On Sat, Jun 18, 2005 at 12:54:40PM +0200, Mattias Karlsson wrote: > On Sat, 18 Jun 2005, Vincent Lefevre wrote: > > >On 2005-06-16 17:54:03 -0400, Robert Dewar wrote: > >>As you well know, not everyone agrees this is a bug, and this does > >>not have to do with performance. Saying over and over again that you > >>think it is a bug does not make it so. > > > >I haven't seen any correct argument why it could not be a bug. > >Saying that the x86 processor is buggy is just completely silly. > >Only some gcc developers think so. > > Don't know about you, but I consider any processor that is unable to store > a register to memory and then read back the same value to be buggy.
That would indeed be a funny kind of processor, but x86 can store its registers in memory exactly : simply store/reread them as long doubles. > Sure, you can change rounding precision but according to my 2003 version > of "IA-32 Intel(r) Architecture Software Developer's Manual - Volume > 1: Basic Architecture" > a) That takes at least 4 instructions. > b) Only affects some instructions, and then only the result. > c) Only affects the significand and not the exponent. > > Disclaimer: I haven't done any testing to verify that this is actually the > case since I have no access to x86 hardware. -- Sylvain
