Esempio n. 1
0
/*
 * generate high multiply:
 *   res = (nl*nr) >> width
 */
func cgen_hmul(nl *gc.Node, nr *gc.Node, res *gc.Node) {
	t := nl.Type
	a := optoas(gc.OHMUL, t)
	if nl.Ullman < nr.Ullman {
		tmp := nl
		nl = nr
		nr = tmp
	}

	var n1 gc.Node
	gc.Cgenr(nl, &n1, res)
	var n2 gc.Node
	gc.Cgenr(nr, &n2, nil)
	var ax gc.Node
	gc.Nodreg(&ax, t, x86.REG_AX)
	gmove(&n1, &ax)
	gins(a, &n2, nil)
	gc.Regfree(&n2)
	gc.Regfree(&n1)

	var dx gc.Node
	if t.Width == 1 {
		// byte multiply behaves differently.
		gc.Nodreg(&ax, t, x86.REG_AH)

		gc.Nodreg(&dx, t, x86.REG_DX)
		gmove(&ax, &dx)
	}

	gc.Nodreg(&dx, t, x86.REG_DX)
	gmove(&dx, res)
}
Esempio n. 2
0
File: ggen.go Progetto: tidatida/go
/*
 * generate high multiply:
 *   res = (nl*nr) >> width
 */
func cgen_hmul(nl *gc.Node, nr *gc.Node, res *gc.Node) {
	// largest ullman on left.
	if nl.Ullman < nr.Ullman {
		tmp := (*gc.Node)(nl)
		nl = nr
		nr = tmp
	}

	t := (*gc.Type)(nl.Type)
	w := int(int(t.Width * 8))
	var n1 gc.Node
	gc.Cgenr(nl, &n1, res)
	var n2 gc.Node
	gc.Cgenr(nr, &n2, nil)
	switch gc.Simtype[t.Etype] {
	case gc.TINT8,
		gc.TINT16,
		gc.TINT32:
		gins(optoas(gc.OMUL, t), &n2, &n1)
		p := (*obj.Prog)(gins(ppc64.ASRAD, nil, &n1))
		p.From.Type = obj.TYPE_CONST
		p.From.Offset = int64(w)

	case gc.TUINT8,
		gc.TUINT16,
		gc.TUINT32:
		gins(optoas(gc.OMUL, t), &n2, &n1)
		p := (*obj.Prog)(gins(ppc64.ASRD, nil, &n1))
		p.From.Type = obj.TYPE_CONST
		p.From.Offset = int64(w)

	case gc.TINT64,
		gc.TUINT64:
		if gc.Issigned[t.Etype] {
			gins(ppc64.AMULHD, &n2, &n1)
		} else {
			gins(ppc64.AMULHDU, &n2, &n1)
		}

	default:
		gc.Fatal("cgen_hmul %v", gc.Tconv(t, 0))
	}

	gc.Cgen(&n1, res)
	gc.Regfree(&n1)
	gc.Regfree(&n2)
}