{name: "LoweredGetCallerSP", argLength: 1, reg: gp01, rematerializeable: true},                                     // returns the SP of the caller of the current function. arg0=mem.
		{name: "LoweredNilCheck", argLength: 2, reg: regInfo{inputs: []regMask{gp}}, nilCheck: true, faultOnNilArg0: true}, // panic if arg0 is nil. arg1=mem

// Miscellaneous
(Convert ...) => (LoweredConvert ...)
(IsNonNil p) => (I64Eqz (I64Eqz p))
(IsInBounds ...) => (I64LtU ...)
(IsSliceInBounds ...) => (I64LeU ...)
(NilCheck ...) => (LoweredNilCheck ...)
(GetClosurePtr ...) => (LoweredGetClosurePtr ...)
(GetCallerPC ...) => (LoweredGetCallerPC ...)
(GetCallerSP ...) => (LoweredGetCallerSP ...)
(Addr {sym} base) => (LoweredAddr {sym} [0] base)

				inputs:   []regMask{buildReg("R2"), buildReg("R1"), gp},
				clobbers: buildReg("R1 R2"),
			},
			faultOnNilArg0: true,
			faultOnNilArg1: true,
		},

		// pseudo-ops
		{name: "LoweredNilCheck", argLength: 2, reg: regInfo{inputs: []regMask{gpg}}, nilCheck: true, faultOnNilArg0: true}, // panic if arg0 is nil.  arg1=mem.

		{name: "FPFlagTrue", argLength: 1, reg: readflags},  // bool, true if FP flag is true

		{name: "LoweredAtomicCas64", argLength: 4, reg: gpcas, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true},

		// pseudo-ops
		{name: "LoweredNilCheck", argLength: 2, reg: regInfo{inputs: []regMask{gpg}}, nilCheck: true, faultOnNilArg0: true}, // panic if arg0 is nil.  arg1=mem.

		{name: "FPFlagTrue", argLength: 1, reg: readflags},  // bool, true if FP flag is true

		{name: "LoweredAtomicCas64", argLength: 4, reg: gpcas, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true},

		// pseudo-ops
		{name: "LoweredNilCheck", argLength: 2, reg: regInfo{inputs: []regMask{gpg}}, nilCheck: true, faultOnNilArg0: true}, // panic if arg0 is nil.  arg1=mem.

		{name: "FPFlagTrue", argLength: 1, reg: readflags},  // bool, true if FP flag is true

		{name: "LoweredAtomicOr32", argLength: 3, reg: gpatomic, asm: "AMOORW", faultOnNilArg0: true, hasSideEffects: true},

		// Lowering pass-throughs
		{name: "LoweredNilCheck", argLength: 2, faultOnNilArg0: true, nilCheck: true, reg: regInfo{inputs: []regMask{gpspMask}}}, // arg0=ptr,arg1=mem, returns void.  Faults if ptr is nil.

		// pseudo-ops
		{name: "LoweredNilCheck", argLength: 2, reg: regInfo{inputs: []regMask{gpg}}, nilCheck: true, faultOnNilArg0: true}, // panic if arg0 is nil.  arg1=mem.

(AtomicCompareAndSwap32 ptr old new mem) => (LoweredAtomicCas32 ptr (SignExt32to64 old) new mem)
(AtomicCompareAndSwap64 ...) => (LoweredAtomicCas64 ...)

// checks
(NilCheck ...) => (LoweredNilCheck ...)
(IsNonNil ptr) => (SGTU ptr (MOVVconst [0]))
(IsInBounds idx len) => (SGTU len idx)
(IsSliceInBounds idx len) => (XOR (MOVVconst [1]) (SGTU idx len))

// pseudo-ops

		mem)

// Checks
(IsNonNil ...) => (SNEZ ...)
(IsInBounds ...) => (Less64U ...)
(IsSliceInBounds ...) => (Leq64U ...)

// Trivial lowering
(NilCheck ...) => (LoweredNilCheck ...)
(GetClosurePtr ...) => (LoweredGetClosurePtr ...)
(GetCallerSP ...) => (LoweredGetCallerSP ...)
(GetCallerPC ...) => (LoweredGetCallerPC ...)

// Write barrier.
(WB ...) => (LoweredWB ...)

				(ANDconst <typ.UInt32> [3]
					(XORconst <typ.UInt32> [3] ptr)))))) mem)

(AtomicAnd32 ...) => (LoweredAtomicAnd ...)
(AtomicOr32  ...) => (LoweredAtomicOr  ...)


// checks
(NilCheck ...) => (LoweredNilCheck ...)
(IsNonNil ptr) => (SGTU ptr (MOVWconst [0]))
(IsInBounds idx len) => (SGTU len idx)
(IsSliceInBounds idx len) => (XORconst [1] (SGTU idx len))

// pseudo-ops