// sure that we don't end up doing O(n^2) work
	// for a chain of n copies.
	for v != w {
		x := v.Args[0]
		v.SetArg(0, w)
		v = x
	}
	return w
}

// copyelimValue ensures that no args of v are copies.
func copyelimValue(v *Value) {
	for i, a := range v.Args {
		if a.Op == OpCopy {
			v.SetArg(i, copySource(a))
		}
	}
}

// phielim eliminates redundant phi values from f.

			if fwdSig[i] != _SIG_DFL && fwdSig[i] != _SIG_IGN {
				setsigstack(i)
			} else if fwdSig[i] == _SIG_IGN {
				sigInitIgnored(i)
			}
			continue
		}

		handlingSig[i] = 1
		setsig(i, abi.FuncPCABIInternal(sighandler))
	}
}

//go:nosplit
//go:nowritebarrierrec
func sigInstallGoHandler(sig uint32) bool {
	// For some signals, we respect an inherited SIG_IGN handler

func (x *Nat) set(y *Nat) *Nat {
	x.reset(len(y.limbs))
	copy(x.limbs, y.limbs)
	return x
}

// setBig assigns x = n, optionally resizing n to the appropriate size.
//
// The announced length of x is set based on the actual bit size of the input,
// ignoring leading zeroes.
func (x *Nat) setBig(n *big.Int) *Nat {
	limbs := n.Bits()
	x.reset(len(limbs))
	for i := range limbs {
		x.limbs[i] = uint(limbs[i])

}

func (v *Value) AddArgs(a ...*Value) {
	if v.Args == nil {
		v.resetArgs() // use argstorage
	}
	v.Args = append(v.Args, a...)
	for _, x := range a {
		x.Uses++
	}
}
func (v *Value) SetArg(i int, w *Value) {
	v.Args[i].Uses--
	v.Args[i] = w
	w.Uses++
}
func (v *Value) SetArgs1(a *Value) {
	v.resetArgs()
	v.AddArg(a)
}
func (v *Value) SetArgs2(a, b *Value) {
	v.resetArgs()

				// of a value so that a x.Uses==1 rule condition
				// fires reliably.
				for i, a := range v.Args {
					if a.Op != OpCopy {
						continue
					}
					aa := copySource(a)
					v.SetArg(i, aa)
					// If a, a copy, has a line boundary indicator, attempt to find a new value
					// to hold it.  The first candidate is the value that will replace a (aa),
					// if it shares the same block and line and is eligible.