Must I use -use_fast_math to generate ptx files?

Gaming and Visualization Technologies Visualization OptiX
1

What I’ve found is yes. But I want to try whether avoiding fast_math helps improve accuracy.

If I don’t use -use_fast_math while generating .ptx files, I’ll have runtime error:
OptiX Error: Invalid value (Details: Function “RTresult _rtProgramCreateFromPTXFile(RTcontext, const char*, const char*, RTprogram_api**)” caught exception: defs/uses not defined for PTX instruction (Try --use_fast_math): madc.hi, [1310866])
(sample2.cxx:219)

If I use -ftz -prec-div -prec-sqrt -fmad instead, I got the same error as using nothing.
Even if I use -ftz=true -prec-div=false -prec-sqrt=false -fmad=true to get the same effect as -use_fast_math, I got the same error.

Any ideas?
Thanks!

2

Is that with OptiX 3.6.3?
If not, please try again with that version because there have been fixes for the madc.hi case.

See OptiX 3.6.3 released - OptiX - NVIDIA Developer Forums
“Bug fix Double-precision cosine and other transcendentals now work properly, although ray tracing internals are still single-precision.”