From: Guy Harris <guy@alum.mit.edu>
Date: Mon, 18 Sep 2017 00:45:27 +0000 (-0700)
Subject: Merge pull request #613 from mkubecek/mk/master/opt-unknown
X-Git-Tag: libpcap-1.9-bp~675
X-Git-Url: https://git.tcpdump.org/libpcap/commitdiff_plain/d7bdf180b158a11d116bb8a77674200e72baff44?ds=inline;hp=-c

Merge pull request #613 from mkubecek/mk/master/opt-unknown

optimizer: replacing unknown value with unknown value is not a no-op
---

d7bdf180b158a11d116bb8a77674200e72baff44
diff --combined optimize.c
index 53e98133,8544f3e1..0bf52cdd
--- a/optimize.c
+++ b/optimize.c
@@@ -115,7 -115,7 +115,7 @@@ struct vmapinfo 
  	bpf_int32 const_val;
  };
  
 -struct _opt_state {
 +typedef struct {
  	/*
  	 * A flag to indicate that further optimization is needed.
  	 * Iterative passes are continued until a given pass yields no
@@@ -198,7 -198,7 +198,7 @@@
  	struct vmapinfo *vmap;
  	struct valnode *vnode_base;
  	struct valnode *next_vnode;
 -};
 +} opt_state_t;
  
  typedef struct {
  	/*
@@@ -578,7 -578,7 +578,7 @@@ F(opt_state_t *opt_state, int code, in
  static inline void
  vstore(struct stmt *s, int *valp, int newval, int alter)
  {
- 	if (alter && *valp == newval)
+ 	if (alter && newval != 0 && *valp == newval)
  		s->code = NOP;
  	else
  		*valp = newval;
@@@ -2334,8 -2334,10 +2334,8 @@@ dot_dump(compiler_state_t *cstate, stru
  	f.bf_insns = icode_to_fcode(cstate, ic, ic->root, &f.bf_len);
  
  	fprintf(out, "digraph BPF {\n");
 -	ic->cur_mark = 0;
  	unMarkAll(ic);
  	dot_dump_node(ic, ic->root, &f, out);
 -	ic->cur_mark = 0;
  	unMarkAll(ic);
  	dot_dump_edge(ic, ic->root, out);
  	fprintf(out, "}\n");