ref: db710d46c1f43cf7e23ea8ed278454b772a2cea3
dir: /maxstack.inc/
static uint32_t compute_maxstack(uint8_t *code, size_t len)
{
uint8_t *ip = code+4, *end = code+len;
uint8_t op;
uint32_t i, n, sp = 0, maxsp = 0;
while (1) {
if ((int32_t)sp > (int32_t)maxsp) maxsp = sp;
if (ip >= end) break;
op = *ip++;
switch (op) {
case OP_ARGC:
n = *ip++;
USED(n);
break;
case OP_VARGC:
n = *ip++;
sp += (n+2);
break;
case OP_LARGC:
SWAP_INT32(ip);
n = GET_INT32(ip); ip+=4;
USED(n);
break;
case OP_LVARGC:
SWAP_INT32(ip);
n = GET_INT32(ip); ip+=4;
sp += (n+2);
break;
case OP_OPTARGS:
SWAP_INT32(ip);
i = GET_INT32(ip); ip+=4;
SWAP_INT32(ip);
n = abs(GET_INT32(ip)); ip+=4;
sp += (n-i);
break;
case OP_KEYARGS:
SWAP_INT32(ip);
i = GET_INT32(ip); ip+=4;
SWAP_INT32(ip);
n = GET_INT32(ip); ip+=4;
USED(n);
SWAP_INT32(ip);
n = abs(GET_INT32(ip)); ip+=4;
sp += (n-i);
break;
case OP_BRBOUND:
SWAP_INT32(ip);
ip+=4;
sp++;
break;
case OP_TCALL: case OP_CALL:
n = *ip++; // nargs
sp -= n;
break;
case OP_TCALLL: case OP_CALLL:
SWAP_INT32(ip);
n = GET_INT32(ip); ip+=4;
sp -= n;
break;
case OP_JMP:
SWAP_INT16(ip);
ip += 2; break;
case OP_JMPL:
SWAP_INT32(ip);
ip += 4; break;
case OP_BRF: case OP_BRT:
SWAP_INT16(ip);
ip+=2;
sp--;
break;
case OP_BRFL: case OP_BRTL:
SWAP_INT32(ip);
ip += 4;
sp--;
break;
case OP_BRNE:
SWAP_INT16(ip);
ip += 2;
sp -= 2;
break;
case OP_BRNEL:
SWAP_INT32(ip);
ip += 4;
sp -= 2;
break;
case OP_BRNN: case OP_BRN:
SWAP_INT16(ip);
ip += 2;
sp--;
break;
case OP_BRNNL: case OP_BRNL:
SWAP_INT32(ip);
ip += 4;
sp--;
break;
case OP_RET: sp--; break;
case OP_CONS: case OP_SETCAR: case OP_SETCDR: case OP_POP:
case OP_EQ: case OP_EQV: case OP_EQUAL: case OP_ADD2: case OP_SUB2:
case OP_IDIV: case OP_NUMEQ: case OP_LT: case OP_COMPARE:
case OP_AREF: case OP_TRYCATCH:
sp--;
break;
case OP_PAIRP: case OP_ATOMP: case OP_NOT: case OP_NULLP:
case OP_BOOLEANP: case OP_SYMBOLP: case OP_NUMBERP: case OP_FIXNUMP:
case OP_BOUNDP: case OP_BUILTINP: case OP_FUNCTIONP: case OP_VECTORP:
case OP_NOP: case OP_CAR: case OP_CDR: case OP_NEG: case OP_CLOSURE:
break;
case OP_TAPPLY: case OP_APPLY:
n = *ip++;
sp -= (n-1);
break;
case OP_LIST: case OP_ADD: case OP_SUB: case OP_MUL: case OP_DIV:
case OP_VECTOR:
n = *ip++;
sp -= (n-1);
break;
case OP_ASET:
sp -= 2;
break;
case OP_FOR:
if (sp+2 > maxsp) maxsp = sp+2;
sp -=2;
break;
case OP_LOADT: case OP_LOADF: case OP_LOADNIL: case OP_LOAD0:
case OP_LOAD1: case OP_LOADA0: case OP_LOADA1: case OP_LOADC00:
case OP_LOADC01: case OP_DUP:
sp++;
break;
case OP_LOADI8: case OP_LOADV: case OP_LOADG: case OP_LOADA:
ip++;
sp++;
break;
case OP_LOADVL: case OP_LOADGL: case OP_LOADAL:
SWAP_INT32(ip);
ip+=4;
sp++;
break;
case OP_SETG: case OP_SETA:
ip++;
break;
case OP_SETGL: case OP_SETAL:
SWAP_INT32(ip);
ip+=4;
break;
case OP_LOADC: ip+=2; sp++; break;
case OP_SETC:
ip+=2;
break;
case OP_LOADCL:
SWAP_INT32(ip);
ip+=4;
SWAP_INT32(ip);
ip+=4;
sp++; break;
case OP_SETCL:
SWAP_INT32(ip);
ip+=4;
SWAP_INT32(ip);
ip+=4;
break;
}
}
return maxsp+5;
}