Пример #1
0
Файл: ggen.go Проект: rsc/tmp
func defframe(ptxt *obj.Prog) {
	var n *gc.Node

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

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

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

	hi := int64(0)
	lo := hi
	ax := uint32(0)

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

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

			continue
		}

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

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

		lo = n.Xoffset
	}

	// zero final range
	zerorange(p, int64(frame), lo, hi, &ax)
}
Пример #2
0
Файл: gsubr.go Проект: rsc/tmp
/*
 * 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
		gc.Convconst(&con, t.Type, &f.Val)
		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 gc.Mpcmpfixfix(con.Val.U.Xval, gc.Minintval[gc.TINT32]) < 0 {
					goto hard
				}
				if gc.Mpcmpfixfix(con.Val.U.Xval, gc.Maxintval[gc.TINT32]) > 0 {
					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.Fatal("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
}