Golang cmd-compile-internal-gc.Cgenr类(方法)实例源码

/*
 * 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)
}

/*
 * 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 {
		nl, nr = nr, nl
	}

	var n1 gc.Node
	gc.Cgenr(nl, &n1, res)
	var n2 gc.Node
	gc.Cgenr(nr, &n2, nil)
	var ax, oldax, dx, olddx gc.Node
	savex(x86.REG_AX, &ax, &oldax, res, gc.Types[gc.TUINT64])
	savex(x86.REG_DX, &dx, &olddx, res, gc.Types[gc.TUINT64])
	gmove(&n1, &ax)
	gins(a, &n2, nil)
	gc.Regfree(&n2)
	gc.Regfree(&n1)

	if t.Width == 1 {
		// byte multiply behaves differently.
		var byteAH, byteDX gc.Node
		gc.Nodreg(&byteAH, t, x86.REG_AH)
		gc.Nodreg(&byteDX, t, x86.REG_DX)
		gmove(&byteAH, &byteDX)
	}
	gmove(&dx, res)

	restx(&ax, &oldax)
	restx(&dx, &olddx)
}

/*
 * 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 {
		nl, nr = nr, nl
	}

	t := nl.Type
	w := 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:
		gins3(optoas(gc.OMUL, t), &n2, &n1, nil)
		var lo gc.Node
		gc.Nodreg(&lo, gc.Types[gc.TUINT64], mips.REG_LO)
		gins(mips.AMOVV, &lo, &n1)
		p := gins(mips.ASRAV, nil, &n1)
		p.From.Type = obj.TYPE_CONST
		p.From.Offset = w

	case gc.TUINT8,
		gc.TUINT16,
		gc.TUINT32:
		gins3(optoas(gc.OMUL, t), &n2, &n1, nil)
		var lo gc.Node
		gc.Nodreg(&lo, gc.Types[gc.TUINT64], mips.REG_LO)
		gins(mips.AMOVV, &lo, &n1)
		p := gins(mips.ASRLV, nil, &n1)
		p.From.Type = obj.TYPE_CONST
		p.From.Offset = w

	case gc.TINT64,
		gc.TUINT64:
		if t.IsSigned() {
			gins3(mips.AMULV, &n2, &n1, nil)
		} else {
			gins3(mips.AMULVU, &n2, &n1, nil)
		}
		var hi gc.Node
		gc.Nodreg(&hi, gc.Types[gc.TUINT64], mips.REG_HI)
		gins(mips.AMOVV, &hi, &n1)

	default:
		gc.Fatalf("cgen_hmul %v", t)
	}

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

/*
 * 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", t)
	}

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

/*
 * 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 {
		nl, nr = nr, nl
	}

	t := nl.Type
	w := 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 := gins(s390x.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 := gins(s390x.ASRD, nil, &n1)
		p.From.Type = obj.TYPE_CONST
		p.From.Offset = int64(w)

	case gc.TINT64:
		gins(s390x.AMULHD, &n2, &n1)

	case gc.TUINT64:
		gins(s390x.AMULHDU, &n2, &n1)

	default:
		gc.Fatalf("cgen_hmul %v", t)
	}

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