Example #1
0
func ginscmp(op int, t *gc.Type, n1, n2 *gc.Node, likely int) *obj.Prog {
	if gc.Isint[t.Etype] && n1.Op == gc.OLITERAL && gc.Smallintconst(n1) && n2.Op != gc.OLITERAL {
		// Reverse comparison to place constant last.
		op = gc.Brrev(op)
		n1, n2 = n2, n1
	}
	// General case.
	var r1, r2, g1, g2 gc.Node
	if n1.Op == gc.ONAME && n1.Class&gc.PHEAP == 0 || n1.Op == gc.OINDREG {
		r1 = *n1
	} else {
		gc.Regalloc(&r1, t, n1)
		gc.Regalloc(&g1, n1.Type, &r1)
		gc.Cgen(n1, &g1)
		gmove(&g1, &r1)
	}
	if n2.Op == gc.OLITERAL && gc.Isint[t.Etype] && gc.Smallintconst(n2) {
		r2 = *n2
	} else {
		gc.Regalloc(&r2, t, n2)
		gc.Regalloc(&g2, n1.Type, &r2)
		gc.Cgen(n2, &g2)
		gmove(&g2, &r2)
	}
	gins(optoas(gc.OCMP, t), &r1, &r2)
	if r1.Op == gc.OREGISTER {
		gc.Regfree(&g1)
		gc.Regfree(&r1)
	}
	if r2.Op == gc.OREGISTER {
		gc.Regfree(&g2)
		gc.Regfree(&r2)
	}
	return gc.Gbranch(optoas(op, t), nil, likely)
}
Example #2
0
/*
 * generate:
 *	res = n;
 * simplifies and calls gmove.
 */
func cgen(n *gc.Node, res *gc.Node) {
	//print("cgen %N(%d) -> %N(%d)\n", n, n->addable, res, res->addable);
	if gc.Debug['g'] != 0 {
		gc.Dump("\ncgen-n", n)
		gc.Dump("cgen-res", res)
	}

	if n == nil || n.Type == nil {
		return
	}

	if res == nil || res.Type == nil {
		gc.Fatal("cgen: res nil")
	}

	for n.Op == gc.OCONVNOP {
		n = n.Left
	}

	switch n.Op {
	case gc.OSLICE,
		gc.OSLICEARR,
		gc.OSLICESTR,
		gc.OSLICE3,
		gc.OSLICE3ARR:
		if res.Op != gc.ONAME || res.Addable == 0 {
			var n1 gc.Node
			gc.Tempname(&n1, n.Type)
			gc.Cgen_slice(n, &n1)
			cgen(&n1, res)
		} else {
			gc.Cgen_slice(n, res)
		}
		return

	case gc.OEFACE:
		if res.Op != gc.ONAME || res.Addable == 0 {
			var n1 gc.Node
			gc.Tempname(&n1, n.Type)
			gc.Cgen_eface(n, &n1)
			cgen(&n1, res)
		} else {
			gc.Cgen_eface(n, res)
		}
		return
	}

	if n.Ullman >= gc.UINF {
		if n.Op == gc.OINDREG {
			gc.Fatal("cgen: this is going to misscompile")
		}
		if res.Ullman >= gc.UINF {
			var n1 gc.Node
			gc.Tempname(&n1, n.Type)
			cgen(n, &n1)
			cgen(&n1, res)
			return
		}
	}

	if gc.Isfat(n.Type) {
		if n.Type.Width < 0 {
			gc.Fatal("forgot to compute width for %v", gc.Tconv(n.Type, 0))
		}
		sgen(n, res, n.Type.Width)
		return
	}

	if res.Addable == 0 {
		if n.Ullman > res.Ullman {
			var n1 gc.Node
			regalloc(&n1, n.Type, res)
			cgen(n, &n1)
			if n1.Ullman > res.Ullman {
				gc.Dump("n1", &n1)
				gc.Dump("res", res)
				gc.Fatal("loop in cgen")
			}

			cgen(&n1, res)
			regfree(&n1)
			return
		}

		var f int
		if res.Ullman >= gc.UINF {
			goto gen
		}

		if gc.Complexop(n, res) {
			gc.Complexgen(n, res)
			return
		}

		f = 1 // gen thru register
		switch n.Op {
		case gc.OLITERAL:
			if gc.Smallintconst(n) {
				f = 0
			}

		case gc.OREGISTER:
			f = 0
		}

		if !gc.Iscomplex[n.Type.Etype] {
			a := optoas(gc.OAS, res.Type)
			var addr obj.Addr
			if sudoaddable(a, res, &addr) {
				var p1 *obj.Prog
				if f != 0 {
					var n2 gc.Node
					regalloc(&n2, res.Type, nil)
					cgen(n, &n2)
					p1 = gins(a, &n2, nil)
					regfree(&n2)
				} else {
					p1 = gins(a, n, nil)
				}
				p1.To = addr
				if gc.Debug['g'] != 0 {
					fmt.Printf("%v [ignore previous line]\n", p1)
				}
				sudoclean()
				return
			}
		}

	gen:
		var n1 gc.Node
		igen(res, &n1, nil)
		cgen(n, &n1)
		regfree(&n1)
		return
	}

	// update addressability for string, slice
	// can't do in walk because n->left->addable
	// changes if n->left is an escaping local variable.
	switch n.Op {
	case gc.OSPTR,
		gc.OLEN:
		if gc.Isslice(n.Left.Type) || gc.Istype(n.Left.Type, gc.TSTRING) {
			n.Addable = n.Left.Addable
		}

	case gc.OCAP:
		if gc.Isslice(n.Left.Type) {
			n.Addable = n.Left.Addable
		}

	case gc.OITAB:
		n.Addable = n.Left.Addable
	}

	if gc.Complexop(n, res) {
		gc.Complexgen(n, res)
		return
	}

	// if both are addressable, move
	if n.Addable != 0 {
		if n.Op == gc.OREGISTER || res.Op == gc.OREGISTER {
			gmove(n, res)
		} else {
			var n1 gc.Node
			regalloc(&n1, n.Type, nil)
			gmove(n, &n1)
			cgen(&n1, res)
			regfree(&n1)
		}

		return
	}

	nl := n.Left
	nr := n.Right

	if nl != nil && nl.Ullman >= gc.UINF {
		if nr != nil && nr.Ullman >= gc.UINF {
			var n1 gc.Node
			gc.Tempname(&n1, nl.Type)
			cgen(nl, &n1)
			n2 := *n
			n2.Left = &n1
			cgen(&n2, res)
			return
		}
	}

	if !gc.Iscomplex[n.Type.Etype] {
		a := optoas(gc.OAS, n.Type)
		var addr obj.Addr
		if sudoaddable(a, n, &addr) {
			if res.Op == gc.OREGISTER {
				p1 := gins(a, nil, res)
				p1.From = addr
			} else {
				var n2 gc.Node
				regalloc(&n2, n.Type, nil)
				p1 := gins(a, nil, &n2)
				p1.From = addr
				gins(a, &n2, res)
				regfree(&n2)
			}

			sudoclean()
			return
		}
	}

	// TODO(minux): we shouldn't reverse FP comparisons, but then we need to synthesize
	// OGE, OLE, and ONE ourselves.
	// if(nl != N && isfloat[n->type->etype] && isfloat[nl->type->etype]) goto flt;

	var a int
	switch n.Op {
	default:
		gc.Dump("cgen", n)
		gc.Fatal("cgen: unknown op %v", gc.Nconv(n, obj.FmtShort|obj.FmtSign))

		// these call bgen to get a bool value
	case gc.OOROR,
		gc.OANDAND,
		gc.OEQ,
		gc.ONE,
		gc.OLT,
		gc.OLE,
		gc.OGE,
		gc.OGT,
		gc.ONOT:
		p1 := gc.Gbranch(ppc64.ABR, nil, 0)

		p2 := gc.Pc
		gmove(gc.Nodbool(true), res)
		p3 := gc.Gbranch(ppc64.ABR, nil, 0)
		gc.Patch(p1, gc.Pc)
		bgen(n, true, 0, p2)
		gmove(gc.Nodbool(false), res)
		gc.Patch(p3, gc.Pc)
		return

	case gc.OPLUS:
		cgen(nl, res)
		return

		// unary
	case gc.OCOM:
		a := optoas(gc.OXOR, nl.Type)

		var n1 gc.Node
		regalloc(&n1, nl.Type, nil)
		cgen(nl, &n1)
		var n2 gc.Node
		gc.Nodconst(&n2, nl.Type, -1)
		gins(a, &n2, &n1)
		gmove(&n1, res)
		regfree(&n1)
		return

	case gc.OMINUS:
		if gc.Isfloat[nl.Type.Etype] {
			nr = gc.Nodintconst(-1)
			gc.Convlit(&nr, n.Type)
			a = optoas(gc.OMUL, nl.Type)
			goto sbop
		}

		a := optoas(int(n.Op), nl.Type)
		// unary
		var n1 gc.Node
		regalloc(&n1, nl.Type, res)

		cgen(nl, &n1)
		gins(a, nil, &n1)
		gmove(&n1, res)
		regfree(&n1)
		return

		// symmetric binary
	case gc.OAND,
		gc.OOR,
		gc.OXOR,
		gc.OADD,
		gc.OMUL:
		a = optoas(int(n.Op), nl.Type)

		goto sbop

		// asymmetric binary
	case gc.OSUB:
		a = optoas(int(n.Op), nl.Type)

		goto abop

	case gc.OHMUL:
		cgen_hmul(nl, nr, res)

	case gc.OCONV:
		if n.Type.Width > nl.Type.Width {
			// If loading from memory, do conversion during load,
			// so as to avoid use of 8-bit register in, say, int(*byteptr).
			switch nl.Op {
			case gc.ODOT,
				gc.ODOTPTR,
				gc.OINDEX,
				gc.OIND,
				gc.ONAME:
				var n1 gc.Node
				igen(nl, &n1, res)
				var n2 gc.Node
				regalloc(&n2, n.Type, res)
				gmove(&n1, &n2)
				gmove(&n2, res)
				regfree(&n2)
				regfree(&n1)
				return
			}
		}

		var n1 gc.Node
		regalloc(&n1, nl.Type, res)
		var n2 gc.Node
		regalloc(&n2, n.Type, &n1)
		cgen(nl, &n1)

		// if we do the conversion n1 -> n2 here
		// reusing the register, then gmove won't
		// have to allocate its own register.
		gmove(&n1, &n2)

		gmove(&n2, res)
		regfree(&n2)
		regfree(&n1)

	case gc.ODOT,
		gc.ODOTPTR,
		gc.OINDEX,
		gc.OIND,
		gc.ONAME: // PHEAP or PPARAMREF var
		var n1 gc.Node
		igen(n, &n1, res)

		gmove(&n1, res)
		regfree(&n1)

		// interface table is first word of interface value
	case gc.OITAB:
		var n1 gc.Node
		igen(nl, &n1, res)

		n1.Type = n.Type
		gmove(&n1, res)
		regfree(&n1)

		// pointer is the first word of string or slice.
	case gc.OSPTR:
		if gc.Isconst(nl, gc.CTSTR) {
			var n1 gc.Node
			regalloc(&n1, gc.Types[gc.Tptr], res)
			p1 := gins(ppc64.AMOVD, nil, &n1)
			gc.Datastring(nl.Val.U.Sval, &p1.From)
			gmove(&n1, res)
			regfree(&n1)
			break
		}

		var n1 gc.Node
		igen(nl, &n1, res)
		n1.Type = n.Type
		gmove(&n1, res)
		regfree(&n1)

	case gc.OLEN:
		if gc.Istype(nl.Type, gc.TMAP) || gc.Istype(nl.Type, gc.TCHAN) {
			// map and chan have len in the first int-sized word.
			// a zero pointer means zero length
			var n1 gc.Node
			regalloc(&n1, gc.Types[gc.Tptr], res)

			cgen(nl, &n1)

			var n2 gc.Node
			gc.Nodconst(&n2, gc.Types[gc.Tptr], 0)
			gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &n2)
			p1 := gc.Gbranch(optoas(gc.OEQ, gc.Types[gc.Tptr]), nil, 0)

			n2 = n1
			n2.Op = gc.OINDREG
			n2.Type = gc.Types[gc.Simtype[gc.TINT]]
			gmove(&n2, &n1)

			gc.Patch(p1, gc.Pc)

			gmove(&n1, res)
			regfree(&n1)
			break
		}

		if gc.Istype(nl.Type, gc.TSTRING) || gc.Isslice(nl.Type) {
			// both slice and string have len one pointer into the struct.
			// a zero pointer means zero length
			var n1 gc.Node
			igen(nl, &n1, res)

			n1.Type = gc.Types[gc.Simtype[gc.TUINT]]
			n1.Xoffset += int64(gc.Array_nel)
			gmove(&n1, res)
			regfree(&n1)
			break
		}

		gc.Fatal("cgen: OLEN: unknown type %v", gc.Tconv(nl.Type, obj.FmtLong))

	case gc.OCAP:
		if gc.Istype(nl.Type, gc.TCHAN) {
			// chan has cap in the second int-sized word.
			// a zero pointer means zero length
			var n1 gc.Node
			regalloc(&n1, gc.Types[gc.Tptr], res)

			cgen(nl, &n1)

			var n2 gc.Node
			gc.Nodconst(&n2, gc.Types[gc.Tptr], 0)
			gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &n2)
			p1 := gc.Gbranch(optoas(gc.OEQ, gc.Types[gc.Tptr]), nil, 0)

			n2 = n1
			n2.Op = gc.OINDREG
			n2.Xoffset = int64(gc.Widthint)
			n2.Type = gc.Types[gc.Simtype[gc.TINT]]
			gmove(&n2, &n1)

			gc.Patch(p1, gc.Pc)

			gmove(&n1, res)
			regfree(&n1)
			break
		}

		if gc.Isslice(nl.Type) {
			var n1 gc.Node
			igen(nl, &n1, res)
			n1.Type = gc.Types[gc.Simtype[gc.TUINT]]
			n1.Xoffset += int64(gc.Array_cap)
			gmove(&n1, res)
			regfree(&n1)
			break
		}

		gc.Fatal("cgen: OCAP: unknown type %v", gc.Tconv(nl.Type, obj.FmtLong))

	case gc.OADDR:
		if n.Bounded { // let race detector avoid nil checks
			gc.Disable_checknil++
		}
		agen(nl, res)
		if n.Bounded {
			gc.Disable_checknil--
		}

	case gc.OCALLMETH:
		gc.Cgen_callmeth(n, 0)
		cgen_callret(n, res)

	case gc.OCALLINTER:
		cgen_callinter(n, res, 0)
		cgen_callret(n, res)

	case gc.OCALLFUNC:
		cgen_call(n, 0)
		cgen_callret(n, res)

	case gc.OMOD,
		gc.ODIV:
		if gc.Isfloat[n.Type.Etype] {
			a = optoas(int(n.Op), nl.Type)
			goto abop
		}

		if nl.Ullman >= nr.Ullman {
			var n1 gc.Node
			regalloc(&n1, nl.Type, res)
			cgen(nl, &n1)
			cgen_div(int(n.Op), &n1, nr, res)
			regfree(&n1)
		} else {
			var n2 gc.Node
			if !gc.Smallintconst(nr) {
				regalloc(&n2, nr.Type, res)
				cgen(nr, &n2)
			} else {
				n2 = *nr
			}

			cgen_div(int(n.Op), nl, &n2, res)
			if n2.Op != gc.OLITERAL {
				regfree(&n2)
			}
		}

	case gc.OLSH,
		gc.ORSH,
		gc.OLROT:
		cgen_shift(int(n.Op), n.Bounded, nl, nr, res)
	}

	return

	/*
	 * put simplest on right - we'll generate into left
	 * and then adjust it using the computation of right.
	 * constants and variables have the same ullman
	 * count, so look for constants specially.
	 *
	 * an integer constant we can use as an immediate
	 * is simpler than a variable - we can use the immediate
	 * in the adjustment instruction directly - so it goes
	 * on the right.
	 *
	 * other constants, like big integers or floating point
	 * constants, require a mov into a register, so those
	 * might as well go on the left, so we can reuse that
	 * register for the computation.
	 */
sbop: // symmetric binary
	if nl.Ullman < nr.Ullman || (nl.Ullman == nr.Ullman && (gc.Smallintconst(nl) || (nr.Op == gc.OLITERAL && !gc.Smallintconst(nr)))) {
		r := nl
		nl = nr
		nr = r
	}

abop: // asymmetric binary
	var n1 gc.Node
	var n2 gc.Node
	if nl.Ullman >= nr.Ullman {
		regalloc(&n1, nl.Type, res)
		cgen(nl, &n1)

		/*
			 * This generates smaller code - it avoids a MOV - but it's
			 * easily 10% slower due to not being able to
			 * optimize/manipulate the move.
			 * To see, run: go test -bench . crypto/md5
			 * with and without.
			 *
				if(sudoaddable(a, nr, &addr)) {
					p1 = gins(a, N, &n1);
					p1->from = addr;
					gmove(&n1, res);
					sudoclean();
					regfree(&n1);
					goto ret;
				}
			 *
		*/
		// TODO(minux): enable using constants directly in certain instructions.
		//if(smallintconst(nr))
		//	n2 = *nr;
		//else {
		regalloc(&n2, nr.Type, nil)

		cgen(nr, &n2)
	} else //}
	{
		//if(smallintconst(nr))
		//	n2 = *nr;
		//else {
		regalloc(&n2, nr.Type, res)

		cgen(nr, &n2)

		//}
		regalloc(&n1, nl.Type, nil)

		cgen(nl, &n1)
	}

	gins(a, &n2, &n1)

	// Normalize result for types smaller than word.
	if n.Type.Width < int64(gc.Widthreg) {
		switch n.Op {
		case gc.OADD,
			gc.OSUB,
			gc.OMUL,
			gc.OLSH:
			gins(optoas(gc.OAS, n.Type), &n1, &n1)
		}
	}

	gmove(&n1, res)
	regfree(&n1)
	if n2.Op != gc.OLITERAL {
		regfree(&n2)
	}
	return
}
Example #3
0
/*
 * 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) {
	var w int

	if nr.Op != gc.OLITERAL {
		goto longdiv
	}
	w = int(nl.Type.Width * 8)

	// Front end handled 32-bit division. We only need to handle 64-bit.
	// try to do division by multiply by (2^w)/d
	// see hacker's delight chapter 10
	switch gc.Simtype[nl.Type.Etype] {
	default:
		goto longdiv

	case gc.TUINT64:
		var m gc.Magic
		m.W = w
		m.Ud = uint64(gc.Mpgetfix(nr.Val.U.Xval))
		gc.Umagic(&m)
		if m.Bad != 0 {
			break
		}
		if op == gc.OMOD {
			goto longmod
		}

		var n1 gc.Node
		cgenr(nl, &n1, nil)
		var n2 gc.Node
		gc.Nodconst(&n2, nl.Type, int64(m.Um))
		var n3 gc.Node
		regalloc(&n3, nl.Type, res)
		cgen_hmul(&n1, &n2, &n3)

		if m.Ua != 0 {
			// need to add numerator accounting for overflow
			gins(optoas(gc.OADD, nl.Type), &n1, &n3)

			gc.Nodconst(&n2, nl.Type, 1)
			gins(optoas(gc.ORROTC, nl.Type), &n2, &n3)
			gc.Nodconst(&n2, nl.Type, int64(m.S)-1)
			gins(optoas(gc.ORSH, nl.Type), &n2, &n3)
		} else {
			gc.Nodconst(&n2, nl.Type, int64(m.S))
			gins(optoas(gc.ORSH, nl.Type), &n2, &n3) // shift dx
		}

		gmove(&n3, res)
		regfree(&n1)
		regfree(&n3)
		return

	case gc.TINT64:
		var m gc.Magic
		m.W = w
		m.Sd = gc.Mpgetfix(nr.Val.U.Xval)
		gc.Smagic(&m)
		if m.Bad != 0 {
			break
		}
		if op == gc.OMOD {
			goto longmod
		}

		var n1 gc.Node
		cgenr(nl, &n1, res)
		var n2 gc.Node
		gc.Nodconst(&n2, nl.Type, m.Sm)
		var n3 gc.Node
		regalloc(&n3, nl.Type, nil)
		cgen_hmul(&n1, &n2, &n3)

		if m.Sm < 0 {
			// need to add numerator
			gins(optoas(gc.OADD, nl.Type), &n1, &n3)
		}

		gc.Nodconst(&n2, nl.Type, int64(m.S))
		gins(optoas(gc.ORSH, nl.Type), &n2, &n3) // shift n3

		gc.Nodconst(&n2, nl.Type, int64(w)-1)

		gins(optoas(gc.ORSH, nl.Type), &n2, &n1) // -1 iff num is neg
		gins(optoas(gc.OSUB, nl.Type), &n1, &n3) // added

		if m.Sd < 0 {
			// this could probably be removed
			// by factoring it into the multiplier
			gins(optoas(gc.OMINUS, nl.Type), nil, &n3)
		}

		gmove(&n3, res)
		regfree(&n1)
		regfree(&n3)
		return
	}

	goto longdiv

	// division and mod using (slow) hardware instruction
longdiv:
	dodiv(op, nl, nr, res)

	return

	// mod using formula A%B = A-(A/B*B) but
	// we know that there is a fast algorithm for A/B
longmod:
	var n1 gc.Node
	regalloc(&n1, nl.Type, res)

	cgen(nl, &n1)
	var n2 gc.Node
	regalloc(&n2, nl.Type, nil)
	cgen_div(gc.ODIV, &n1, nr, &n2)
	a := optoas(gc.OMUL, nl.Type)
	if w == 8 {
		// use 2-operand 16-bit multiply
		// because there is no 2-operand 8-bit multiply
		a = x86.AIMULW
	}

	if !gc.Smallintconst(nr) {
		var n3 gc.Node
		regalloc(&n3, nl.Type, nil)
		cgen(nr, &n3)
		gins(a, &n3, &n2)
		regfree(&n3)
	} else {
		gins(a, nr, &n2)
	}
	gins(optoas(gc.OSUB, nl.Type), &n2, &n1)
	gmove(&n1, res)
	regfree(&n1)
	regfree(&n2)
}
Example #4
0
/*
 * allocate a register (reusing res if possible) and generate
 * a = &n
 * The caller must call regfree(a).
 * The generated code checks that the result is not nil.
 */
func agenr(n *gc.Node, a *gc.Node, res *gc.Node) {
	if gc.Debug['g'] != 0 {
		gc.Dump("\nagenr-n", n)
	}

	nl := n.Left
	nr := n.Right

	switch n.Op {
	case gc.ODOT,
		gc.ODOTPTR,
		gc.OCALLFUNC,
		gc.OCALLMETH,
		gc.OCALLINTER:
		var n1 gc.Node
		igen(n, &n1, res)
		regalloc(a, gc.Types[gc.Tptr], &n1)
		agen(&n1, a)
		regfree(&n1)

	case gc.OIND:
		cgenr(n.Left, a, res)
		gc.Cgen_checknil(a)

	case gc.OINDEX:
		freelen := 0
		w := uint64(n.Type.Width)

		// Generate the non-addressable child first.
		var n3 gc.Node
		var nlen gc.Node
		var tmp gc.Node
		var n1 gc.Node
		if nr.Addable != 0 {
			goto irad
		}
		if nl.Addable != 0 {
			cgenr(nr, &n1, nil)
			if !gc.Isconst(nl, gc.CTSTR) {
				if gc.Isfixedarray(nl.Type) {
					agenr(nl, &n3, res)
				} else {
					igen(nl, &nlen, res)
					freelen = 1
					nlen.Type = gc.Types[gc.Tptr]
					nlen.Xoffset += int64(gc.Array_array)
					regalloc(&n3, gc.Types[gc.Tptr], res)
					gmove(&nlen, &n3)
					nlen.Type = gc.Types[gc.Simtype[gc.TUINT]]
					nlen.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
				}
			}

			goto index
		}

		gc.Tempname(&tmp, nr.Type)
		cgen(nr, &tmp)
		nr = &tmp

	irad:
		if !gc.Isconst(nl, gc.CTSTR) {
			if gc.Isfixedarray(nl.Type) {
				agenr(nl, &n3, res)
			} else {
				if nl.Addable == 0 {
					// igen will need an addressable node.
					var tmp2 gc.Node
					gc.Tempname(&tmp2, nl.Type)

					cgen(nl, &tmp2)
					nl = &tmp2
				}

				igen(nl, &nlen, res)
				freelen = 1
				nlen.Type = gc.Types[gc.Tptr]
				nlen.Xoffset += int64(gc.Array_array)
				regalloc(&n3, gc.Types[gc.Tptr], res)
				gmove(&nlen, &n3)
				nlen.Type = gc.Types[gc.Simtype[gc.TUINT]]
				nlen.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
			}
		}

		if !gc.Isconst(nr, gc.CTINT) {
			cgenr(nr, &n1, nil)
		}

		goto index

		// &a is in &n3 (allocated in res)
		// i is in &n1 (if not constant)
		// len(a) is in nlen (if needed)
		// w is width

		// constant index
	index:
		if gc.Isconst(nr, gc.CTINT) {
			if gc.Isconst(nl, gc.CTSTR) {
				gc.Fatal("constant string constant index") // front end should handle
			}
			v := uint64(gc.Mpgetfix(nr.Val.U.Xval))
			if gc.Isslice(nl.Type) || nl.Type.Etype == gc.TSTRING {
				if gc.Debug['B'] == 0 && !n.Bounded {
					var n2 gc.Node
					gc.Nodconst(&n2, gc.Types[gc.Simtype[gc.TUINT]], int64(v))
					if gc.Smallintconst(nr) {
						gins(optoas(gc.OCMP, gc.Types[gc.Simtype[gc.TUINT]]), &nlen, &n2)
					} else {
						regalloc(&tmp, gc.Types[gc.Simtype[gc.TUINT]], nil)
						gmove(&n2, &tmp)
						gins(optoas(gc.OCMP, gc.Types[gc.Simtype[gc.TUINT]]), &nlen, &tmp)
						regfree(&tmp)
					}

					p1 := gc.Gbranch(optoas(gc.OGT, gc.Types[gc.Simtype[gc.TUINT]]), nil, +1)
					ginscall(gc.Panicindex, -1)
					gc.Patch(p1, gc.Pc)
				}

				regfree(&nlen)
			}

			if v*w != 0 {
				ginscon(optoas(gc.OADD, gc.Types[gc.Tptr]), int64(v*w), &n3)
			}
			*a = n3
			break
		}

		// type of the index
		t := gc.Types[gc.TUINT64]

		if gc.Issigned[n1.Type.Etype] {
			t = gc.Types[gc.TINT64]
		}

		var n2 gc.Node
		regalloc(&n2, t, &n1) // i
		gmove(&n1, &n2)
		regfree(&n1)

		if gc.Debug['B'] == 0 && !n.Bounded {
			// check bounds
			t = gc.Types[gc.Simtype[gc.TUINT]]

			if gc.Is64(nr.Type) {
				t = gc.Types[gc.TUINT64]
			}
			if gc.Isconst(nl, gc.CTSTR) {
				gc.Nodconst(&nlen, t, int64(len(nl.Val.U.Sval)))
			} else if gc.Isslice(nl.Type) || nl.Type.Etype == gc.TSTRING {
				if gc.Is64(nr.Type) {
					var n5 gc.Node
					regalloc(&n5, t, nil)
					gmove(&nlen, &n5)
					regfree(&nlen)
					nlen = n5
				}
			} else {
				gc.Nodconst(&nlen, t, nl.Type.Bound)
				if !gc.Smallintconst(&nlen) {
					var n5 gc.Node
					regalloc(&n5, t, nil)
					gmove(&nlen, &n5)
					nlen = n5
					freelen = 1
				}
			}

			gins(optoas(gc.OCMP, t), &n2, &nlen)
			p1 := gc.Gbranch(optoas(gc.OLT, t), nil, +1)
			ginscall(gc.Panicindex, -1)
			gc.Patch(p1, gc.Pc)
		}

		if gc.Isconst(nl, gc.CTSTR) {
			regalloc(&n3, gc.Types[gc.Tptr], res)
			p1 := gins(x86.ALEAQ, nil, &n3)
			gc.Datastring(nl.Val.U.Sval, &p1.From)
			gins(x86.AADDQ, &n2, &n3)
			goto indexdone
		}

		if w == 0 {
		} else // nothing to do
		if w == 1 || w == 2 || w == 4 || w == 8 {
			p1 := gins(x86.ALEAQ, &n2, &n3)
			p1.From.Type = obj.TYPE_MEM
			p1.From.Scale = int16(w)
			p1.From.Index = p1.From.Reg
			p1.From.Reg = p1.To.Reg
		} else {
			ginscon(optoas(gc.OMUL, t), int64(w), &n2)
			gins(optoas(gc.OADD, gc.Types[gc.Tptr]), &n2, &n3)
		}

	indexdone:
		*a = n3
		regfree(&n2)
		if freelen != 0 {
			regfree(&nlen)
		}

	default:
		regalloc(a, gc.Types[gc.Tptr], res)
		agen(n, a)
	}
}
Example #5
0
/*
 * generate:
 *	if(n == true) goto to;
 */
func bgen(n *gc.Node, true_ bool, likely int, to *obj.Prog) {
	if gc.Debug['g'] != 0 {
		gc.Dump("\nbgen", n)
	}

	if n == nil {
		n = gc.Nodbool(true)
	}

	if n.Ninit != nil {
		gc.Genlist(n.Ninit)
	}

	if n.Type == nil {
		gc.Convlit(&n, gc.Types[gc.TBOOL])
		if n.Type == nil {
			return
		}
	}

	et := int(n.Type.Etype)
	if et != gc.TBOOL {
		gc.Yyerror("cgen: bad type %v for %v", gc.Tconv(n.Type, 0), gc.Oconv(int(n.Op), 0))
		gc.Patch(gins(obj.AEND, nil, nil), to)
		return
	}

	for n.Op == gc.OCONVNOP {
		n = n.Left
		if n.Ninit != nil {
			gc.Genlist(n.Ninit)
		}
	}

	var nl *gc.Node
	var nr *gc.Node
	switch n.Op {
	default:
		goto def

		// need to ask if it is bool?
	case gc.OLITERAL:
		if !true_ == (n.Val.U.Bval == 0) {
			gc.Patch(gc.Gbranch(obj.AJMP, nil, likely), to)
		}
		return

	case gc.ONAME:
		if n.Addable == 0 {
			goto def
		}
		var n1 gc.Node
		gc.Nodconst(&n1, n.Type, 0)
		gins(optoas(gc.OCMP, n.Type), n, &n1)
		a := x86.AJNE
		if !true_ {
			a = x86.AJEQ
		}
		gc.Patch(gc.Gbranch(a, n.Type, likely), to)
		return

	case gc.OANDAND,
		gc.OOROR:
		if (n.Op == gc.OANDAND) == true_ {
			p1 := gc.Gbranch(obj.AJMP, nil, 0)
			p2 := gc.Gbranch(obj.AJMP, nil, 0)
			gc.Patch(p1, gc.Pc)
			bgen(n.Left, !true_, -likely, p2)
			bgen(n.Right, !true_, -likely, p2)
			p1 = gc.Gbranch(obj.AJMP, nil, 0)
			gc.Patch(p1, to)
			gc.Patch(p2, gc.Pc)
		} else {
			bgen(n.Left, true_, likely, to)
			bgen(n.Right, true_, likely, to)
		}

		return

	case gc.OEQ,
		gc.ONE,
		gc.OLT,
		gc.OGT,
		gc.OLE,
		gc.OGE:
		nr = n.Right
		if nr == nil || nr.Type == nil {
			return
		}
		fallthrough

	case gc.ONOT: // unary
		nl = n.Left

		if nl == nil || nl.Type == nil {
			return
		}
	}

	switch n.Op {
	case gc.ONOT:
		bgen(nl, !true_, likely, to)
		return

	case gc.OEQ,
		gc.ONE,
		gc.OLT,
		gc.OGT,
		gc.OLE,
		gc.OGE:
		a := int(n.Op)
		if !true_ {
			if gc.Isfloat[nr.Type.Etype] {
				// brcom is not valid on floats when NaN is involved.
				p1 := gc.Gbranch(obj.AJMP, nil, 0)

				p2 := gc.Gbranch(obj.AJMP, nil, 0)
				gc.Patch(p1, gc.Pc)
				ll := n.Ninit // avoid re-genning ninit
				n.Ninit = nil
				bgen(n, true, -likely, p2)
				n.Ninit = ll
				gc.Patch(gc.Gbranch(obj.AJMP, nil, 0), to)
				gc.Patch(p2, gc.Pc)
				return
			}

			a = gc.Brcom(a)
			true_ = !true_
		}

		// make simplest on right
		if nl.Op == gc.OLITERAL || (nl.Ullman < nr.Ullman && nl.Ullman < gc.UINF) {
			a = gc.Brrev(a)
			r := nl
			nl = nr
			nr = r
		}

		if gc.Isslice(nl.Type) {
			// front end should only leave cmp to literal nil
			if (a != gc.OEQ && a != gc.ONE) || nr.Op != gc.OLITERAL {
				gc.Yyerror("illegal slice comparison")
				break
			}

			a = optoas(a, gc.Types[gc.Tptr])
			var n1 gc.Node
			igen(nl, &n1, nil)
			n1.Xoffset += int64(gc.Array_array)
			n1.Type = gc.Types[gc.Tptr]
			var tmp gc.Node
			gc.Nodconst(&tmp, gc.Types[gc.Tptr], 0)
			gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &tmp)
			gc.Patch(gc.Gbranch(a, gc.Types[gc.Tptr], likely), to)
			regfree(&n1)
			break
		}

		if gc.Isinter(nl.Type) {
			// front end should only leave cmp to literal nil
			if (a != gc.OEQ && a != gc.ONE) || nr.Op != gc.OLITERAL {
				gc.Yyerror("illegal interface comparison")
				break
			}

			a = optoas(a, gc.Types[gc.Tptr])
			var n1 gc.Node
			igen(nl, &n1, nil)
			n1.Type = gc.Types[gc.Tptr]
			var tmp gc.Node
			gc.Nodconst(&tmp, gc.Types[gc.Tptr], 0)
			gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &tmp)
			gc.Patch(gc.Gbranch(a, gc.Types[gc.Tptr], likely), to)
			regfree(&n1)
			break
		}

		if gc.Iscomplex[nl.Type.Etype] {
			gc.Complexbool(a, nl, nr, true_, likely, to)
			break
		}

		var n2 gc.Node
		var n1 gc.Node
		if nr.Ullman >= gc.UINF {
			regalloc(&n1, nl.Type, nil)
			cgen(nl, &n1)

			var tmp gc.Node
			gc.Tempname(&tmp, nl.Type)
			gmove(&n1, &tmp)
			regfree(&n1)

			regalloc(&n2, nr.Type, nil)
			cgen(nr, &n2)

			regalloc(&n1, nl.Type, nil)
			cgen(&tmp, &n1)

			goto cmp
		}

		regalloc(&n1, nl.Type, nil)
		cgen(nl, &n1)

		if gc.Smallintconst(nr) {
			gins(optoas(gc.OCMP, nr.Type), &n1, nr)
			gc.Patch(gc.Gbranch(optoas(a, nr.Type), nr.Type, likely), to)
			regfree(&n1)
			break
		}

		regalloc(&n2, nr.Type, nil)
		cgen(nr, &n2)

		// only < and <= work right with NaN; reverse if needed
	cmp:
		l := &n1

		r := &n2
		if gc.Isfloat[nl.Type.Etype] && (a == gc.OGT || a == gc.OGE) {
			l = &n2
			r = &n1
			a = gc.Brrev(a)
		}

		gins(optoas(gc.OCMP, nr.Type), l, r)

		if gc.Isfloat[nr.Type.Etype] && (n.Op == gc.OEQ || n.Op == gc.ONE) {
			if n.Op == gc.OEQ {
				// neither NE nor P
				p1 := gc.Gbranch(x86.AJNE, nil, -likely)

				p2 := gc.Gbranch(x86.AJPS, nil, -likely)
				gc.Patch(gc.Gbranch(obj.AJMP, nil, 0), to)
				gc.Patch(p1, gc.Pc)
				gc.Patch(p2, gc.Pc)
			} else {
				// either NE or P
				gc.Patch(gc.Gbranch(x86.AJNE, nil, likely), to)

				gc.Patch(gc.Gbranch(x86.AJPS, nil, likely), to)
			}
		} else {
			gc.Patch(gc.Gbranch(optoas(a, nr.Type), nr.Type, likely), to)
		}
		regfree(&n1)
		regfree(&n2)
	}

	return

def:
	var n1 gc.Node
	regalloc(&n1, n.Type, nil)
	cgen(n, &n1)
	var n2 gc.Node
	gc.Nodconst(&n2, n.Type, 0)
	gins(optoas(gc.OCMP, n.Type), &n1, &n2)
	a := x86.AJNE
	if !true_ {
		a = x86.AJEQ
	}
	gc.Patch(gc.Gbranch(a, n.Type, likely), to)
	regfree(&n1)
	return
}
Example #6
0
/*
 * generate:
 *	res = n;
 * simplifies and calls gmove.
 */
func cgen(n *gc.Node, res *gc.Node) {
	if gc.Debug['g'] != 0 {
		gc.Dump("\ncgen-n", n)
		gc.Dump("cgen-res", res)
	}

	if n == nil || n.Type == nil {
		return
	}

	if res == nil || res.Type == nil {
		gc.Fatal("cgen: res nil")
	}

	switch n.Op {
	case gc.OSLICE,
		gc.OSLICEARR,
		gc.OSLICESTR,
		gc.OSLICE3,
		gc.OSLICE3ARR:
		if res.Op != gc.ONAME || res.Addable == 0 {
			var n1 gc.Node
			gc.Tempname(&n1, n.Type)
			gc.Cgen_slice(n, &n1)
			cgen(&n1, res)
		} else {
			gc.Cgen_slice(n, res)
		}
		return

	case gc.OEFACE:
		if res.Op != gc.ONAME || res.Addable == 0 {
			var n1 gc.Node
			gc.Tempname(&n1, n.Type)
			gc.Cgen_eface(n, &n1)
			cgen(&n1, res)
		} else {
			gc.Cgen_eface(n, res)
		}
		return
	}

	for n.Op == gc.OCONVNOP {
		n = n.Left
	}

	if n.Ullman >= gc.UINF {
		if n.Op == gc.OINDREG {
			gc.Fatal("cgen: this is going to misscompile")
		}
		if res.Ullman >= gc.UINF {
			var n1 gc.Node
			gc.Tempname(&n1, n.Type)
			cgen(n, &n1)
			cgen(&n1, res)
			return
		}
	}

	if gc.Isfat(n.Type) {
		if n.Type.Width < 0 {
			gc.Fatal("forgot to compute width for %v", gc.Tconv(n.Type, 0))
		}
		sgen(n, res, n.Type.Width)
		return
	}

	// update addressability for string, slice
	// can't do in walk because n->left->addable
	// changes if n->left is an escaping local variable.
	switch n.Op {
	case gc.OSPTR,
		gc.OLEN:
		if gc.Isslice(n.Left.Type) || gc.Istype(n.Left.Type, gc.TSTRING) {
			n.Addable = n.Left.Addable
		}

	case gc.OCAP:
		if gc.Isslice(n.Left.Type) {
			n.Addable = n.Left.Addable
		}

	case gc.OITAB:
		n.Addable = n.Left.Addable
	}

	// if both are addressable, move
	if n.Addable != 0 && res.Addable != 0 {
		if gc.Is64(n.Type) || gc.Is64(res.Type) || n.Op == gc.OREGISTER || res.Op == gc.OREGISTER || gc.Iscomplex[n.Type.Etype] || gc.Iscomplex[res.Type.Etype] {
			gmove(n, res)
		} else {
			var n1 gc.Node
			regalloc(&n1, n.Type, nil)
			gmove(n, &n1)
			cgen(&n1, res)
			regfree(&n1)
		}

		return
	}

	// if both are not addressable, use a temporary.
	if n.Addable == 0 && res.Addable == 0 {
		// could use regalloc here sometimes,
		// but have to check for ullman >= UINF.
		var n1 gc.Node
		gc.Tempname(&n1, n.Type)

		cgen(n, &n1)
		cgen(&n1, res)
		return
	}

	// if result is not addressable directly but n is,
	// compute its address and then store via the address.
	if res.Addable == 0 {
		var n1 gc.Node
		igen(res, &n1, nil)
		cgen(n, &n1)
		regfree(&n1)
		return
	}

	if gc.Complexop(n, res) {
		gc.Complexgen(n, res)
		return
	}

	// if n is sudoaddable generate addr and move
	if !gc.Is64(n.Type) && !gc.Is64(res.Type) && !gc.Iscomplex[n.Type.Etype] && !gc.Iscomplex[res.Type.Etype] {
		a := optoas(gc.OAS, n.Type)
		var w int
		var addr obj.Addr
		if sudoaddable(a, n, &addr, &w) {
			if res.Op != gc.OREGISTER {
				var n2 gc.Node
				regalloc(&n2, res.Type, nil)
				p1 := gins(a, nil, &n2)
				p1.From = addr
				if gc.Debug['g'] != 0 {
					fmt.Printf("%v [ignore previous line]\n", p1)
				}
				gmove(&n2, res)
				regfree(&n2)
			} else {
				p1 := gins(a, nil, res)
				p1.From = addr
				if gc.Debug['g'] != 0 {
					fmt.Printf("%v [ignore previous line]\n", p1)
				}
			}

			sudoclean()
			return
		}
	}

	// otherwise, the result is addressable but n is not.
	// let's do some computation.

	nl := n.Left

	nr := n.Right

	if nl != nil && nl.Ullman >= gc.UINF {
		if nr != nil && nr.Ullman >= gc.UINF {
			var n1 gc.Node
			gc.Tempname(&n1, nl.Type)
			cgen(nl, &n1)
			n2 := *n
			n2.Left = &n1
			cgen(&n2, res)
			return
		}
	}

	// 64-bit ops are hard on 32-bit machine.
	if gc.Is64(n.Type) || gc.Is64(res.Type) || n.Left != nil && gc.Is64(n.Left.Type) {
		switch n.Op {
		// math goes to cgen64.
		case gc.OMINUS,
			gc.OCOM,
			gc.OADD,
			gc.OSUB,
			gc.OMUL,
			gc.OLROT,
			gc.OLSH,
			gc.ORSH,
			gc.OAND,
			gc.OOR,
			gc.OXOR:
			cgen64(n, res)

			return
		}
	}

	var a int
	var f0 gc.Node
	var n1 gc.Node
	var n2 gc.Node
	if nl != nil && gc.Isfloat[n.Type.Etype] && gc.Isfloat[nl.Type.Etype] {
		// floating-point.
		regalloc(&f0, nl.Type, res)

		if nr != nil {
			goto flt2
		}

		if n.Op == gc.OMINUS {
			nr = gc.Nodintconst(-1)
			gc.Convlit(&nr, n.Type)
			n.Op = gc.OMUL
			goto flt2
		}

		// unary
		cgen(nl, &f0)

		if n.Op != gc.OCONV && n.Op != gc.OPLUS {
			gins(optoas(int(n.Op), n.Type), &f0, &f0)
		}
		gmove(&f0, res)
		regfree(&f0)
		return
	}
	switch n.Op {
	default:
		gc.Dump("cgen", n)
		gc.Fatal("cgen: unknown op %v", gc.Nconv(n, obj.FmtShort|obj.FmtSign))

	case gc.OREAL,
		gc.OIMAG,
		gc.OCOMPLEX:
		gc.Fatal("unexpected complex")

		// these call bgen to get a bool value
	case gc.OOROR,
		gc.OANDAND,
		gc.OEQ,
		gc.ONE,
		gc.OLT,
		gc.OLE,
		gc.OGE,
		gc.OGT,
		gc.ONOT:
		p1 := gc.Gbranch(arm.AB, nil, 0)

		p2 := gc.Pc
		gmove(gc.Nodbool(true), res)
		p3 := gc.Gbranch(arm.AB, nil, 0)
		gc.Patch(p1, gc.Pc)
		bgen(n, true, 0, p2)
		gmove(gc.Nodbool(false), res)
		gc.Patch(p3, gc.Pc)
		return

	case gc.OPLUS:
		cgen(nl, res)
		return

		// unary
	case gc.OCOM:
		a := optoas(gc.OXOR, nl.Type)

		regalloc(&n1, nl.Type, nil)
		cgen(nl, &n1)
		gc.Nodconst(&n2, nl.Type, -1)
		gins(a, &n2, &n1)
		goto norm

	case gc.OMINUS:
		regalloc(&n1, nl.Type, nil)
		cgen(nl, &n1)
		gc.Nodconst(&n2, nl.Type, 0)
		gins(optoas(gc.OMINUS, nl.Type), &n2, &n1)
		goto norm

		// symmetric binary
	case gc.OAND,
		gc.OOR,
		gc.OXOR,
		gc.OADD,
		gc.OMUL:
		a = optoas(int(n.Op), nl.Type)

		// symmetric binary
		if nl.Ullman < nr.Ullman {
			r := nl
			nl = nr
			nr = r
		}
		goto abop

		// asymmetric binary
	case gc.OSUB:
		a = optoas(int(n.Op), nl.Type)

		goto abop

	case gc.OHMUL:
		cgen_hmul(nl, nr, res)

	case gc.OLROT,
		gc.OLSH,
		gc.ORSH:
		cgen_shift(int(n.Op), n.Bounded, nl, nr, res)

	case gc.OCONV:
		if gc.Eqtype(n.Type, nl.Type) || gc.Noconv(n.Type, nl.Type) {
			cgen(nl, res)
			break
		}

		var n1 gc.Node
		if nl.Addable != 0 && !gc.Is64(nl.Type) {
			regalloc(&n1, nl.Type, res)
			gmove(nl, &n1)
		} else {
			if n.Type.Width > int64(gc.Widthptr) || gc.Is64(nl.Type) || gc.Isfloat[nl.Type.Etype] {
				gc.Tempname(&n1, nl.Type)
			} else {
				regalloc(&n1, nl.Type, res)
			}
			cgen(nl, &n1)
		}

		var n2 gc.Node
		if n.Type.Width > int64(gc.Widthptr) || gc.Is64(n.Type) || gc.Isfloat[n.Type.Etype] {
			gc.Tempname(&n2, n.Type)
		} else {
			regalloc(&n2, n.Type, nil)
		}
		gmove(&n1, &n2)
		gmove(&n2, res)
		if n1.Op == gc.OREGISTER {
			regfree(&n1)
		}
		if n2.Op == gc.OREGISTER {
			regfree(&n2)
		}

	case gc.ODOT,
		gc.ODOTPTR,
		gc.OINDEX,
		gc.OIND,
		gc.ONAME: // PHEAP or PPARAMREF var
		var n1 gc.Node
		igen(n, &n1, res)

		gmove(&n1, res)
		regfree(&n1)

		// interface table is first word of interface value
	case gc.OITAB:
		var n1 gc.Node
		igen(nl, &n1, res)

		n1.Type = n.Type
		gmove(&n1, res)
		regfree(&n1)

		// pointer is the first word of string or slice.
	case gc.OSPTR:
		if gc.Isconst(nl, gc.CTSTR) {
			var n1 gc.Node
			regalloc(&n1, gc.Types[gc.Tptr], res)
			p1 := gins(arm.AMOVW, nil, &n1)
			gc.Datastring(nl.Val.U.Sval, &p1.From)
			gmove(&n1, res)
			regfree(&n1)
			break
		}

		var n1 gc.Node
		igen(nl, &n1, res)
		n1.Type = n.Type
		gmove(&n1, res)
		regfree(&n1)

	case gc.OLEN:
		if gc.Istype(nl.Type, gc.TMAP) || gc.Istype(nl.Type, gc.TCHAN) {
			// map has len in the first 32-bit word.
			// a zero pointer means zero length
			var n1 gc.Node
			regalloc(&n1, gc.Types[gc.Tptr], res)

			cgen(nl, &n1)

			var n2 gc.Node
			gc.Nodconst(&n2, gc.Types[gc.Tptr], 0)
			gcmp(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &n2)
			p1 := gc.Gbranch(optoas(gc.OEQ, gc.Types[gc.Tptr]), nil, -1)

			n2 = n1
			n2.Op = gc.OINDREG
			n2.Type = gc.Types[gc.TINT32]
			gmove(&n2, &n1)

			gc.Patch(p1, gc.Pc)

			gmove(&n1, res)
			regfree(&n1)
			break
		}

		if gc.Istype(nl.Type, gc.TSTRING) || gc.Isslice(nl.Type) {
			// both slice and string have len one pointer into the struct.
			var n1 gc.Node
			igen(nl, &n1, res)

			n1.Type = gc.Types[gc.TUINT32]
			n1.Xoffset += int64(gc.Array_nel)
			gmove(&n1, res)
			regfree(&n1)
			break
		}

		gc.Fatal("cgen: OLEN: unknown type %v", gc.Tconv(nl.Type, obj.FmtLong))

	case gc.OCAP:
		if gc.Istype(nl.Type, gc.TCHAN) {
			// chan has cap in the second 32-bit word.
			// a zero pointer means zero length
			var n1 gc.Node
			regalloc(&n1, gc.Types[gc.Tptr], res)

			cgen(nl, &n1)

			var n2 gc.Node
			gc.Nodconst(&n2, gc.Types[gc.Tptr], 0)
			gcmp(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &n2)
			p1 := gc.Gbranch(optoas(gc.OEQ, gc.Types[gc.Tptr]), nil, -1)

			n2 = n1
			n2.Op = gc.OINDREG
			n2.Xoffset = 4
			n2.Type = gc.Types[gc.TINT32]
			gmove(&n2, &n1)

			gc.Patch(p1, gc.Pc)

			gmove(&n1, res)
			regfree(&n1)
			break
		}

		if gc.Isslice(nl.Type) {
			var n1 gc.Node
			igen(nl, &n1, res)
			n1.Type = gc.Types[gc.TUINT32]
			n1.Xoffset += int64(gc.Array_cap)
			gmove(&n1, res)
			regfree(&n1)
			break
		}

		gc.Fatal("cgen: OCAP: unknown type %v", gc.Tconv(nl.Type, obj.FmtLong))

	case gc.OADDR:
		agen(nl, res)

		// Release res so that it is available for cgen_call.
	// Pick it up again after the call.
	case gc.OCALLMETH,
		gc.OCALLFUNC:
		rg := -1

		if n.Ullman >= gc.UINF {
			if res != nil && (res.Op == gc.OREGISTER || res.Op == gc.OINDREG) {
				rg = int(res.Val.U.Reg)
				reg[rg]--
			}
		}

		if n.Op == gc.OCALLMETH {
			gc.Cgen_callmeth(n, 0)
		} else {
			cgen_call(n, 0)
		}
		if rg >= 0 {
			reg[rg]++
		}
		cgen_callret(n, res)

	case gc.OCALLINTER:
		cgen_callinter(n, res, 0)
		cgen_callret(n, res)

	case gc.OMOD,
		gc.ODIV:
		a = optoas(int(n.Op), nl.Type)
		goto abop
	}

	return

	// TODO(kaib): use fewer registers here.
abop: // asymmetric binary
	if nl.Ullman >= nr.Ullman {
		regalloc(&n1, nl.Type, res)
		cgen(nl, &n1)
		switch n.Op {
		case gc.OADD,
			gc.OSUB,
			gc.OAND,
			gc.OOR,
			gc.OXOR:
			if gc.Smallintconst(nr) {
				n2 = *nr
				break
			}
			fallthrough

		default:
			regalloc(&n2, nr.Type, nil)
			cgen(nr, &n2)
		}
	} else {
		switch n.Op {
		case gc.OADD,
			gc.OSUB,
			gc.OAND,
			gc.OOR,
			gc.OXOR:
			if gc.Smallintconst(nr) {
				n2 = *nr
				break
			}
			fallthrough

		default:
			regalloc(&n2, nr.Type, res)
			cgen(nr, &n2)
		}

		regalloc(&n1, nl.Type, nil)
		cgen(nl, &n1)
	}

	gins(a, &n2, &n1)

	// Normalize result for types smaller than word.
norm:
	if n.Type.Width < int64(gc.Widthptr) {
		switch n.Op {
		case gc.OADD,
			gc.OSUB,
			gc.OMUL,
			gc.OCOM,
			gc.OMINUS:
			gins(optoas(gc.OAS, n.Type), &n1, &n1)
		}
	}

	gmove(&n1, res)
	regfree(&n1)
	if n2.Op != gc.OLITERAL {
		regfree(&n2)
	}
	return

flt2: // binary
	var f1 gc.Node
	if nl.Ullman >= nr.Ullman {
		cgen(nl, &f0)
		regalloc(&f1, n.Type, nil)
		gmove(&f0, &f1)
		cgen(nr, &f0)
		gins(optoas(int(n.Op), n.Type), &f0, &f1)
	} else {
		cgen(nr, &f0)
		regalloc(&f1, n.Type, nil)
		cgen(nl, &f1)
		gins(optoas(int(n.Op), n.Type), &f0, &f1)
	}

	gmove(&f1, res)
	regfree(&f0)
	regfree(&f1)
	return
}
Example #7
0
/*
 * branch gen
 *	if(n == true) goto to;
 */
func bgen(n *gc.Node, true_ bool, likely int, to *obj.Prog) {
	if gc.Debug['g'] != 0 {
		gc.Dump("\nbgen", n)
	}

	if n == nil {
		n = gc.Nodbool(true)
	}

	if n.Ninit != nil {
		gc.Genlist(n.Ninit)
	}

	if n.Type == nil {
		gc.Convlit(&n, gc.Types[gc.TBOOL])
		if n.Type == nil {
			return
		}
	}

	et := int(n.Type.Etype)
	if et != gc.TBOOL {
		gc.Yyerror("cgen: bad type %v for %v", gc.Tconv(n.Type, 0), gc.Oconv(int(n.Op), 0))
		gc.Patch(gins(obj.AEND, nil, nil), to)
		return
	}

	for n.Op == gc.OCONVNOP {
		n = n.Left
		if n.Ninit != nil {
			gc.Genlist(n.Ninit)
		}
	}

	nl := n.Left
	var nr *gc.Node

	if nl != nil && gc.Isfloat[nl.Type.Etype] {
		bgen_float(n, bool2int(true_), likely, to)
		return
	}

	switch n.Op {
	default:
		goto def

		// need to ask if it is bool?
	case gc.OLITERAL:
		if !true_ == (n.Val.U.Bval == 0) {
			gc.Patch(gc.Gbranch(obj.AJMP, nil, 0), to)
		}
		return

	case gc.ONAME:
		if n.Addable == 0 {
			goto def
		}
		var n1 gc.Node
		gc.Nodconst(&n1, n.Type, 0)
		gins(optoas(gc.OCMP, n.Type), n, &n1)
		a := x86.AJNE
		if !true_ {
			a = x86.AJEQ
		}
		gc.Patch(gc.Gbranch(a, n.Type, likely), to)
		return

	case gc.OANDAND,
		gc.OOROR:
		if (n.Op == gc.OANDAND) == true_ {
			p1 := gc.Gbranch(obj.AJMP, nil, 0)
			p2 := gc.Gbranch(obj.AJMP, nil, 0)
			gc.Patch(p1, gc.Pc)
			bgen(n.Left, !true_, -likely, p2)
			bgen(n.Right, !true_, -likely, p2)
			p1 = gc.Gbranch(obj.AJMP, nil, 0)
			gc.Patch(p1, to)
			gc.Patch(p2, gc.Pc)
		} else {
			bgen(n.Left, true_, likely, to)
			bgen(n.Right, true_, likely, to)
		}

		return

	case gc.OEQ,
		gc.ONE,
		gc.OLT,
		gc.OGT,
		gc.OLE,
		gc.OGE:
		nr = n.Right
		if nr == nil || nr.Type == nil {
			return
		}
		fallthrough

	case gc.ONOT: // unary
		nl = n.Left

		if nl == nil || nl.Type == nil {
			return
		}
	}

	switch n.Op {
	case gc.ONOT:
		bgen(nl, !true_, likely, to)

	case gc.OEQ,
		gc.ONE,
		gc.OLT,
		gc.OGT,
		gc.OLE,
		gc.OGE:
		a := int(n.Op)
		if !true_ {
			a = gc.Brcom(a)
			true_ = !true_
		}

		// make simplest on right
		if nl.Op == gc.OLITERAL || (nl.Ullman < nr.Ullman && nl.Ullman < gc.UINF) {
			a = gc.Brrev(a)
			r := nl
			nl = nr
			nr = r
		}

		if gc.Isslice(nl.Type) {
			// front end should only leave cmp to literal nil
			if (a != gc.OEQ && a != gc.ONE) || nr.Op != gc.OLITERAL {
				gc.Yyerror("illegal slice comparison")
				break
			}

			a = optoas(a, gc.Types[gc.Tptr])
			var n1 gc.Node
			igen(nl, &n1, nil)
			n1.Xoffset += int64(gc.Array_array)
			n1.Type = gc.Types[gc.Tptr]
			var tmp gc.Node
			gc.Nodconst(&tmp, gc.Types[gc.Tptr], 0)
			gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &tmp)
			gc.Patch(gc.Gbranch(a, gc.Types[gc.Tptr], likely), to)
			regfree(&n1)
			break
		}

		if gc.Isinter(nl.Type) {
			// front end should only leave cmp to literal nil
			if (a != gc.OEQ && a != gc.ONE) || nr.Op != gc.OLITERAL {
				gc.Yyerror("illegal interface comparison")
				break
			}

			a = optoas(a, gc.Types[gc.Tptr])
			var n1 gc.Node
			igen(nl, &n1, nil)
			n1.Type = gc.Types[gc.Tptr]
			var tmp gc.Node
			gc.Nodconst(&tmp, gc.Types[gc.Tptr], 0)
			gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &tmp)
			gc.Patch(gc.Gbranch(a, gc.Types[gc.Tptr], likely), to)
			regfree(&n1)
			break
		}

		if gc.Iscomplex[nl.Type.Etype] {
			gc.Complexbool(a, nl, nr, true_, likely, to)
			break
		}

		if gc.Is64(nr.Type) {
			if nl.Addable == 0 || gc.Isconst(nl, gc.CTINT) {
				var n1 gc.Node
				gc.Tempname(&n1, nl.Type)
				cgen(nl, &n1)
				nl = &n1
			}

			if nr.Addable == 0 {
				var n2 gc.Node
				gc.Tempname(&n2, nr.Type)
				cgen(nr, &n2)
				nr = &n2
			}

			cmp64(nl, nr, a, likely, to)
			break
		}

		var n2 gc.Node
		if nr.Ullman >= gc.UINF {
			if nl.Addable == 0 {
				var n1 gc.Node
				gc.Tempname(&n1, nl.Type)
				cgen(nl, &n1)
				nl = &n1
			}

			if nr.Addable == 0 {
				var tmp gc.Node
				gc.Tempname(&tmp, nr.Type)
				cgen(nr, &tmp)
				nr = &tmp
			}

			var n2 gc.Node
			regalloc(&n2, nr.Type, nil)
			cgen(nr, &n2)
			nr = &n2
			goto cmp
		}

		if nl.Addable == 0 {
			var n1 gc.Node
			gc.Tempname(&n1, nl.Type)
			cgen(nl, &n1)
			nl = &n1
		}

		if gc.Smallintconst(nr) {
			gins(optoas(gc.OCMP, nr.Type), nl, nr)
			gc.Patch(gc.Gbranch(optoas(a, nr.Type), nr.Type, likely), to)
			break
		}

		if nr.Addable == 0 {
			var tmp gc.Node
			gc.Tempname(&tmp, nr.Type)
			cgen(nr, &tmp)
			nr = &tmp
		}

		regalloc(&n2, nr.Type, nil)
		gmove(nr, &n2)
		nr = &n2

	cmp:
		gins(optoas(gc.OCMP, nr.Type), nl, nr)
		gc.Patch(gc.Gbranch(optoas(a, nr.Type), nr.Type, likely), to)

		if nl.Op == gc.OREGISTER {
			regfree(nl)
		}
		regfree(nr)
	}

	return

def:
	var n1 gc.Node
	regalloc(&n1, n.Type, nil)
	cgen(n, &n1)
	var n2 gc.Node
	gc.Nodconst(&n2, n.Type, 0)
	gins(optoas(gc.OCMP, n.Type), &n1, &n2)
	a := x86.AJNE
	if !true_ {
		a = x86.AJEQ
	}
	gc.Patch(gc.Gbranch(a, n.Type, likely), to)
	regfree(&n1)
	return
}
Example #8
0
/*
 * generate:
 *	res = n;
 * simplifies and calls gmove.
 *
 * TODO:
 *	sudoaddable
 */
func cgen(n *gc.Node, res *gc.Node) {
	if gc.Debug['g'] != 0 {
		gc.Dump("\ncgen-n", n)
		gc.Dump("cgen-res", res)
	}

	if n == nil || n.Type == nil {
		gc.Fatal("cgen: n nil")
	}
	if res == nil || res.Type == nil {
		gc.Fatal("cgen: res nil")
	}

	switch n.Op {
	case gc.OSLICE,
		gc.OSLICEARR,
		gc.OSLICESTR,
		gc.OSLICE3,
		gc.OSLICE3ARR:
		if res.Op != gc.ONAME || res.Addable == 0 {
			var n1 gc.Node
			gc.Tempname(&n1, n.Type)
			gc.Cgen_slice(n, &n1)
			cgen(&n1, res)
		} else {
			gc.Cgen_slice(n, res)
		}
		return

	case gc.OEFACE:
		if res.Op != gc.ONAME || res.Addable == 0 {
			var n1 gc.Node
			gc.Tempname(&n1, n.Type)
			gc.Cgen_eface(n, &n1)
			cgen(&n1, res)
		} else {
			gc.Cgen_eface(n, res)
		}
		return
	}

	for n.Op == gc.OCONVNOP {
		n = n.Left
	}

	// function calls on both sides?  introduce temporary
	if n.Ullman >= gc.UINF && res.Ullman >= gc.UINF {
		var n1 gc.Node
		gc.Tempname(&n1, n.Type)
		cgen(n, &n1)
		cgen(&n1, res)
		return
	}

	// structs etc get handled specially
	if gc.Isfat(n.Type) {
		if n.Type.Width < 0 {
			gc.Fatal("forgot to compute width for %v", gc.Tconv(n.Type, 0))
		}
		sgen(n, res, n.Type.Width)
		return
	}

	// update addressability for string, slice
	// can't do in walk because n->left->addable
	// changes if n->left is an escaping local variable.
	switch n.Op {
	case gc.OSPTR,
		gc.OLEN:
		if gc.Isslice(n.Left.Type) || gc.Istype(n.Left.Type, gc.TSTRING) {
			n.Addable = n.Left.Addable
		}

	case gc.OCAP:
		if gc.Isslice(n.Left.Type) {
			n.Addable = n.Left.Addable
		}

	case gc.OITAB:
		n.Addable = n.Left.Addable
	}

	// if both are addressable, move
	if n.Addable != 0 && res.Addable != 0 {
		gmove(n, res)
		return
	}

	// if both are not addressable, use a temporary.
	if n.Addable == 0 && res.Addable == 0 {
		// could use regalloc here sometimes,
		// but have to check for ullman >= UINF.
		var n1 gc.Node
		gc.Tempname(&n1, n.Type)

		cgen(n, &n1)
		cgen(&n1, res)
		return
	}

	// if result is not addressable directly but n is,
	// compute its address and then store via the address.
	if res.Addable == 0 {
		var n1 gc.Node
		igen(res, &n1, nil)
		cgen(n, &n1)
		regfree(&n1)
		return
	}

	// complex types
	if gc.Complexop(n, res) {
		gc.Complexgen(n, res)
		return
	}

	// otherwise, the result is addressable but n is not.
	// let's do some computation.

	// use ullman to pick operand to eval first.
	nl := n.Left

	nr := n.Right
	if nl != nil && nl.Ullman >= gc.UINF {
		if nr != nil && nr.Ullman >= gc.UINF {
			// both are hard
			var n1 gc.Node
			gc.Tempname(&n1, nl.Type)

			cgen(nl, &n1)
			n2 := *n
			n2.Left = &n1
			cgen(&n2, res)
			return
		}
	}

	// 64-bit ops are hard on 32-bit machine.
	if gc.Is64(n.Type) || gc.Is64(res.Type) || n.Left != nil && gc.Is64(n.Left.Type) {
		switch n.Op {
		// math goes to cgen64.
		case gc.OMINUS,
			gc.OCOM,
			gc.OADD,
			gc.OSUB,
			gc.OMUL,
			gc.OLROT,
			gc.OLSH,
			gc.ORSH,
			gc.OAND,
			gc.OOR,
			gc.OXOR:
			cgen64(n, res)

			return
		}
	}

	if nl != nil && gc.Isfloat[n.Type.Etype] && gc.Isfloat[nl.Type.Etype] {
		cgen_float(n, res)
		return
	}

	var a int
	switch n.Op {
	default:
		gc.Dump("cgen", n)
		gc.Fatal("cgen %v", gc.Oconv(int(n.Op), 0))

	case gc.OREAL,
		gc.OIMAG,
		gc.OCOMPLEX:
		gc.Fatal("unexpected complex")
		return

		// these call bgen to get a bool value
	case gc.OOROR,
		gc.OANDAND,
		gc.OEQ,
		gc.ONE,
		gc.OLT,
		gc.OLE,
		gc.OGE,
		gc.OGT,
		gc.ONOT:
		p1 := gc.Gbranch(obj.AJMP, nil, 0)

		p2 := gc.Pc
		gmove(gc.Nodbool(true), res)
		p3 := gc.Gbranch(obj.AJMP, nil, 0)
		gc.Patch(p1, gc.Pc)
		bgen(n, true, 0, p2)
		gmove(gc.Nodbool(false), res)
		gc.Patch(p3, gc.Pc)
		return

	case gc.OPLUS:
		cgen(nl, res)
		return

	case gc.OMINUS,
		gc.OCOM:
		a := optoas(int(n.Op), nl.Type)
		// unary
		var n1 gc.Node
		gc.Tempname(&n1, nl.Type)

		cgen(nl, &n1)
		gins(a, nil, &n1)
		gmove(&n1, res)
		return

		// symmetric binary
	case gc.OAND,
		gc.OOR,
		gc.OXOR,
		gc.OADD,
		gc.OMUL:
		a = optoas(int(n.Op), nl.Type)

		if a == x86.AIMULB {
			cgen_bmul(int(n.Op), nl, nr, res)
			break
		}

		// symmetric binary
		if nl.Ullman < nr.Ullman || nl.Op == gc.OLITERAL {
			r := nl
			nl = nr
			nr = r
		}
		goto abop

		// asymmetric binary
	case gc.OSUB:
		a = optoas(int(n.Op), nl.Type)

		goto abop

	case gc.OHMUL:
		cgen_hmul(nl, nr, res)

	case gc.OCONV:
		if gc.Eqtype(n.Type, nl.Type) || gc.Noconv(n.Type, nl.Type) {
			cgen(nl, res)
			break
		}

		var n2 gc.Node
		gc.Tempname(&n2, n.Type)
		var n1 gc.Node
		mgen(nl, &n1, res)
		gmove(&n1, &n2)
		gmove(&n2, res)
		mfree(&n1)

	case gc.ODOT,
		gc.ODOTPTR,
		gc.OINDEX,
		gc.OIND,
		gc.ONAME: // PHEAP or PPARAMREF var
		var n1 gc.Node
		igen(n, &n1, res)

		gmove(&n1, res)
		regfree(&n1)

	case gc.OITAB:
		var n1 gc.Node
		igen(nl, &n1, res)
		n1.Type = gc.Ptrto(gc.Types[gc.TUINTPTR])
		gmove(&n1, res)
		regfree(&n1)

		// pointer is the first word of string or slice.
	case gc.OSPTR:
		if gc.Isconst(nl, gc.CTSTR) {
			var n1 gc.Node
			regalloc(&n1, gc.Types[gc.Tptr], res)
			p1 := gins(x86.ALEAL, nil, &n1)
			gc.Datastring(nl.Val.U.Sval, &p1.From)
			gmove(&n1, res)
			regfree(&n1)
			break
		}

		var n1 gc.Node
		igen(nl, &n1, res)
		n1.Type = n.Type
		gmove(&n1, res)
		regfree(&n1)

	case gc.OLEN:
		if gc.Istype(nl.Type, gc.TMAP) || gc.Istype(nl.Type, gc.TCHAN) {
			// map has len in the first 32-bit word.
			// a zero pointer means zero length
			var n1 gc.Node
			gc.Tempname(&n1, gc.Types[gc.Tptr])

			cgen(nl, &n1)
			var n2 gc.Node
			regalloc(&n2, gc.Types[gc.Tptr], nil)
			gmove(&n1, &n2)
			n1 = n2

			gc.Nodconst(&n2, gc.Types[gc.Tptr], 0)
			gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &n2)
			p1 := gc.Gbranch(optoas(gc.OEQ, gc.Types[gc.Tptr]), nil, -1)

			n2 = n1
			n2.Op = gc.OINDREG
			n2.Type = gc.Types[gc.TINT32]
			gmove(&n2, &n1)

			gc.Patch(p1, gc.Pc)

			gmove(&n1, res)
			regfree(&n1)
			break
		}

		if gc.Istype(nl.Type, gc.TSTRING) || gc.Isslice(nl.Type) {
			// both slice and string have len one pointer into the struct.
			var n1 gc.Node
			igen(nl, &n1, res)

			n1.Type = gc.Types[gc.TUINT32]
			n1.Xoffset += int64(gc.Array_nel)
			gmove(&n1, res)
			regfree(&n1)
			break
		}

		gc.Fatal("cgen: OLEN: unknown type %v", gc.Tconv(nl.Type, obj.FmtLong))

	case gc.OCAP:
		if gc.Istype(nl.Type, gc.TCHAN) {
			// chan has cap in the second 32-bit word.
			// a zero pointer means zero length
			var n1 gc.Node
			gc.Tempname(&n1, gc.Types[gc.Tptr])

			cgen(nl, &n1)
			var n2 gc.Node
			regalloc(&n2, gc.Types[gc.Tptr], nil)
			gmove(&n1, &n2)
			n1 = n2

			gc.Nodconst(&n2, gc.Types[gc.Tptr], 0)
			gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &n2)
			p1 := gc.Gbranch(optoas(gc.OEQ, gc.Types[gc.Tptr]), nil, -1)

			n2 = n1
			n2.Op = gc.OINDREG
			n2.Xoffset = 4
			n2.Type = gc.Types[gc.TINT32]
			gmove(&n2, &n1)

			gc.Patch(p1, gc.Pc)

			gmove(&n1, res)
			regfree(&n1)
			break
		}

		if gc.Isslice(nl.Type) {
			var n1 gc.Node
			igen(nl, &n1, res)
			n1.Type = gc.Types[gc.TUINT32]
			n1.Xoffset += int64(gc.Array_cap)
			gmove(&n1, res)
			regfree(&n1)
			break
		}

		gc.Fatal("cgen: OCAP: unknown type %v", gc.Tconv(nl.Type, obj.FmtLong))

	case gc.OADDR:
		agen(nl, res)

	case gc.OCALLMETH:
		gc.Cgen_callmeth(n, 0)
		cgen_callret(n, res)

	case gc.OCALLINTER:
		cgen_callinter(n, res, 0)
		cgen_callret(n, res)

	case gc.OCALLFUNC:
		cgen_call(n, 0)
		cgen_callret(n, res)

	case gc.OMOD,
		gc.ODIV:
		cgen_div(int(n.Op), nl, nr, res)

	case gc.OLSH,
		gc.ORSH,
		gc.OLROT:
		cgen_shift(int(n.Op), n.Bounded, nl, nr, res)
	}

	return

abop: // asymmetric binary
	if gc.Smallintconst(nr) {
		var n1 gc.Node
		mgen(nl, &n1, res)
		var n2 gc.Node
		regalloc(&n2, nl.Type, &n1)
		gmove(&n1, &n2)
		gins(a, nr, &n2)
		gmove(&n2, res)
		regfree(&n2)
		mfree(&n1)
	} else if nl.Ullman >= nr.Ullman {
		var nt gc.Node
		gc.Tempname(&nt, nl.Type)
		cgen(nl, &nt)
		var n2 gc.Node
		mgen(nr, &n2, nil)
		var n1 gc.Node
		regalloc(&n1, nl.Type, res)
		gmove(&nt, &n1)
		gins(a, &n2, &n1)
		gmove(&n1, res)
		regfree(&n1)
		mfree(&n2)
	} else {
		var n2 gc.Node
		regalloc(&n2, nr.Type, res)
		cgen(nr, &n2)
		var n1 gc.Node
		regalloc(&n1, nl.Type, nil)
		cgen(nl, &n1)
		gins(a, &n2, &n1)
		regfree(&n2)
		gmove(&n1, res)
		regfree(&n1)
	}

	return
}