Golang gc.Fatal函數代碼示例

/*
 * n is a 64-bit value.  fill in lo and hi to refer to its 32-bit halves.
 */
func split64(n *gc.Node, lo *gc.Node, hi *gc.Node) {
	if !gc.Is64(n.Type) {
		gc.Fatal("split64 %v", n.Type)
	}

	if nsclean >= len(sclean) {
		gc.Fatal("split64 clean")
	}
	sclean[nsclean].Op = gc.OEMPTY
	nsclean++
	switch n.Op {
	default:
		switch n.Op {
		default:
			var n1 gc.Node
			if !dotaddable(n, &n1) {
				gc.Igen(n, &n1, nil)
				sclean[nsclean-1] = n1
			}

			n = &n1

		case gc.ONAME:
			if n.Class == gc.PPARAMREF {
				var n1 gc.Node
				gc.Cgen(n.Name.Heapaddr, &n1)
				sclean[nsclean-1] = n1
				n = &n1
			}

			// nothing
		case gc.OINDREG:
			break
		}

		*lo = *n
		*hi = *n
		lo.Type = gc.Types[gc.TUINT32]
		if n.Type.Etype == gc.TINT64 {
			hi.Type = gc.Types[gc.TINT32]
		} else {
			hi.Type = gc.Types[gc.TUINT32]
		}
		hi.Xoffset += 4

	case gc.OLITERAL:
		var n1 gc.Node
		n.Convconst(&n1, n.Type)
		i := n1.Int()
		gc.Nodconst(lo, gc.Types[gc.TUINT32], int64(uint32(i)))
		i >>= 32
		if n.Type.Etype == gc.TINT64 {
			gc.Nodconst(hi, gc.Types[gc.TINT32], int64(int32(i)))
		} else {
			gc.Nodconst(hi, gc.Types[gc.TUINT32], int64(uint32(i)))
		}
	}
}

func defframe(ptxt *obj.Prog) {
	var n *gc.Node

	// fill in argument size, stack size
	ptxt.To.Type = obj.TYPE_TEXTSIZE

	ptxt.To.Val = int32(gc.Rnd(gc.Curfn.Type.Argwid, int64(gc.Widthptr)))
	frame := uint32(gc.Rnd(gc.Stksize+gc.Maxarg, int64(gc.Widthreg)))

	// arm64 requires that the frame size (not counting saved LR)
	// be empty or be 8 mod 16. If not, pad it.
	if frame != 0 && frame%16 != 8 {
		frame += 8
	}

	ptxt.To.Offset = int64(frame)

	// insert code to zero ambiguously live variables
	// so that the garbage collector only sees initialized values
	// when it looks for pointers.
	p := ptxt

	hi := int64(0)
	lo := hi

	// iterate through declarations - they are sorted in decreasing xoffset order.
	for l := gc.Curfn.Func.Dcl; l != nil; l = l.Next {
		n = l.N
		if !n.Name.Needzero {
			continue
		}
		if n.Class != gc.PAUTO {
			gc.Fatal("needzero class %d", n.Class)
		}
		if n.Type.Width%int64(gc.Widthptr) != 0 || n.Xoffset%int64(gc.Widthptr) != 0 || n.Type.Width == 0 {
			gc.Fatal("var %v has size %d offset %d", gc.Nconv(n, obj.FmtLong), int(n.Type.Width), int(n.Xoffset))
		}

		if lo != hi && n.Xoffset+n.Type.Width >= lo-int64(2*gc.Widthreg) {
			// merge with range we already have
			lo = n.Xoffset

			continue
		}

		// zero old range
		p = zerorange(p, int64(frame), lo, hi)

		// set new range
		hi = n.Xoffset + n.Type.Width

		lo = n.Xoffset
	}

	// zero final range
	zerorange(p, int64(frame), lo, hi)
}

/*
 * insert n into reg slot of p
 */
func raddr(n *gc.Node, p *obj.Prog) {
	var a obj.Addr
	gc.Naddr(&a, n)
	if a.Type != obj.TYPE_REG {
		if n != nil {
			gc.Fatal("bad in raddr: %v", gc.Oconv(int(n.Op), 0))
		} else {
			gc.Fatal("bad in raddr: <null>")
		}
		p.Reg = 0
	} else {
		p.Reg = a.Reg
	}
}

func defframe(ptxt *obj.Prog) {
	var n *gc.Node

	// fill in argument size, stack size
	ptxt.To.Type = obj.TYPE_TEXTSIZE

	ptxt.To.Val = int32(gc.Rnd(gc.Curfn.Type.Argwid, int64(gc.Widthptr)))
	frame := uint32(gc.Rnd(gc.Stksize+gc.Maxarg, int64(gc.Widthreg)))
	ptxt.To.Offset = int64(frame)

	// insert code to zero ambiguously live variables
	// so that the garbage collector only sees initialized values
	// when it looks for pointers.
	p := ptxt

	hi := int64(0)
	lo := hi
	ax := uint32(0)
	for l := gc.Curfn.Func.Dcl; l != nil; l = l.Next {
		n = l.N
		if !n.Name.Needzero {
			continue
		}
		if n.Class != gc.PAUTO {
			gc.Fatal("needzero class %d", n.Class)
		}
		if n.Type.Width%int64(gc.Widthptr) != 0 || n.Xoffset%int64(gc.Widthptr) != 0 || n.Type.Width == 0 {
			gc.Fatal("var %v has size %d offset %d", gc.Nconv(n, obj.FmtLong), int(n.Type.Width), int(n.Xoffset))
		}
		if lo != hi && n.Xoffset+n.Type.Width == lo-int64(2*gc.Widthptr) {
			// merge with range we already have
			lo = n.Xoffset

			continue
		}

		// zero old range
		p = zerorange(p, int64(frame), lo, hi, &ax)

		// set new range
		hi = n.Xoffset + n.Type.Width

		lo = n.Xoffset
	}

	// zero final range
	zerorange(p, int64(frame), lo, hi, &ax)
}

/*
 * generate
 *	as n, $c (CMP/CMPU)
 */
func ginscon2(as int, n2 *gc.Node, c int64) {
	var n1 gc.Node

	gc.Nodconst(&n1, gc.Types[gc.TINT64], c)

	switch as {
	default:
		gc.Fatal("ginscon2")

	case ppc64.ACMP:
		if -ppc64.BIG <= c && c <= ppc64.BIG {
			rawgins(as, n2, &n1)
			return
		}

	case ppc64.ACMPU:
		if 0 <= c && c <= 2*ppc64.BIG {
			rawgins(as, n2, &n1)
			return
		}
	}

	// MOV n1 into register first
	var ntmp gc.Node
	gc.Regalloc(&ntmp, gc.Types[gc.TINT64], nil)

	rawgins(ppc64.AMOVD, &n1, &ntmp)
	rawgins(as, n2, &ntmp)
	gc.Regfree(&ntmp)
}

func proginfo(p *obj.Prog) {
	info := &p.Info
	*info = progtable[p.As]
	if info.Flags == 0 {
		gc.Fatal("unknown instruction %v", p)
	}

	if (info.Flags&gc.ShiftCX != 0) && p.From.Type != obj.TYPE_CONST {
		info.Reguse |= CX
	}

	if info.Flags&gc.ImulAXDX != 0 {
		if p.To.Type == obj.TYPE_NONE {
			info.Reguse |= AX
			info.Regset |= AX | DX
		} else {
			info.Flags |= RightRdwr
		}
	}

	// Addressing makes some registers used.
	if p.From.Type == obj.TYPE_MEM && p.From.Name == obj.NAME_NONE {
		info.Regindex |= RtoB(int(p.From.Reg))
	}
	if p.From.Index != x86.REG_NONE {
		info.Regindex |= RtoB(int(p.From.Index))
	}
	if p.To.Type == obj.TYPE_MEM && p.To.Name == obj.NAME_NONE {
		info.Regindex |= RtoB(int(p.To.Reg))
	}
	if p.To.Index != x86.REG_NONE {
		info.Regindex |= RtoB(int(p.To.Index))
	}
}

func proginfo(p *obj.Prog) {
	info := &p.Info
	*info = progtable[p.As]
	if info.Flags == 0 {
		gc.Fatal("unknown instruction %v", p)
	}

	if p.From.Type == obj.TYPE_ADDR && p.From.Sym != nil && (info.Flags&gc.LeftRead != 0) {
		info.Flags &^= gc.LeftRead
		info.Flags |= gc.LeftAddr
	}

	if (info.Flags&gc.RegRead != 0) && p.Reg == 0 {
		info.Flags &^= gc.RegRead
		info.Flags |= gc.CanRegRead | gc.RightRead
	}

	if (p.Scond&arm.C_SCOND != arm.C_SCOND_NONE) && (info.Flags&gc.RightWrite != 0) {
		info.Flags |= gc.RightRead
	}

	switch p.As {
	case arm.ADIV,
		arm.ADIVU,
		arm.AMOD,
		arm.AMODU:
		info.Regset |= RtoB(arm.REG_R12)
	}
}

func splitclean() {
	if nsclean <= 0 {
		gc.Fatal("splitclean")
	}
	nsclean--
	if sclean[nsclean].Op != gc.OEMPTY {
		gc.Regfree(&sclean[nsclean])
	}
}

func gcmp(as int, lhs *gc.Node, rhs *gc.Node) *obj.Prog {
	if lhs.Op != gc.OREGISTER {
		gc.Fatal("bad operands to gcmp: %v %v", gc.Oconv(int(lhs.Op), 0), gc.Oconv(int(rhs.Op), 0))
	}

	p := rawgins(as, rhs, nil)
	raddr(lhs, p)
	return p
}

// as2variant returns the variant (V_*) flags of instruction as.
func as2variant(as int) int {
	initvariants()
	for i := int(0); i < len(varianttable[as]); i++ {
		if varianttable[as][i] == as {
			return i
		}
	}
	gc.Fatal("as2variant: instruction %v is not a variant of itself", obj.Aconv(as))
	return 0
}

/* generate a constant shift
 * arm encodes a shift by 32 as 0, thus asking for 0 shift is illegal.
 */
func gshift(as int, lhs *gc.Node, stype int32, sval int32, rhs *gc.Node) *obj.Prog {
	if sval <= 0 || sval > 32 {
		gc.Fatal("bad shift value: %d", sval)
	}

	sval = sval & 0x1f

	p := gins(as, nil, rhs)
	p.From.Type = obj.TYPE_SHIFT
	p.From.Offset = int64(stype) | int64(sval)<<7 | int64(lhs.Reg)&15
	return p
}

/*
 * direct reference,
 * could be set/use depending on
 * semantics
 */
func copyas(a *obj.Addr, v *obj.Addr) bool {
	if x86.REG_AL <= a.Reg && a.Reg <= x86.REG_R15B {
		gc.Fatal("use of byte register")
	}
	if x86.REG_AL <= v.Reg && v.Reg <= x86.REG_R15B {
		gc.Fatal("use of byte register")
	}

	if a.Type != v.Type || a.Name != v.Name || a.Reg != v.Reg {
		return false
	}
	if regtyp(v) {
		return true
	}
	if v.Type == obj.TYPE_MEM && (v.Name == obj.NAME_AUTO || v.Name == obj.NAME_PARAM) {
		if v.Offset == a.Offset {
			return true
		}
	}
	return false
}

/*
 * generate high multiply
 *  res = (nl * nr) >> wordsize
 */
func cgen_hmul(nl *gc.Node, nr *gc.Node, res *gc.Node) {
	if nl.Ullman < nr.Ullman {
		tmp := nl
		nl = nr
		nr = tmp
	}

	t := nl.Type
	w := int(t.Width * 8)
	var n1 gc.Node
	gc.Regalloc(&n1, t, res)
	gc.Cgen(nl, &n1)
	var n2 gc.Node
	gc.Regalloc(&n2, t, nil)
	gc.Cgen(nr, &n2)
	switch gc.Simtype[t.Etype] {
	case gc.TINT8,
		gc.TINT16:
		gins(optoas(gc.OMUL, t), &n2, &n1)
		gshift(arm.AMOVW, &n1, arm.SHIFT_AR, int32(w), &n1)

	case gc.TUINT8,
		gc.TUINT16:
		gins(optoas(gc.OMUL, t), &n2, &n1)
		gshift(arm.AMOVW, &n1, arm.SHIFT_LR, int32(w), &n1)

		// perform a long multiplication.
	case gc.TINT32,
		gc.TUINT32:
		var p *obj.Prog
		if gc.Issigned[t.Etype] {
			p = gins(arm.AMULL, &n2, nil)
		} else {
			p = gins(arm.AMULLU, &n2, nil)
		}

		// n2 * n1 -> (n1 n2)
		p.Reg = n1.Reg

		p.To.Type = obj.TYPE_REGREG
		p.To.Reg = n1.Reg
		p.To.Offset = int64(n2.Reg)

	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 {
		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 division according to op, one of:
 *	res = nl / nr
 *	res = nl % nr
 */
func cgen_div(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
	if gc.Is64(nl.Type) {
		gc.Fatal("cgen_div %v", nl.Type)
	}

	var t *gc.Type
	if gc.Issigned[nl.Type.Etype] {
		t = gc.Types[gc.TINT32]
	} else {
		t = gc.Types[gc.TUINT32]
	}
	var ax gc.Node
	var oldax gc.Node
	savex(x86.REG_AX, &ax, &oldax, res, t)
	var olddx gc.Node
	var dx gc.Node
	savex(x86.REG_DX, &dx, &olddx, res, t)
	dodiv(op, nl, nr, res, &ax, &dx)
	restx(&dx, &olddx)
	restx(&ax, &oldax)
}