VMOVQ X20, -15(R11)(CX*1) // 62c1fd087ea40bf1ffffff or 62c1fd08d6a40bf1ffffff
	VMOVQ X20, (SP)(AX*2)     // 62e1fd087e2444 or 62e1fd08d62444
	// VMOVHPD: overlapping VEX and EVEX variants.
	VMOVHPD (AX), X5, X5             // c5d11628 or c4e1d11628 or 62f1d5281628 or 62f1d5481628
	VMOVHPD 7(DX), X5, X5            // c5d1166a07 or 62f1d52816aa07000000 or 62f1d54816aa07000000

	VPGATHERDQ (BP)(X15*2), K1, Y15 // ERROR "index and destination registers should be distinct"
	VPGATHERDQ (BP)(Y20*2), K1, Z20 // ERROR "index and destination registers should be distinct"
	// Instructions without EVEX variant can't use High-16 registers.
	VADDSUBPD X20, X1, X2           // ERROR "invalid instruction"
	VADDSUBPS X0, X20, X2           // ERROR "invalid instruction"
	// Use of K0 for write mask (Yknot0).