By Dan Weil Chip stocks have 23% free-cash-flow margins, making them more than twice as profitable as S&P; 500 stocks, Bank of America analysts say. It’s been a rough 2022 for semiconductor stocks amid fears of a sharp economic slowdown that would depress chip demand. The PHLX Semiconductor Sector index has dropped 22% year to date. But Bank of America analysts see some reasons for optimism. “Macro factors can enhance stock volatility,” they said in a commentary. But “the recent 36% peak-to-trough [price-to-earnings-multiple] contraction in the semiconductor index (versus a 27% downturn histor…