------- Comment #3 from ghazi at gcc dot gnu dot org 2009-08-12 22:28 ------- (In reply to comment #2)
Joseph - Thanks for your reply and testvalues. > There are also cases for exact rounding where you'd expect MPC to produce > the right results but would *not* expect operations executed at runtime to > produce exactly those results. For example, (1.0 + DBL_EPSILON + 1.0i) * > (1.0 - DBL_EPSILON + 1.0i), which would only work at runtime if the code > happens to use exactly the right fused multiply-add operation. What is the "right result" for this case? GCC with MPC produces: -4.93038065763132378382330353301741393545754021943139377981e-32 + 2.0i) Unpatched GCC as well as the runtime on my x86_64 box says: 0.0 + 2.0i So the runtime here is not using the fused instruction? Is the MPC value correct? Thanks. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30789