xunxun <xunxun1982@xxxxxxxxx> writes: > And I think it's related with -funsafe-math-optimizations > > If I only use the option, gcc also don't generate the symbol > > The fastmath other option > > -fno-math-errno, -ffinite-math-only, -fno-rounding-math, > -fno-signaling-nans, and -fcx-limited-range > > don't have the effect. I presume you're compiling for i386 32-bit, which defaults to using the legacy 387 FP unit? If you switch to using SSE floating-point, e.g. using "-mfpmath=sse", it will still call the library functions even when using -ffast-math (because the SSE unit doesn't have special instructions like "fsin" or "f2xm1"). I think SSE FP is typically faster than the 387 for many CPUs anyway. [If you compile for the x86_64 arch, it will default to using SSE FP.] -miles -- Guilt, n. The condition of one who is known to have committed an indiscretion, as distinguished from the state of him who has covered his tracks.
