Hi! Am 09.12.2013 23:13, schrieb Raoux, Thomas F: > Is it safe to transform “%add = fadd fast float undef, 2.000000e+00” to > “undef”? http://llvm.org/docs/LangRef.html#fastmath "fast" implies "nnan" which means the result is undefined if any argument is NaN. Since undef could be NaN, I guess the transformation is safe. Regards, Tobias