code */
-  int lineno;				/* Line number */
-  union {
-    m4_undivert(3)
-  };
-};
-')
-
-m4_changequote([[,]])
diff --git a/filter/tree.c b/filter/tree.c
index 879b0859..46d6e529 100644
--- a/filter/tree.c
+++ b/filter/tree.c
@@ -10,7 +10,7 @@
 #include "nest/bird.h"
 #include "conf/conf.h"
 #include "filter/filter.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 
 /**
  * find_tree
diff --git a/filter/tree_test.c b/filter/tree_test.c
index 9e0de50f..6472d17e 100644
--- a/filter/tree_test.c
+++ b/filter/tree_test.c
@@ -10,7 +10,7 @@
 #include "test/bt-utils.h"
 
 #include "filter/filter.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 #include "conf/conf.h"
 
 #define MAX_TREE_HEIGHT 13
diff --git a/filter/trie.c b/filter/trie.c
index dccf9130..3038f5ec 100644
--- a/filter/trie.c
+++ b/filter/trie.c
@@ -73,7 +73,7 @@
 #include "lib/string.h"
 #include "conf/conf.h"
 #include "filter/filter.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 
 
 /*
diff --git a/filter/trie_test.c b/filter/trie_test.c
index b6959c4a..38c387b0 100644
--- a/filter/trie_test.c
+++ b/filter/trie_test.c
@@ -10,7 +10,7 @@
 #include "test/bt-utils.h"
 
 #include "filter/filter.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 #include "conf/conf.h"
 
 #define TESTS_NUM		10
diff --git a/nest/a-path.c b/nest/a-path.c
index ac13d0fa..62369af3 100644
--- a/nest/a-path.c
+++ b/nest/a-path.c
@@ -13,7 +13,7 @@
 #include "lib/resource.h"
 #include "lib/unaligned.h"
 #include "lib/string.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 
 // static inline void put_as(byte *data, u32 as) { put_u32(data, as); }
 // static inline u32 get_as(byte *data) { return get_u32(data); }
diff --git a/nest/cmds.c b/nest/cmds.c
index 40d397cc..2b83033f 100644
--- a/nest/cmds.c
+++ b/nest/cmds.c
@@ -15,7 +15,7 @@
 #include "lib/string.h"
 #include "lib/resource.h"
 #include "filter/filter.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 
 extern int shutting_down;
 extern int configuring;
diff --git a/nest/rt-table.c b/nest/rt-table.c
index d72a8695..6c8e662e 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -39,7 +39,7 @@
 #include "lib/string.h"
 #include "conf/conf.h"
 #include "filter/filter.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 #include "lib/hash.h"
 #include "lib/string.h"
 #include "lib/alloca.h"
diff --git a/proto/static/config.Y b/proto/static/config.Y
index 0e53c978..3e9ac578 100644
--- a/proto/static/config.Y
+++ b/proto/static/config.Y
@@ -139,7 +139,7 @@ stat_route:
 stat_route_item:
    cmd {
      if (this_srt_last_cmd)
-       f_inst_next(this_srt_last_cmd, $1);
+       this_srt_last_cmd->next = $1;
      else
        this_srt_cmds = $1;
      this_srt_last_cmd = $1;
diff --git a/sysdep/unix/main.c b/sysdep/unix/main.c
index f9002d58..0fdd5b34 100644
--- a/sysdep/unix/main.c
+++ b/sysdep/unix/main.c
@@ -36,7 +36,7 @@
 #include "nest/locks.h"
 #include "conf/conf.h"
 #include "filter/filter.h"
-#include "filter/f-util.h"
+#include "filter/data.h"
 
 #include "unix.h"
 #include "krt.h"