// fold constant into arithmetic ops
(ADDV x (MOVVconst <t> [c])) && is32Bit(c) && !t.IsPtr() => (ADDVconst [c] x)
(SUBV x (MOVVconst [c])) && is32Bit(c) => (SUBVconst [c] x)
(AND x (MOVVconst [c])) && is32Bit(c) => (ANDconst [c] x)
(OR  x (MOVVconst [c])) && is32Bit(c) => (ORconst  [c] x)
(XOR x (MOVVconst [c])) && is32Bit(c) => (XORconst [c] x)
(NOR x (MOVVconst [c])) && is32Bit(c) => (NORconst [c] x)

	(MOVHUload [off1+int32(off2)] {sym} base mem)
(MOVHload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
	(MOVHload  [off1+int32(off2)] {sym} base mem)
(MOVWUload [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
	(MOVWUload [off1+int32(off2)] {sym} base mem)
(MOVWload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>

// fold constant into arithmetic ops
(ADDV x (MOVVconst <t> [c])) && is32Bit(c) && !t.IsPtr() => (ADDVconst [c] x)
(SUBV x (MOVVconst [c])) && is32Bit(c) => (SUBVconst [c] x)
(AND x (MOVVconst [c])) && is32Bit(c) => (ANDconst [c] x)
(OR  x (MOVVconst [c])) && is32Bit(c) => (ORconst  [c] x)
(XOR x (MOVVconst [c])) && is32Bit(c) => (XORconst [c] x)
(NOR x (MOVVconst [c])) && is32Bit(c) => (NORconst [c] x)

	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 {

(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))])