BCL $20,CR0LT,$1,LR             // 4e800821
	BCL $20,CR0LT,$0,LR             // 4e800021
	BCL $20,CR0LT,LR                // 4e800021
	BCL $20,CR0GT,LR                // 4e810021
	BCL 20,CR0LT,LR                 // BCL $20,CR0LT,LR // 4e800021
	BCL 20,undefined_symbol,LR      // BCL $20,CR0LT,LR // 4e800021
	BCL 20,undefined_symbol+1,LR    // BCL $20,CR0GT,LR // 4e810021

	OP_MFLR_R0       = OP_MFLR | 0<<21            // mflr r0
	OP_MTLR_R0       = OP_MTLR | 0<<21            // mtlr r0

	// This is a special, preferred form of bcl to obtain the next
	// instruction address (NIA, aka PC+4) in LR.
	OP_BCL_NIA = OP_BCL | 20<<21 | 31<<16 | 1<<2 // bcl 20,31,$+4

	// Masks to match opcodes
	MASK_PLD_PFX  = 0xfff70000
	MASK_PLD_SFX  = 0xfc1f0000 // Also checks RA = 0 if check value is OP_PLD_SFX.