int instrFpToArDelta(const Func* func, PC opcode) {
// This function should only be called for instructions that read the current
// FPI
assertx(instrReadsCurrentFpi(peek_op(opcode)));
auto const fpi = func->findFPI(func->unit()->offsetOf(opcode));
assertx(fpi != nullptr);
return fpi->m_fpOff;
}
int instrSpToArDelta(const Op* opcode) {
// This function should only be called for instructions that read
// the current FPI
assert(instrReadsCurrentFpi(*opcode));
// The delta from sp to ar is equal to the number of values on the stack
// that will be consumed by this instruction (numPops) plus the number of
// parameters pushed onto the stack so far that are not being consumed by
// this instruction (numExtra). For the FPass* instructions, numExtra will
// be equal to the first immediate argument (param id). For the FCall
// instructions, numExtra will be 0 because all of the parameters on the
// stack are already accounted for by numPops.
int numPops = instrNumPops(opcode);
int numExtra = isFCallStar(*opcode) ? 0 : getImm(opcode, 0).u_IVA;
return numPops + numExtra;
}