*
* Optimization module for tcpdump intermediate representation.
*/
-#ifndef lint
-static const char rcsid[] _U_ =
- "@(#) $Header: /tcpdump/master/libpcap/optimize.c,v 1.91 2008-01-02 04:16:46 guy Exp $ (LBL)";
-#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
static void opt_init(struct block *);
static void opt_cleanup(void);
-static void make_marks(struct block *);
-static void mark_code(struct block *);
-
static void intern_blocks(struct block *);
-static int eq_slist(struct slist *, struct slist *);
-
-static void find_levels_r(struct block *);
-
-static void find_levels(struct block *);
-static void find_dom(struct block *);
-static void propedom(struct edge *);
-static void find_edom(struct block *);
-static void find_closure(struct block *);
-static int atomuse(struct stmt *);
-static int atomdef(struct stmt *);
-static void compute_local_ud(struct block *);
-static void find_ud(struct block *);
-static void init_val(void);
-static int F(int, int, int);
-static inline void vstore(struct stmt *, int *, int, int);
-static void opt_blk(struct block *, int);
-static int use_conflict(struct block *, struct block *);
-static void opt_j(struct edge *);
-static void or_pullup(struct block *);
-static void and_pullup(struct block *);
-static void opt_blks(struct block *, int);
-static inline void link_inedge(struct edge *, struct block *);
static void find_inedges(struct block *);
-static void opt_root(struct block **);
-static void opt_loop(struct block *, int);
-static void fold_op(struct stmt *, int, int);
-static inline struct slist *this_op(struct slist *);
-static void opt_not(struct block *);
-static void opt_peep(struct block *);
-static void opt_stmt(struct stmt *, int[], int);
-static void deadstmt(struct stmt *, struct stmt *[]);
-static void opt_deadstores(struct block *);
-static struct block *fold_edge(struct block *, struct edge *);
-static inline int eq_blk(struct block *, struct block *);
-static int slength(struct slist *);
-static int count_blocks(struct block *);
-static void number_blks_r(struct block *);
-static int count_stmts(struct block *);
-static int convert_code_r(struct block *);
#ifdef BDEBUG
static void opt_dump(struct block *);
#endif
#endif
static void
-find_levels_r(b)
- struct block *b;
+find_levels_r(struct block *b)
{
int level;
* with the 'link' field of the struct block.
*/
static void
-find_levels(root)
- struct block *root;
+find_levels(struct block *root)
{
memset((char *)levels, 0, n_blocks * sizeof(*levels));
unMarkAll();
* Assumes graph has been leveled.
*/
static void
-find_dom(root)
- struct block *root;
+find_dom(struct block *root)
{
int i;
struct block *b;
}
static void
-propedom(ep)
- struct edge *ep;
+propedom(struct edge *ep)
{
SET_INSERT(ep->edom, ep->id);
if (ep->succ) {
* Assumes graph has been leveled and predecessors established.
*/
static void
-find_edom(root)
- struct block *root;
+find_edom(struct block *root)
{
int i;
uset x;
* Assumes graph has been leveled.
*/
static void
-find_closure(root)
- struct block *root;
+find_closure(struct block *root)
{
int i;
struct block *b;
* The implementation should probably change to an array access.
*/
static int
-atomuse(s)
- struct stmt *s;
+atomuse(struct stmt *s)
{
register int c = s->code;
* The implementation should probably change to an array access.
*/
static int
-atomdef(s)
- struct stmt *s;
+atomdef(struct stmt *s)
{
if (s->code == NOP)
return -1;
* register by a predecessor block of this block.
*/
static void
-compute_local_ud(b)
- struct block *b;
+compute_local_ud(struct block *b)
{
struct slist *s;
atomset def = 0, use = 0, kill = 0;
* Assume graph is already leveled.
*/
static void
-find_ud(root)
- struct block *root;
+find_ud(struct block *root)
{
int i, maxlevel;
struct block *p;
struct valnode *next_vnode;
static void
-init_val()
+init_val(void)
{
curval = 0;
next_vnode = vnode_base;
/* Because we really don't have an IR, this stuff is a little messy. */
static int
-F(code, v0, v1)
- int code;
- int v0, v1;
+F(int code, int v0, int v1)
{
u_int hash;
int val;
}
static inline void
-vstore(s, valp, newval, alter)
- struct stmt *s;
- int *valp;
- int newval;
- int alter;
+vstore(struct stmt *s, int *valp, int newval, int alter)
{
if (alter && *valp == newval)
s->code = NOP;
*valp = newval;
}
+/*
+ * Do constant-folding on binary operators.
+ * (Unary operators are handled elsewhere.)
+ */
static void
-fold_op(s, v0, v1)
- struct stmt *s;
- int v0, v1;
+fold_op(struct stmt *s, int v0, int v1)
{
bpf_u_int32 a, b;
a /= b;
break;
+ case BPF_MOD:
+ if (b == 0)
+ bpf_error("modulus by zero");
+ a %= b;
+ break;
+
case BPF_AND:
a &= b;
break;
a |= b;
break;
+ case BPF_XOR:
+ a ^= b;
+ break;
+
case BPF_LSH:
a <<= b;
break;
a >>= b;
break;
- case BPF_NEG:
- a = -a;
- break;
-
default:
abort();
}
}
static inline struct slist *
-this_op(s)
- struct slist *s;
+this_op(struct slist *s)
{
while (s != 0 && s->s.code == NOP)
s = s->next;
}
static void
-opt_not(b)
- struct block *b;
+opt_not(struct block *b)
{
struct block *tmp = JT(b);
}
static void
-opt_peep(b)
- struct block *b;
+opt_peep(struct block *b)
{
struct slist *s;
struct slist *next, *last;
* evaluation and code transformations weren't folded together.
*/
static void
-opt_stmt(s, val, alter)
- struct stmt *s;
- int val[];
- int alter;
+opt_stmt(struct stmt *s, int val[], int alter)
{
int op;
int v;
case BPF_ALU|BPF_SUB|BPF_K:
case BPF_ALU|BPF_MUL|BPF_K:
case BPF_ALU|BPF_DIV|BPF_K:
+ case BPF_ALU|BPF_MOD|BPF_K:
case BPF_ALU|BPF_AND|BPF_K:
case BPF_ALU|BPF_OR|BPF_K:
+ case BPF_ALU|BPF_XOR|BPF_K:
case BPF_ALU|BPF_LSH|BPF_K:
case BPF_ALU|BPF_RSH|BPF_K:
op = BPF_OP(s->code);
* fixup the generated math code */
if (op == BPF_ADD ||
op == BPF_LSH || op == BPF_RSH ||
- op == BPF_OR) {
+ op == BPF_OR || op == BPF_XOR) {
s->code = NOP;
break;
}
case BPF_ALU|BPF_SUB|BPF_X:
case BPF_ALU|BPF_MUL|BPF_X:
case BPF_ALU|BPF_DIV|BPF_X:
+ case BPF_ALU|BPF_MOD|BPF_X:
case BPF_ALU|BPF_AND|BPF_X:
case BPF_ALU|BPF_OR|BPF_X:
+ case BPF_ALU|BPF_XOR|BPF_X:
case BPF_ALU|BPF_LSH|BPF_X:
case BPF_ALU|BPF_RSH|BPF_X:
op = BPF_OP(s->code);
*/
if (alter && vmap[val[A_ATOM]].is_const
&& vmap[val[A_ATOM]].const_val == 0) {
- if (op == BPF_ADD || op == BPF_OR) {
+ if (op == BPF_ADD || op == BPF_OR || op == BPF_XOR) {
s->code = BPF_MISC|BPF_TXA;
vstore(s, &val[A_ATOM], val[X_ATOM], alter);
break;
}
- else if (op == BPF_MUL || op == BPF_DIV ||
+ else if (op == BPF_MUL || op == BPF_DIV || op == BPF_MOD ||
op == BPF_AND || op == BPF_LSH || op == BPF_RSH) {
s->code = BPF_LD|BPF_IMM;
s->k = 0;
}
static void
-deadstmt(s, last)
- register struct stmt *s;
- register struct stmt *last[];
+deadstmt(register struct stmt *s, register struct stmt *last[])
{
register int atom;
}
static void
-opt_deadstores(b)
- register struct block *b;
+opt_deadstores(register struct block *b)
{
register struct slist *s;
register int atom;
}
static void
-opt_blk(b, do_stmts)
- struct block *b;
- int do_stmts;
+opt_blk(struct block *b, int do_stmts)
{
struct slist *s;
struct edge *p;
* from 'b'.
*/
static int
-use_conflict(b, succ)
- struct block *b, *succ;
+use_conflict(struct block *b, struct block *succ)
{
int atom;
atomset use = succ->out_use;
}
static struct block *
-fold_edge(child, ep)
- struct block *child;
- struct edge *ep;
+fold_edge(struct block *child, struct edge *ep)
{
int sense;
int aval0, aval1, oval0, oval1;
}
static void
-opt_j(ep)
- struct edge *ep;
+opt_j(struct edge *ep)
{
register int i, k;
register struct block *target;
static void
-or_pullup(b)
- struct block *b;
+or_pullup(struct block *b)
{
int val, at_top;
struct block *pull;
}
static void
-and_pullup(b)
- struct block *b;
+and_pullup(struct block *b)
{
int val, at_top;
struct block *pull;
}
static void
-opt_blks(root, do_stmts)
- struct block *root;
- int do_stmts;
+opt_blks(struct block *root, int do_stmts)
{
int i, maxlevel;
struct block *p;
}
static inline void
-link_inedge(parent, child)
- struct edge *parent;
- struct block *child;
+link_inedge(struct edge *parent, struct block *child)
{
parent->next = child->in_edges;
child->in_edges = parent;
}
static void
-find_inedges(root)
- struct block *root;
+find_inedges(struct block *root)
{
int i;
struct block *b;
}
static void
-opt_root(b)
- struct block **b;
+opt_root(struct block **b)
{
struct slist *tmp, *s;
}
static void
-opt_loop(root, do_stmts)
- struct block *root;
- int do_stmts;
+opt_loop(struct block *root, int do_stmts)
{
#ifdef BDEBUG
* Optimize the filter code in its dag representation.
*/
void
-bpf_optimize(rootp)
- struct block **rootp;
+bpf_optimize(struct block **rootp)
{
struct block *root;
}
static void
-make_marks(p)
- struct block *p;
+make_marks(struct block *p)
{
if (!isMarked(p)) {
Mark(p);
* only for nodes that are alive.
*/
static void
-mark_code(p)
- struct block *p;
+mark_code(struct block *p)
{
cur_mark += 1;
make_marks(p);
* the accumulator.
*/
static int
-eq_slist(x, y)
- struct slist *x, *y;
+eq_slist(struct slist *x, struct slist *y)
{
while (1) {
while (x && x->s.code == NOP)
}
static inline int
-eq_blk(b0, b1)
- struct block *b0, *b1;
+eq_blk(struct block *b0, struct block *b1)
{
if (b0->s.code == b1->s.code &&
b0->s.k == b1->s.k &&
}
static void
-intern_blocks(root)
- struct block *root;
+intern_blocks(struct block *root)
{
struct block *p;
int i, j;
}
static void
-opt_cleanup()
+opt_cleanup(void)
{
free((void *)vnode_base);
free((void *)vmap);
/*
* Return the number of stmts in 's'.
*/
-static int
-slength(s)
- struct slist *s;
+static u_int
+slength(struct slist *s)
{
- int n = 0;
+ u_int n = 0;
for (; s; s = s->next)
if (s->s.code != NOP)
* All nodes should be initially unmarked.
*/
static int
-count_blocks(p)
- struct block *p;
+count_blocks(struct block *p)
{
if (p == 0 || isMarked(p))
return 0;
* the basic blocks, and entering them into the 'blocks' array.`
*/
static void
-number_blks_r(p)
- struct block *p;
+number_blks_r(struct block *p)
{
int n;
*
* an extra long jump if the false branch requires it (p->longjf).
*/
-static int
-count_stmts(p)
- struct block *p;
+static u_int
+count_stmts(struct block *p)
{
- int n;
+ u_int n;
if (p == 0 || isMarked(p))
return 0;
* from the total number of blocks and/or statements.
*/
static void
-opt_init(root)
- struct block *root;
+opt_init(struct block *root)
{
bpf_u_int32 *p;
int i, n, max_stmts;
* properly.
*/
static int
-convert_code_r(p)
- struct block *p;
+convert_code_r(struct block *p)
{
struct bpf_insn *dst;
struct slist *src;
* done with the filter program. See the pcap man page.
*/
struct bpf_insn *
-icode_to_fcode(root, lenp)
- struct block *root;
- int *lenp;
+icode_to_fcode(struct block *root, u_int *lenp)
{
- int n;
+ u_int n;
struct bpf_insn *fp;
/*
#ifdef BDEBUG
static void
-opt_dump(root)
- struct block *root;
+opt_dump(struct block *root)
{
struct bpf_program f;
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