// It saves all GP registers if necessary,
		// but clobbers R30 (LR) because it's a call.
		// R16 and R17 may be clobbered by linker trampoline.
		// Returns a pointer to a write barrier buffer in R25.
		{name: "LoweredWB", argLength: 1, reg: regInfo{clobbers: (callerSave &^ gpg) | buildReg("R16 R17 R30"), outputs: []regMask{buildReg("R25")}}, clobberFlags: true, aux: "Int64"},