Пример #1
0
func outgcode(a int, g1 *obj.Addr, reg int, g2, g3 *obj.Addr) {
	var p *obj.Prog
	var pl *obj.Plist

	if asm.Pass == 1 {
		goto out
	}

	p = asm.Ctxt.NewProg()
	p.As = int16(a)
	p.Lineno = stmtline
	if nosched != 0 {
		p.Mark |= ppc64.NOSCHED
	}
	p.From = *g1
	p.Reg = int16(reg)
	p.From3 = *g2
	p.To = *g3
	p.Pc = int64(asm.PC)

	if lastpc == nil {
		pl = obj.Linknewplist(asm.Ctxt)
		pl.Firstpc = p
	} else {
		lastpc.Link = p
	}
	lastpc = p

out:
	if a != obj.AGLOBL && a != obj.ADATA {
		asm.PC++
	}
}
Пример #2
0
Файл: lex.go Проект: Ericean/go
func outcode(a int, g2 *Addr2) {
	var p *obj.Prog
	var pl *obj.Plist

	if asm.Pass == 1 {
		goto out
	}

	p = new(obj.Prog)
	*p = obj.Prog{}
	p.Ctxt = asm.Ctxt
	p.As = int16(a)
	p.Lineno = stmtline
	p.From = g2.from
	p.To = g2.to
	p.Pc = int64(asm.PC)

	if lastpc == nil {
		pl = obj.Linknewplist(asm.Ctxt)
		pl.Firstpc = p
	} else {

		lastpc.Link = p
	}
	lastpc = p

out:
	if a != obj.AGLOBL && a != obj.ADATA {
		asm.PC++
	}
}
Пример #3
0
func outcode(a int, g1 *obj.Addr, reg int, g2 *obj.Addr) {
	var p *obj.Prog
	var pl *obj.Plist

	if asm.Pass == 1 {
		goto out
	}

	if g1.Scale != 0 {
		if reg != 0 || g2.Scale != 0 {
			yyerror("bad addressing modes")
		}
		reg = int(g1.Scale)
	} else if g2.Scale != 0 {
		if reg != 0 {
			yyerror("bad addressing modes")
		}
		reg = int(g2.Scale)
	}

	p = asm.Ctxt.NewProg()
	p.As = int16(a)
	p.Lineno = stmtline
	if nosched != 0 {
		p.Mark |= ppc64.NOSCHED
	}
	p.From = *g1
	p.Reg = int16(reg)
	p.To = *g2
	p.Pc = int64(asm.PC)

	if lastpc == nil {
		pl = obj.Linknewplist(asm.Ctxt)
		pl.Firstpc = p
	} else {
		lastpc.Link = p
	}
	lastpc = p

out:
	if a != obj.AGLOBL && a != obj.ADATA {
		asm.PC++
	}
}
Пример #4
0
Файл: lex.go Проект: Ericean/go
func outcode(a, scond int32, g1 *obj.Addr, reg int32, g2 *obj.Addr) {
	var p *obj.Prog
	var pl *obj.Plist

	/* hack to make B.NE etc. work: turn it into the corresponding conditional */
	if a == arm.AB {
		a = int32(bcode[(scond^arm.C_SCOND_XOR)&0xf])
		scond = (scond &^ 0xf) | Always
	}

	if asm.Pass == 1 {
		goto out
	}

	p = new(obj.Prog)
	*p = obj.Prog{}
	p.Ctxt = asm.Ctxt
	p.As = int16(a)
	p.Lineno = stmtline
	p.Scond = uint8(scond)
	p.From = *g1
	p.Reg = int16(reg)
	p.To = *g2
	p.Pc = int64(asm.PC)

	if lastpc == nil {
		pl = obj.Linknewplist(asm.Ctxt)
		pl.Firstpc = p
	} else {
		lastpc.Link = p
	}
	lastpc = p

out:
	if a != obj.AGLOBL && a != obj.ADATA {
		asm.PC++
	}
}
Пример #5
0
/*
 * The idea is to remove redundant constants.
 *	$c1->v1
 *	($c1->v2 s/$c1/v1)*
 *	set v1  return
 * The v1->v2 should be eliminated by copy propagation.
 */
func constprop(c1 *obj.Addr, v1 *obj.Addr, r *gc.Flow) {
	if gc.Debug['P'] != 0 {
		fmt.Printf("constprop %v->%v\n", gc.Ctxt.Dconv(c1), gc.Ctxt.Dconv(v1))
	}
	var p *obj.Prog
	for ; r != nil; r = r.S1 {
		p = r.Prog
		if gc.Debug['P'] != 0 {
			fmt.Printf("%v", p)
		}
		if gc.Uniqp(r) == nil {
			if gc.Debug['P'] != 0 {
				fmt.Printf("; merge; return\n")
			}
			return
		}

		if p.As == arm.AMOVW && copyas(&p.From, c1) {
			if gc.Debug['P'] != 0 {
				fmt.Printf("; sub%v/%v", gc.Ctxt.Dconv(&p.From), gc.Ctxt.Dconv(v1))
			}
			p.From = *v1
		} else if copyu(p, v1, nil) > 1 {
			if gc.Debug['P'] != 0 {
				fmt.Printf("; %vset; return\n", gc.Ctxt.Dconv(v1))
			}
			return
		}

		if gc.Debug['P'] != 0 {
			fmt.Printf("\n")
		}
		if r.S2 != nil {
			constprop(c1, v1, r.S2)
		}
	}
}
Пример #6
0
Файл: peep.go Проект: hurkgu/go
// If s==nil, copyu returns the set/use of v in p; otherwise, it
// modifies p to replace reads of v with reads of s and returns 0 for
// success or non-zero for failure.
//
// If s==nil, copy returns one of the following values:
// 	_Read           if v only used
//	_ReadWriteSame  if v is set and used in one address (read-alter-rewrite;
// 	                can't substitute)
//	_Write          if v is only set
//	_ReadWriteDiff  if v is set in one address and used in another (so addresses
// 	                can be rewritten independently)
//	_None           otherwise (not touched)
func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) usage {
	if p.From3Type() != obj.TYPE_NONE && p.From3Type() != obj.TYPE_CONST {
		// Currently we never generate a From3 with anything other than a constant in it.
		fmt.Printf("copyu: From3 (%v) not implemented\n", gc.Ctxt.Dconv(p.From3))
	}

	switch p.As {
	default:
		fmt.Printf("copyu: can't find %v\n", p.As)
		return _ReadWriteSame

	case // read p.From, write p.To
		s390x.AMOVH,
		s390x.AMOVHZ,
		s390x.AMOVB,
		s390x.AMOVBZ,
		s390x.AMOVW,
		s390x.AMOVWZ,
		s390x.AMOVD,
		s390x.ANEG,
		s390x.AADDME,
		s390x.AADDZE,
		s390x.ASUBME,
		s390x.ASUBZE,
		s390x.AFMOVS,
		s390x.AFMOVD,
		s390x.ALEDBR,
		s390x.AFNEG,
		s390x.ALDEBR,
		s390x.ACLFEBR,
		s390x.ACLGEBR,
		s390x.ACLFDBR,
		s390x.ACLGDBR,
		s390x.ACFEBRA,
		s390x.ACGEBRA,
		s390x.ACFDBRA,
		s390x.ACGDBRA,
		s390x.ACELFBR,
		s390x.ACELGBR,
		s390x.ACDLFBR,
		s390x.ACDLGBR,
		s390x.ACEFBRA,
		s390x.ACEGBRA,
		s390x.ACDFBRA,
		s390x.ACDGBRA,
		s390x.AFSQRT:

		if s != nil {
			copysub(&p.From, v, s)

			// Update only indirect uses of v in p.To
			if !copyas(&p.To, v) {
				copysub(&p.To, v, s)
			}
			return _None
		}

		if copyas(&p.To, v) {
			// Fix up implicit from
			if p.From.Type == obj.TYPE_NONE {
				p.From = p.To
			}
			if copyau(&p.From, v) {
				return _ReadWriteDiff
			}
			return _Write
		}

		if copyau(&p.From, v) {
			return _Read
		}
		if copyau(&p.To, v) {
			// p.To only indirectly uses v
			return _Read
		}

		return _None

	// read p.From, read p.Reg, write p.To
	case s390x.AADD,
		s390x.AADDC,
		s390x.AADDE,
		s390x.ASUB,
		s390x.ASLW,
		s390x.ASRW,
		s390x.ASRAW,
		s390x.ASLD,
		s390x.ASRD,
		s390x.ASRAD,
		s390x.ARLL,
		s390x.ARLLG,
		s390x.AOR,
		s390x.AORN,
		s390x.AAND,
		s390x.AANDN,
		s390x.ANAND,
		s390x.ANOR,
		s390x.AXOR,
		s390x.AMULLW,
		s390x.AMULLD,
		s390x.AMULHD,
		s390x.AMULHDU,
		s390x.ADIVW,
		s390x.ADIVD,
		s390x.ADIVWU,
		s390x.ADIVDU,
		s390x.AFADDS,
		s390x.AFADD,
		s390x.AFSUBS,
		s390x.AFSUB,
		s390x.AFMULS,
		s390x.AFMUL,
		s390x.AFDIVS,
		s390x.AFDIV:
		if s != nil {
			copysub(&p.From, v, s)
			copysub1(p, v, s)

			// Update only indirect uses of v in p.To
			if !copyas(&p.To, v) {
				copysub(&p.To, v, s)
			}
		}

		if copyas(&p.To, v) {
			if p.Reg == 0 {
				p.Reg = p.To.Reg
			}
			if copyau(&p.From, v) || copyau1(p, v) {
				return _ReadWriteDiff
			}
			return _Write
		}

		if copyau(&p.From, v) {
			return _Read
		}
		if copyau1(p, v) {
			return _Read
		}
		if copyau(&p.To, v) {
			return _Read
		}
		return _None

	case s390x.ABEQ,
		s390x.ABGT,
		s390x.ABGE,
		s390x.ABLT,
		s390x.ABLE,
		s390x.ABNE,
		s390x.ABVC,
		s390x.ABVS:
		return _None

	case obj.ACHECKNIL, // read p.From
		s390x.ACMP, // read p.From, read p.To
		s390x.ACMPU,
		s390x.ACMPW,
		s390x.ACMPWU,
		s390x.AFCMPO,
		s390x.AFCMPU,
		s390x.ACEBR,
		s390x.AMVC,
		s390x.ACLC,
		s390x.AXC,
		s390x.AOC,
		s390x.ANC:
		if s != nil {
			copysub(&p.From, v, s)
			copysub(&p.To, v, s)
			return _None
		}

		if copyau(&p.From, v) {
			return _Read
		}
		if copyau(&p.To, v) {
			return _Read
		}
		return _None

	case s390x.ACMPBNE, s390x.ACMPBEQ,
		s390x.ACMPBLT, s390x.ACMPBLE,
		s390x.ACMPBGT, s390x.ACMPBGE,
		s390x.ACMPUBNE, s390x.ACMPUBEQ,
		s390x.ACMPUBLT, s390x.ACMPUBLE,
		s390x.ACMPUBGT, s390x.ACMPUBGE:
		if s != nil {
			copysub(&p.From, v, s)
			copysub1(p, v, s)
			return _None
		}
		if copyau(&p.From, v) {
			return _Read
		}
		if copyau1(p, v) {
			return _Read
		}
		return _None

	case s390x.ACLEAR:
		if s != nil {
			copysub(&p.To, v, s)
			return _None
		}
		if copyau(&p.To, v) {
			return _Read
		}
		return _None

	// go never generates a branch to a GPR
	// read p.To
	case s390x.ABR:
		if s != nil {
			copysub(&p.To, v, s)
			return _None
		}

		if copyau(&p.To, v) {
			return _Read
		}
		return _None

	case obj.ARET, obj.AUNDEF:
		if s != nil {
			return _None
		}

		// All registers die at this point, so claim
		// everything is set (and not used).
		return _Write

	case s390x.ABL:
		if v.Type == obj.TYPE_REG {
			if s390x.REGARG != -1 && v.Reg == s390x.REGARG {
				return _ReadWriteSame
			}
			if p.From.Type == obj.TYPE_REG && p.From.Reg == v.Reg {
				return _ReadWriteSame
			}
			if v.Reg == s390x.REGZERO {
				// Deliberately inserted nops set R0.
				return _ReadWriteSame
			}
			if v.Reg == s390x.REGCTXT {
				// Context register for closures.
				// TODO(mundaym): not sure if we need to exclude this.
				return _ReadWriteSame
			}
		}
		if s != nil {
			copysub(&p.To, v, s)
			return _None
		}
		if copyau(&p.To, v) {
			return _ReadWriteDiff
		}
		return _Write

	case obj.ATEXT:
		if v.Type == obj.TYPE_REG {
			if v.Reg == s390x.REGARG {
				return _Write
			}
		}
		return _None

	case obj.APCDATA,
		obj.AFUNCDATA,
		obj.AVARDEF,
		obj.AVARKILL,
		obj.AVARLIVE,
		obj.AUSEFIELD,
		obj.ANOP:
		return _None
	}
}
Пример #7
0
func peep(firstp *obj.Prog) {
	g := (*gc.Graph)(gc.Flowstart(firstp, nil))
	if g == nil {
		return
	}
	gactive = 0

	// byte, word arithmetic elimination.
	elimshortmov(g)

	// constant propagation
	// find MOV $con,R followed by
	// another MOV $con,R without
	// setting R in the interim
	var p *obj.Prog
	for r := (*gc.Flow)(g.Start); r != nil; r = r.Link {
		p = r.Prog
		switch p.As {
		case x86.ALEAL,
			x86.ALEAQ:
			if regtyp(&p.To) {
				if p.From.Sym != nil {
					if p.From.Index == x86.REG_NONE {
						conprop(r)
					}
				}
			}

		case x86.AMOVB,
			x86.AMOVW,
			x86.AMOVL,
			x86.AMOVQ,
			x86.AMOVSS,
			x86.AMOVSD:
			if regtyp(&p.To) {
				if p.From.Type == obj.TYPE_CONST || p.From.Type == obj.TYPE_FCONST {
					conprop(r)
				}
			}
		}
	}

	var r *gc.Flow
	var r1 *gc.Flow
	var p1 *obj.Prog
	var t int
loop1:
	if gc.Debug['P'] != 0 && gc.Debug['v'] != 0 {
		gc.Dumpit("loop1", g.Start, 0)
	}

	t = 0
	for r = g.Start; r != nil; r = r.Link {
		p = r.Prog
		switch p.As {
		case x86.AMOVL,
			x86.AMOVQ,
			x86.AMOVSS,
			x86.AMOVSD:
			if regtyp(&p.To) {
				if regtyp(&p.From) {
					if copyprop(g, r) {
						excise(r)
						t++
					} else if subprop(r) && copyprop(g, r) {
						excise(r)
						t++
					}
				}
			}

		case x86.AMOVBLZX,
			x86.AMOVWLZX,
			x86.AMOVBLSX,
			x86.AMOVWLSX:
			if regtyp(&p.To) {
				r1 = rnops(gc.Uniqs(r))
				if r1 != nil {
					p1 = r1.Prog
					if p.As == p1.As && p.To.Type == p1.From.Type && p.To.Reg == p1.From.Reg {
						p1.As = x86.AMOVL
						t++
					}
				}
			}

		case x86.AMOVBQSX,
			x86.AMOVBQZX,
			x86.AMOVWQSX,
			x86.AMOVWQZX,
			x86.AMOVLQSX,
			x86.AMOVLQZX,
			x86.AMOVQL:
			if regtyp(&p.To) {
				r1 = rnops(gc.Uniqs(r))
				if r1 != nil {
					p1 = r1.Prog
					if p.As == p1.As && p.To.Type == p1.From.Type && p.To.Reg == p1.From.Reg {
						p1.As = x86.AMOVQ
						t++
					}
				}
			}

		case x86.AADDL,
			x86.AADDQ,
			x86.AADDW:
			if p.From.Type != obj.TYPE_CONST || needc(p.Link) {
				break
			}
			if p.From.Offset == -1 {
				if p.As == x86.AADDQ {
					p.As = x86.ADECQ
				} else if p.As == x86.AADDL {
					p.As = x86.ADECL
				} else {
					p.As = x86.ADECW
				}
				p.From = obj.Addr{}
				break
			}

			if p.From.Offset == 1 {
				if p.As == x86.AADDQ {
					p.As = x86.AINCQ
				} else if p.As == x86.AADDL {
					p.As = x86.AINCL
				} else {
					p.As = x86.AINCW
				}
				p.From = obj.Addr{}
				break
			}

		case x86.ASUBL,
			x86.ASUBQ,
			x86.ASUBW:
			if p.From.Type != obj.TYPE_CONST || needc(p.Link) {
				break
			}
			if p.From.Offset == -1 {
				if p.As == x86.ASUBQ {
					p.As = x86.AINCQ
				} else if p.As == x86.ASUBL {
					p.As = x86.AINCL
				} else {
					p.As = x86.AINCW
				}
				p.From = obj.Addr{}
				break
			}

			if p.From.Offset == 1 {
				if p.As == x86.ASUBQ {
					p.As = x86.ADECQ
				} else if p.As == x86.ASUBL {
					p.As = x86.ADECL
				} else {
					p.As = x86.ADECW
				}
				p.From = obj.Addr{}
				break
			}
		}
	}

	if t != 0 {
		goto loop1
	}

	// MOVLQZX removal.
	// The MOVLQZX exists to avoid being confused for a
	// MOVL that is just copying 32-bit data around during
	// copyprop.  Now that copyprop is done, remov MOVLQZX R1, R2
	// if it is dominated by an earlier ADDL/MOVL/etc into R1 that
	// will have already cleared the high bits.
	//
	// MOVSD removal.
	// We never use packed registers, so a MOVSD between registers
	// can be replaced by MOVAPD, which moves the pair of float64s
	// instead of just the lower one.  We only use the lower one, but
	// the processor can do better if we do moves using both.
	for r := (*gc.Flow)(g.Start); r != nil; r = r.Link {
		p = r.Prog
		if p.As == x86.AMOVLQZX {
			if regtyp(&p.From) {
				if p.From.Type == p.To.Type && p.From.Reg == p.To.Reg {
					if prevl(r, int(p.From.Reg)) {
						excise(r)
					}
				}
			}
		}

		if p.As == x86.AMOVSD {
			if regtyp(&p.From) {
				if regtyp(&p.To) {
					p.As = x86.AMOVAPD
				}
			}
		}
	}

	// load pipelining
	// push any load from memory as early as possible
	// to give it time to complete before use.
	for r := (*gc.Flow)(g.Start); r != nil; r = r.Link {
		p = r.Prog
		switch p.As {
		case x86.AMOVB,
			x86.AMOVW,
			x86.AMOVL,
			x86.AMOVQ,
			x86.AMOVLQZX:
			if regtyp(&p.To) && !regconsttyp(&p.From) {
				pushback(r)
			}
		}
	}

	gc.Flowend(g)
}
Пример #8
0
func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
	// TODO(minux): add morestack short-cuts with small fixed frame-size.
	ctxt.Cursym = cursym

	if cursym.Text == nil || cursym.Text.Link == nil {
		return
	}

	p := cursym.Text
	textstksiz := p.To.Offset

	cursym.Args = p.To.Val.(int32)
	cursym.Locals = int32(textstksiz)

	/*
	 * find leaf subroutines
	 * strip NOPs
	 * expand RET
	 * expand BECOME pseudo
	 */
	if ctxt.Debugvlog != 0 {
		fmt.Fprintf(ctxt.Bso, "%5.2f noops\n", obj.Cputime())
	}
	ctxt.Bso.Flush()

	var q *obj.Prog
	var q1 *obj.Prog
	for p := cursym.Text; p != nil; p = p.Link {
		switch p.As {
		/* too hard, just leave alone */
		case obj.ATEXT:
			q = p

			p.Mark |= LABEL | LEAF | SYNC
			if p.Link != nil {
				p.Link.Mark |= LABEL
			}

		case ANOR:
			q = p
			if p.To.Type == obj.TYPE_REG {
				if p.To.Reg == REGZERO {
					p.Mark |= LABEL | SYNC
				}
			}

		case ASYNC,
			AWORD:
			q = p
			p.Mark |= LABEL | SYNC
			continue

		case AMOVW, AMOVWZ, AMOVD:
			q = p
			if p.From.Reg >= REG_RESERVED || p.To.Reg >= REG_RESERVED {
				p.Mark |= LABEL | SYNC
			}
			continue

		case AFABS,
			AFADD,
			AFDIV,
			AFMADD,
			AFMOVD,
			/* case AFMOVDS: */
			AFMOVS,

			/* case AFMOVSD: */
			AFMSUB,
			AFMUL,
			AFNABS,
			AFNEG,
			AFNMADD,
			AFNMSUB,
			AFRSP,
			AFSUB:
			q = p

			p.Mark |= FLOAT
			continue

		case ABL,
			ABCL,
			obj.ADUFFZERO,
			obj.ADUFFCOPY:
			cursym.Text.Mark &^= LEAF
			fallthrough

		case ABC,
			ABEQ,
			ABGE,
			ABGT,
			ABLE,
			ABLT,
			ABNE,
			ABR,
			ABVC,
			ABVS,
			ACMPBEQ,
			ACMPBGE,
			ACMPBGT,
			ACMPBLE,
			ACMPBLT,
			ACMPBNE,
			ACMPUBEQ,
			ACMPUBGE,
			ACMPUBGT,
			ACMPUBLE,
			ACMPUBLT,
			ACMPUBNE:
			p.Mark |= BRANCH
			q = p
			q1 = p.Pcond
			if q1 != nil {
				for q1.As == obj.ANOP {
					q1 = q1.Link
					p.Pcond = q1
				}

				if q1.Mark&LEAF == 0 {
					q1.Mark |= LABEL
				}
			} else {
				p.Mark |= LABEL
			}
			q1 = p.Link
			if q1 != nil {
				q1.Mark |= LABEL
			}
			continue

		case AFCMPO, AFCMPU:
			q = p
			p.Mark |= FCMP | FLOAT
			continue

		case obj.ARET:
			q = p
			if p.Link != nil {
				p.Link.Mark |= LABEL
			}
			continue

		case obj.ANOP:
			q1 = p.Link
			q.Link = q1 /* q is non-nop */
			q1.Mark |= p.Mark
			continue

		default:
			q = p
			continue
		}
	}

	autosize := int32(0)
	var o int
	var p1 *obj.Prog
	var p2 *obj.Prog
	for p := cursym.Text; p != nil; p = p.Link {
		o = int(p.As)
		switch o {
		case obj.ATEXT:
			autosize = int32(textstksiz + 8)
			if (p.Mark&LEAF != 0) && autosize <= 8 {
				autosize = 0
			} else if autosize&4 != 0 {
				autosize += 4
			}
			p.To.Offset = int64(autosize) - 8
			if p.From3.Offset&obj.NOSPLIT == 0 {
				p = stacksplit(ctxt, p, autosize) // emit split check
			}

			q = p

			if autosize != 0 {
				q = obj.Appendp(ctxt, p)
				q.As = AADD
				q.From.Type = obj.TYPE_CONST
				q.From.Offset = int64(-autosize)
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REGSP
				q.Spadj = autosize
			} else if cursym.Text.Mark&LEAF == 0 {
				if ctxt.Debugvlog != 0 {
					fmt.Fprintf(ctxt.Bso, "save suppressed in: %s\n", cursym.Name)
					ctxt.Bso.Flush()
				}
				cursym.Text.Mark |= LEAF
			}

			if cursym.Text.Mark&LEAF != 0 {
				cursym.Leaf = 1
				break
			}

			q = obj.Appendp(ctxt, q)
			q.As = AMOVD
			q.From.Type = obj.TYPE_REG
			q.From.Reg = REG_LR
			q.To.Type = obj.TYPE_MEM
			q.To.Reg = REGSP
			q.To.Offset = 0

			if cursym.Text.From3.Offset&obj.WRAPPER != 0 {
				// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
				//
				//	MOVD g_panic(g), R3
				//	CMP R0, R3
				//	BEQ end
				//	MOVD panic_argp(R3), R4
				//	ADD $(autosize+8), R1, R5
				//	CMP R4, R5
				//	BNE end
				//	ADD $8, R1, R6
				//	MOVD R6, panic_argp(R3)
				// end:
				//	NOP
				//
				// The NOP is needed to give the jumps somewhere to land.
				// It is a liblink NOP, not a s390x NOP: it encodes to 0 instruction bytes.

				q = obj.Appendp(ctxt, q)

				q.As = AMOVD
				q.From.Type = obj.TYPE_MEM
				q.From.Reg = REGG
				q.From.Offset = 4 * int64(ctxt.Arch.Ptrsize) // G.panic
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_R3

				q = obj.Appendp(ctxt, q)
				q.As = ACMP
				q.From.Type = obj.TYPE_REG
				q.From.Reg = REG_R0
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_R3

				q = obj.Appendp(ctxt, q)
				q.As = ABEQ
				q.To.Type = obj.TYPE_BRANCH
				p1 = q

				q = obj.Appendp(ctxt, q)
				q.As = AMOVD
				q.From.Type = obj.TYPE_MEM
				q.From.Reg = REG_R3
				q.From.Offset = 0 // Panic.argp
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_R4

				q = obj.Appendp(ctxt, q)
				q.As = AADD
				q.From.Type = obj.TYPE_CONST
				q.From.Offset = int64(autosize) + 8
				q.Reg = REGSP
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_R5

				q = obj.Appendp(ctxt, q)
				q.As = ACMP
				q.From.Type = obj.TYPE_REG
				q.From.Reg = REG_R4
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_R5

				q = obj.Appendp(ctxt, q)
				q.As = ABNE
				q.To.Type = obj.TYPE_BRANCH
				p2 = q

				q = obj.Appendp(ctxt, q)
				q.As = AADD
				q.From.Type = obj.TYPE_CONST
				q.From.Offset = 8
				q.Reg = REGSP
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_R6

				q = obj.Appendp(ctxt, q)
				q.As = AMOVD
				q.From.Type = obj.TYPE_REG
				q.From.Reg = REG_R6
				q.To.Type = obj.TYPE_MEM
				q.To.Reg = REG_R3
				q.To.Offset = 0 // Panic.argp

				q = obj.Appendp(ctxt, q)

				q.As = obj.ANOP
				p1.Pcond = q
				p2.Pcond = q
			}

		case obj.ARET:
			if p.From.Type == obj.TYPE_CONST {
				ctxt.Diag("using BECOME (%v) is not supported!", p)
				break
			}

			if p.To.Sym != nil { // retjmp
				p.As = ABR
				p.To.Type = obj.TYPE_BRANCH
				break
			}

			if cursym.Text.Mark&LEAF != 0 {
				if autosize == 0 {
					p.As = ABR
					p.From = obj.Addr{}
					p.To.Type = obj.TYPE_REG
					p.To.Reg = REG_LR
					p.Mark |= BRANCH
					break
				}
				p.As = AADD
				p.From.Type = obj.TYPE_CONST
				p.From.Offset = int64(autosize)
				p.To.Type = obj.TYPE_REG
				p.To.Reg = REGSP
				p.Spadj = -autosize

				q = obj.Appendp(ctxt, p)
				q.As = ABR
				q.From = obj.Addr{}
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_LR
				q.Mark |= BRANCH
				q.Spadj = autosize
				break
			}

			p.As = AMOVD
			p.From.Type = obj.TYPE_MEM
			p.From.Reg = REGSP
			p.From.Offset = 0
			p.To.Type = obj.TYPE_REG
			p.To.Reg = REG_LR

			q = p

			if autosize != 0 {
				q = obj.Appendp(ctxt, q)
				q.As = AADD
				q.From.Type = obj.TYPE_CONST
				q.From.Offset = int64(autosize)
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REGSP
				q.Spadj = -autosize
			}

			q = obj.Appendp(ctxt, q)
			q.As = ABR
			q.From = obj.Addr{}
			q.To.Type = obj.TYPE_REG
			q.To.Reg = REG_LR
			q.Mark |= BRANCH
			q.Spadj = autosize

		case AADD:
			if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST {
				p.Spadj = int32(-p.From.Offset)
			}
		}
	}
}
Пример #9
0
// If s==nil, copyu returns the set/use of v in p; otherwise, it
// modifies p to replace reads of v with reads of s and returns 0 for
// success or non-zero for failure.
//
// If s==nil, copy returns one of the following values:
// 	1 if v only used
//	2 if v is set and used in one address (read-alter-rewrite;
// 	  can't substitute)
//	3 if v is only set
//	4 if v is set in one address and used in another (so addresses
// 	  can be rewritten independently)
//	0 otherwise (not touched)
func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
	if p.From3Type() != obj.TYPE_NONE {
		// never generates a from3
		fmt.Printf("copyu: from3 (%v) not implemented\n", gc.Ctxt.Dconv(p.From3))
	}

	switch p.As {
	default:
		fmt.Printf("copyu: can't find %v\n", obj.Aconv(int(p.As)))
		return 2

	case obj.ANOP, /* read p->from, write p->to */
		mips.AMOVV,
		mips.AMOVF,
		mips.AMOVD,
		mips.AMOVH,
		mips.AMOVHU,
		mips.AMOVB,
		mips.AMOVBU,
		mips.AMOVW,
		mips.AMOVWU,
		mips.AMOVFD,
		mips.AMOVDF,
		mips.AMOVDW,
		mips.AMOVWD,
		mips.AMOVFW,
		mips.AMOVWF,
		mips.AMOVDV,
		mips.AMOVVD,
		mips.AMOVFV,
		mips.AMOVVF,
		mips.ATRUNCFV,
		mips.ATRUNCDV,
		mips.ATRUNCFW,
		mips.ATRUNCDW:
		if s != nil {
			if copysub(&p.From, v, s, 1) != 0 {
				return 1
			}

			// Update only indirect uses of v in p->to
			if !copyas(&p.To, v) {
				if copysub(&p.To, v, s, 1) != 0 {
					return 1
				}
			}
			return 0
		}

		if copyas(&p.To, v) {
			// Fix up implicit from
			if p.From.Type == obj.TYPE_NONE {
				p.From = p.To
			}
			if copyau(&p.From, v) {
				return 4
			}
			return 3
		}

		if copyau(&p.From, v) {
			return 1
		}
		if copyau(&p.To, v) {
			// p->to only indirectly uses v
			return 1
		}

		return 0

	case mips.ASGT, /* read p->from, read p->reg, write p->to */
		mips.ASGTU,

		mips.AADD,
		mips.AADDU,
		mips.ASUB,
		mips.ASUBU,
		mips.ASLL,
		mips.ASRL,
		mips.ASRA,
		mips.AOR,
		mips.ANOR,
		mips.AAND,
		mips.AXOR,

		mips.AADDV,
		mips.AADDVU,
		mips.ASUBV,
		mips.ASUBVU,
		mips.ASLLV,
		mips.ASRLV,
		mips.ASRAV,

		mips.AADDF,
		mips.AADDD,
		mips.ASUBF,
		mips.ASUBD,
		mips.AMULF,
		mips.AMULD,
		mips.ADIVF,
		mips.ADIVD:
		if s != nil {
			if copysub(&p.From, v, s, 1) != 0 {
				return 1
			}
			if copysub1(p, v, s, 1) != 0 {
				return 1
			}

			// Update only indirect uses of v in p->to
			if !copyas(&p.To, v) {
				if copysub(&p.To, v, s, 1) != 0 {
					return 1
				}
			}
			return 0
		}

		if copyas(&p.To, v) {
			if p.Reg == 0 {
				// Fix up implicit reg (e.g., ADD
				// R3,R4 -> ADD R3,R4,R4) so we can
				// update reg and to separately.
				p.Reg = p.To.Reg
			}

			if copyau(&p.From, v) {
				return 4
			}
			if copyau1(p, v) {
				return 4
			}
			return 3
		}

		if copyau(&p.From, v) {
			return 1
		}
		if copyau1(p, v) {
			return 1
		}
		if copyau(&p.To, v) {
			return 1
		}
		return 0

	case obj.ACHECKNIL, /* read p->from */
		mips.ABEQ, /* read p->from, read p->reg */
		mips.ABNE,
		mips.ABGTZ,
		mips.ABGEZ,
		mips.ABLTZ,
		mips.ABLEZ,

		mips.ACMPEQD,
		mips.ACMPEQF,
		mips.ACMPGED,
		mips.ACMPGEF,
		mips.ACMPGTD,
		mips.ACMPGTF,
		mips.ABFPF,
		mips.ABFPT,

		mips.AMUL,
		mips.AMULU,
		mips.ADIV,
		mips.ADIVU,
		mips.AMULV,
		mips.AMULVU,
		mips.ADIVV,
		mips.ADIVVU:
		if s != nil {
			if copysub(&p.From, v, s, 1) != 0 {
				return 1
			}
			return copysub1(p, v, s, 1)
		}

		if copyau(&p.From, v) {
			return 1
		}
		if copyau1(p, v) {
			return 1
		}
		return 0

	case mips.AJMP: /* read p->to */
		if s != nil {
			if copysub(&p.To, v, s, 1) != 0 {
				return 1
			}
			return 0
		}

		if copyau(&p.To, v) {
			return 1
		}
		return 0

	case mips.ARET: /* funny */
		if s != nil {
			return 0
		}

		// All registers die at this point, so claim
		// everything is set (and not used).
		return 3

	case mips.AJAL: /* funny */
		if v.Type == obj.TYPE_REG {
			// TODO(rsc): REG_R0 and REG_F0 used to be
			// (when register numbers started at 0) exregoffset and exfregoffset,
			// which are unset entirely.
			// It's strange that this handles R0 and F0 differently from the other
			// registers. Possible failure to optimize?
			if mips.REG_R0 < v.Reg && v.Reg <= mips.REG_R31 {
				return 2
			}
			if v.Reg == mips.REGARG {
				return 2
			}
			if mips.REG_F0 < v.Reg && v.Reg <= mips.REG_F31 {
				return 2
			}
		}

		if p.From.Type == obj.TYPE_REG && v.Type == obj.TYPE_REG && p.From.Reg == v.Reg {
			return 2
		}

		if s != nil {
			if copysub(&p.To, v, s, 1) != 0 {
				return 1
			}
			return 0
		}

		if copyau(&p.To, v) {
			return 4
		}
		return 3

	// R0 is zero, used by DUFFZERO, cannot be substituted.
	// R1 is ptr to memory, used and set, cannot be substituted.
	case obj.ADUFFZERO:
		if v.Type == obj.TYPE_REG {
			if v.Reg == 0 {
				return 1
			}
			if v.Reg == 1 {
				return 2
			}
		}

		return 0

	// R1, R2 are ptr to src, dst, used and set, cannot be substituted.
	// R3 is scratch, set by DUFFCOPY, cannot be substituted.
	case obj.ADUFFCOPY:
		if v.Type == obj.TYPE_REG {
			if v.Reg == 1 || v.Reg == 2 {
				return 2
			}
			if v.Reg == 3 {
				return 3
			}
		}

		return 0

	case obj.ATEXT: /* funny */
		if v.Type == obj.TYPE_REG {
			if v.Reg == mips.REGARG {
				return 3
			}
		}
		return 0

	case obj.APCDATA,
		obj.AFUNCDATA,
		obj.AVARDEF,
		obj.AVARKILL,
		obj.AVARLIVE,
		obj.AUSEFIELD:
		return 0
	}
}
Пример #10
0
func progedit(ctxt *obj.Link, p *obj.Prog) {
	// Maintain information about code generation mode.
	if ctxt.Mode == 0 {
		ctxt.Mode = ctxt.Arch.Regsize * 8
	}
	p.Mode = int8(ctxt.Mode)

	switch p.As {
	case AMODE:
		if p.From.Type == obj.TYPE_CONST || (p.From.Type == obj.TYPE_MEM && p.From.Reg == REG_NONE) {
			switch int(p.From.Offset) {
			case 16, 32, 64:
				ctxt.Mode = int(p.From.Offset)
			}
		}
		obj.Nopout(p)
	}

	// Thread-local storage references use the TLS pseudo-register.
	// As a register, TLS refers to the thread-local storage base, and it
	// can only be loaded into another register:
	//
	//         MOVQ TLS, AX
	//
	// An offset from the thread-local storage base is written off(reg)(TLS*1).
	// Semantically it is off(reg), but the (TLS*1) annotation marks this as
	// indexing from the loaded TLS base. This emits a relocation so that
	// if the linker needs to adjust the offset, it can. For example:
	//
	//         MOVQ TLS, AX
	//         MOVQ 0(AX)(TLS*1), CX // load g into CX
	//
	// On systems that support direct access to the TLS memory, this
	// pair of instructions can be reduced to a direct TLS memory reference:
	//
	//         MOVQ 0(TLS), CX // load g into CX
	//
	// The 2-instruction and 1-instruction forms correspond to the two code
	// sequences for loading a TLS variable in the local exec model given in "ELF
	// Handling For Thread-Local Storage".
	//
	// We apply this rewrite on systems that support the 1-instruction form.
	// The decision is made using only the operating system and the -shared flag,
	// not the link mode. If some link modes on a particular operating system
	// require the 2-instruction form, then all builds for that operating system
	// will use the 2-instruction form, so that the link mode decision can be
	// delayed to link time.
	//
	// In this way, all supported systems use identical instructions to
	// access TLS, and they are rewritten appropriately first here in
	// liblink and then finally using relocations in the linker.
	//
	// When -shared is passed, we leave the code in the 2-instruction form but
	// assemble (and relocate) them in different ways to generate the initial
	// exec code sequence. It's a bit of a fluke that this is possible without
	// rewriting the instructions more comprehensively, and it only does because
	// we only support a single TLS variable (g).

	if CanUse1InsnTLS(ctxt) {
		// Reduce 2-instruction sequence to 1-instruction sequence.
		// Sequences like
		//	MOVQ TLS, BX
		//	... off(BX)(TLS*1) ...
		// become
		//	NOP
		//	... off(TLS) ...
		//
		// TODO(rsc): Remove the Hsolaris special case. It exists only to
		// guarantee we are producing byte-identical binaries as before this code.
		// But it should be unnecessary.
		if (p.As == AMOVQ || p.As == AMOVL) && p.From.Type == obj.TYPE_REG && p.From.Reg == REG_TLS && p.To.Type == obj.TYPE_REG && REG_AX <= p.To.Reg && p.To.Reg <= REG_R15 && ctxt.Headtype != obj.Hsolaris {
			obj.Nopout(p)
		}
		if p.From.Type == obj.TYPE_MEM && p.From.Index == REG_TLS && REG_AX <= p.From.Reg && p.From.Reg <= REG_R15 {
			p.From.Reg = REG_TLS
			p.From.Scale = 0
			p.From.Index = REG_NONE
		}

		if p.To.Type == obj.TYPE_MEM && p.To.Index == REG_TLS && REG_AX <= p.To.Reg && p.To.Reg <= REG_R15 {
			p.To.Reg = REG_TLS
			p.To.Scale = 0
			p.To.Index = REG_NONE
		}
	} else {
		// load_g_cx, below, always inserts the 1-instruction sequence. Rewrite it
		// as the 2-instruction sequence if necessary.
		//	MOVQ 0(TLS), BX
		// becomes
		//	MOVQ TLS, BX
		//	MOVQ 0(BX)(TLS*1), BX
		if (p.As == AMOVQ || p.As == AMOVL) && p.From.Type == obj.TYPE_MEM && p.From.Reg == REG_TLS && p.To.Type == obj.TYPE_REG && REG_AX <= p.To.Reg && p.To.Reg <= REG_R15 {
			q := obj.Appendp(ctxt, p)
			q.As = p.As
			q.From = p.From
			q.From.Type = obj.TYPE_MEM
			q.From.Reg = p.To.Reg
			q.From.Index = REG_TLS
			q.From.Scale = 2 // TODO: use 1
			q.To = p.To
			p.From.Type = obj.TYPE_REG
			p.From.Reg = REG_TLS
			p.From.Index = REG_NONE
			p.From.Offset = 0
		}
	}

	// TODO: Remove.
	if ctxt.Headtype == obj.Hwindows && p.Mode == 64 || ctxt.Headtype == obj.Hplan9 {
		if p.From.Scale == 1 && p.From.Index == REG_TLS {
			p.From.Scale = 2
		}
		if p.To.Scale == 1 && p.To.Index == REG_TLS {
			p.To.Scale = 2
		}
	}

	// Rewrite 0 to $0 in 3rd argument to CMPPS etc.
	// That's what the tables expect.
	switch p.As {
	case ACMPPD, ACMPPS, ACMPSD, ACMPSS:
		if p.To.Type == obj.TYPE_MEM && p.To.Name == obj.NAME_NONE && p.To.Reg == REG_NONE && p.To.Index == REG_NONE && p.To.Sym == nil {
			p.To.Type = obj.TYPE_CONST
		}
	}

	// Rewrite CALL/JMP/RET to symbol as TYPE_BRANCH.
	switch p.As {
	case obj.ACALL, obj.AJMP, obj.ARET:
		if p.To.Type == obj.TYPE_MEM && (p.To.Name == obj.NAME_EXTERN || p.To.Name == obj.NAME_STATIC) && p.To.Sym != nil {
			p.To.Type = obj.TYPE_BRANCH
		}
	}

	// Rewrite MOVL/MOVQ $XXX(FP/SP) as LEAL/LEAQ.
	if p.From.Type == obj.TYPE_ADDR && (ctxt.Arch.Thechar == '6' || p.From.Name != obj.NAME_EXTERN && p.From.Name != obj.NAME_STATIC) {
		switch p.As {
		case AMOVL:
			p.As = ALEAL
			p.From.Type = obj.TYPE_MEM
		case AMOVQ:
			p.As = ALEAQ
			p.From.Type = obj.TYPE_MEM
		}
	}

	if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
		if p.From3 != nil {
			nacladdr(ctxt, p, p.From3)
		}
		nacladdr(ctxt, p, &p.From)
		nacladdr(ctxt, p, &p.To)
	}

	// Rewrite float constants to values stored in memory.
	switch p.As {
	// Convert AMOVSS $(0), Xx to AXORPS Xx, Xx
	case AMOVSS:
		if p.From.Type == obj.TYPE_FCONST {
			//  f == 0 can't be used here due to -0, so use Float64bits
			if f := p.From.Val.(float64); math.Float64bits(f) == 0 {
				if p.To.Type == obj.TYPE_REG && REG_X0 <= p.To.Reg && p.To.Reg <= REG_X15 {
					p.As = AXORPS
					p.From = p.To
					break
				}
			}
		}
		fallthrough

	case AFMOVF,
		AFADDF,
		AFSUBF,
		AFSUBRF,
		AFMULF,
		AFDIVF,
		AFDIVRF,
		AFCOMF,
		AFCOMFP,
		AADDSS,
		ASUBSS,
		AMULSS,
		ADIVSS,
		ACOMISS,
		AUCOMISS:
		if p.From.Type == obj.TYPE_FCONST {
			f32 := float32(p.From.Val.(float64))
			i32 := math.Float32bits(f32)
			literal := fmt.Sprintf("$f32.%08x", i32)
			s := obj.Linklookup(ctxt, literal, 0)
			p.From.Type = obj.TYPE_MEM
			p.From.Name = obj.NAME_EXTERN
			p.From.Sym = s
			p.From.Sym.Local = true
			p.From.Offset = 0
		}

	case AMOVSD:
		// Convert AMOVSD $(0), Xx to AXORPS Xx, Xx
		if p.From.Type == obj.TYPE_FCONST {
			//  f == 0 can't be used here due to -0, so use Float64bits
			if f := p.From.Val.(float64); math.Float64bits(f) == 0 {
				if p.To.Type == obj.TYPE_REG && REG_X0 <= p.To.Reg && p.To.Reg <= REG_X15 {
					p.As = AXORPS
					p.From = p.To
					break
				}
			}
		}
		fallthrough

	case AFMOVD,
		AFADDD,
		AFSUBD,
		AFSUBRD,
		AFMULD,
		AFDIVD,
		AFDIVRD,
		AFCOMD,
		AFCOMDP,
		AADDSD,
		ASUBSD,
		AMULSD,
		ADIVSD,
		ACOMISD,
		AUCOMISD:
		if p.From.Type == obj.TYPE_FCONST {
			i64 := math.Float64bits(p.From.Val.(float64))
			literal := fmt.Sprintf("$f64.%016x", i64)
			s := obj.Linklookup(ctxt, literal, 0)
			p.From.Type = obj.TYPE_MEM
			p.From.Name = obj.NAME_EXTERN
			p.From.Sym = s
			p.From.Sym.Local = true
			p.From.Offset = 0
		}
	}

	if ctxt.Flag_dynlink {
		rewriteToUseGot(ctxt, p)
	}

	if ctxt.Flag_shared != 0 && p.Mode == 32 {
		rewriteToPcrel(ctxt, p)
	}
}
Пример #11
0
func peep(firstp *obj.Prog) {
	g := gc.Flowstart(firstp, nil)
	if g == nil {
		return
	}
	gactive = 0

	var p *obj.Prog
	var r *gc.Flow
	var t int
loop1:
	if gc.Debug['P'] != 0 && gc.Debug['v'] != 0 {
		gc.Dumpit("loop1", g.Start, 0)
	}

	t = 0
	for r = g.Start; r != nil; r = r.Link {
		p = r.Prog

		// TODO(minux) Handle smaller moves. arm and amd64
		// distinguish between moves that *must* sign/zero
		// extend and moves that don't care so they
		// can eliminate moves that don't care without
		// breaking moves that do care. This might let us
		// simplify or remove the next peep loop, too.
		if p.As == arm64.AMOVD || p.As == arm64.AFMOVD {
			if regtyp(&p.To) {
				// Try to eliminate reg->reg moves
				if regtyp(&p.From) {
					if p.From.Type == p.To.Type {
						if copyprop(r) {
							excise(r)
							t++
						} else if subprop(r) && copyprop(r) {
							excise(r)
							t++
						}
					}
				}
			}
		}
	}

	if t != 0 {
		goto loop1
	}

	/*
	 * look for MOVB x,R; MOVB R,R (for small MOVs not handled above)
	 */
	var p1 *obj.Prog
	var r1 *gc.Flow
	for r := g.Start; r != nil; r = r.Link {
		p = r.Prog
		switch p.As {
		default:
			continue

		case arm64.AMOVH,
			arm64.AMOVHU,
			arm64.AMOVB,
			arm64.AMOVBU,
			arm64.AMOVW,
			arm64.AMOVWU:
			if p.To.Type != obj.TYPE_REG {
				continue
			}
		}

		r1 = r.Link
		if r1 == nil {
			continue
		}
		p1 = r1.Prog
		if p1.As != p.As {
			continue
		}
		if p1.From.Type != obj.TYPE_REG || p1.From.Reg != p.To.Reg {
			continue
		}
		if p1.To.Type != obj.TYPE_REG || p1.To.Reg != p.To.Reg {
			continue
		}
		excise(r1)
	}

	if gc.Debug['D'] > 1 {
		goto ret /* allow following code improvement to be suppressed */
	}

	// MOVD $c, R'; ADD R', R (R' unused) -> ADD $c, R
	for r := g.Start; r != nil; r = r.Link {
		p = r.Prog
		switch p.As {
		default:
			continue

		case arm64.AMOVD:
			if p.To.Type != obj.TYPE_REG {
				continue
			}
			if p.From.Type != obj.TYPE_CONST {
				continue
			}
			if p.From.Offset < 0 || 4096 <= p.From.Offset {
				continue
			}
		}
		r1 = r.Link
		if r1 == nil {
			continue
		}
		p1 = r1.Prog
		if p1.As != arm64.AADD && p1.As != arm64.ASUB { // TODO(aram): also logical after we have bimm.
			continue
		}
		if p1.From.Type != obj.TYPE_REG || p1.From.Reg != p.To.Reg {
			continue
		}
		if p1.To.Type != obj.TYPE_REG {
			continue
		}
		if gc.Debug['P'] != 0 {
			fmt.Printf("encoding $%d directly into %v in:\n%v\n%v\n", p.From.Offset, obj.Aconv(p1.As), p, p1)
		}
		p1.From.Type = obj.TYPE_CONST
		p1.From = p.From
		excise(r)
	}

	/* TODO(minux):
	 * look for OP x,y,R; CMP R, $0 -> OP.S x,y,R
	 * when OP can set condition codes correctly
	 */

ret:
	gc.Flowend(g)
}
Пример #12
0
// If s==nil, copyu returns the set/use of v in p; otherwise, it
// modifies p to replace reads of v with reads of s and returns 0 for
// success or non-zero for failure.
//
// If s==nil, copy returns one of the following values:
//	1 if v only used
//	2 if v is set and used in one address (read-alter-rewrite;
//	  can't substitute)
//	3 if v is only set
//	4 if v is set in one address and used in another (so addresses
//	  can be rewritten independently)
//	0 otherwise (not touched)
func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
	if p.From3.Type != obj.TYPE_NONE {
		// 7g never generates a from3
		fmt.Printf("copyu: from3 (%v) not implemented\n", gc.Ctxt.Dconv(&p.From3))
	}
	if p.To2.Type != obj.TYPE_NONE {
		// 7g never generates a to2
		fmt.Printf("copyu: to2 (%v) not implemented\n", gc.Ctxt.Dconv(&p.To2))
	}

	switch p.As {
	default:
		fmt.Printf("copyu: can't find %v\n", obj.Aconv(int(p.As)))
		return 2

	case obj.ANOP, /* read p->from, write p->to */
		arm64.ANEG,
		arm64.AFNEGD,
		arm64.AFNEGS,
		arm64.AFSQRTD,
		arm64.AFCVTZSD,
		arm64.AFCVTZSS,
		arm64.AFCVTZSDW,
		arm64.AFCVTZSSW,
		arm64.AFCVTZUD,
		arm64.AFCVTZUS,
		arm64.AFCVTZUDW,
		arm64.AFCVTZUSW,
		arm64.AFCVTSD,
		arm64.AFCVTDS,
		arm64.ASCVTFD,
		arm64.ASCVTFS,
		arm64.ASCVTFWD,
		arm64.ASCVTFWS,
		arm64.AUCVTFD,
		arm64.AUCVTFS,
		arm64.AUCVTFWD,
		arm64.AUCVTFWS,
		arm64.AMOVB,
		arm64.AMOVBU,
		arm64.AMOVH,
		arm64.AMOVHU,
		arm64.AMOVW,
		arm64.AMOVWU,
		arm64.AMOVD,
		arm64.AFMOVS,
		arm64.AFMOVD:
		if p.Scond == 0 {
			if s != nil {
				if copysub(&p.From, v, s, 1) != 0 {
					return 1
				}

				// Update only indirect uses of v in p->to
				if !copyas(&p.To, v) {
					if copysub(&p.To, v, s, 1) != 0 {
						return 1
					}
				}
				return 0
			}

			if copyas(&p.To, v) {
				// Fix up implicit from
				if p.From.Type == obj.TYPE_NONE {
					p.From = p.To
				}
				if copyau(&p.From, v) {
					return 4
				}
				return 3
			}

			if copyau(&p.From, v) {
				return 1
			}
			if copyau(&p.To, v) {
				// p->to only indirectly uses v
				return 1
			}

			return 0
		}

		/* rar p->from, write p->to or read p->from, rar p->to */
		if p.From.Type == obj.TYPE_MEM {
			if copyas(&p.From, v) {
				// No s!=nil check; need to fail
				// anyway in that case
				return 2
			}

			if s != nil {
				if copysub(&p.To, v, s, 1) != 0 {
					return 1
				}
				return 0
			}

			if copyas(&p.To, v) {
				return 3
			}
		} else if p.To.Type == obj.TYPE_MEM {
			if copyas(&p.To, v) {
				return 2
			}
			if s != nil {
				if copysub(&p.From, v, s, 1) != 0 {
					return 1
				}
				return 0
			}

			if copyau(&p.From, v) {
				return 1
			}
		} else {
			fmt.Printf("copyu: bad %v\n", p)
		}

		return 0

	case arm64.AADD, /* read p->from, read p->reg, write p->to */
		arm64.ASUB,
		arm64.AAND,
		arm64.AORR,
		arm64.AEOR,
		arm64.AMUL,
		arm64.ASMULL,
		arm64.AUMULL,
		arm64.ASMULH,
		arm64.AUMULH,
		arm64.ASDIV,
		arm64.AUDIV,
		arm64.ALSL,
		arm64.ALSR,
		arm64.AASR,
		arm64.AFADDD,
		arm64.AFADDS,
		arm64.AFSUBD,
		arm64.AFSUBS,
		arm64.AFMULD,
		arm64.AFMULS,
		arm64.AFDIVD,
		arm64.AFDIVS:
		if s != nil {
			if copysub(&p.From, v, s, 1) != 0 {
				return 1
			}
			if copysub1(p, v, s, 1) != 0 {
				return 1
			}

			// Update only indirect uses of v in p->to
			if !copyas(&p.To, v) {
				if copysub(&p.To, v, s, 1) != 0 {
					return 1
				}
			}
			return 0
		}

		if copyas(&p.To, v) {
			if p.Reg == 0 {
				// Fix up implicit reg (e.g., ADD
				// R3,R4 -> ADD R3,R4,R4) so we can
				// update reg and to separately.
				p.Reg = p.To.Reg
			}

			if copyau(&p.From, v) {
				return 4
			}
			if copyau1(p, v) {
				return 4
			}
			return 3
		}

		if copyau(&p.From, v) {
			return 1
		}
		if copyau1(p, v) {
			return 1
		}
		if copyau(&p.To, v) {
			return 1
		}
		return 0

	case arm64.ABEQ,
		arm64.ABNE,
		arm64.ABGE,
		arm64.ABLT,
		arm64.ABGT,
		arm64.ABLE,
		arm64.ABLO,
		arm64.ABLS,
		arm64.ABHI,
		arm64.ABHS:
		return 0

	case obj.ACHECKNIL, /* read p->from */
		arm64.ACMP, /* read p->from, read p->reg */
		arm64.AFCMPD,
		arm64.AFCMPS:
		if s != nil {
			if copysub(&p.From, v, s, 1) != 0 {
				return 1
			}
			return copysub1(p, v, s, 1)
		}

		if copyau(&p.From, v) {
			return 1
		}
		if copyau1(p, v) {
			return 1
		}
		return 0

	case arm64.AB: /* read p->to */
		if s != nil {
			if copysub(&p.To, v, s, 1) != 0 {
				return 1
			}
			return 0
		}

		if copyau(&p.To, v) {
			return 1
		}
		return 0

	case obj.ARET: /* funny */
		if s != nil {
			return 0
		}

		// All registers die at this point, so claim
		// everything is set (and not used).
		return 3

	case arm64.ABL: /* funny */
		if p.From.Type == obj.TYPE_REG && v.Type == obj.TYPE_REG && p.From.Reg == v.Reg {
			return 2
		}

		if s != nil {
			if copysub(&p.To, v, s, 1) != 0 {
				return 1
			}
			return 0
		}

		if copyau(&p.To, v) {
			return 4
		}
		return 3

	// R31 is zero, used by DUFFZERO, cannot be substituted.
	// R16 is ptr to memory, used and set, cannot be substituted.
	case obj.ADUFFZERO:
		if v.Type == obj.TYPE_REG {
			if v.Reg == 31 {
				return 1
			}
			if v.Reg == 16 {
				return 2
			}
		}

		return 0

	// R16, R17 are ptr to src, dst, used and set, cannot be substituted.
	// R27 is scratch, set by DUFFCOPY, cannot be substituted.
	case obj.ADUFFCOPY:
		if v.Type == obj.TYPE_REG {
			if v.Reg == 16 || v.Reg == 17 {
				return 2
			}
			if v.Reg == 27 {
				return 3
			}
		}

		return 0

	case arm64.AHINT,
		obj.ATEXT,
		obj.APCDATA,
		obj.AFUNCDATA,
		obj.AVARDEF,
		obj.AVARKILL:
		return 0
	}
}
Пример #13
0
// If s==nil, copyu returns the set/use of v in p; otherwise, it
// modifies p to replace reads of v with reads of s and returns 0 for
// success or non-zero for failure.
//
// If s==nil, copy returns one of the following values:
// 	1 if v only used
//	2 if v is set and used in one address (read-alter-rewrite;
// 	  can't substitute)
//	3 if v is only set
//	4 if v is set in one address and used in another (so addresses
// 	  can be rewritten independently)
//	0 otherwise (not touched)
func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
	if p.From3Type() != obj.TYPE_NONE && p.From3Type() != obj.TYPE_CONST {
		// Currently we never generate a From3 with anything other than a constant in it.
		fmt.Printf("copyu: From3 (%v) not implemented\n", gc.Ctxt.Dconv(p.From3))
	}

	switch p.As {
	default:
		fmt.Printf("copyu: can't find %v\n", obj.Aconv(int(p.As)))
		return 2

	case obj.ANOP, /* read p->from, write p->to */
		s390x.AMOVH,
		s390x.AMOVHZ,
		s390x.AMOVB,
		s390x.AMOVBZ,
		s390x.AMOVW,
		s390x.AMOVWZ,
		s390x.AMOVD,
		s390x.ANEG,
		s390x.AADDME,
		s390x.AADDZE,
		s390x.ASUBME,
		s390x.ASUBZE,
		s390x.AFMOVS,
		s390x.AFMOVD,
		s390x.AFRSP,
		s390x.AFNEG,
		s390x.ALDEBR,
		s390x.ACLFEBR,
		s390x.ACLGEBR,
		s390x.ACLFDBR,
		s390x.ACLGDBR,
		s390x.ACFEBRA,
		s390x.ACGEBRA,
		s390x.ACFDBRA,
		s390x.ACGDBRA,
		s390x.ACELFBR,
		s390x.ACELGBR,
		s390x.ACDLFBR,
		s390x.ACDLGBR,
		s390x.ACEFBRA,
		s390x.ACEGBRA,
		s390x.ACDFBRA,
		s390x.ACDGBRA,
		s390x.AFSQRT:

		if s != nil {
			if copysub(&p.From, v, s, 1) != 0 {
				return 1
			}

			// Update only indirect uses of v in p->to
			if !copyas(&p.To, v) {
				if copysub(&p.To, v, s, 1) != 0 {
					return 1
				}
			}
			return 0
		}

		if copyas(&p.To, v) {
			// Fix up implicit from
			if p.From.Type == obj.TYPE_NONE {
				p.From = p.To
			}
			if copyau(&p.From, v) {
				return 4
			}
			return 3
		}

		if copyau(&p.From, v) {
			return 1
		}
		if copyau(&p.To, v) {
			// p->to only indirectly uses v
			return 1
		}

		return 0

	// read p->from, read p->reg, rar p->to
	case s390x.ARLWMI:
		if copyas(&p.To, v) {
			return 2
		}
		fallthrough
	// read p->from, read p->reg, write p->to
	case s390x.AADD,
		s390x.AADDC,
		s390x.AADDE,
		s390x.ASUB,
		s390x.ASLW,
		s390x.ASRW,
		s390x.ASRAW,
		s390x.ASLD,
		s390x.ASRD,
		s390x.ASRAD,
		s390x.AOR,
		s390x.AORN,
		s390x.AAND,
		s390x.AANDN,
		s390x.ANAND,
		s390x.ANOR,
		s390x.AXOR,
		s390x.AMULLW,
		s390x.AMULLD,
		s390x.ADIVW,
		s390x.ADIVD,
		s390x.ADIVWU,
		s390x.ADIVDU,
		s390x.AREM,
		s390x.AREMU,
		s390x.AREMD,
		s390x.AREMDU,
		s390x.ARLWNM,
		s390x.AFADDS,
		s390x.AFADD,
		s390x.AFSUBS,
		s390x.AFSUB,
		s390x.AFMULS,
		s390x.AFMUL,
		s390x.AFDIVS,
		s390x.AFDIV:
		if s != nil {
			if copysub(&p.From, v, s, 1) != 0 {
				return 1
			}
			if copysub1(p, v, s, 1) != 0 {
				return 1
			}

			// Update only indirect uses of v in p->to
			if !copyas(&p.To, v) {
				if copysub(&p.To, v, s, 1) != 0 {
					return 1
				}
			}
			return 0
		}

		if copyas(&p.To, v) {
			if p.Reg == 0 {
				// Fix up implicit reg (e.g., ADD
				// R3,R4 -> ADD R3,R4,R4) so we can
				// update reg and to separately.
				p.Reg = p.To.Reg
			}

			if copyau(&p.From, v) {
				return 4
			}
			if copyau1(p, v) {
				return 4
			}
			return 3
		}

		if copyau(&p.From, v) {
			return 1
		}
		if copyau1(p, v) {
			return 1
		}
		if copyau(&p.To, v) {
			return 1
		}
		return 0

	case s390x.ABEQ,
		s390x.ABGT,
		s390x.ABGE,
		s390x.ABLT,
		s390x.ABLE,
		s390x.ABNE,
		s390x.ABVC,
		s390x.ABVS:
		return 0

	case obj.ACHECKNIL, /* read p->from */
		s390x.ACMP, /* read p->from, read p->to */
		s390x.ACMPU,
		s390x.ACMPW,
		s390x.ACMPWU,
		s390x.AFCMPO,
		s390x.AFCMPU,
		s390x.ACEBR,
		s390x.AMVC,
		s390x.ACLC,
		s390x.AXC,
		s390x.AOC,
		s390x.ANC:
		if s != nil {
			if copysub(&p.From, v, s, 1) != 0 {
				return 1
			}
			return copysub(&p.To, v, s, 1)
		}

		if copyau(&p.From, v) {
			return 1
		}
		if copyau(&p.To, v) {
			return 1
		}
		return 0

	// go never generates a branch to a GPR
	// read p->to
	case s390x.ABR:
		if s != nil {
			if copysub(&p.To, v, s, 1) != 0 {
				return 1
			}
			return 0
		}

		if copyau(&p.To, v) {
			return 1
		}
		return 0

	case obj.ARET:
		if s != nil {
			return 0
		}

		// All registers die at this point, so claim
		// everything is set (and not used).
		return 3

	case s390x.ABL:
		if v.Type == obj.TYPE_REG {
			// TODO(rsc): REG_R0 and REG_F0 used to be
			// (when register numbers started at 0) exregoffset and exfregoffset,
			// which are unset entirely.
			// It's strange that this handles R0 and F0 differently from the other
			// registers. Possible failure to optimize?
			if s390x.REG_R0 < v.Reg && v.Reg <= s390x.REGEXT {
				return 2
			}
			if v.Reg == s390x.REGARG {
				return 2
			}
			if s390x.REG_F0 < v.Reg && v.Reg <= s390x.FREGEXT {
				return 2
			}
		}

		if p.From.Type == obj.TYPE_REG && v.Type == obj.TYPE_REG && p.From.Reg == v.Reg {
			return 2
		}

		if s != nil {
			if copysub(&p.To, v, s, 1) != 0 {
				return 1
			}
			return 0
		}

		if copyau(&p.To, v) {
			return 4
		}
		return 3

	case obj.ATEXT:
		if v.Type == obj.TYPE_REG {
			if v.Reg == s390x.REGARG {
				return 3
			}
		}
		return 0

	case obj.APCDATA,
		obj.AFUNCDATA,
		obj.AVARDEF,
		obj.AVARKILL:
		return 0
	}
}
Пример #14
0
Файл: peep.go Проект: hurkgu/go
// If s==nil, copyu returns the set/use of v in p; otherwise, it
// modifies p to replace reads of v with reads of s and returns 0 for
// success or non-zero for failure.
//
// If s==nil, copy returns one of the following values:
// 	1 if v only used
//	2 if v is set and used in one address (read-alter-rewrite;
// 	  can't substitute)
//	3 if v is only set
//	4 if v is set in one address and used in another (so addresses
// 	  can be rewritten independently)
//	0 otherwise (not touched)
func copyu(p *obj.Prog, v *obj.Addr, s *obj.Addr) int {
	if p.From3Type() != obj.TYPE_NONE {
		// 9g never generates a from3
		fmt.Printf("copyu: from3 (%v) not implemented\n", gc.Ctxt.Dconv(p.From3))
	}

	switch p.As {
	default:
		fmt.Printf("copyu: can't find %v\n", p.As)
		return 2

	case obj.ANOP, /* read p->from, write p->to */
		ppc64.AMOVH,
		ppc64.AMOVHZ,
		ppc64.AMOVB,
		ppc64.AMOVBZ,
		ppc64.AMOVW,
		ppc64.AMOVWZ,
		ppc64.AMOVD,
		ppc64.ANEG,
		ppc64.ANEGCC,
		ppc64.AADDME,
		ppc64.AADDMECC,
		ppc64.AADDZE,
		ppc64.AADDZECC,
		ppc64.ASUBME,
		ppc64.ASUBMECC,
		ppc64.ASUBZE,
		ppc64.ASUBZECC,
		ppc64.AFCTIW,
		ppc64.AFCTIWZ,
		ppc64.AFCTID,
		ppc64.AFCTIDZ,
		ppc64.AFCFID,
		ppc64.AFCFIDCC,
		ppc64.AFCFIDU,
		ppc64.AFCFIDUCC,
		ppc64.AFMOVS,
		ppc64.AFMOVD,
		ppc64.AFRSP,
		ppc64.AFNEG,
		ppc64.AFNEGCC,
		ppc64.AFSQRT:
		if s != nil {
			if copysub(&p.From, v, s, true) {
				return 1
			}

			// Update only indirect uses of v in p->to
			if !copyas(&p.To, v) {
				if copysub(&p.To, v, s, true) {
					return 1
				}
			}
			return 0
		}

		if copyas(&p.To, v) {
			// Fix up implicit from
			if p.From.Type == obj.TYPE_NONE {
				p.From = p.To
			}
			if copyau(&p.From, v) {
				return 4
			}
			return 3
		}

		if copyau(&p.From, v) {
			return 1
		}
		if copyau(&p.To, v) {
			// p->to only indirectly uses v
			return 1
		}

		return 0

	case ppc64.AMOVBU, /* rar p->from, write p->to or read p->from, rar p->to */
		ppc64.AMOVBZU,
		ppc64.AMOVHU,
		ppc64.AMOVHZU,
		ppc64.AMOVWZU,
		ppc64.AMOVDU:
		if p.From.Type == obj.TYPE_MEM {
			if copyas(&p.From, v) {
				// No s!=nil check; need to fail
				// anyway in that case
				return 2
			}

			if s != nil {
				if copysub(&p.To, v, s, true) {
					return 1
				}
				return 0
			}

			if copyas(&p.To, v) {
				return 3
			}
		} else if p.To.Type == obj.TYPE_MEM {
			if copyas(&p.To, v) {
				return 2
			}
			if s != nil {
				if copysub(&p.From, v, s, true) {
					return 1
				}
				return 0
			}

			if copyau(&p.From, v) {
				return 1
			}
		} else {
			fmt.Printf("copyu: bad %v\n", p)
		}

		return 0

	case ppc64.ARLWMI, /* read p->from, read p->reg, rar p->to */
		ppc64.ARLWMICC:
		if copyas(&p.To, v) {
			return 2
		}
		fallthrough

		/* fall through */
	case ppc64.AADD,
		/* read p->from, read p->reg, write p->to */
		ppc64.AADDC,
		ppc64.AADDE,
		ppc64.ASUB,
		ppc64.ASLW,
		ppc64.ASRW,
		ppc64.ASRAW,
		ppc64.ASLD,
		ppc64.ASRD,
		ppc64.ASRAD,
		ppc64.AOR,
		ppc64.AORCC,
		ppc64.AORN,
		ppc64.AORNCC,
		ppc64.AAND,
		ppc64.AANDCC,
		ppc64.AANDN,
		ppc64.AANDNCC,
		ppc64.ANAND,
		ppc64.ANANDCC,
		ppc64.ANOR,
		ppc64.ANORCC,
		ppc64.AXOR,
		ppc64.AMULHW,
		ppc64.AMULHWU,
		ppc64.AMULLW,
		ppc64.AMULLD,
		ppc64.ADIVW,
		ppc64.ADIVD,
		ppc64.ADIVWU,
		ppc64.ADIVDU,
		ppc64.AREM,
		ppc64.AREMU,
		ppc64.AREMD,
		ppc64.AREMDU,
		ppc64.ARLWNM,
		ppc64.ARLWNMCC,
		ppc64.AFADDS,
		ppc64.AFADD,
		ppc64.AFSUBS,
		ppc64.AFSUB,
		ppc64.AFMULS,
		ppc64.AFMUL,
		ppc64.AFDIVS,
		ppc64.AFDIV:
		if s != nil {
			if copysub(&p.From, v, s, true) {
				return 1
			}
			if copysub1(p, v, s, true) {
				return 1
			}

			// Update only indirect uses of v in p->to
			if !copyas(&p.To, v) {
				if copysub(&p.To, v, s, true) {
					return 1
				}
			}
			return 0
		}

		if copyas(&p.To, v) {
			if p.Reg == 0 {
				// Fix up implicit reg (e.g., ADD
				// R3,R4 -> ADD R3,R4,R4) so we can
				// update reg and to separately.
				p.Reg = p.To.Reg
			}

			if copyau(&p.From, v) {
				return 4
			}
			if copyau1(p, v) {
				return 4
			}
			return 3
		}

		if copyau(&p.From, v) {
			return 1
		}
		if copyau1(p, v) {
			return 1
		}
		if copyau(&p.To, v) {
			return 1
		}
		return 0

	case ppc64.ABEQ,
		ppc64.ABGT,
		ppc64.ABGE,
		ppc64.ABLT,
		ppc64.ABLE,
		ppc64.ABNE,
		ppc64.ABVC,
		ppc64.ABVS:
		return 0

	case obj.ACHECKNIL, /* read p->from */
		ppc64.ACMP, /* read p->from, read p->to */
		ppc64.ACMPU,
		ppc64.ACMPW,
		ppc64.ACMPWU,
		ppc64.AFCMPO,
		ppc64.AFCMPU:
		if s != nil {
			if copysub(&p.From, v, s, true) {
				return 1
			}
			if copysub(&p.To, v, s, true) {
				return 1
			}
			return 0
		}

		if copyau(&p.From, v) {
			return 1
		}
		if copyau(&p.To, v) {
			return 1
		}
		return 0

		// 9g never generates a branch to a GPR (this isn't
	// even a normal instruction; liblink turns it in to a
	// mov and a branch).
	case ppc64.ABR: /* read p->to */
		if s != nil {
			if copysub(&p.To, v, s, true) {
				return 1
			}
			return 0
		}

		if copyau(&p.To, v) {
			return 1
		}
		return 0

	case obj.ARET: /* funny */
		if s != nil {
			return 0
		}

		// All registers die at this point, so claim
		// everything is set (and not used).
		return 3

	case ppc64.ABL: /* funny */
		if v.Type == obj.TYPE_REG {
			// TODO(rsc): REG_R0 and REG_F0 used to be
			// (when register numbers started at 0) exregoffset and exfregoffset,
			// which are unset entirely.
			// It's strange that this handles R0 and F0 differently from the other
			// registers. Possible failure to optimize?
			if ppc64.REG_R0 < v.Reg && v.Reg <= ppc64.REGEXT {
				return 2
			}
			if v.Reg == ppc64.REGARG {
				return 2
			}
			if ppc64.REG_F0 < v.Reg && v.Reg <= ppc64.FREGEXT {
				return 2
			}
		}

		if p.From.Type == obj.TYPE_REG && v.Type == obj.TYPE_REG && p.From.Reg == v.Reg {
			return 2
		}

		if s != nil {
			if copysub(&p.To, v, s, true) {
				return 1
			}
			return 0
		}
		if copyau(&p.To, v) {
			return 4
		}
		return 3

		// R0 is zero, used by DUFFZERO, cannot be substituted.
	// R3 is ptr to memory, used and set, cannot be substituted.
	case obj.ADUFFZERO:
		if v.Type == obj.TYPE_REG {
			if v.Reg == 0 {
				return 1
			}
			if v.Reg == 3 {
				return 2
			}
		}

		return 0

		// R3, R4 are ptr to src, dst, used and set, cannot be substituted.
	// R5 is scratch, set by DUFFCOPY, cannot be substituted.
	case obj.ADUFFCOPY:
		if v.Type == obj.TYPE_REG {
			if v.Reg == 3 || v.Reg == 4 {
				return 2
			}
			if v.Reg == 5 {
				return 3
			}
		}

		return 0

	case obj.ATEXT: /* funny */
		if v.Type == obj.TYPE_REG {
			if v.Reg == ppc64.REGARG {
				return 3
			}
		}
		return 0

	case obj.APCDATA,
		obj.AFUNCDATA,
		obj.AVARDEF,
		obj.AVARKILL,
		obj.AVARLIVE,
		obj.AUSEFIELD:
		return 0
	}
}
Пример #15
0
func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
	// TODO(minux): add morestack short-cuts with small fixed frame-size.
	ctxt.Cursym = cursym

	if cursym.Text == nil || cursym.Text.Link == nil {
		return
	}

	p := cursym.Text
	textstksiz := p.To.Offset
	if textstksiz == -8 {
		// Compatibility hack.
		p.From3.Offset |= obj.NOFRAME
		textstksiz = 0
	}
	if textstksiz%8 != 0 {
		ctxt.Diag("frame size %d not a multiple of 8", textstksiz)
	}
	if p.From3.Offset&obj.NOFRAME != 0 {
		if textstksiz != 0 {
			ctxt.Diag("NOFRAME functions must have a frame size of 0, not %d", textstksiz)
		}
	}

	cursym.Args = p.To.Val.(int32)
	cursym.Locals = int32(textstksiz)

	/*
	 * find leaf subroutines
	 * strip NOPs
	 * expand RET
	 * expand BECOME pseudo
	 */
	if ctxt.Debugvlog != 0 {
		ctxt.Logf("%5.2f noops\n", obj.Cputime())
	}

	var q *obj.Prog
	var q1 *obj.Prog
	for p := cursym.Text; p != nil; p = p.Link {
		switch p.As {
		/* too hard, just leave alone */
		case obj.ATEXT:
			q = p

			p.Mark |= LABEL | LEAF | SYNC
			if p.Link != nil {
				p.Link.Mark |= LABEL
			}

		case ASYNC,
			AWORD:
			q = p
			p.Mark |= LABEL | SYNC
			continue

		case AMOVW, AMOVWZ, AMOVD:
			q = p
			if p.From.Reg >= REG_RESERVED || p.To.Reg >= REG_RESERVED {
				p.Mark |= LABEL | SYNC
			}
			continue

		case AFABS,
			AFADD,
			AFDIV,
			AFMADD,
			AFMOVD,
			AFMOVS,
			AFMSUB,
			AFMUL,
			AFNABS,
			AFNEG,
			AFNMADD,
			AFNMSUB,
			ALEDBR,
			ALDEBR,
			AFSUB:
			q = p

			p.Mark |= FLOAT
			continue

		case ABL,
			ABCL,
			obj.ADUFFZERO,
			obj.ADUFFCOPY:
			cursym.Text.Mark &^= LEAF
			fallthrough

		case ABC,
			ABEQ,
			ABGE,
			ABGT,
			ABLE,
			ABLT,
			ABLEU,
			ABLTU,
			ABNE,
			ABR,
			ABVC,
			ABVS,
			ACMPBEQ,
			ACMPBGE,
			ACMPBGT,
			ACMPBLE,
			ACMPBLT,
			ACMPBNE,
			ACMPUBEQ,
			ACMPUBGE,
			ACMPUBGT,
			ACMPUBLE,
			ACMPUBLT,
			ACMPUBNE:
			p.Mark |= BRANCH
			q = p
			q1 = p.Pcond
			if q1 != nil {
				for q1.As == obj.ANOP {
					q1 = q1.Link
					p.Pcond = q1
				}

				if q1.Mark&LEAF == 0 {
					q1.Mark |= LABEL
				}
			} else {
				p.Mark |= LABEL
			}
			q1 = p.Link
			if q1 != nil {
				q1.Mark |= LABEL
			}
			continue

		case AFCMPO, AFCMPU:
			q = p
			p.Mark |= FCMP | FLOAT
			continue

		case obj.ARET:
			q = p
			if p.Link != nil {
				p.Link.Mark |= LABEL
			}
			continue

		case obj.ANOP:
			q1 = p.Link
			q.Link = q1 /* q is non-nop */
			q1.Mark |= p.Mark
			continue

		default:
			q = p
			continue
		}
	}

	autosize := int32(0)
	var p1 *obj.Prog
	var p2 *obj.Prog
	var pLast *obj.Prog
	var pPre *obj.Prog
	var pPreempt *obj.Prog
	wasSplit := false
	for p := cursym.Text; p != nil; p = p.Link {
		pLast = p
		switch p.As {
		case obj.ATEXT:
			autosize = int32(textstksiz)

			if p.Mark&LEAF != 0 && autosize == 0 && p.From3.Offset&obj.NOFRAME == 0 {
				// A leaf function with no locals has no frame.
				p.From3.Offset |= obj.NOFRAME
			}

			if p.From3.Offset&obj.NOFRAME == 0 {
				// If there is a stack frame at all, it includes
				// space to save the LR.
				autosize += int32(ctxt.FixedFrameSize())
			}

			p.To.Offset = int64(autosize)

			q = p

			if p.From3.Offset&obj.NOSPLIT == 0 && p.From3.Offset&obj.NOFRAME == 0 {
				p, pPreempt = stacksplitPre(ctxt, p, autosize) // emit pre part of split check
				pPre = p
				wasSplit = true //need post part of split
			}

			if autosize != 0 {
				q = obj.Appendp(ctxt, p)
				q.As = AMOVD
				q.From.Type = obj.TYPE_ADDR
				q.From.Offset = int64(-autosize)
				q.From.Reg = REGSP // not actually needed - REGSP is assumed if no reg is provided
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REGSP
				q.Spadj = autosize
			} else if cursym.Text.Mark&LEAF == 0 {
				// A very few functions that do not return to their caller
				// (e.g. gogo) are not identified as leaves but still have
				// no frame.
				cursym.Text.Mark |= LEAF
			}

			if cursym.Text.Mark&LEAF != 0 {
				cursym.Leaf = true
				break
			}

			q = obj.Appendp(ctxt, q)
			q.As = AMOVD
			q.From.Type = obj.TYPE_REG
			q.From.Reg = REG_LR
			q.To.Type = obj.TYPE_MEM
			q.To.Reg = REGSP
			q.To.Offset = 0

			if cursym.Text.From3.Offset&obj.WRAPPER != 0 {
				// if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
				//
				//	MOVD g_panic(g), R3
				//	CMP R3, $0
				//	BEQ end
				//	MOVD panic_argp(R3), R4
				//	ADD $(autosize+8), R1, R5
				//	CMP R4, R5
				//	BNE end
				//	ADD $8, R1, R6
				//	MOVD R6, panic_argp(R3)
				// end:
				//	NOP
				//
				// The NOP is needed to give the jumps somewhere to land.
				// It is a liblink NOP, not a s390x NOP: it encodes to 0 instruction bytes.

				q = obj.Appendp(ctxt, q)

				q.As = AMOVD
				q.From.Type = obj.TYPE_MEM
				q.From.Reg = REGG
				q.From.Offset = 4 * int64(ctxt.Arch.PtrSize) // G.panic
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_R3

				q = obj.Appendp(ctxt, q)
				q.As = ACMP
				q.From.Type = obj.TYPE_REG
				q.From.Reg = REG_R3
				q.To.Type = obj.TYPE_CONST
				q.To.Offset = 0

				q = obj.Appendp(ctxt, q)
				q.As = ABEQ
				q.To.Type = obj.TYPE_BRANCH
				p1 = q

				q = obj.Appendp(ctxt, q)
				q.As = AMOVD
				q.From.Type = obj.TYPE_MEM
				q.From.Reg = REG_R3
				q.From.Offset = 0 // Panic.argp
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_R4

				q = obj.Appendp(ctxt, q)
				q.As = AADD
				q.From.Type = obj.TYPE_CONST
				q.From.Offset = int64(autosize) + ctxt.FixedFrameSize()
				q.Reg = REGSP
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_R5

				q = obj.Appendp(ctxt, q)
				q.As = ACMP
				q.From.Type = obj.TYPE_REG
				q.From.Reg = REG_R4
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_R5

				q = obj.Appendp(ctxt, q)
				q.As = ABNE
				q.To.Type = obj.TYPE_BRANCH
				p2 = q

				q = obj.Appendp(ctxt, q)
				q.As = AADD
				q.From.Type = obj.TYPE_CONST
				q.From.Offset = ctxt.FixedFrameSize()
				q.Reg = REGSP
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_R6

				q = obj.Appendp(ctxt, q)
				q.As = AMOVD
				q.From.Type = obj.TYPE_REG
				q.From.Reg = REG_R6
				q.To.Type = obj.TYPE_MEM
				q.To.Reg = REG_R3
				q.To.Offset = 0 // Panic.argp

				q = obj.Appendp(ctxt, q)

				q.As = obj.ANOP
				p1.Pcond = q
				p2.Pcond = q
			}

		case obj.ARET:
			if p.From.Type == obj.TYPE_CONST {
				ctxt.Diag("using BECOME (%v) is not supported!", p)
				break
			}

			retTarget := p.To.Sym

			if cursym.Text.Mark&LEAF != 0 {
				if autosize == 0 {
					p.As = ABR
					p.From = obj.Addr{}
					if retTarget == nil {
						p.To.Type = obj.TYPE_REG
						p.To.Reg = REG_LR
					} else {
						p.To.Type = obj.TYPE_BRANCH
						p.To.Sym = retTarget
					}
					p.Mark |= BRANCH
					break
				}

				p.As = AADD
				p.From.Type = obj.TYPE_CONST
				p.From.Offset = int64(autosize)
				p.To.Type = obj.TYPE_REG
				p.To.Reg = REGSP
				p.Spadj = -autosize

				q = obj.Appendp(ctxt, p)
				q.As = ABR
				q.From = obj.Addr{}
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_LR
				q.Mark |= BRANCH
				q.Spadj = autosize
				break
			}

			p.As = AMOVD
			p.From.Type = obj.TYPE_MEM
			p.From.Reg = REGSP
			p.From.Offset = 0
			p.To.Type = obj.TYPE_REG
			p.To.Reg = REG_LR

			q = p

			if autosize != 0 {
				q = obj.Appendp(ctxt, q)
				q.As = AADD
				q.From.Type = obj.TYPE_CONST
				q.From.Offset = int64(autosize)
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REGSP
				q.Spadj = -autosize
			}

			q = obj.Appendp(ctxt, q)
			q.As = ABR
			q.From = obj.Addr{}
			if retTarget == nil {
				q.To.Type = obj.TYPE_REG
				q.To.Reg = REG_LR
			} else {
				q.To.Type = obj.TYPE_BRANCH
				q.To.Sym = retTarget
			}
			q.Mark |= BRANCH
			q.Spadj = autosize

		case AADD:
			if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST {
				p.Spadj = int32(-p.From.Offset)
			}
		}
	}
	if wasSplit {
		pLast = stacksplitPost(ctxt, pLast, pPre, pPreempt, autosize) // emit post part of split check
	}
}
Пример #16
0
func progedit(ctxt *obj.Link, p *obj.Prog) {
	// Maintain information about code generation mode.
	if ctxt.Mode == 0 {
		ctxt.Mode = ctxt.Arch.Regsize * 8
	}
	p.Mode = int8(ctxt.Mode)

	switch p.As {
	case AMODE:
		if p.From.Type == obj.TYPE_CONST || (p.From.Type == obj.TYPE_MEM && p.From.Reg == REG_NONE) {
			switch int(p.From.Offset) {
			case 16, 32, 64:
				ctxt.Mode = int(p.From.Offset)
			}
		}
		obj.Nopout(p)
	}

	// Thread-local storage references use the TLS pseudo-register.
	// As a register, TLS refers to the thread-local storage base, and it
	// can only be loaded into another register:
	//
	//         MOVQ TLS, AX
	//
	// An offset from the thread-local storage base is written off(reg)(TLS*1).
	// Semantically it is off(reg), but the (TLS*1) annotation marks this as
	// indexing from the loaded TLS base. This emits a relocation so that
	// if the linker needs to adjust the offset, it can. For example:
	//
	//         MOVQ TLS, AX
	//         MOVQ 8(AX)(TLS*1), CX // load m into CX
	//
	// On systems that support direct access to the TLS memory, this
	// pair of instructions can be reduced to a direct TLS memory reference:
	//
	//         MOVQ 8(TLS), CX // load m into CX
	//
	// The 2-instruction and 1-instruction forms correspond roughly to
	// ELF TLS initial exec mode and ELF TLS local exec mode, respectively.
	//
	// We applies this rewrite on systems that support the 1-instruction form.
	// The decision is made using only the operating system (and probably
	// the -shared flag, eventually), not the link mode. If some link modes
	// on a particular operating system require the 2-instruction form,
	// then all builds for that operating system will use the 2-instruction
	// form, so that the link mode decision can be delayed to link time.
	//
	// In this way, all supported systems use identical instructions to
	// access TLS, and they are rewritten appropriately first here in
	// liblink and then finally using relocations in the linker.

	if canuselocaltls(ctxt) {
		// Reduce TLS initial exec model to TLS local exec model.
		// Sequences like
		//	MOVQ TLS, BX
		//	... off(BX)(TLS*1) ...
		// become
		//	NOP
		//	... off(TLS) ...
		//
		// TODO(rsc): Remove the Hsolaris special case. It exists only to
		// guarantee we are producing byte-identical binaries as before this code.
		// But it should be unnecessary.
		if (p.As == AMOVQ || p.As == AMOVL) && p.From.Type == obj.TYPE_REG && p.From.Reg == REG_TLS && p.To.Type == obj.TYPE_REG && REG_AX <= p.To.Reg && p.To.Reg <= REG_R15 && ctxt.Headtype != obj.Hsolaris {
			obj.Nopout(p)
		}
		if p.From.Type == obj.TYPE_MEM && p.From.Index == REG_TLS && REG_AX <= p.From.Reg && p.From.Reg <= REG_R15 {
			p.From.Reg = REG_TLS
			p.From.Scale = 0
			p.From.Index = REG_NONE
		}

		if p.To.Type == obj.TYPE_MEM && p.To.Index == REG_TLS && REG_AX <= p.To.Reg && p.To.Reg <= REG_R15 {
			p.To.Reg = REG_TLS
			p.To.Scale = 0
			p.To.Index = REG_NONE
		}
	} else {
		// As a courtesy to the C compilers, rewrite TLS local exec load as TLS initial exec load.
		// The instruction
		//	MOVQ off(TLS), BX
		// becomes the sequence
		//	MOVQ TLS, BX
		//	MOVQ off(BX)(TLS*1), BX
		// This allows the C compilers to emit references to m and g using the direct off(TLS) form.
		if (p.As == AMOVQ || p.As == AMOVL) && p.From.Type == obj.TYPE_MEM && p.From.Reg == REG_TLS && p.To.Type == obj.TYPE_REG && REG_AX <= p.To.Reg && p.To.Reg <= REG_R15 {
			q := obj.Appendp(ctxt, p)
			q.As = p.As
			q.From = p.From
			q.From.Type = obj.TYPE_MEM
			q.From.Reg = p.To.Reg
			q.From.Index = REG_TLS
			q.From.Scale = 2 // TODO: use 1
			q.To = p.To
			p.From.Type = obj.TYPE_REG
			p.From.Reg = REG_TLS
			p.From.Index = REG_NONE
			p.From.Offset = 0
		}
	}

	// TODO: Remove.
	if ctxt.Headtype == obj.Hwindows && p.Mode == 64 || ctxt.Headtype == obj.Hplan9 {
		if p.From.Scale == 1 && p.From.Index == REG_TLS {
			p.From.Scale = 2
		}
		if p.To.Scale == 1 && p.To.Index == REG_TLS {
			p.To.Scale = 2
		}
	}

	// Rewrite 0 to $0 in 3rd argment to CMPPS etc.
	// That's what the tables expect.
	switch p.As {
	case ACMPPD, ACMPPS, ACMPSD, ACMPSS:
		if p.To.Type == obj.TYPE_MEM && p.To.Name == obj.NAME_NONE && p.To.Reg == REG_NONE && p.To.Index == REG_NONE && p.To.Sym == nil {
			p.To.Type = obj.TYPE_CONST
		}
	}

	// Rewrite CALL/JMP/RET to symbol as TYPE_BRANCH.
	switch p.As {
	case obj.ACALL, obj.AJMP, obj.ARET:
		if p.To.Type == obj.TYPE_MEM && (p.To.Name == obj.NAME_EXTERN || p.To.Name == obj.NAME_STATIC) && p.To.Sym != nil {
			p.To.Type = obj.TYPE_BRANCH
		}
	}

	if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
		nacladdr(ctxt, p, &p.From3)
		nacladdr(ctxt, p, &p.From)
		nacladdr(ctxt, p, &p.To)
	}

	// Rewrite float constants to values stored in memory.
	switch p.As {
	// Convert AMOVSS $(0), Xx to AXORPS Xx, Xx
	case AMOVSS:
		if p.From.Type == obj.TYPE_FCONST {
			if p.From.U.Dval == 0 {
				if p.To.Type == obj.TYPE_REG && REG_X0 <= p.To.Reg && p.To.Reg <= REG_X15 {
					p.As = AXORPS
					p.From = p.To
					break
				}
			}
		}
		fallthrough

	case AFMOVF,
		AFADDF,
		AFSUBF,
		AFSUBRF,
		AFMULF,
		AFDIVF,
		AFDIVRF,
		AFCOMF,
		AFCOMFP,
		AADDSS,
		ASUBSS,
		AMULSS,
		ADIVSS,
		ACOMISS,
		AUCOMISS:
		if p.From.Type == obj.TYPE_FCONST {
			f32 := float32(p.From.U.Dval)
			i32 := math.Float32bits(f32)
			literal := fmt.Sprintf("$f32.%08x", i32)
			s := obj.Linklookup(ctxt, literal, 0)
			if s.Type == 0 {
				s.Type = obj.SRODATA
				obj.Adduint32(ctxt, s, i32)
				s.Reachable = 0
			}

			p.From.Type = obj.TYPE_MEM
			p.From.Name = obj.NAME_EXTERN
			p.From.Sym = s
			p.From.Offset = 0
		}

	case AMOVSD:
		// Convert AMOVSD $(0), Xx to AXORPS Xx, Xx
		if p.From.Type == obj.TYPE_FCONST {
			if p.From.U.Dval == 0 {
				if p.To.Type == obj.TYPE_REG && REG_X0 <= p.To.Reg && p.To.Reg <= REG_X15 {
					p.As = AXORPS
					p.From = p.To
					break
				}
			}
		}
		fallthrough

	case AFMOVD,
		AFADDD,
		AFSUBD,
		AFSUBRD,
		AFMULD,
		AFDIVD,
		AFDIVRD,
		AFCOMD,
		AFCOMDP,
		AADDSD,
		ASUBSD,
		AMULSD,
		ADIVSD,
		ACOMISD,
		AUCOMISD:
		if p.From.Type == obj.TYPE_FCONST {
			i64 := math.Float64bits(p.From.U.Dval)
			literal := fmt.Sprintf("$f64.%016x", i64)
			s := obj.Linklookup(ctxt, literal, 0)
			if s.Type == 0 {
				s.Type = obj.SRODATA
				obj.Adduint64(ctxt, s, i64)
				s.Reachable = 0
			}

			p.From.Type = obj.TYPE_MEM
			p.From.Name = obj.NAME_EXTERN
			p.From.Sym = s
			p.From.Offset = 0
		}
	}
}
Пример #17
0
func mergetemp(firstp *obj.Prog) {
	const (
		debugmerge = 1
	)

	g := Flowstart(firstp, nil)
	if g == nil {
		return
	}

	// Build list of all mergeable variables.
	nvar := 0
	for l := Curfn.Dcl; l != nil; l = l.Next {
		if canmerge(l.N) {
			nvar++
		}
	}

	var_ := make([]TempVar, nvar)
	nvar = 0
	var n *Node
	var v *TempVar
	for l := Curfn.Dcl; l != nil; l = l.Next {
		n = l.N
		if canmerge(n) {
			v = &var_[nvar]
			nvar++
			n.Opt = v
			v.node = n
		}
	}

	// Build list of uses.
	// We assume that the earliest reference to a temporary is its definition.
	// This is not true of variables in general but our temporaries are all
	// single-use (that's why we have so many!).
	var p *obj.Prog
	var info ProgInfo
	for f := g.Start; f != nil; f = f.Link {
		p = f.Prog
		info = Thearch.Proginfo(p)

		if p.From.Node != nil && ((p.From.Node).(*Node)).Opt != nil && p.To.Node != nil && ((p.To.Node).(*Node)).Opt != nil {
			Fatal("double node %v", p)
		}
		v = nil
		n, _ = p.From.Node.(*Node)
		if n != nil {
			v, _ = n.Opt.(*TempVar)
		}
		if v == nil {
			n, _ = p.To.Node.(*Node)
			if n != nil {
				v, _ = n.Opt.(*TempVar)
			}
		}
		if v != nil {
			if v.def == nil {
				v.def = f
			}
			f.Data = v.use
			v.use = f
			if n == p.From.Node && (info.Flags&LeftAddr != 0) {
				v.addr = 1
			}
		}
	}

	if debugmerge > 1 && Debug['v'] != 0 {
		Dumpit("before", g.Start, 0)
	}

	nkill := 0

	// Special case.
	var p1 *obj.Prog
	var info1 ProgInfo
	var f *Flow
	for i := 0; i < len(var_); i++ {
		v = &var_[i]
		if v.addr != 0 {
			continue
		}

		// Used in only one instruction, which had better be a write.
		f = v.use
		if f != nil && f.Data.(*Flow) == nil {
			p = f.Prog
			info = Thearch.Proginfo(p)
			if p.To.Node == v.node && (info.Flags&RightWrite != 0) && info.Flags&RightRead == 0 {
				p.As = obj.ANOP
				p.To = obj.Addr{}
				v.removed = 1
				if debugmerge > 0 && Debug['v'] != 0 {
					fmt.Printf("drop write-only %v\n", Sconv(v.node.Sym, 0))
				}
			} else {
				Fatal("temp used and not set: %v", p)
			}
			nkill++
			continue
		}

		// Written in one instruction, read in the next, otherwise unused,
		// no jumps to the next instruction. Happens mainly in 386 compiler.
		f = v.use
		if f != nil && f.Link == f.Data.(*Flow) && (f.Data.(*Flow)).Data.(*Flow) == nil && Uniqp(f.Link) == f {
			p = f.Prog
			info = Thearch.Proginfo(p)
			p1 = f.Link.Prog
			info1 = Thearch.Proginfo(p1)
			const (
				SizeAny = SizeB | SizeW | SizeL | SizeQ | SizeF | SizeD
			)
			if p.From.Node == v.node && p1.To.Node == v.node && (info.Flags&Move != 0) && (info.Flags|info1.Flags)&(LeftAddr|RightAddr) == 0 && info.Flags&SizeAny == info1.Flags&SizeAny {
				p1.From = p.From
				Thearch.Excise(f)
				v.removed = 1
				if debugmerge > 0 && Debug['v'] != 0 {
					fmt.Printf("drop immediate-use %v\n", Sconv(v.node.Sym, 0))
				}
			}

			nkill++
			continue
		}
	}

	// Traverse live range of each variable to set start, end.
	// Each flood uses a new value of gen so that we don't have
	// to clear all the r->active words after each variable.
	gen := int32(0)

	for i := 0; i < len(var_); i++ {
		v = &var_[i]
		gen++
		for f = v.use; f != nil; f = f.Data.(*Flow) {
			mergewalk(v, f, uint32(gen))
		}
		if v.addr != 0 {
			gen++
			for f = v.use; f != nil; f = f.Data.(*Flow) {
				varkillwalk(v, f, uint32(gen))
			}
		}
	}

	// Sort variables by start.
	bystart := make([]*TempVar, len(var_))

	for i := 0; i < len(var_); i++ {
		bystart[i] = &var_[i]
	}
	sort.Sort(startcmp(bystart[:len(var_)]))

	// List of in-use variables, sorted by end, so that the ones that
	// will last the longest are the earliest ones in the array.
	// The tail inuse[nfree:] holds no-longer-used variables.
	// In theory we should use a sorted tree so that insertions are
	// guaranteed O(log n) and then the loop is guaranteed O(n log n).
	// In practice, it doesn't really matter.
	inuse := make([]*TempVar, len(var_))

	ninuse := 0
	nfree := len(var_)
	var t *Type
	var v1 *TempVar
	var j int
	for i := 0; i < len(var_); i++ {
		v = bystart[i]
		if debugmerge > 0 && Debug['v'] != 0 {
			fmt.Printf("consider %v: removed=%d\n", Nconv(v.node, obj.FmtSharp), v.removed)
		}

		if v.removed != 0 {
			continue
		}

		// Expire no longer in use.
		for ninuse > 0 && inuse[ninuse-1].end < v.start {
			ninuse--
			v1 = inuse[ninuse]
			nfree--
			inuse[nfree] = v1
		}

		if debugmerge > 0 && Debug['v'] != 0 {
			fmt.Printf("consider %v: removed=%d nfree=%d nvar=%d\n", Nconv(v.node, obj.FmtSharp), v.removed, nfree, len(var_))
		}

		// Find old temp to reuse if possible.
		t = v.node.Type

		for j = nfree; j < len(var_); j++ {
			v1 = inuse[j]
			if debugmerge > 0 && Debug['v'] != 0 {
				fmt.Printf("consider %v: maybe %v: type=%v,%v addrtaken=%v,%v\n", Nconv(v.node, obj.FmtSharp), Nconv(v1.node, obj.FmtSharp), Tconv(t, 0), Tconv(v1.node.Type, 0), v.node.Addrtaken, v1.node.Addrtaken)
			}

			// Require the types to match but also require the addrtaken bits to match.
			// If a variable's address is taken, that disables registerization for the individual
			// words of the variable (for example, the base,len,cap of a slice).
			// We don't want to merge a non-addressed var with an addressed one and
			// inhibit registerization of the former.
			if Eqtype(t, v1.node.Type) && v.node.Addrtaken == v1.node.Addrtaken {
				inuse[j] = inuse[nfree]
				nfree++
				if v1.merge != nil {
					v.merge = v1.merge
				} else {
					v.merge = v1
				}
				nkill++
				break
			}
		}

		// Sort v into inuse.
		j = ninuse
		ninuse++

		for j > 0 && inuse[j-1].end < v.end {
			inuse[j] = inuse[j-1]
			j--
		}

		inuse[j] = v
	}

	if debugmerge > 0 && Debug['v'] != 0 {
		fmt.Printf("%v [%d - %d]\n", Sconv(Curfn.Nname.Sym, 0), len(var_), nkill)
		var v *TempVar
		for i := 0; i < len(var_); i++ {
			v = &var_[i]
			fmt.Printf("var %v %v %d-%d", Nconv(v.node, obj.FmtSharp), Tconv(v.node.Type, 0), v.start, v.end)
			if v.addr != 0 {
				fmt.Printf(" addr=1")
			}
			if v.removed != 0 {
				fmt.Printf(" dead=1")
			}
			if v.merge != nil {
				fmt.Printf(" merge %v", Nconv(v.merge.node, obj.FmtSharp))
			}
			if v.start == v.end && v.def != nil {
				fmt.Printf(" %v", v.def.Prog)
			}
			fmt.Printf("\n")
		}

		if debugmerge > 1 && Debug['v'] != 0 {
			Dumpit("after", g.Start, 0)
		}
	}

	// Update node references to use merged temporaries.
	for f := g.Start; f != nil; f = f.Link {
		p = f.Prog
		n, _ = p.From.Node.(*Node)
		if n != nil {
			v, _ = n.Opt.(*TempVar)
			if v != nil && v.merge != nil {
				p.From.Node = v.merge.node
			}
		}
		n, _ = p.To.Node.(*Node)
		if n != nil {
			v, _ = n.Opt.(*TempVar)
			if v != nil && v.merge != nil {
				p.To.Node = v.merge.node
			}
		}
	}

	// Delete merged nodes from declaration list.
	var l *NodeList
	for lp := &Curfn.Dcl; ; {
		l = *lp
		if l == nil {
			break
		}

		Curfn.Dcl.End = l
		n = l.N
		v, _ = n.Opt.(*TempVar)
		if v != nil && (v.merge != nil || v.removed != 0) {
			*lp = l.Next
			continue
		}

		lp = &l.Next
	}

	// Clear aux structures.
	for i := 0; i < len(var_); i++ {
		var_[i].node.Opt = nil
	}

	Flowend(g)
}
Пример #18
0
func peep(firstp *obj.Prog) {
	g := gc.Flowstart(firstp, nil)
	if g == nil {
		return
	}
	gactive = 0

	// byte, word arithmetic elimination.
	elimshortmov(g)

	// constant propagation
	// find MOV $con,R followed by
	// another MOV $con,R without
	// setting R in the interim
	var p *obj.Prog
	for r := g.Start; r != nil; r = r.Link {
		p = r.Prog
		switch p.As {
		case x86.ALEAL:
			if regtyp(&p.To) {
				if p.From.Sym != nil {
					if p.From.Index == x86.REG_NONE {
						conprop(r)
					}
				}
			}

		case x86.AMOVB,
			x86.AMOVW,
			x86.AMOVL,
			x86.AMOVSS,
			x86.AMOVSD:
			if regtyp(&p.To) {
				if p.From.Type == obj.TYPE_CONST || p.From.Type == obj.TYPE_FCONST {
					conprop(r)
				}
			}
		}
	}

	var r1 *gc.Flow
	var p1 *obj.Prog
	var r *gc.Flow
	var t int
loop1:
	if gc.Debug['P'] != 0 && gc.Debug['v'] != 0 {
		gc.Dumpit("loop1", g.Start, 0)
	}

	t = 0
	for r = g.Start; r != nil; r = r.Link {
		p = r.Prog
		switch p.As {
		case x86.AMOVL,
			x86.AMOVSS,
			x86.AMOVSD:
			if regtyp(&p.To) {
				if regtyp(&p.From) {
					if copyprop(g, r) {
						excise(r)
						t++
					} else if subprop(r) && copyprop(g, r) {
						excise(r)
						t++
					}
				}
			}

		case x86.AMOVBLZX,
			x86.AMOVWLZX,
			x86.AMOVBLSX,
			x86.AMOVWLSX:
			if regtyp(&p.To) {
				r1 = rnops(gc.Uniqs(r))
				if r1 != nil {
					p1 = r1.Prog
					if p.As == p1.As && p.To.Type == p1.From.Type && p.To.Reg == p1.From.Reg {
						p1.As = x86.AMOVL
						t++
					}
				}
			}

		case x86.AADDL,
			x86.AADDW:
			if p.From.Type != obj.TYPE_CONST || needc(p.Link) {
				break
			}
			if p.From.Offset == -1 {
				if p.As == x86.AADDL {
					p.As = x86.ADECL
				} else {
					p.As = x86.ADECW
				}
				p.From = obj.Addr{}
				break
			}

			if p.From.Offset == 1 {
				if p.As == x86.AADDL {
					p.As = x86.AINCL
				} else {
					p.As = x86.AINCW
				}
				p.From = obj.Addr{}
				break
			}

		case x86.ASUBL,
			x86.ASUBW:
			if p.From.Type != obj.TYPE_CONST || needc(p.Link) {
				break
			}
			if p.From.Offset == -1 {
				if p.As == x86.ASUBL {
					p.As = x86.AINCL
				} else {
					p.As = x86.AINCW
				}
				p.From = obj.Addr{}
				break
			}

			if p.From.Offset == 1 {
				if p.As == x86.ASUBL {
					p.As = x86.ADECL
				} else {
					p.As = x86.ADECW
				}
				p.From = obj.Addr{}
				break
			}
		}
	}

	if t != 0 {
		goto loop1
	}

	// MOVSD removal.
	// We never use packed registers, so a MOVSD between registers
	// can be replaced by MOVAPD, which moves the pair of float64s
	// instead of just the lower one.  We only use the lower one, but
	// the processor can do better if we do moves using both.
	for r := g.Start; r != nil; r = r.Link {
		p = r.Prog
		if p.As == x86.AMOVSD {
			if regtyp(&p.From) {
				if regtyp(&p.To) {
					p.As = x86.AMOVAPD
				}
			}
		}
	}

	gc.Flowend(g)
}
Пример #19
0
func peep(firstp *obj.Prog) {
	g := (*gc.Graph)(gc.Flowstart(firstp, nil))
	if g == nil {
		return
	}
	gactive = 0

	var p *obj.Prog

	if false {
		// constant propagation
		// find MOV $con,R followed by
		// another MOV $con,R without
		// setting R in the interim
		for r := (*gc.Flow)(g.Start); r != nil; r = r.Link {
			p = r.Prog
			switch p.As {
			case s390x.AMOVB,
				s390x.AMOVW,
				s390x.AMOVD:
				if regtyp(&p.To) {
					if p.From.Type == obj.TYPE_CONST || p.From.Type == obj.TYPE_FCONST {
						conprop(r)
					}
				}
			}
		}
	}

	var r *gc.Flow
	var t int
loop1:
	//	if gc.Debug['P'] != 0 && gc.Debug['v'] != 0 {
	//		gc.Dumpit("loop1", g.Start, 0)
	//	}

	t = 0
	for r = g.Start; r != nil; r = r.Link {
		p = r.Prog

		// TODO(austin) Handle smaller moves.  arm and amd64
		// distinguish between moves that moves that *must*
		// sign/zero extend and moves that don't care so they
		// can eliminate moves that don't care without
		// breaking moves that do care.  This might let us
		// simplify or remove the next peep loop, too.
		if p.As == s390x.AMOVD || p.As == s390x.AFMOVD {
			if regtyp(&p.To) {
				// Try to eliminate reg->reg moves
				if regtyp(&p.From) {
					if p.From.Type == p.To.Type {
						if copyprop(r) {
							excise(r)
							t++
						} else if subprop(r) && copyprop(r) {
							excise(r)
							t++
						}
					}
				}

				// Convert uses to $0 to uses of R0 and
				// propagate R0
				if regzer(&p.From) != 0 {
					if p.To.Type == obj.TYPE_REG {
						p.From.Type = obj.TYPE_REG
						p.From.Reg = s390x.REGZERO
						if copyprop(r) {
							excise(r)
							t++
						} else if subprop(r) && copyprop(r) {
							excise(r)
							t++
						}
					}
				}
			}
		}
	}

	if t != 0 {
		goto loop1
	}

	if gc.Debug['P'] != 0 && gc.Debug['v'] != 0 {
		gc.Dumpit("pass7 copyprop", g.Start, 0)
	}

	/*
	 * look for MOVB x,R; MOVB R,R (for small MOVs not handled above)
	 */
	var p1 *obj.Prog
	var r1 *gc.Flow
	for r := (*gc.Flow)(g.Start); r != nil; r = r.Link {
		p = r.Prog
		switch p.As {
		default:
			continue

		case s390x.AMOVH,
			s390x.AMOVHZ,
			s390x.AMOVB,
			s390x.AMOVBZ,
			s390x.AMOVW,
			s390x.AMOVWZ:
			if p.To.Type != obj.TYPE_REG {
				continue
			}
		}

		r1 = r.Link
		if r1 == nil {
			continue
		}
		p1 = r1.Prog
		if p1.As != p.As {
			continue
		}
		if p1.From.Type != obj.TYPE_REG || p1.From.Reg != p.To.Reg {
			continue
		}
		if p1.To.Type != obj.TYPE_REG || p1.To.Reg != p.To.Reg {
			continue
		}
		excise(r1)
	}

	if gc.Debug['P'] > 1 {
		goto ret /* allow following code improvement to be suppressed */
	}

	if gc.Debug['p'] == 0 {
		// load pipelining
		// push any load from memory as early as possible
		// to give it time to complete before use.
		for r := (*gc.Flow)(g.Start); r != nil; r = r.Link {
			p = r.Prog
			switch p.As {
			case s390x.AMOVB,
				s390x.AMOVW,
				s390x.AMOVD:

				if regtyp(&p.To) && !regconsttyp(&p.From) {
					pushback(r)
				}
			}
		}
		if gc.Debug['P'] != 0 && gc.Debug['v'] != 0 {
			gc.Dumpit("pass8 push load as early as possible", g.Start, 0)
		}

	}

	/*
	 * look for OP a, b, c; MOV c, d; -> OP a, b, d;
	 */

	for r := (*gc.Flow)(g.Start); r != nil; r = r.Link {

		if (gc.Debugmergeopmv != -1) && (mergeopmv_cnt >= gc.Debugmergeopmv) {
			break
		}

		p = r.Prog

		switch p.As {
		case s390x.AADD,
			s390x.AADDC,
			s390x.AADDME,
			s390x.AADDE,
			s390x.AADDZE,
			s390x.AAND,
			s390x.AANDN,
			s390x.ADIVW,
			s390x.ADIVWU,
			s390x.ADIVD,
			s390x.ADIVDU,
			s390x.AMULLW,
			s390x.AMULHD,
			s390x.AMULHDU,
			s390x.AMULLD,
			s390x.ANAND,
			s390x.ANOR,
			s390x.AOR,
			s390x.AORN,
			s390x.AREM,
			s390x.AREMU,
			s390x.AREMD,
			s390x.AREMDU,
			s390x.ARLWMI,
			s390x.ARLWNM,
			s390x.ASLW,
			s390x.ASRAW,
			s390x.ASRW,
			s390x.ASLD,
			s390x.ASRAD,
			s390x.ASRD,
			s390x.ASUB,
			s390x.ASUBC,
			s390x.ASUBME,
			s390x.ASUBE,
			s390x.ASUBZE,
			s390x.AXOR:
			if p.To.Type != obj.TYPE_REG {
				continue
			}
			if p.Reg == 0 { // Only for 3 ops instruction
				continue
			}
		default:
			continue
		}

		r1 := r.Link
		for ; r1 != nil; r1 = r1.Link {
			if r1.Prog.As != obj.ANOP {
				break
			}
		}

		if r1 == nil {
			continue
		}

		p1 := r1.Prog
		switch p1.As {
		case s390x.AMOVD,
			s390x.AMOVW, s390x.AMOVWZ,
			s390x.AMOVH, s390x.AMOVHZ,
			s390x.AMOVB, s390x.AMOVBZ:
			if p1.To.Type != obj.TYPE_REG {
				continue
			}

		default:
			continue
		}
		if p1.From.Type != obj.TYPE_REG || p1.From.Reg != p.To.Reg {
			continue
		}

		if trymergeopmv(r1) {
			p.To = p1.To
			excise(r1)
			mergeopmv_cnt += 1
		}
	}

	if gc.Debug['v'] != 0 {
		gc.Dumpit("Merge operation and move", g.Start, 0)
	}

	/*
	 * look for CMP x, y; Branch -> Compare and branch
	 */

	if gc.Debugcnb == 0 {
		goto ret
	}

	for r := (*gc.Flow)(g.Start); r != nil; r = r.Link {
		if (gc.Debugcnb != -1) && (cnb_cnt >= gc.Debugcnb) {
			break
		}
		p = r.Prog
		r1 = gc.Uniqs(r)
		if r1 == nil {
			continue
		}
		p1 = r1.Prog

		switch p.As {
		case s390x.ACMP:
			switch p1.As {
			case s390x.ABCL, s390x.ABC:
				continue
			case s390x.ABEQ:
				t = s390x.ACMPBEQ
			case s390x.ABGE:
				t = s390x.ACMPBGE
			case s390x.ABGT:
				t = s390x.ACMPBGT
			case s390x.ABLE:
				t = s390x.ACMPBLE
			case s390x.ABLT:
				t = s390x.ACMPBLT
			case s390x.ABNE:
				t = s390x.ACMPBNE
			default:
				continue
			}

		case s390x.ACMPU:
			switch p1.As {
			case s390x.ABCL, s390x.ABC:
				continue
			case s390x.ABEQ:
				t = s390x.ACMPUBEQ
			case s390x.ABGE:
				t = s390x.ACMPUBGE
			case s390x.ABGT:
				t = s390x.ACMPUBGT
			case s390x.ABLE:
				t = s390x.ACMPUBLE
			case s390x.ABLT:
				t = s390x.ACMPUBLT
			case s390x.ABNE:
				t = s390x.ACMPUBNE
			default:
				continue
			}

		case s390x.ACMPW, s390x.ACMPWU:
			continue

		default:
			continue
		}

		if gc.Debug['D'] != 0 {
			fmt.Printf("cnb %v; %v -> ", p, p1)
		}

		if p1.To.Sym != nil {
			continue
		}

		if p.To.Type == obj.TYPE_REG {
			p1.As = int16(t)
			p1.From = p.From
			p1.Reg = p.To.Reg
			p1.From3 = nil
		} else if p.To.Type == obj.TYPE_CONST {
			switch p.As {
			case s390x.ACMP, s390x.ACMPW:
				if (p.To.Offset < -(1 << 7)) || (p.To.Offset >= ((1 << 7) - 1)) {
					continue
				}
			case s390x.ACMPU, s390x.ACMPWU:
				if p.To.Offset >= (1 << 8) {
					continue
				}
			default:
			}
			p1.As = int16(t)
			p1.From = p.From
			p1.Reg = 0
			p1.From3 = new(obj.Addr)
			*(p1.From3) = p.To
		} else {
			continue
		}

		if gc.Debug['D'] != 0 {
			fmt.Printf("%v\n", p1)
		}
		cnb_cnt += 1
		excise(r)
	}

	if gc.Debug['v'] != 0 {
		gc.Dumpit("compare and branch", g.Start, 0)
	}

ret:
	gc.Flowend(g)
}