is there a compiler flag for opening/closing flush-to-zero mode in c++ armv8?

Question

my compiler is clang, I don't know how to open flush-to-zero mode in armv8, could anyone tell me? I find some flag like this-fdenormal-fp-math=[values],but it doesn't work.

Answer 1

It depends on the clang version, for example, I had clang 3.8 and got the following error clang: error: unknown argument: '-fdenormal-fp-math=preserve-sign', but then installed clang 5.0 and it works just fine.

clang++-5.0 hello.cpp -fdenormal-fp-math=preserve-sign

Values are:

• ieee
• preserve-sign
• and positive-zero

Hope it helps.