"Clem Taylor" <clem.taylor@xxxxxxxxx> writes: > I'm working on taking PowerPC VMX code that uses altivec intrinsics > and rescheduling it with inline assembly. gcc is making some fairly > bad scheduling choices in with the code, resulting in code that is > running 4x slower then I was hoping for. I have a simplified version > working, but with the real version gcc is failing with: "error: more > than 30 operands in 'asm'". The code is using 28 vector registers and > 6 serial registers. > > The code is a mixture of setup code in C and only the inner loop is in > assembly, so it wouldn't be convenient to write this directly in > assembly. Also, because the code is highly pipelined (to overcome the > latency of the VMX floating point unit) it is a mess to split this up > into multiple asm() statements. Beyond recompiling gcc with a larger > operand count, is there a workaround for this problem? Use fewer operands? Otherwise, no. It's a hard limit in gcc. Since you mention the number of registers you are using, note that that only matters if they are inputs or outputs. If you need a temporary register, just pick one, and add it the clobber list. But if you really have that many inputs and outputs, then you are stuck. Ian
