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authornobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2015-11-14 06:26:15 (GMT)
committernobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2015-11-14 06:26:15 (GMT)
commit8aa3ac137350a70b65037bfdbe8f0f0564e0133e (patch)
treebf657dfc8096a331229c3deae3ed7979d72695d5 /compile.c
parentdb1387905a5186aff6c29c9304ed4fe3af551372 (diff)
compile.c: remove unused labels
* compile.c (iseq_label_data): manage reference count. * compile.c (iseq_peephole_optimize): remove unreferred labels which may disturb optimization. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52567 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'compile.c')
-rw-r--r--compile.c41
1 files changed, 36 insertions, 5 deletions
diff --git a/compile.c b/compile.c
index 9e17f9b..e75a702 100644
--- a/compile.c
+++ b/compile.c
@@ -48,6 +48,7 @@ typedef struct iseq_label_data {
int sc_state;
int set;
int sp;
+ int refcnt;
} LABEL;
typedef struct iseq_insn_data {
@@ -190,8 +191,10 @@ r_value(VALUE value)
ADD_ELEM((seq), (LINK_ELEMENT *) \
new_insn_body(iseq, (line), BIN(insn), 1, (VALUE)(op1)))
+#define LABEL_REF(label) ((label)->refcnt++)
+
/* add an instruction with label operand (alias of ADD_INSN1) */
-#define ADD_INSNL(seq, line, insn, label) ADD_INSN1(seq, line, insn, label)
+#define ADD_INSNL(seq, line, insn, label) (ADD_INSN1(seq, line, insn, label), LABEL_REF(label))
#define ADD_INSN2(seq, line, insn, op1, op2) \
ADD_ELEM((seq), (LINK_ELEMENT *) \
@@ -253,6 +256,9 @@ r_value(VALUE value)
VALUE _e = rb_ary_new3(5, (type), \
(VALUE)(ls) | 1, (VALUE)(le) | 1, \
(VALUE)(iseqv), (VALUE)(lc) | 1); \
+ if (ls) LABEL_REF(ls); \
+ if (le) LABEL_REF(le); \
+ if (lc) LABEL_REF(lc); \
rb_ary_push(iseq->compile_data->catch_table_ary, freeze_hide_obj(_e)); \
} while (0)
@@ -915,6 +921,7 @@ new_label_body(rb_iseq_t *iseq, long line)
labelobj->label_no = iseq->compile_data->label_no++;
labelobj->sc_state = 0;
labelobj->sp = -1;
+ labelobj->refcnt = 0;
return labelobj;
}
@@ -1873,6 +1880,26 @@ get_prev_insn(INSN *iobj)
return 0;
}
+static void
+unref_destination(INSN *iobj)
+{
+ LABEL *lobj = (LABEL *)OPERAND_AT(iobj, 0);
+ --lobj->refcnt;
+ if (!lobj->refcnt) REMOVE_ELEM(&lobj->link);
+}
+
+static void
+replace_destination(INSN *dobj, INSN *nobj)
+{
+ VALUE n = OPERAND_AT(nobj, 0);
+ LABEL *dl = (LABEL *)OPERAND_AT(dobj, 0);
+ LABEL *nl = (LABEL *)n;
+ --dl->refcnt;
+ ++nl->refcnt;
+ OPERAND_AT(dobj, 0) = n;
+ if (!dl->refcnt) REMOVE_ELEM(&dl->link);
+}
+
static int
iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcallopt)
{
@@ -1900,11 +1927,12 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal
* =>
* LABEL:
*/
+ unref_destination(iobj);
REMOVE_ELEM(&iobj->link);
}
else if (iobj != diobj && diobj->insn_id == BIN(jump)) {
if (OPERAND_AT(iobj, 0) != OPERAND_AT(diobj, 0)) {
- OPERAND_AT(iobj, 0) = OPERAND_AT(diobj, 0);
+ replace_destination(iobj, diobj);
goto again;
}
}
@@ -1925,6 +1953,7 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal
INSN *popiobj = new_insn_core(iseq, iobj->line_no,
BIN(pop), 0, 0);
/* replace */
+ unref_destination(iobj);
REPLACE_ELEM((LINK_ELEMENT *)iobj, (LINK_ELEMENT *)eiobj);
INSERT_ELEM_NEXT((LINK_ELEMENT *)eiobj, (LINK_ELEMENT *)popiobj);
iobj = popiobj;
@@ -1949,7 +1978,7 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal
if (niobj == (INSN *)get_destination_insn(piobj)) {
piobj->insn_id = (piobj->insn_id == BIN(branchif))
? BIN(branchunless) : BIN(branchif);
- OPERAND_AT(piobj, 0) = OPERAND_AT(iobj, 0);
+ replace_destination(piobj, iobj);
REMOVE_ELEM(&iobj->link);
}
}
@@ -1972,7 +2001,7 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal
for (;;) {
if (nobj->insn_id == BIN(jump)) {
- OPERAND_AT(iobj, 0) = OPERAND_AT(nobj, 0);
+ replace_destination(iobj, nobj);
}
else if (prev_dup && nobj->insn_id == BIN(dup) &&
!!(nobj = (INSN *)nobj->link.next) &&
@@ -1993,7 +2022,7 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal
* dup
* if L2
*/
- OPERAND_AT(iobj, 0) = OPERAND_AT(nobj, 0);
+ replace_destination(iobj, nobj);
}
else break;
nobj = (INSN *)get_destination_insn(nobj);
@@ -3595,6 +3624,7 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
ADD_INSN(ret, nd_line(tempnode), dup);
ADD_INSN2(ret, nd_line(tempnode), opt_case_dispatch, literals, elselabel);
+ LABEL_REF(elselabel);
}
ADD_SEQ(ret, cond_seq);
@@ -5948,6 +5978,7 @@ register_label(rb_iseq_t *iseq, struct st_table *labels_table, VALUE obj)
else {
label = (LABEL *)tmp;
}
+ LABEL_REF(label);
return label;
}