> Can you add testcases? Also the current restriction is because > the variants you add are not always correct and I don't see any > checks that the intermediate type doesn't lose significant bits?
The testcases I wanted to add with a follow-up RISC-V patch but I can also try an aarch64 one. So for my understanding, please correct, we have: promoting int -> float, should always be safe. We currently vectorize this with WIDEN and NONE. demoting float -> int, this is safe as long as the float value can be represented in the int type, otherwise we must trap. We currently vectorize this on x86 using NARROW (regardless of -ftrapping-math) and using NONE only with -fno-trapping-math. demoting int -> float, this is safe as long as the intermediate types can hold the initial value? How is this different to demoting e.g. int64_t -> int8_t? We currently do not vectorize this with either NARROW or NONE. LLVM vectorizes but only with their default(?) -fno-trapping-math. Yet I don't see how we could trap here? promoting float -> int, this is safe as long as the float value can be represented (as above)? We currently vectorize this (regardless of -ftrapping-math) with WIDEN but not NONE. So apart from unifying the -ftrapping-math behavior I think only the third variant is somewhat critical? Regards Robin
