search for: fr64regclass

...it have anything that was innovative for the time of release, etc. Second question: I am trying to implement swaps of floating point registers, but I do not know how to do it. I am basically trying something like: // r1 and r2 are unsigned of either class X86::FR32RegClass // or X86::FR64RegClass unsigned Opc = X86::FXCH; BuildMI(mbb, mi, Opc, 1).addReg(r1); BuildMI(mbb, mi, Opc, 1).addReg(r2); BuildMI(mbb, mi, Opc, 1).addReg(r1); This produces code like: "fxch %xmm0", that gcc does not compile. Could some generous soul shed some light on my misery? best, F...