On Mon, Feb 07, 2011, Roman Divacky wrote: > should clang follow the same and default to -fno-math-errno > on FreeBSD? > > I guess so but I want to be sure, thank you!
Yes. All the flag does, at least in gcc, is inform the compiler that we don't have an old System V-style math library that sets errno instead of using floating point exception flags. The flag affects the way gcc handles built-in math functions. For instance, with -fno-math-errno, gcc is able to inline sqrt(x) into a single instruction. Without the flag, however, gcc wrongly assumes that sqrt(3) might set errno, so it generates extra code to check the sign of x and call the math library if x is negative. _______________________________________________ freebsd-toolchain@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-toolchain To unsubscribe, send any mail to "freebsd-toolchain-unsubscr...@freebsd.org"
