Exemplo n.º 1
0
/*
 * generate
 *	as $c, n
 */
func ginscon(as int, c int64, n2 *gc.Node) {
	var n1 gc.Node

	switch as {
	case x86.AADDL,
		x86.AMOVL,
		x86.ALEAL:
		gc.Nodconst(&n1, gc.Types[gc.TINT32], c)

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

	if as != x86.AMOVQ && (c < -(1<<31) || c >= 1<<31) {
		// cannot have 64-bit immediate in ADD, etc.
		// instead, MOV into register first.
		var ntmp gc.Node
		gc.Regalloc(&ntmp, gc.Types[gc.TINT64], nil)

		gins(x86.AMOVQ, &n1, &ntmp)
		gins(as, &ntmp, n2)
		gc.Regfree(&ntmp)
		return
	}

	gins(as, &n1, n2)
}
Exemplo n.º 2
0
/*
 * 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.Fatalf("split64 %v", n.Type)
	}

	if nsclean >= len(sclean) {
		gc.Fatalf("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)))
		}
	}
}
Exemplo n.º 3
0
Arquivo: cgen.go Projeto: ckeyer/gosrc
/*
 * generate array index into res.
 * n might be any size; res is 32-bit.
 * returns Prog* to patch to panic call.
 */
func cgenindex(n *gc.Node, res *gc.Node, bounded bool) *obj.Prog {
	if !gc.Is64(n.Type) {
		gc.Cgen(n, res)
		return nil
	}

	var tmp gc.Node
	gc.Tempname(&tmp, gc.Types[gc.TINT64])
	gc.Cgen(n, &tmp)
	var lo gc.Node
	var hi gc.Node
	split64(&tmp, &lo, &hi)
	gmove(&lo, res)
	if bounded {
		splitclean()
		return nil
	}

	var n1 gc.Node
	gc.Regalloc(&n1, gc.Types[gc.TINT32], nil)
	var n2 gc.Node
	gc.Regalloc(&n2, gc.Types[gc.TINT32], nil)
	var zero gc.Node
	gc.Nodconst(&zero, gc.Types[gc.TINT32], 0)
	gmove(&hi, &n1)
	gmove(&zero, &n2)
	gins(arm.ACMP, &n1, &n2)
	gc.Regfree(&n2)
	gc.Regfree(&n1)
	splitclean()
	return gc.Gbranch(arm.ABNE, nil, -1)
}
Exemplo n.º 4
0
/*
 * 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.Fatalf("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)
}
Exemplo n.º 5
0
Arquivo: cgen.go Projeto: ckeyer/gosrc
/*
 * generate an addressable node in res, containing the value of n.
 * n is an array index, and might be any size; res width is <= 32-bit.
 * returns Prog* to patch to panic call.
 */
func igenindex(n *gc.Node, res *gc.Node, bounded bool) *obj.Prog {
	if !gc.Is64(n.Type) {
		if n.Addable && (gc.Simtype[n.Etype] == gc.TUINT32 || gc.Simtype[n.Etype] == gc.TINT32) {
			// nothing to do.
			*res = *n
		} else {
			gc.Tempname(res, gc.Types[gc.TUINT32])
			gc.Cgen(n, res)
		}

		return nil
	}

	var tmp gc.Node
	gc.Tempname(&tmp, gc.Types[gc.TINT64])
	gc.Cgen(n, &tmp)
	var lo gc.Node
	var hi gc.Node
	split64(&tmp, &lo, &hi)
	gc.Tempname(res, gc.Types[gc.TUINT32])
	gmove(&lo, res)
	if bounded {
		splitclean()
		return nil
	}

	var zero gc.Node
	gc.Nodconst(&zero, gc.Types[gc.TINT32], 0)
	gins(x86.ACMPL, &hi, &zero)
	splitclean()
	return gc.Gbranch(x86.AJNE, nil, +1)
}
Exemplo n.º 6
0
func ncon(i uint32) *gc.Node {
	if ncon_n.Type == nil {
		gc.Nodconst(&ncon_n, gc.Types[gc.TUINT32], 0)
	}
	ncon_n.SetInt(int64(i))
	return &ncon_n
}
Exemplo n.º 7
0
/*
 * generate
 *	as $c, reg
 */
func gconreg(as int, c int64, reg int) {
	var n1 gc.Node
	var n2 gc.Node

	gc.Nodconst(&n1, gc.Types[gc.TINT64], c)
	gc.Nodreg(&n2, gc.Types[gc.TINT64], reg)
	gins(as, &n1, &n2)
}
Exemplo n.º 8
0
Arquivo: ggen.go Projeto: ckeyer/gosrc
/*
 * generate
 *	as $c, n
 */
func ginscon(as int, c int64, n *gc.Node) {
	var n1 gc.Node
	gc.Nodconst(&n1, gc.Types[gc.TINT32], c)
	var n2 gc.Node
	gc.Regalloc(&n2, gc.Types[gc.TINT32], nil)
	gmove(&n1, &n2)
	gins(as, &n2, n)
	gc.Regfree(&n2)
}
Exemplo n.º 9
0
func bignodes() {
	if bignodes_did {
		return
	}
	bignodes_did = true

	gc.Nodconst(&zerof, gc.Types[gc.TINT64], 0)
	zerof.Convconst(&zerof, gc.Types[gc.TFLOAT64])

	var i big.Int
	i.SetInt64(1)
	i.Lsh(&i, 63)
	var bigi gc.Node

	gc.Nodconst(&bigi, gc.Types[gc.TUINT64], 0)
	bigi.SetBigInt(&i)
	bigi.Convconst(&two63f, gc.Types[gc.TFLOAT64])

	gc.Nodconst(&bigi, gc.Types[gc.TUINT64], 0)
	i.Lsh(&i, 1)
	bigi.SetBigInt(&i)
	bigi.Convconst(&two64f, gc.Types[gc.TFLOAT64])
}
Exemplo n.º 10
0
func bignodes() {
	if bignodes_did {
		return
	}
	bignodes_did = true

	var i big.Int
	i.SetInt64(1)
	i.Lsh(&i, 63)

	gc.Nodconst(&bigi, gc.Types[gc.TUINT64], 0)
	bigi.SetBigInt(&i)

	bigi.Convconst(&bigf, gc.Types[gc.TFLOAT64])
}
Exemplo n.º 11
0
/*
 * generate
 *	as $c, n
 */
func ginscon(as int, c int64, n2 *gc.Node) {
	var n1 gc.Node

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

	if as != ppc64.AMOVD && (c < -ppc64.BIG || c > ppc64.BIG) || n2.Op != gc.OREGISTER || as == ppc64.AMULLD {
		// cannot have more than 16-bit of immediate in ADD, etc.
		// instead, MOV into register first.
		var ntmp gc.Node
		gc.Regalloc(&ntmp, gc.Types[gc.TINT64], nil)

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

	rawgins(as, &n1, n2)
}
Exemplo n.º 12
0
/*
 * generate move:
 *	t = f
 * hard part is conversions.
 */
func gmove(f *gc.Node, t *gc.Node) {
	if gc.Debug['M'] != 0 {
		fmt.Printf("gmove %v -> %v\n", gc.Nconv(f, obj.FmtLong), gc.Nconv(t, obj.FmtLong))
	}

	ft := gc.Simsimtype(f.Type)
	tt := gc.Simsimtype(t.Type)
	cvt := t.Type

	if gc.Iscomplex[ft] || gc.Iscomplex[tt] {
		gc.Complexmove(f, t)
		return
	}

	// cannot have two memory operands
	var a int
	if gc.Ismem(f) && gc.Ismem(t) {
		goto hard
	}

	// convert constant to desired type
	if f.Op == gc.OLITERAL {
		var con gc.Node
		f.Convconst(&con, t.Type)
		f = &con
		ft = tt // so big switch will choose a simple mov

		// some constants can't move directly to memory.
		if gc.Ismem(t) {
			// float constants come from memory.
			if gc.Isfloat[tt] {
				goto hard
			}

			// 64-bit immediates are really 32-bit sign-extended
			// unless moving into a register.
			if gc.Isint[tt] {
				if i := con.Int(); int64(int32(i)) != i {
					goto hard
				}
			}
		}
	}

	// value -> value copy, only one memory operand.
	// figure out the instruction to use.
	// break out of switch for one-instruction gins.
	// goto rdst for "destination must be register".
	// goto hard for "convert to cvt type first".
	// otherwise handle and return.

	switch uint32(ft)<<16 | uint32(tt) {
	default:
		gc.Fatalf("gmove %v -> %v", gc.Tconv(f.Type, obj.FmtLong), gc.Tconv(t.Type, obj.FmtLong))

		/*
		 * integer copy and truncate
		 */
	case gc.TINT8<<16 | gc.TINT8, // same size
		gc.TINT8<<16 | gc.TUINT8,
		gc.TUINT8<<16 | gc.TINT8,
		gc.TUINT8<<16 | gc.TUINT8,
		gc.TINT16<<16 | gc.TINT8,
		// truncate
		gc.TUINT16<<16 | gc.TINT8,
		gc.TINT32<<16 | gc.TINT8,
		gc.TUINT32<<16 | gc.TINT8,
		gc.TINT64<<16 | gc.TINT8,
		gc.TUINT64<<16 | gc.TINT8,
		gc.TINT16<<16 | gc.TUINT8,
		gc.TUINT16<<16 | gc.TUINT8,
		gc.TINT32<<16 | gc.TUINT8,
		gc.TUINT32<<16 | gc.TUINT8,
		gc.TINT64<<16 | gc.TUINT8,
		gc.TUINT64<<16 | gc.TUINT8:
		a = x86.AMOVB

	case gc.TINT16<<16 | gc.TINT16, // same size
		gc.TINT16<<16 | gc.TUINT16,
		gc.TUINT16<<16 | gc.TINT16,
		gc.TUINT16<<16 | gc.TUINT16,
		gc.TINT32<<16 | gc.TINT16,
		// truncate
		gc.TUINT32<<16 | gc.TINT16,
		gc.TINT64<<16 | gc.TINT16,
		gc.TUINT64<<16 | gc.TINT16,
		gc.TINT32<<16 | gc.TUINT16,
		gc.TUINT32<<16 | gc.TUINT16,
		gc.TINT64<<16 | gc.TUINT16,
		gc.TUINT64<<16 | gc.TUINT16:
		a = x86.AMOVW

	case gc.TINT32<<16 | gc.TINT32, // same size
		gc.TINT32<<16 | gc.TUINT32,
		gc.TUINT32<<16 | gc.TINT32,
		gc.TUINT32<<16 | gc.TUINT32:
		a = x86.AMOVL

	case gc.TINT64<<16 | gc.TINT32, // truncate
		gc.TUINT64<<16 | gc.TINT32,
		gc.TINT64<<16 | gc.TUINT32,
		gc.TUINT64<<16 | gc.TUINT32:
		a = x86.AMOVQL

	case gc.TINT64<<16 | gc.TINT64, // same size
		gc.TINT64<<16 | gc.TUINT64,
		gc.TUINT64<<16 | gc.TINT64,
		gc.TUINT64<<16 | gc.TUINT64:
		a = x86.AMOVQ

		/*
		 * integer up-conversions
		 */
	case gc.TINT8<<16 | gc.TINT16, // sign extend int8
		gc.TINT8<<16 | gc.TUINT16:
		a = x86.AMOVBWSX

		goto rdst

	case gc.TINT8<<16 | gc.TINT32,
		gc.TINT8<<16 | gc.TUINT32:
		a = x86.AMOVBLSX
		goto rdst

	case gc.TINT8<<16 | gc.TINT64,
		gc.TINT8<<16 | gc.TUINT64:
		a = x86.AMOVBQSX
		goto rdst

	case gc.TUINT8<<16 | gc.TINT16, // zero extend uint8
		gc.TUINT8<<16 | gc.TUINT16:
		a = x86.AMOVBWZX

		goto rdst

	case gc.TUINT8<<16 | gc.TINT32,
		gc.TUINT8<<16 | gc.TUINT32:
		a = x86.AMOVBLZX
		goto rdst

	case gc.TUINT8<<16 | gc.TINT64,
		gc.TUINT8<<16 | gc.TUINT64:
		a = x86.AMOVBQZX
		goto rdst

	case gc.TINT16<<16 | gc.TINT32, // sign extend int16
		gc.TINT16<<16 | gc.TUINT32:
		a = x86.AMOVWLSX

		goto rdst

	case gc.TINT16<<16 | gc.TINT64,
		gc.TINT16<<16 | gc.TUINT64:
		a = x86.AMOVWQSX
		goto rdst

	case gc.TUINT16<<16 | gc.TINT32, // zero extend uint16
		gc.TUINT16<<16 | gc.TUINT32:
		a = x86.AMOVWLZX

		goto rdst

	case gc.TUINT16<<16 | gc.TINT64,
		gc.TUINT16<<16 | gc.TUINT64:
		a = x86.AMOVWQZX
		goto rdst

	case gc.TINT32<<16 | gc.TINT64, // sign extend int32
		gc.TINT32<<16 | gc.TUINT64:
		a = x86.AMOVLQSX

		goto rdst

		// AMOVL into a register zeros the top of the register,
	// so this is not always necessary, but if we rely on AMOVL
	// the optimizer is almost certain to screw with us.
	case gc.TUINT32<<16 | gc.TINT64, // zero extend uint32
		gc.TUINT32<<16 | gc.TUINT64:
		a = x86.AMOVLQZX

		goto rdst

		/*
		* float to integer
		 */
	case gc.TFLOAT32<<16 | gc.TINT32:
		a = x86.ACVTTSS2SL

		goto rdst

	case gc.TFLOAT64<<16 | gc.TINT32:
		a = x86.ACVTTSD2SL
		goto rdst

	case gc.TFLOAT32<<16 | gc.TINT64:
		a = x86.ACVTTSS2SQ
		goto rdst

	case gc.TFLOAT64<<16 | gc.TINT64:
		a = x86.ACVTTSD2SQ
		goto rdst

		// convert via int32.
	case gc.TFLOAT32<<16 | gc.TINT16,
		gc.TFLOAT32<<16 | gc.TINT8,
		gc.TFLOAT32<<16 | gc.TUINT16,
		gc.TFLOAT32<<16 | gc.TUINT8,
		gc.TFLOAT64<<16 | gc.TINT16,
		gc.TFLOAT64<<16 | gc.TINT8,
		gc.TFLOAT64<<16 | gc.TUINT16,
		gc.TFLOAT64<<16 | gc.TUINT8:
		cvt = gc.Types[gc.TINT32]

		goto hard

		// convert via int64.
	case gc.TFLOAT32<<16 | gc.TUINT32,
		gc.TFLOAT64<<16 | gc.TUINT32:
		cvt = gc.Types[gc.TINT64]

		goto hard

		// algorithm is:
	//	if small enough, use native float64 -> int64 conversion.
	//	otherwise, subtract 2^63, convert, and add it back.
	case gc.TFLOAT32<<16 | gc.TUINT64,
		gc.TFLOAT64<<16 | gc.TUINT64:
		a := x86.ACVTTSS2SQ

		if ft == gc.TFLOAT64 {
			a = x86.ACVTTSD2SQ
		}
		bignodes()
		var r1 gc.Node
		gc.Regalloc(&r1, gc.Types[ft], nil)
		var r2 gc.Node
		gc.Regalloc(&r2, gc.Types[tt], t)
		var r3 gc.Node
		gc.Regalloc(&r3, gc.Types[ft], nil)
		var r4 gc.Node
		gc.Regalloc(&r4, gc.Types[tt], nil)
		gins(optoas(gc.OAS, f.Type), f, &r1)
		gins(optoas(gc.OCMP, f.Type), &bigf, &r1)
		p1 := gc.Gbranch(optoas(gc.OLE, f.Type), nil, +1)
		gins(a, &r1, &r2)
		p2 := gc.Gbranch(obj.AJMP, nil, 0)
		gc.Patch(p1, gc.Pc)
		gins(optoas(gc.OAS, f.Type), &bigf, &r3)
		gins(optoas(gc.OSUB, f.Type), &r3, &r1)
		gins(a, &r1, &r2)
		gins(x86.AMOVQ, &bigi, &r4)
		gins(x86.AXORQ, &r4, &r2)
		gc.Patch(p2, gc.Pc)
		gmove(&r2, t)
		gc.Regfree(&r4)
		gc.Regfree(&r3)
		gc.Regfree(&r2)
		gc.Regfree(&r1)
		return

		/*
		 * integer to float
		 */
	case gc.TINT32<<16 | gc.TFLOAT32:
		a = x86.ACVTSL2SS

		goto rdst

	case gc.TINT32<<16 | gc.TFLOAT64:
		a = x86.ACVTSL2SD
		goto rdst

	case gc.TINT64<<16 | gc.TFLOAT32:
		a = x86.ACVTSQ2SS
		goto rdst

	case gc.TINT64<<16 | gc.TFLOAT64:
		a = x86.ACVTSQ2SD
		goto rdst

		// convert via int32
	case gc.TINT16<<16 | gc.TFLOAT32,
		gc.TINT16<<16 | gc.TFLOAT64,
		gc.TINT8<<16 | gc.TFLOAT32,
		gc.TINT8<<16 | gc.TFLOAT64,
		gc.TUINT16<<16 | gc.TFLOAT32,
		gc.TUINT16<<16 | gc.TFLOAT64,
		gc.TUINT8<<16 | gc.TFLOAT32,
		gc.TUINT8<<16 | gc.TFLOAT64:
		cvt = gc.Types[gc.TINT32]

		goto hard

		// convert via int64.
	case gc.TUINT32<<16 | gc.TFLOAT32,
		gc.TUINT32<<16 | gc.TFLOAT64:
		cvt = gc.Types[gc.TINT64]

		goto hard

		// algorithm is:
	//	if small enough, use native int64 -> uint64 conversion.
	//	otherwise, halve (rounding to odd?), convert, and double.
	case gc.TUINT64<<16 | gc.TFLOAT32,
		gc.TUINT64<<16 | gc.TFLOAT64:
		a := x86.ACVTSQ2SS

		if tt == gc.TFLOAT64 {
			a = x86.ACVTSQ2SD
		}
		var zero gc.Node
		gc.Nodconst(&zero, gc.Types[gc.TUINT64], 0)
		var one gc.Node
		gc.Nodconst(&one, gc.Types[gc.TUINT64], 1)
		var r1 gc.Node
		gc.Regalloc(&r1, f.Type, f)
		var r2 gc.Node
		gc.Regalloc(&r2, t.Type, t)
		var r3 gc.Node
		gc.Regalloc(&r3, f.Type, nil)
		var r4 gc.Node
		gc.Regalloc(&r4, f.Type, nil)
		gmove(f, &r1)
		gins(x86.ACMPQ, &r1, &zero)
		p1 := gc.Gbranch(x86.AJLT, nil, +1)
		gins(a, &r1, &r2)
		p2 := gc.Gbranch(obj.AJMP, nil, 0)
		gc.Patch(p1, gc.Pc)
		gmove(&r1, &r3)
		gins(x86.ASHRQ, &one, &r3)
		gmove(&r1, &r4)
		gins(x86.AANDL, &one, &r4)
		gins(x86.AORQ, &r4, &r3)
		gins(a, &r3, &r2)
		gins(optoas(gc.OADD, t.Type), &r2, &r2)
		gc.Patch(p2, gc.Pc)
		gmove(&r2, t)
		gc.Regfree(&r4)
		gc.Regfree(&r3)
		gc.Regfree(&r2)
		gc.Regfree(&r1)
		return

		/*
		 * float to float
		 */
	case gc.TFLOAT32<<16 | gc.TFLOAT32:
		a = x86.AMOVSS

	case gc.TFLOAT64<<16 | gc.TFLOAT64:
		a = x86.AMOVSD

	case gc.TFLOAT32<<16 | gc.TFLOAT64:
		a = x86.ACVTSS2SD
		goto rdst

	case gc.TFLOAT64<<16 | gc.TFLOAT32:
		a = x86.ACVTSD2SS
		goto rdst
	}

	gins(a, f, t)
	return

	// requires register destination
rdst:
	{
		var r1 gc.Node
		gc.Regalloc(&r1, t.Type, t)

		gins(a, f, &r1)
		gmove(&r1, t)
		gc.Regfree(&r1)
		return
	}

	// requires register intermediate
hard:
	var r1 gc.Node
	gc.Regalloc(&r1, cvt, t)

	gmove(f, &r1)
	gmove(&r1, t)
	gc.Regfree(&r1)
	return
}
Exemplo n.º 13
0
Arquivo: ggen.go Projeto: ckeyer/gosrc
/*
 * generate shift according to op, one of:
 *	res = nl << nr
 *	res = nl >> nr
 */
func cgen_shift(op gc.Op, bounded bool, nl *gc.Node, nr *gc.Node, res *gc.Node) {
	a := int(optoas(op, nl.Type))

	if nr.Op == gc.OLITERAL {
		var n1 gc.Node
		gc.Regalloc(&n1, nl.Type, res)
		gc.Cgen(nl, &n1)
		sc := uint64(nr.Int())
		if sc >= uint64(nl.Type.Width*8) {
			// large shift gets 2 shifts by width-1
			var n3 gc.Node
			gc.Nodconst(&n3, gc.Types[gc.TUINT32], nl.Type.Width*8-1)

			gins(a, &n3, &n1)
			gins(a, &n3, &n1)
		} else {
			gins(a, nr, &n1)
		}
		gmove(&n1, res)
		gc.Regfree(&n1)
		return
	}

	if nl.Ullman >= gc.UINF {
		var n4 gc.Node
		gc.Tempname(&n4, nl.Type)
		gc.Cgen(nl, &n4)
		nl = &n4
	}

	if nr.Ullman >= gc.UINF {
		var n5 gc.Node
		gc.Tempname(&n5, nr.Type)
		gc.Cgen(nr, &n5)
		nr = &n5
	}

	// Allow either uint32 or uint64 as shift type,
	// to avoid unnecessary conversion from uint32 to uint64
	// just to do the comparison.
	tcount := gc.Types[gc.Simtype[nr.Type.Etype]]

	if tcount.Etype < gc.TUINT32 {
		tcount = gc.Types[gc.TUINT32]
	}

	var n1 gc.Node
	gc.Regalloc(&n1, nr.Type, nil) // to hold the shift type in CX
	var n3 gc.Node
	gc.Regalloc(&n3, tcount, &n1) // to clear high bits of CX

	var n2 gc.Node
	gc.Regalloc(&n2, nl.Type, res)

	if nl.Ullman >= nr.Ullman {
		gc.Cgen(nl, &n2)
		gc.Cgen(nr, &n1)
		gmove(&n1, &n3)
	} else {
		gc.Cgen(nr, &n1)
		gmove(&n1, &n3)
		gc.Cgen(nl, &n2)
	}

	gc.Regfree(&n3)

	// test and fix up large shifts
	if !bounded {
		gc.Nodconst(&n3, tcount, nl.Type.Width*8)
		gcmp(optoas(gc.OCMP, tcount), &n1, &n3)
		p1 := (*obj.Prog)(gc.Gbranch(optoas(gc.OLT, tcount), nil, +1))
		if op == gc.ORSH && gc.Issigned[nl.Type.Etype] {
			gc.Nodconst(&n3, gc.Types[gc.TUINT32], nl.Type.Width*8-1)
			gins(a, &n3, &n2)
		} else {
			gc.Nodconst(&n3, nl.Type, 0)
			gmove(&n3, &n2)
		}

		gc.Patch(p1, gc.Pc)
	}

	gins(a, &n1, &n2)

	gmove(&n2, res)

	gc.Regfree(&n1)
	gc.Regfree(&n2)
}
Exemplo n.º 14
0
Arquivo: ggen.go Projeto: ckeyer/gosrc
/*
 * generate division.
 * generates one of:
 *	res = nl / nr
 *	res = nl % nr
 * according to op.
 */
func dodiv(op gc.Op, nl *gc.Node, nr *gc.Node, res *gc.Node) {
	// Have to be careful about handling
	// most negative int divided by -1 correctly.
	// The hardware will generate undefined result.
	// Also need to explicitly trap on division on zero,
	// the hardware will silently generate undefined result.
	// DIVW will leave unpredicable result in higher 32-bit,
	// so always use DIVD/DIVDU.
	t := nl.Type

	t0 := t
	check := false
	if gc.Issigned[t.Etype] {
		check = true
		if gc.Isconst(nl, gc.CTINT) && nl.Int() != -(1<<uint64(t.Width*8-1)) {
			check = false
		} else if gc.Isconst(nr, gc.CTINT) && nr.Int() != -1 {
			check = false
		}
	}

	if t.Width < 8 {
		if gc.Issigned[t.Etype] {
			t = gc.Types[gc.TINT64]
		} else {
			t = gc.Types[gc.TUINT64]
		}
		check = false
	}

	a := optoas(gc.ODIV, t)

	var tl gc.Node
	gc.Regalloc(&tl, t0, nil)
	var tr gc.Node
	gc.Regalloc(&tr, t0, nil)
	if nl.Ullman >= nr.Ullman {
		gc.Cgen(nl, &tl)
		gc.Cgen(nr, &tr)
	} else {
		gc.Cgen(nr, &tr)
		gc.Cgen(nl, &tl)
	}

	if t != t0 {
		// Convert
		tl2 := tl

		tr2 := tr
		tl.Type = t
		tr.Type = t
		gmove(&tl2, &tl)
		gmove(&tr2, &tr)
	}

	// Handle divide-by-zero panic.
	p1 := gins(optoas(gc.OCMP, t), &tr, nil)
	p1.Reg = arm64.REGZERO
	p1 = gc.Gbranch(optoas(gc.ONE, t), nil, +1)
	if panicdiv == nil {
		panicdiv = gc.Sysfunc("panicdivide")
	}
	gc.Ginscall(panicdiv, -1)
	gc.Patch(p1, gc.Pc)

	var p2 *obj.Prog
	if check {
		var nm1 gc.Node
		gc.Nodconst(&nm1, t, -1)
		gcmp(optoas(gc.OCMP, t), &tr, &nm1)
		p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
		if op == gc.ODIV {
			// a / (-1) is -a.
			gins(optoas(gc.OMINUS, t), &tl, &tl)

			gmove(&tl, res)
		} else {
			// a % (-1) is 0.
			var nz gc.Node
			gc.Nodconst(&nz, t, 0)

			gmove(&nz, res)
		}

		p2 = gc.Gbranch(obj.AJMP, nil, 0)
		gc.Patch(p1, gc.Pc)
	}

	p1 = gins(a, &tr, &tl)
	if op == gc.ODIV {
		gc.Regfree(&tr)
		gmove(&tl, res)
	} else {
		// A%B = A-(A/B*B)
		var tm gc.Node
		gc.Regalloc(&tm, t, nil)

		// patch div to use the 3 register form
		// TODO(minux): add gins3?
		p1.Reg = p1.To.Reg

		p1.To.Reg = tm.Reg
		gins(optoas(gc.OMUL, t), &tr, &tm)
		gc.Regfree(&tr)
		gins(optoas(gc.OSUB, t), &tm, &tl)
		gc.Regfree(&tm)
		gmove(&tl, res)
	}

	gc.Regfree(&tl)
	if check {
		gc.Patch(p2, gc.Pc)
	}
}
Exemplo n.º 15
0
Arquivo: ggen.go Projeto: ckeyer/gosrc
func ginsnop() {
	var con gc.Node
	gc.Nodconst(&con, gc.Types[gc.TINT], 0)
	gins(arm64.AHINT, &con, nil)
}
Exemplo n.º 16
0
/*
 * attempt to generate 64-bit
 *	res = n
 * return 1 on success, 0 if op not handled.
 */
func cgen64(n *gc.Node, res *gc.Node) {
	if res.Op != gc.OINDREG && res.Op != gc.ONAME {
		gc.Dump("n", n)
		gc.Dump("res", res)
		gc.Fatalf("cgen64 %v of %v", gc.Oconv(int(n.Op), 0), gc.Oconv(int(res.Op), 0))
	}

	l := n.Left
	var t1 gc.Node
	if !l.Addable {
		gc.Tempname(&t1, l.Type)
		gc.Cgen(l, &t1)
		l = &t1
	}

	var hi1 gc.Node
	var lo1 gc.Node
	split64(l, &lo1, &hi1)
	switch n.Op {
	default:
		gc.Fatalf("cgen64 %v", gc.Oconv(int(n.Op), 0))

	case gc.OMINUS:
		var lo2 gc.Node
		var hi2 gc.Node
		split64(res, &lo2, &hi2)

		gc.Regalloc(&t1, lo1.Type, nil)
		var al gc.Node
		gc.Regalloc(&al, lo1.Type, nil)
		var ah gc.Node
		gc.Regalloc(&ah, hi1.Type, nil)

		gins(arm.AMOVW, &lo1, &al)
		gins(arm.AMOVW, &hi1, &ah)

		gmove(ncon(0), &t1)
		p1 := gins(arm.ASUB, &al, &t1)
		p1.Scond |= arm.C_SBIT
		gins(arm.AMOVW, &t1, &lo2)

		gmove(ncon(0), &t1)
		gins(arm.ASBC, &ah, &t1)
		gins(arm.AMOVW, &t1, &hi2)

		gc.Regfree(&t1)
		gc.Regfree(&al)
		gc.Regfree(&ah)
		splitclean()
		splitclean()
		return

	case gc.OCOM:
		gc.Regalloc(&t1, lo1.Type, nil)
		gmove(ncon(^uint32(0)), &t1)

		var lo2 gc.Node
		var hi2 gc.Node
		split64(res, &lo2, &hi2)
		var n1 gc.Node
		gc.Regalloc(&n1, lo1.Type, nil)

		gins(arm.AMOVW, &lo1, &n1)
		gins(arm.AEOR, &t1, &n1)
		gins(arm.AMOVW, &n1, &lo2)

		gins(arm.AMOVW, &hi1, &n1)
		gins(arm.AEOR, &t1, &n1)
		gins(arm.AMOVW, &n1, &hi2)

		gc.Regfree(&t1)
		gc.Regfree(&n1)
		splitclean()
		splitclean()
		return

		// binary operators.
	// common setup below.
	case gc.OADD,
		gc.OSUB,
		gc.OMUL,
		gc.OLSH,
		gc.ORSH,
		gc.OAND,
		gc.OOR,
		gc.OXOR,
		gc.OLROT:
		break
	}

	// setup for binary operators
	r := n.Right

	if r != nil && !r.Addable {
		var t2 gc.Node
		gc.Tempname(&t2, r.Type)
		gc.Cgen(r, &t2)
		r = &t2
	}

	var hi2 gc.Node
	var lo2 gc.Node
	if gc.Is64(r.Type) {
		split64(r, &lo2, &hi2)
	}

	var al gc.Node
	gc.Regalloc(&al, lo1.Type, nil)
	var ah gc.Node
	gc.Regalloc(&ah, hi1.Type, nil)

	// Do op.  Leave result in ah:al.
	switch n.Op {
	default:
		gc.Fatalf("cgen64: not implemented: %v\n", n)

		// TODO: Constants
	case gc.OADD:
		var bl gc.Node
		gc.Regalloc(&bl, gc.Types[gc.TPTR32], nil)

		var bh gc.Node
		gc.Regalloc(&bh, gc.Types[gc.TPTR32], nil)
		gins(arm.AMOVW, &hi1, &ah)
		gins(arm.AMOVW, &lo1, &al)
		gins(arm.AMOVW, &hi2, &bh)
		gins(arm.AMOVW, &lo2, &bl)
		p1 := gins(arm.AADD, &bl, &al)
		p1.Scond |= arm.C_SBIT
		gins(arm.AADC, &bh, &ah)
		gc.Regfree(&bl)
		gc.Regfree(&bh)

		// TODO: Constants.
	case gc.OSUB:
		var bl gc.Node
		gc.Regalloc(&bl, gc.Types[gc.TPTR32], nil)

		var bh gc.Node
		gc.Regalloc(&bh, gc.Types[gc.TPTR32], nil)
		gins(arm.AMOVW, &lo1, &al)
		gins(arm.AMOVW, &hi1, &ah)
		gins(arm.AMOVW, &lo2, &bl)
		gins(arm.AMOVW, &hi2, &bh)
		p1 := gins(arm.ASUB, &bl, &al)
		p1.Scond |= arm.C_SBIT
		gins(arm.ASBC, &bh, &ah)
		gc.Regfree(&bl)
		gc.Regfree(&bh)

		// TODO(kaib): this can be done with 4 regs and does not need 6
	case gc.OMUL:
		var bl gc.Node
		gc.Regalloc(&bl, gc.Types[gc.TPTR32], nil)

		var bh gc.Node
		gc.Regalloc(&bh, gc.Types[gc.TPTR32], nil)
		var cl gc.Node
		gc.Regalloc(&cl, gc.Types[gc.TPTR32], nil)
		var ch gc.Node
		gc.Regalloc(&ch, gc.Types[gc.TPTR32], nil)

		// load args into bh:bl and bh:bl.
		gins(arm.AMOVW, &hi1, &bh)

		gins(arm.AMOVW, &lo1, &bl)
		gins(arm.AMOVW, &hi2, &ch)
		gins(arm.AMOVW, &lo2, &cl)

		// bl * cl -> ah al
		p1 := gins(arm.AMULLU, nil, nil)

		p1.From.Type = obj.TYPE_REG
		p1.From.Reg = bl.Reg
		p1.Reg = cl.Reg
		p1.To.Type = obj.TYPE_REGREG
		p1.To.Reg = ah.Reg
		p1.To.Offset = int64(al.Reg)

		//print("%v\n", p1);

		// bl * ch + ah -> ah
		p1 = gins(arm.AMULA, nil, nil)

		p1.From.Type = obj.TYPE_REG
		p1.From.Reg = bl.Reg
		p1.Reg = ch.Reg
		p1.To.Type = obj.TYPE_REGREG2
		p1.To.Reg = ah.Reg
		p1.To.Offset = int64(ah.Reg)

		//print("%v\n", p1);

		// bh * cl + ah -> ah
		p1 = gins(arm.AMULA, nil, nil)

		p1.From.Type = obj.TYPE_REG
		p1.From.Reg = bh.Reg
		p1.Reg = cl.Reg
		p1.To.Type = obj.TYPE_REGREG2
		p1.To.Reg = ah.Reg
		p1.To.Offset = int64(ah.Reg)

		//print("%v\n", p1);

		gc.Regfree(&bh)

		gc.Regfree(&bl)
		gc.Regfree(&ch)
		gc.Regfree(&cl)

		// We only rotate by a constant c in [0,64).
	// if c >= 32:
	//	lo, hi = hi, lo
	//	c -= 32
	// if c == 0:
	//	no-op
	// else:
	//	t = hi
	//	shld hi:lo, c
	//	shld lo:t, c
	case gc.OLROT:
		v := uint64(r.Int())

		var bl gc.Node
		gc.Regalloc(&bl, lo1.Type, nil)
		var bh gc.Node
		gc.Regalloc(&bh, hi1.Type, nil)
		if v >= 32 {
			// reverse during load to do the first 32 bits of rotate
			v -= 32

			gins(arm.AMOVW, &hi1, &bl)
			gins(arm.AMOVW, &lo1, &bh)
		} else {
			gins(arm.AMOVW, &hi1, &bh)
			gins(arm.AMOVW, &lo1, &bl)
		}

		if v == 0 {
			gins(arm.AMOVW, &bh, &ah)
			gins(arm.AMOVW, &bl, &al)
		} else {
			// rotate by 1 <= v <= 31
			//	MOVW	bl<<v, al
			//	MOVW	bh<<v, ah
			//	OR		bl>>(32-v), ah
			//	OR		bh>>(32-v), al
			gshift(arm.AMOVW, &bl, arm.SHIFT_LL, int32(v), &al)

			gshift(arm.AMOVW, &bh, arm.SHIFT_LL, int32(v), &ah)
			gshift(arm.AORR, &bl, arm.SHIFT_LR, int32(32-v), &ah)
			gshift(arm.AORR, &bh, arm.SHIFT_LR, int32(32-v), &al)
		}

		gc.Regfree(&bl)
		gc.Regfree(&bh)

	case gc.OLSH:
		var bl gc.Node
		gc.Regalloc(&bl, lo1.Type, nil)
		var bh gc.Node
		gc.Regalloc(&bh, hi1.Type, nil)
		gins(arm.AMOVW, &hi1, &bh)
		gins(arm.AMOVW, &lo1, &bl)

		var p6 *obj.Prog
		var s gc.Node
		var n1 gc.Node
		var creg gc.Node
		var p1 *obj.Prog
		var p2 *obj.Prog
		var p3 *obj.Prog
		var p4 *obj.Prog
		var p5 *obj.Prog
		if r.Op == gc.OLITERAL {
			v := uint64(r.Int())
			if v >= 64 {
				// TODO(kaib): replace with gins(AMOVW, nodintconst(0), &al)
				// here and below (verify it optimizes to EOR)
				gins(arm.AEOR, &al, &al)

				gins(arm.AEOR, &ah, &ah)
			} else if v > 32 {
				gins(arm.AEOR, &al, &al)

				//	MOVW	bl<<(v-32), ah
				gshift(arm.AMOVW, &bl, arm.SHIFT_LL, int32(v-32), &ah)
			} else if v == 32 {
				gins(arm.AEOR, &al, &al)
				gins(arm.AMOVW, &bl, &ah)
			} else if v > 0 {
				//	MOVW	bl<<v, al
				gshift(arm.AMOVW, &bl, arm.SHIFT_LL, int32(v), &al)

				//	MOVW	bh<<v, ah
				gshift(arm.AMOVW, &bh, arm.SHIFT_LL, int32(v), &ah)

				//	OR		bl>>(32-v), ah
				gshift(arm.AORR, &bl, arm.SHIFT_LR, int32(32-v), &ah)
			} else {
				gins(arm.AMOVW, &bl, &al)
				gins(arm.AMOVW, &bh, &ah)
			}

			goto olsh_break
		}

		gc.Regalloc(&s, gc.Types[gc.TUINT32], nil)
		gc.Regalloc(&creg, gc.Types[gc.TUINT32], nil)
		if gc.Is64(r.Type) {
			// shift is >= 1<<32
			var cl gc.Node
			var ch gc.Node
			split64(r, &cl, &ch)

			gmove(&ch, &s)
			gins(arm.ATST, &s, nil)
			p6 = gc.Gbranch(arm.ABNE, nil, 0)
			gmove(&cl, &s)
			splitclean()
		} else {
			gmove(r, &s)
			p6 = nil
		}

		gins(arm.ATST, &s, nil)

		// shift == 0
		p1 = gins(arm.AMOVW, &bl, &al)

		p1.Scond = arm.C_SCOND_EQ
		p1 = gins(arm.AMOVW, &bh, &ah)
		p1.Scond = arm.C_SCOND_EQ
		p2 = gc.Gbranch(arm.ABEQ, nil, 0)

		// shift is < 32
		gc.Nodconst(&n1, gc.Types[gc.TUINT32], 32)

		gmove(&n1, &creg)
		gins(arm.ACMP, &s, &creg)

		//	MOVW.LO		bl<<s, al
		p1 = gregshift(arm.AMOVW, &bl, arm.SHIFT_LL, &s, &al)

		p1.Scond = arm.C_SCOND_LO

		//	MOVW.LO		bh<<s, ah
		p1 = gregshift(arm.AMOVW, &bh, arm.SHIFT_LL, &s, &ah)

		p1.Scond = arm.C_SCOND_LO

		//	SUB.LO		s, creg
		p1 = gins(arm.ASUB, &s, &creg)

		p1.Scond = arm.C_SCOND_LO

		//	OR.LO		bl>>creg, ah
		p1 = gregshift(arm.AORR, &bl, arm.SHIFT_LR, &creg, &ah)

		p1.Scond = arm.C_SCOND_LO

		//	BLO	end
		p3 = gc.Gbranch(arm.ABLO, nil, 0)

		// shift == 32
		p1 = gins(arm.AEOR, &al, &al)

		p1.Scond = arm.C_SCOND_EQ
		p1 = gins(arm.AMOVW, &bl, &ah)
		p1.Scond = arm.C_SCOND_EQ
		p4 = gc.Gbranch(arm.ABEQ, nil, 0)

		// shift is < 64
		gc.Nodconst(&n1, gc.Types[gc.TUINT32], 64)

		gmove(&n1, &creg)
		gins(arm.ACMP, &s, &creg)

		//	EOR.LO	al, al
		p1 = gins(arm.AEOR, &al, &al)

		p1.Scond = arm.C_SCOND_LO

		//	MOVW.LO		creg>>1, creg
		p1 = gshift(arm.AMOVW, &creg, arm.SHIFT_LR, 1, &creg)

		p1.Scond = arm.C_SCOND_LO

		//	SUB.LO		creg, s
		p1 = gins(arm.ASUB, &creg, &s)

		p1.Scond = arm.C_SCOND_LO

		//	MOVW	bl<<s, ah
		p1 = gregshift(arm.AMOVW, &bl, arm.SHIFT_LL, &s, &ah)

		p1.Scond = arm.C_SCOND_LO

		p5 = gc.Gbranch(arm.ABLO, nil, 0)

		// shift >= 64
		if p6 != nil {
			gc.Patch(p6, gc.Pc)
		}
		gins(arm.AEOR, &al, &al)
		gins(arm.AEOR, &ah, &ah)

		gc.Patch(p2, gc.Pc)
		gc.Patch(p3, gc.Pc)
		gc.Patch(p4, gc.Pc)
		gc.Patch(p5, gc.Pc)
		gc.Regfree(&s)
		gc.Regfree(&creg)

	olsh_break:
		gc.Regfree(&bl)
		gc.Regfree(&bh)

	case gc.ORSH:
		var bl gc.Node
		gc.Regalloc(&bl, lo1.Type, nil)
		var bh gc.Node
		gc.Regalloc(&bh, hi1.Type, nil)
		gins(arm.AMOVW, &hi1, &bh)
		gins(arm.AMOVW, &lo1, &bl)

		var p4 *obj.Prog
		var p5 *obj.Prog
		var n1 gc.Node
		var p6 *obj.Prog
		var s gc.Node
		var p1 *obj.Prog
		var p2 *obj.Prog
		var creg gc.Node
		var p3 *obj.Prog
		if r.Op == gc.OLITERAL {
			v := uint64(r.Int())
			if v >= 64 {
				if bh.Type.Etype == gc.TINT32 {
					//	MOVW	bh->31, al
					gshift(arm.AMOVW, &bh, arm.SHIFT_AR, 31, &al)

					//	MOVW	bh->31, ah
					gshift(arm.AMOVW, &bh, arm.SHIFT_AR, 31, &ah)
				} else {
					gins(arm.AEOR, &al, &al)
					gins(arm.AEOR, &ah, &ah)
				}
			} else if v > 32 {
				if bh.Type.Etype == gc.TINT32 {
					//	MOVW	bh->(v-32), al
					gshift(arm.AMOVW, &bh, arm.SHIFT_AR, int32(v-32), &al)

					//	MOVW	bh->31, ah
					gshift(arm.AMOVW, &bh, arm.SHIFT_AR, 31, &ah)
				} else {
					//	MOVW	bh>>(v-32), al
					gshift(arm.AMOVW, &bh, arm.SHIFT_LR, int32(v-32), &al)

					gins(arm.AEOR, &ah, &ah)
				}
			} else if v == 32 {
				gins(arm.AMOVW, &bh, &al)
				if bh.Type.Etype == gc.TINT32 {
					//	MOVW	bh->31, ah
					gshift(arm.AMOVW, &bh, arm.SHIFT_AR, 31, &ah)
				} else {
					gins(arm.AEOR, &ah, &ah)
				}
			} else if v > 0 {
				//	MOVW	bl>>v, al
				gshift(arm.AMOVW, &bl, arm.SHIFT_LR, int32(v), &al)

				//	OR		bh<<(32-v), al
				gshift(arm.AORR, &bh, arm.SHIFT_LL, int32(32-v), &al)

				if bh.Type.Etype == gc.TINT32 {
					//	MOVW	bh->v, ah
					gshift(arm.AMOVW, &bh, arm.SHIFT_AR, int32(v), &ah)
				} else {
					//	MOVW	bh>>v, ah
					gshift(arm.AMOVW, &bh, arm.SHIFT_LR, int32(v), &ah)
				}
			} else {
				gins(arm.AMOVW, &bl, &al)
				gins(arm.AMOVW, &bh, &ah)
			}

			goto orsh_break
		}

		gc.Regalloc(&s, gc.Types[gc.TUINT32], nil)
		gc.Regalloc(&creg, gc.Types[gc.TUINT32], nil)
		if gc.Is64(r.Type) {
			// shift is >= 1<<32
			var ch gc.Node
			var cl gc.Node
			split64(r, &cl, &ch)

			gmove(&ch, &s)
			gins(arm.ATST, &s, nil)
			var p1 *obj.Prog
			if bh.Type.Etype == gc.TINT32 {
				p1 = gshift(arm.AMOVW, &bh, arm.SHIFT_AR, 31, &ah)
			} else {
				p1 = gins(arm.AEOR, &ah, &ah)
			}
			p1.Scond = arm.C_SCOND_NE
			p6 = gc.Gbranch(arm.ABNE, nil, 0)
			gmove(&cl, &s)
			splitclean()
		} else {
			gmove(r, &s)
			p6 = nil
		}

		gins(arm.ATST, &s, nil)

		// shift == 0
		p1 = gins(arm.AMOVW, &bl, &al)

		p1.Scond = arm.C_SCOND_EQ
		p1 = gins(arm.AMOVW, &bh, &ah)
		p1.Scond = arm.C_SCOND_EQ
		p2 = gc.Gbranch(arm.ABEQ, nil, 0)

		// check if shift is < 32
		gc.Nodconst(&n1, gc.Types[gc.TUINT32], 32)

		gmove(&n1, &creg)
		gins(arm.ACMP, &s, &creg)

		//	MOVW.LO		bl>>s, al
		p1 = gregshift(arm.AMOVW, &bl, arm.SHIFT_LR, &s, &al)

		p1.Scond = arm.C_SCOND_LO

		//	SUB.LO		s,creg
		p1 = gins(arm.ASUB, &s, &creg)

		p1.Scond = arm.C_SCOND_LO

		//	OR.LO		bh<<(32-s), al
		p1 = gregshift(arm.AORR, &bh, arm.SHIFT_LL, &creg, &al)

		p1.Scond = arm.C_SCOND_LO

		if bh.Type.Etype == gc.TINT32 {
			//	MOVW	bh->s, ah
			p1 = gregshift(arm.AMOVW, &bh, arm.SHIFT_AR, &s, &ah)
		} else {
			//	MOVW	bh>>s, ah
			p1 = gregshift(arm.AMOVW, &bh, arm.SHIFT_LR, &s, &ah)
		}

		p1.Scond = arm.C_SCOND_LO

		//	BLO	end
		p3 = gc.Gbranch(arm.ABLO, nil, 0)

		// shift == 32
		p1 = gins(arm.AMOVW, &bh, &al)

		p1.Scond = arm.C_SCOND_EQ
		if bh.Type.Etype == gc.TINT32 {
			gshift(arm.AMOVW, &bh, arm.SHIFT_AR, 31, &ah)
		} else {
			gins(arm.AEOR, &ah, &ah)
		}
		p4 = gc.Gbranch(arm.ABEQ, nil, 0)

		// check if shift is < 64
		gc.Nodconst(&n1, gc.Types[gc.TUINT32], 64)

		gmove(&n1, &creg)
		gins(arm.ACMP, &s, &creg)

		//	MOVW.LO		creg>>1, creg
		p1 = gshift(arm.AMOVW, &creg, arm.SHIFT_LR, 1, &creg)

		p1.Scond = arm.C_SCOND_LO

		//	SUB.LO		creg, s
		p1 = gins(arm.ASUB, &creg, &s)

		p1.Scond = arm.C_SCOND_LO

		if bh.Type.Etype == gc.TINT32 {
			//	MOVW	bh->(s-32), al
			p1 := gregshift(arm.AMOVW, &bh, arm.SHIFT_AR, &s, &al)

			p1.Scond = arm.C_SCOND_LO
		} else {
			//	MOVW	bh>>(v-32), al
			p1 := gregshift(arm.AMOVW, &bh, arm.SHIFT_LR, &s, &al)

			p1.Scond = arm.C_SCOND_LO
		}

		//	BLO	end
		p5 = gc.Gbranch(arm.ABLO, nil, 0)

		// s >= 64
		if p6 != nil {
			gc.Patch(p6, gc.Pc)
		}
		if bh.Type.Etype == gc.TINT32 {
			//	MOVW	bh->31, al
			gshift(arm.AMOVW, &bh, arm.SHIFT_AR, 31, &al)
		} else {
			gins(arm.AEOR, &al, &al)
		}

		gc.Patch(p2, gc.Pc)
		gc.Patch(p3, gc.Pc)
		gc.Patch(p4, gc.Pc)
		gc.Patch(p5, gc.Pc)
		gc.Regfree(&s)
		gc.Regfree(&creg)

	orsh_break:
		gc.Regfree(&bl)
		gc.Regfree(&bh)

		// TODO(kaib): literal optimizations
	// make constant the right side (it usually is anyway).
	//		if(lo1.op == OLITERAL) {
	//			nswap(&lo1, &lo2);
	//			nswap(&hi1, &hi2);
	//		}
	//		if(lo2.op == OLITERAL) {
	//			// special cases for constants.
	//			lv = mpgetfix(lo2.val.u.xval);
	//			hv = mpgetfix(hi2.val.u.xval);
	//			splitclean();	// right side
	//			split64(res, &lo2, &hi2);
	//			switch(n->op) {
	//			case OXOR:
	//				gmove(&lo1, &lo2);
	//				gmove(&hi1, &hi2);
	//				switch(lv) {
	//				case 0:
	//					break;
	//				case 0xffffffffu:
	//					gins(ANOTL, N, &lo2);
	//					break;
	//				default:
	//					gins(AXORL, ncon(lv), &lo2);
	//					break;
	//				}
	//				switch(hv) {
	//				case 0:
	//					break;
	//				case 0xffffffffu:
	//					gins(ANOTL, N, &hi2);
	//					break;
	//				default:
	//					gins(AXORL, ncon(hv), &hi2);
	//					break;
	//				}
	//				break;

	//			case OAND:
	//				switch(lv) {
	//				case 0:
	//					gins(AMOVL, ncon(0), &lo2);
	//					break;
	//				default:
	//					gmove(&lo1, &lo2);
	//					if(lv != 0xffffffffu)
	//						gins(AANDL, ncon(lv), &lo2);
	//					break;
	//				}
	//				switch(hv) {
	//				case 0:
	//					gins(AMOVL, ncon(0), &hi2);
	//					break;
	//				default:
	//					gmove(&hi1, &hi2);
	//					if(hv != 0xffffffffu)
	//						gins(AANDL, ncon(hv), &hi2);
	//					break;
	//				}
	//				break;

	//			case OOR:
	//				switch(lv) {
	//				case 0:
	//					gmove(&lo1, &lo2);
	//					break;
	//				case 0xffffffffu:
	//					gins(AMOVL, ncon(0xffffffffu), &lo2);
	//					break;
	//				default:
	//					gmove(&lo1, &lo2);
	//					gins(AORL, ncon(lv), &lo2);
	//					break;
	//				}
	//				switch(hv) {
	//				case 0:
	//					gmove(&hi1, &hi2);
	//					break;
	//				case 0xffffffffu:
	//					gins(AMOVL, ncon(0xffffffffu), &hi2);
	//					break;
	//				default:
	//					gmove(&hi1, &hi2);
	//					gins(AORL, ncon(hv), &hi2);
	//					break;
	//				}
	//				break;
	//			}
	//			splitclean();
	//			splitclean();
	//			goto out;
	//		}
	case gc.OXOR,
		gc.OAND,
		gc.OOR:
		var n1 gc.Node
		gc.Regalloc(&n1, lo1.Type, nil)

		gins(arm.AMOVW, &lo1, &al)
		gins(arm.AMOVW, &hi1, &ah)
		gins(arm.AMOVW, &lo2, &n1)
		gins(optoas(n.Op, lo1.Type), &n1, &al)
		gins(arm.AMOVW, &hi2, &n1)
		gins(optoas(n.Op, lo1.Type), &n1, &ah)
		gc.Regfree(&n1)
	}

	if gc.Is64(r.Type) {
		splitclean()
	}
	splitclean()

	split64(res, &lo1, &hi1)
	gins(arm.AMOVW, &al, &lo1)
	gins(arm.AMOVW, &ah, &hi1)
	splitclean()

	//out:
	gc.Regfree(&al)

	gc.Regfree(&ah)
}
Exemplo n.º 17
0
Arquivo: ggen.go Projeto: ckeyer/gosrc
func clearfat_tail(n1 *gc.Node, b int64) {
	if b >= 16 {
		var vec_zero gc.Node
		gc.Regalloc(&vec_zero, gc.Types[gc.TFLOAT64], nil)
		gins(x86.AXORPS, &vec_zero, &vec_zero)

		for b >= 16 {
			gins(x86.AMOVUPS, &vec_zero, n1)
			n1.Xoffset += 16
			b -= 16
		}

		// MOVUPS X0, off(base) is a few bytes shorter than MOV 0, off(base)
		if b != 0 {
			n1.Xoffset -= 16 - b
			gins(x86.AMOVUPS, &vec_zero, n1)
		}

		gc.Regfree(&vec_zero)
		return
	}

	// Write sequence of MOV 0, off(base) instead of using STOSQ.
	// The hope is that although the code will be slightly longer,
	// the MOVs will have no dependencies and pipeline better
	// than the unrolled STOSQ loop.
	var z gc.Node
	gc.Nodconst(&z, gc.Types[gc.TUINT64], 0)
	if b >= 8 {
		n1.Type = z.Type
		gins(x86.AMOVQ, &z, n1)
		n1.Xoffset += 8
		b -= 8

		if b != 0 {
			n1.Xoffset -= 8 - b
			gins(x86.AMOVQ, &z, n1)
		}
		return
	}

	if b >= 4 {
		gc.Nodconst(&z, gc.Types[gc.TUINT32], 0)
		n1.Type = z.Type
		gins(x86.AMOVL, &z, n1)
		n1.Xoffset += 4
		b -= 4

		if b != 0 {
			n1.Xoffset -= 4 - b
			gins(x86.AMOVL, &z, n1)
		}
		return
	}

	if b >= 2 {
		gc.Nodconst(&z, gc.Types[gc.TUINT16], 0)
		n1.Type = z.Type
		gins(x86.AMOVW, &z, n1)
		n1.Xoffset += 2
		b -= 2
	}

	gc.Nodconst(&z, gc.Types[gc.TUINT8], 0)
	for b > 0 {
		n1.Type = z.Type
		gins(x86.AMOVB, &z, n1)
		n1.Xoffset++
		b--
	}

}
Exemplo n.º 18
0
Arquivo: ggen.go Projeto: ckeyer/gosrc
/*
 * generate division.
 * generates one of:
 *	res = nl / nr
 *	res = nl % nr
 * according to op.
 */
func dodiv(op gc.Op, nl *gc.Node, nr *gc.Node, res *gc.Node) {
	// Have to be careful about handling
	// most negative int divided by -1 correctly.
	// The hardware will trap.
	// Also the byte divide instruction needs AH,
	// which we otherwise don't have to deal with.
	// Easiest way to avoid for int8, int16: use int32.
	// For int32 and int64, use explicit test.
	// Could use int64 hw for int32.
	t := nl.Type

	t0 := t
	check := false
	if gc.Issigned[t.Etype] {
		check = true
		if gc.Isconst(nl, gc.CTINT) && nl.Int() != -(1<<uint64(t.Width*8-1)) {
			check = false
		} else if gc.Isconst(nr, gc.CTINT) && nr.Int() != -1 {
			check = false
		}
	}

	if t.Width < 4 {
		if gc.Issigned[t.Etype] {
			t = gc.Types[gc.TINT32]
		} else {
			t = gc.Types[gc.TUINT32]
		}
		check = false
	}

	a := optoas(op, t)

	var n3 gc.Node
	gc.Regalloc(&n3, t0, nil)
	var ax gc.Node
	var oldax gc.Node
	if nl.Ullman >= nr.Ullman {
		savex(x86.REG_AX, &ax, &oldax, res, t0)
		gc.Cgen(nl, &ax)
		gc.Regalloc(&ax, t0, &ax) // mark ax live during cgen
		gc.Cgen(nr, &n3)
		gc.Regfree(&ax)
	} else {
		gc.Cgen(nr, &n3)
		savex(x86.REG_AX, &ax, &oldax, res, t0)
		gc.Cgen(nl, &ax)
	}

	if t != t0 {
		// Convert
		ax1 := ax

		n31 := n3
		ax.Type = t
		n3.Type = t
		gmove(&ax1, &ax)
		gmove(&n31, &n3)
	}

	var n4 gc.Node
	if gc.Nacl {
		// Native Client does not relay the divide-by-zero trap
		// to the executing program, so we must insert a check
		// for ourselves.
		gc.Nodconst(&n4, t, 0)

		gins(optoas(gc.OCMP, t), &n3, &n4)
		p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
		if panicdiv == nil {
			panicdiv = gc.Sysfunc("panicdivide")
		}
		gc.Ginscall(panicdiv, -1)
		gc.Patch(p1, gc.Pc)
	}

	var p2 *obj.Prog
	if check {
		gc.Nodconst(&n4, t, -1)
		gins(optoas(gc.OCMP, t), &n3, &n4)
		p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
		if op == gc.ODIV {
			// a / (-1) is -a.
			gins(optoas(gc.OMINUS, t), nil, &ax)

			gmove(&ax, res)
		} else {
			// a % (-1) is 0.
			gc.Nodconst(&n4, t, 0)

			gmove(&n4, res)
		}

		p2 = gc.Gbranch(obj.AJMP, nil, 0)
		gc.Patch(p1, gc.Pc)
	}

	var olddx gc.Node
	var dx gc.Node
	savex(x86.REG_DX, &dx, &olddx, res, t)
	if !gc.Issigned[t.Etype] {
		gc.Nodconst(&n4, t, 0)
		gmove(&n4, &dx)
	} else {
		gins(optoas(gc.OEXTEND, t), nil, nil)
	}
	gins(a, &n3, nil)
	gc.Regfree(&n3)
	if op == gc.ODIV {
		gmove(&ax, res)
	} else {
		gmove(&dx, res)
	}
	restx(&dx, &olddx)
	if check {
		gc.Patch(p2, gc.Pc)
	}
	restx(&ax, &oldax)
}
Exemplo n.º 19
0
/*
 * generate
 *	as $c, n
 */
func ginscon(as int, c int64, n2 *gc.Node) {
	var n1 gc.Node
	gc.Nodconst(&n1, gc.Types[gc.TINT32], c)
	gins(as, &n1, n2)
}
Exemplo n.º 20
0
Arquivo: ggen.go Projeto: ckeyer/gosrc
/*
 * generate division.
 * caller must set:
 *	ax = allocated AX register
 *	dx = allocated DX register
 * generates one of:
 *	res = nl / nr
 *	res = nl % nr
 * according to op.
 */
func dodiv(op gc.Op, nl *gc.Node, nr *gc.Node, res *gc.Node, ax *gc.Node, dx *gc.Node) {
	// Have to be careful about handling
	// most negative int divided by -1 correctly.
	// The hardware will trap.
	// Also the byte divide instruction needs AH,
	// which we otherwise don't have to deal with.
	// Easiest way to avoid for int8, int16: use int32.
	// For int32 and int64, use explicit test.
	// Could use int64 hw for int32.
	t := nl.Type

	t0 := t
	check := false
	if gc.Issigned[t.Etype] {
		check = true
		if gc.Isconst(nl, gc.CTINT) && nl.Int() != -1<<uint64(t.Width*8-1) {
			check = false
		} else if gc.Isconst(nr, gc.CTINT) && nr.Int() != -1 {
			check = false
		}
	}

	if t.Width < 4 {
		if gc.Issigned[t.Etype] {
			t = gc.Types[gc.TINT32]
		} else {
			t = gc.Types[gc.TUINT32]
		}
		check = false
	}

	var t1 gc.Node
	gc.Tempname(&t1, t)
	var t2 gc.Node
	gc.Tempname(&t2, t)
	if t0 != t {
		var t3 gc.Node
		gc.Tempname(&t3, t0)
		var t4 gc.Node
		gc.Tempname(&t4, t0)
		gc.Cgen(nl, &t3)
		gc.Cgen(nr, &t4)

		// Convert.
		gmove(&t3, &t1)

		gmove(&t4, &t2)
	} else {
		gc.Cgen(nl, &t1)
		gc.Cgen(nr, &t2)
	}

	var n1 gc.Node
	if !gc.Samereg(ax, res) && !gc.Samereg(dx, res) {
		gc.Regalloc(&n1, t, res)
	} else {
		gc.Regalloc(&n1, t, nil)
	}
	gmove(&t2, &n1)
	gmove(&t1, ax)
	var p2 *obj.Prog
	var n4 gc.Node
	if gc.Nacl {
		// Native Client does not relay the divide-by-zero trap
		// to the executing program, so we must insert a check
		// for ourselves.
		gc.Nodconst(&n4, t, 0)

		gins(optoas(gc.OCMP, t), &n1, &n4)
		p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
		if panicdiv == nil {
			panicdiv = gc.Sysfunc("panicdivide")
		}
		gc.Ginscall(panicdiv, -1)
		gc.Patch(p1, gc.Pc)
	}

	if check {
		gc.Nodconst(&n4, t, -1)
		gins(optoas(gc.OCMP, t), &n1, &n4)
		p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
		if op == gc.ODIV {
			// a / (-1) is -a.
			gins(optoas(gc.OMINUS, t), nil, ax)

			gmove(ax, res)
		} else {
			// a % (-1) is 0.
			gc.Nodconst(&n4, t, 0)

			gmove(&n4, res)
		}

		p2 = gc.Gbranch(obj.AJMP, nil, 0)
		gc.Patch(p1, gc.Pc)
	}

	if !gc.Issigned[t.Etype] {
		var nz gc.Node
		gc.Nodconst(&nz, t, 0)
		gmove(&nz, dx)
	} else {
		gins(optoas(gc.OEXTEND, t), nil, nil)
	}
	gins(optoas(op, t), &n1, nil)
	gc.Regfree(&n1)

	if op == gc.ODIV {
		gmove(ax, res)
	} else {
		gmove(dx, res)
	}
	if check {
		gc.Patch(p2, gc.Pc)
	}
}
Exemplo n.º 21
0
Arquivo: ggen.go Projeto: ckeyer/gosrc
func clearfat(nl *gc.Node) {
	/* clear a fat object */
	if gc.Debug['g'] != 0 {
		gc.Dump("\nclearfat", nl)
	}

	w := uint32(nl.Type.Width)

	// Avoid taking the address for simple enough types.
	if gc.Componentgen(nil, nl) {
		return
	}

	c := w % 4 // bytes
	q := w / 4 // quads

	var r0 gc.Node
	r0.Op = gc.OREGISTER

	r0.Reg = arm.REG_R0
	var r1 gc.Node
	r1.Op = gc.OREGISTER
	r1.Reg = arm.REG_R1
	var dst gc.Node
	gc.Regalloc(&dst, gc.Types[gc.Tptr], &r1)
	gc.Agen(nl, &dst)
	var nc gc.Node
	gc.Nodconst(&nc, gc.Types[gc.TUINT32], 0)
	var nz gc.Node
	gc.Regalloc(&nz, gc.Types[gc.TUINT32], &r0)
	gc.Cgen(&nc, &nz)

	if q > 128 {
		var end gc.Node
		gc.Regalloc(&end, gc.Types[gc.Tptr], nil)
		p := gins(arm.AMOVW, &dst, &end)
		p.From.Type = obj.TYPE_ADDR
		p.From.Offset = int64(q) * 4

		p = gins(arm.AMOVW, &nz, &dst)
		p.To.Type = obj.TYPE_MEM
		p.To.Offset = 4
		p.Scond |= arm.C_PBIT
		pl := p

		p = gins(arm.ACMP, &dst, nil)
		raddr(&end, p)
		gc.Patch(gc.Gbranch(arm.ABNE, nil, 0), pl)

		gc.Regfree(&end)
	} else if q >= 4 && !gc.Nacl {
		f := gc.Sysfunc("duffzero")
		p := gins(obj.ADUFFZERO, nil, f)
		gc.Afunclit(&p.To, f)

		// 4 and 128 = magic constants: see ../../runtime/asm_arm.s
		p.To.Offset = 4 * (128 - int64(q))
	} else {
		var p *obj.Prog
		for q > 0 {
			p = gins(arm.AMOVW, &nz, &dst)
			p.To.Type = obj.TYPE_MEM
			p.To.Offset = 4
			p.Scond |= arm.C_PBIT

			//print("1. %v\n", p);
			q--
		}
	}

	var p *obj.Prog
	for c > 0 {
		p = gins(arm.AMOVB, &nz, &dst)
		p.To.Type = obj.TYPE_MEM
		p.To.Offset = 1
		p.Scond |= arm.C_PBIT

		//print("2. %v\n", p);
		c--
	}

	gc.Regfree(&dst)
	gc.Regfree(&nz)
}
Exemplo n.º 22
0
Arquivo: ggen.go Projeto: ckeyer/gosrc
func clearfat(nl *gc.Node) {
	/* clear a fat object */
	if gc.Debug['g'] != 0 {
		gc.Dump("\nclearfat", nl)
	}

	w := uint32(nl.Type.Width)

	// Avoid taking the address for simple enough types.
	if gc.Componentgen(nil, nl) {
		return
	}

	c := w % 4 // bytes
	q := w / 4 // quads

	if q < 4 {
		// Write sequence of MOV 0, off(base) instead of using STOSL.
		// The hope is that although the code will be slightly longer,
		// the MOVs will have no dependencies and pipeline better
		// than the unrolled STOSL loop.
		// NOTE: Must use agen, not igen, so that optimizer sees address
		// being taken. We are not writing on field boundaries.
		var n1 gc.Node
		gc.Regalloc(&n1, gc.Types[gc.Tptr], nil)

		gc.Agen(nl, &n1)
		n1.Op = gc.OINDREG
		var z gc.Node
		gc.Nodconst(&z, gc.Types[gc.TUINT64], 0)
		for ; q > 0; q-- {
			n1.Type = z.Type
			gins(x86.AMOVL, &z, &n1)
			n1.Xoffset += 4
		}

		gc.Nodconst(&z, gc.Types[gc.TUINT8], 0)
		for ; c > 0; c-- {
			n1.Type = z.Type
			gins(x86.AMOVB, &z, &n1)
			n1.Xoffset++
		}

		gc.Regfree(&n1)
		return
	}

	var n1 gc.Node
	gc.Nodreg(&n1, gc.Types[gc.Tptr], x86.REG_DI)
	gc.Agen(nl, &n1)
	gconreg(x86.AMOVL, 0, x86.REG_AX)

	if q > 128 || (q >= 4 && gc.Nacl) {
		gconreg(x86.AMOVL, int64(q), x86.REG_CX)
		gins(x86.AREP, nil, nil)   // repeat
		gins(x86.ASTOSL, nil, nil) // STOL AL,*(DI)+
	} else if q >= 4 {
		p := gins(obj.ADUFFZERO, nil, nil)
		p.To.Type = obj.TYPE_ADDR
		p.To.Sym = gc.Linksym(gc.Pkglookup("duffzero", gc.Runtimepkg))

		// 1 and 128 = magic constants: see ../../runtime/asm_386.s
		p.To.Offset = 1 * (128 - int64(q))
	} else {
		for q > 0 {
			gins(x86.ASTOSL, nil, nil) // STOL AL,*(DI)+
			q--
		}
	}

	for c > 0 {
		gins(x86.ASTOSB, nil, nil) // STOB AL,*(DI)+
		c--
	}
}
Exemplo n.º 23
0
Arquivo: ggen.go Projeto: ckeyer/gosrc
/*
 * generate shift according to op, one of:
 *	res = nl << nr
 *	res = nl >> nr
 */
func cgen_shift(op gc.Op, bounded bool, nl *gc.Node, nr *gc.Node, res *gc.Node) {
	if nl.Type.Width > 4 {
		gc.Fatalf("cgen_shift %v", nl.Type)
	}

	w := int(nl.Type.Width * 8)

	if op == gc.OLROT {
		v := nr.Int()
		var n1 gc.Node
		gc.Regalloc(&n1, nl.Type, res)
		if w == 32 {
			gc.Cgen(nl, &n1)
			gshift(arm.AMOVW, &n1, arm.SHIFT_RR, int32(w)-int32(v), &n1)
		} else {
			var n2 gc.Node
			gc.Regalloc(&n2, nl.Type, nil)
			gc.Cgen(nl, &n2)
			gshift(arm.AMOVW, &n2, arm.SHIFT_LL, int32(v), &n1)
			gshift(arm.AORR, &n2, arm.SHIFT_LR, int32(w)-int32(v), &n1)
			gc.Regfree(&n2)

			// Ensure sign/zero-extended result.
			gins(optoas(gc.OAS, nl.Type), &n1, &n1)
		}

		gmove(&n1, res)
		gc.Regfree(&n1)
		return
	}

	if nr.Op == gc.OLITERAL {
		var n1 gc.Node
		gc.Regalloc(&n1, nl.Type, res)
		gc.Cgen(nl, &n1)
		sc := uint64(nr.Int())
		if sc == 0 {
		} else // nothing to do
		if sc >= uint64(nl.Type.Width*8) {
			if op == gc.ORSH && gc.Issigned[nl.Type.Etype] {
				gshift(arm.AMOVW, &n1, arm.SHIFT_AR, int32(w), &n1)
			} else {
				gins(arm.AEOR, &n1, &n1)
			}
		} else {
			if op == gc.ORSH && gc.Issigned[nl.Type.Etype] {
				gshift(arm.AMOVW, &n1, arm.SHIFT_AR, int32(sc), &n1)
			} else if op == gc.ORSH {
				gshift(arm.AMOVW, &n1, arm.SHIFT_LR, int32(sc), &n1) // OLSH
			} else {
				gshift(arm.AMOVW, &n1, arm.SHIFT_LL, int32(sc), &n1)
			}
		}

		if w < 32 && op == gc.OLSH {
			gins(optoas(gc.OAS, nl.Type), &n1, &n1)
		}
		gmove(&n1, res)
		gc.Regfree(&n1)
		return
	}

	tr := nr.Type
	var t gc.Node
	var n1 gc.Node
	var n2 gc.Node
	var n3 gc.Node
	if tr.Width > 4 {
		var nt gc.Node
		gc.Tempname(&nt, nr.Type)
		if nl.Ullman >= nr.Ullman {
			gc.Regalloc(&n2, nl.Type, res)
			gc.Cgen(nl, &n2)
			gc.Cgen(nr, &nt)
			n1 = nt
		} else {
			gc.Cgen(nr, &nt)
			gc.Regalloc(&n2, nl.Type, res)
			gc.Cgen(nl, &n2)
		}

		var hi gc.Node
		var lo gc.Node
		split64(&nt, &lo, &hi)
		gc.Regalloc(&n1, gc.Types[gc.TUINT32], nil)
		gc.Regalloc(&n3, gc.Types[gc.TUINT32], nil)
		gmove(&lo, &n1)
		gmove(&hi, &n3)
		splitclean()
		gins(arm.ATST, &n3, nil)
		gc.Nodconst(&t, gc.Types[gc.TUINT32], int64(w))
		p1 := gins(arm.AMOVW, &t, &n1)
		p1.Scond = arm.C_SCOND_NE
		tr = gc.Types[gc.TUINT32]
		gc.Regfree(&n3)
	} else {
		if nl.Ullman >= nr.Ullman {
			gc.Regalloc(&n2, nl.Type, res)
			gc.Cgen(nl, &n2)
			gc.Regalloc(&n1, nr.Type, nil)
			gc.Cgen(nr, &n1)
		} else {
			gc.Regalloc(&n1, nr.Type, nil)
			gc.Cgen(nr, &n1)
			gc.Regalloc(&n2, nl.Type, res)
			gc.Cgen(nl, &n2)
		}
	}

	// test for shift being 0
	gins(arm.ATST, &n1, nil)

	p3 := gc.Gbranch(arm.ABEQ, nil, -1)

	// test and fix up large shifts
	// TODO: if(!bounded), don't emit some of this.
	gc.Regalloc(&n3, tr, nil)

	gc.Nodconst(&t, gc.Types[gc.TUINT32], int64(w))
	gmove(&t, &n3)
	gins(arm.ACMP, &n1, &n3)
	if op == gc.ORSH {
		var p1 *obj.Prog
		var p2 *obj.Prog
		if gc.Issigned[nl.Type.Etype] {
			p1 = gshift(arm.AMOVW, &n2, arm.SHIFT_AR, int32(w)-1, &n2)
			p2 = gregshift(arm.AMOVW, &n2, arm.SHIFT_AR, &n1, &n2)
		} else {
			p1 = gins(arm.AEOR, &n2, &n2)
			p2 = gregshift(arm.AMOVW, &n2, arm.SHIFT_LR, &n1, &n2)
		}

		p1.Scond = arm.C_SCOND_HS
		p2.Scond = arm.C_SCOND_LO
	} else {
		p1 := gins(arm.AEOR, &n2, &n2)
		p2 := gregshift(arm.AMOVW, &n2, arm.SHIFT_LL, &n1, &n2)
		p1.Scond = arm.C_SCOND_HS
		p2.Scond = arm.C_SCOND_LO
	}

	gc.Regfree(&n3)

	gc.Patch(p3, gc.Pc)

	// Left-shift of smaller word must be sign/zero-extended.
	if w < 32 && op == gc.OLSH {
		gins(optoas(gc.OAS, nl.Type), &n2, &n2)
	}
	gmove(&n2, res)

	gc.Regfree(&n1)
	gc.Regfree(&n2)
}