Use `JMPLINK_START` instead of zero for a link start marker.
MODIFY
mrbgems/mruby-compiler/core/codegen.c
mrbgems/mruby-compiler/core/codegen.c
@@ -368,17 +368,25 @@ no_peephole(codegen_scope *s)
return no_optimize(s) || s->lastlabel == s->pc || s->pc == 0 || s->pc == s->lastpc;
}
+#define JMPLINK_START UINT32_MAX
+
static void
gen_jmpdst(codegen_scope *s, uint32_t pc)
{
+
+ if (pc == JMPLINK_START) {
+ gen_S(s, 0);
+ }
+ else {
uint32_t pos2 = s->pc+2;
int32_t off = pc - pos2;
if (off > INT16_MAX || INT16_MIN > off) {
- codegen_error(s, "too big jmp offset");
+ codegen_error(s, "too big jump offset");
}
gen_S(s, (uint16_t)off);
}
+}
static uint32_t
genjmp(codegen_scope *s, mrb_code i, uint32_t pc)
@@ -392,17 +400,7 @@ genjmp(codegen_scope *s, mrb_code i, uint32_t pc)
return pos;
}
-static uint32_t
-genjmp_0(codegen_scope *s, mrb_code i)
-{
- uint32_t pos;
-
- s->lastpc = s->pc;
- gen_B(s, i);
- pos = s->pc;
- gen_S(s, (uint16_t)0);
- return pos;
-}
+#define genjmp_0(s,i) genjmp(s,i,JMPLINK_START)
static uint32_t
genjmp2(codegen_scope *s, mrb_code i, uint16_t a, uint32_t pc, int val)
@@ -432,33 +430,7 @@ genjmp2(codegen_scope *s, mrb_code i, uint16_t a, uint32_t pc, int val)
return pos;
}
-static uint32_t
-genjmp2_0(codegen_scope *s, mrb_code i, uint16_t a, int val)
-{
- uint32_t pos;
-
- if (!no_peephole(s) && !val) {
- struct mrb_insn_data data = mrb_last_insn(s);
-
- if (data.insn == OP_MOVE && data.a == a) {
- s->pc = s->lastpc;
- a = data.b;
- }
- }
-
- s->lastpc = s->pc;
- if (a > 0xff) {
- codegen_error(s, "too big operand");
- pos = 0;
- }
- else {
- gen_B(s, i);
- gen_B(s, (uint8_t)a);
- pos = s->pc;
- gen_S(s, (uint16_t)0);
- }
- return pos;
-}
+#define genjmp2_0(s,i,a,val) genjmp2(s,i,a,JMPLINK_START,val)
static void
gen_move(codegen_scope *s, uint16_t dst, uint16_t src, int nopeep)
@@ -561,10 +533,13 @@ gen_addsub(codegen_scope *s, uint8_t op, uint16_t dst)
static uint32_t
dispatch(codegen_scope *s, uint32_t pos0)
{
- int32_t pos1 = pos0 + 2;
+ int32_t pos1;
int32_t offset;
int16_t newpos;
+ if (pos0 == JMPLINK_START) return 0;
+
+ pos1 = pos0 + 2;
offset = s->pc - pos1;
if (offset > INT16_MAX) {
codegen_error(s, "too big jmp offset");
@@ -579,7 +554,7 @@ dispatch(codegen_scope *s, uint32_t pos0)
static void
dispatch_linked(codegen_scope *s, uint32_t pos)
{
- if (pos==0) return;
+ if (pos==JMPLINK_START) return;
for (;;) {
pos = dispatch(s, pos);
if (pos==0) break;
@@ -1550,8 +1525,8 @@ codegen(codegen_scope *s, node *tree, int val)
noexc = genjmp_0(s, OP_JMP);
catch_handler_set(s, catch_entry, MRB_CATCH_RESCUE, begin, end, s->pc);
tree = tree->cdr;
- exend = 0;
- pos1 = 0;
+ exend = JMPLINK_START;
+ pos1 = JMPLINK_START;
if (tree->car) {
node *n2 = tree->car;
int exc = cursp();
@@ -1562,8 +1537,8 @@ codegen(codegen_scope *s, node *tree, int val)
node *n3 = n2->car;
node *n4 = n3->car;
- if (pos1) dispatch(s, pos1);
- pos2 = 0;
+ dispatch(s, pos1);
+ pos2 = JMPLINK_START;
do {
if (n4 && n4->car && nint(n4->car->car) == NODE_SPLAT) {
codegen(s, n4->car, VAL);
@@ -1605,7 +1580,7 @@ codegen(codegen_scope *s, node *tree, int val)
n2 = n2->cdr;
push();
}
- if (pos1) {
+ if (pos1 != JMPLINK_START) {
dispatch(s, pos1);
genop_1(s, OP_RAISEIF, exc);
}
@@ -1812,7 +1787,7 @@ codegen(codegen_scope *s, node *tree, int val)
uint32_t pos1, pos2, pos3, tmp;
node *n;
- pos3 = 0;
+ pos3 = JMPLINK_START;
if (tree->car) {
head = cursp();
codegen(s, tree->car, VAL);
@@ -1820,7 +1795,7 @@ codegen(codegen_scope *s, node *tree, int val)
tree = tree->cdr;
while (tree) {
n = tree->car->car;
- pos1 = pos2 = 0;
+ pos1 = pos2 = JMPLINK_START;
while (n) {
codegen(s, n->car, VAL);
if (head) {
@@ -1848,13 +1823,13 @@ codegen(codegen_scope *s, node *tree, int val)
if (val) pop();
tmp = genjmp(s, OP_JMP, pos3);
pos3 = tmp;
- if (pos1) dispatch(s, pos1);
+ dispatch(s, pos1);
tree = tree->cdr;
}
if (val) {
uint32_t pos = cursp();
genop_1(s, OP_LOADNIL, cursp());
- if (pos3) dispatch_linked(s, pos3);
+ if (pos3 != JMPLINK_START) dispatch_linked(s, pos3);
if (head) pop();
if (cursp() != pos) {
gen_move(s, cursp(), pos, 0);
@@ -1862,7 +1837,7 @@ codegen(codegen_scope *s, node *tree, int val)
push();
}
else {
- if (pos3) {
+ if (pos3 != JMPLINK_START) {
dispatch_linked(s, pos3);
}
if (head) {
@@ -3183,7 +3158,7 @@ loop_push(codegen_scope *s, enum looptype t)
struct loopinfo *p = (struct loopinfo *)codegen_palloc(s, sizeof(struct loopinfo));
p->type = t;
- p->pc0 = p->pc1 = p->pc2 = p->pc3 = 0;
+ p->pc0 = p->pc1 = p->pc2 = p->pc3 = JMPLINK_START;
p->prev = s->loop;
p->acc = cursp();
s->loop = p;

Use `JMPLINK_START` instead of zero for a link start marker.