search for: vmovqq

...g in the register allocator. After splitting an interval the register class can be recomputed. Without the copy constraints a larger register class may be valid, and spilling might be avoided. Ok. > > 5. copyRegToReg() can insert multiple instructions, avoiding fun pseudo-instructions like VMOVQQ and VMOVQQQQ. The reason for VMOVQQ etc. is actually to keep scavenger happy by pretending the whole QQ register is updated / referenced. With sub-register indices on the operands, it's possible for current copyRegToReg to expand to multiple instructions. But then the scavenger can't deter...

...nterval splitting in the register allocator. After splitting an interval the register class can be recomputed. Without the copy constraints a larger register class may be valid, and spilling might be avoided. 5. copyRegToReg() can insert multiple instructions, avoiding fun pseudo-instructions like VMOVQQ and VMOVQQQQ. Why Not? 1. copyRegToReg() won't be able to use register classes to pick a copy opcode. For instance, an XMM register will no longer be copied by MOVSS or MOVSD. Given just the physical register, MOVAPS will be used. Is that a problem? 2. What else?