// Arithmetic constant ops

(ADD x (MOVDconst <t> [c])) && is32Bit(c) && !t.IsPtr() => (ADDconst [c] x)
(ADDconst [c] (ADDconst [d] x)) && is32Bit(c+d) => (ADDconst [c+d] x)
(ADDconst [0] x) => x
(SUB x (MOVDconst [c])) && is32Bit(-c) => (ADDconst [-c] x)

(ADDconst [c] (MOVDaddr [d] {sym} x)) && is32Bit(c+int64(d)) => (MOVDaddr [int32(c+int64(d))] {sym} x)
(ADDconst [c] x:(SP)) && is32Bit(c) => (MOVDaddr [int32(c)] x) // so it is rematerializeable

	// match: (ADDconst [off1] (MOVDaddr [off2] {sym} ptr))
	// cond: is32Bit(off1+int64(off2))
	// result: (MOVDaddr [int32(off1)+off2] {sym} ptr)
	for {
		off1 := auxIntToInt64(v.AuxInt)
		if v_0.Op != OpARM64MOVDaddr {
			break
		}
		off2 := auxIntToInt32(v_0.AuxInt)
		sym := auxToSym(v_0.Aux)
		ptr := v_0.Args[0]
		if !(is32Bit(off1 + int64(off2))) {
			break
		}
		v.reset(OpARM64MOVDaddr)

	// match: (OffPtr [off] ptr:(SP))
	// cond: is32Bit(off)
	// result: (MOVaddr [int32(off)] ptr)
	for {
		off := auxIntToInt64(v.AuxInt)
		ptr := v_0
		if ptr.Op != OpSP || !(is32Bit(off)) {
			break
		}
		v.reset(OpRISCV64MOVaddr)
		v.AuxInt = int32ToAuxInt(int32(off))
		v.AddArg(ptr)
		return true
	}
	// match: (OffPtr [off] ptr)
	// cond: is32Bit(off)
	// result: (ADDI [off] ptr)
	for {

	// match: (ADDconst [c] x:(SP))
	// cond: is32Bit(c)
	// result: (MOVDaddr [int32(c)] x)
	for {
		c := auxIntToInt64(v.AuxInt)
		x := v_0
		if x.Op != OpSP || !(is32Bit(c)) {
			break
		}
		v.reset(OpPPC64MOVDaddr)
		v.AuxInt = int32ToAuxInt(int32(c))
		v.AddArg(x)
		return true
	}
	// match: (ADDconst [c] (SUBFCconst [d] x))
	// cond: is32Bit(c+d)
	// result: (SUBFCconst [c+d] x)

		v.reset(OpS390XMOVDaddr)
		v.AuxInt = int32ToAuxInt(int32(off))
		v.AddArg(ptr)
		return true
	}
	// match: (OffPtr [off] ptr)
	// cond: is32Bit(off)
	// result: (ADDconst [int32(off)] ptr)
	for {
		off := auxIntToInt64(v.AuxInt)
		ptr := v_0
		if !(is32Bit(off)) {
			break
		}
		v.reset(OpS390XADDconst)
		v.AuxInt = int32ToAuxInt(int32(off))
		v.AddArg(ptr)
		return true
	}

	case complexVal:
		return x
	}
	return unknownVal{}
}

// ----------------------------------------------------------------------------
// Operations

// is32bit reports whether x can be represented using 32 bits.
func is32bit(x int64) bool {
	const s = 32
	return -1<<(s-1) <= x && x <= 1<<(s-1)-1
}

// is63bit reports whether x can be represented using 63 bits.
func is63bit(x int64) bool {

	if n == 0 {
		panic("invalid argument to Uint64N")
	}
	return r.uint64n(n)
}

// uint64n is the no-bounds-checks version of Uint64N.
func (r *Rand) uint64n(n uint64) uint64 {
	if is32bit && uint64(uint32(n)) == n {
		return uint64(r.uint32n(uint32(n)))
	}
	if n&(n-1) == 0 { // n is power of two, can mask
		return r.Uint64() & (n - 1)
	}

	// Suppose we have a uint64 x uniform in the range [0,2⁶⁴)

package ssa

// addressingModes combines address calculations into memory operations
// that can perform complicated addressing modes.
func addressingModes(f *Func) {
	isInImmediateRange := is32Bit
	switch f.Config.arch {
	default:
		// Most architectures can't do this.
		return
	case "amd64", "386":
	case "s390x":
		isInImmediateRange = is20Bit
	}

	var tmp []*Value
	for _, b := range f.Blocks {

// isUint32PowerOfTwo reports whether uint32(n) is a power of 2.
func isUint32PowerOfTwo(in int64) bool {
	n := uint64(uint32(in))
	return n > 0 && n&(n-1) == 0
}

// is32Bit reports whether n can be represented as a signed 32 bit integer.
func is32Bit(n int64) bool {
	return n == int64(int32(n))
}

// is16Bit reports whether n can be represented as a signed 16 bit integer.
func is16Bit(n int64) bool {

(I64AddConst [off] (LoweredAddr {sym} [off2] base)) && isU32Bit(off+int64(off2)) =>
	(LoweredAddr {sym} [int32(off)+off2] base)
(I64AddConst [off] x:(SP)) && isU32Bit(off) => (LoweredAddr [int32(off)] x) // so it is rematerializeable

// transforming readonly globals into constants
(I64Load [off] (LoweredAddr {sym} [off2] (SB)) _) && symIsRO(sym) && isU32Bit(off+int64(off2)) => (I64Const [int64(read64(sym, off+int64(off2), config.ctxt.Arch.ByteOrder))])