On 8/23/07, Neil Mitchell
It's not even referentially transparent in all cases. a == b may fail while the double's are in the high precision registers, and then succeed later on in the program once they are truncated. I think you have to specify -fexcess-precision with GHC to get this behaviour.
Also, if you tell GCC to use SSE (there are a number of flags, like -march and -msse, -msse2 etc which can do this). It can stop using the 80-bit x87 registers for floating point and switch to 64-bit SSE registers. Then you *don't* get this affect, but I'm not sure you can be sure that you don't ever get it. Floating point numbers make me sad :( AGL -- Adam Langley agl@imperialviolet.org http://www.imperialviolet.org 650-283-9641