search for: llvm_should_pass_aggregate_as_fca

Hi, guys, If there is a struct {i8, i8, i32}, and there are several parameter GPRs(32bits), say, r0, r1~r5, I can make this struct to be passed in r0, r1 because LLVM_SHOULD_PASS_AGGREGATE_IN_INTEGER_REGS is true in DefaultABI, neither it passed by value, nor it passed as FCA. But if the first parameter register r0 is occupied by other argument, in DefaultABI, that struct passed as a i64, and