github.com/rohankumardubey/syslog-redirector-golang@v0.0.0-20140320174030-4859f03d829a/src/cmd/6g/gsubr.c (about)

     1  // Derived from Inferno utils/6c/txt.c
     2  // http://code.google.com/p/inferno-os/source/browse/utils/6c/txt.c
     3  //
     4  //	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
     5  //	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
     6  //	Portions Copyright © 1997-1999 Vita Nuova Limited
     7  //	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
     8  //	Portions Copyright © 2004,2006 Bruce Ellis
     9  //	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
    10  //	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
    11  //	Portions Copyright © 2009 The Go Authors.  All rights reserved.
    12  //
    13  // Permission is hereby granted, free of charge, to any person obtaining a copy
    14  // of this software and associated documentation files (the "Software"), to deal
    15  // in the Software without restriction, including without limitation the rights
    16  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    17  // copies of the Software, and to permit persons to whom the Software is
    18  // furnished to do so, subject to the following conditions:
    19  //
    20  // The above copyright notice and this permission notice shall be included in
    21  // all copies or substantial portions of the Software.
    22  //
    23  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    24  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    25  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
    26  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    27  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    28  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    29  // THE SOFTWARE.
    30  
    31  #include <u.h>
    32  #include <libc.h>
    33  #include "gg.h"
    34  #include "../../pkg/runtime/funcdata.h"
    35  
    36  // TODO(rsc): Can make this bigger if we move
    37  // the text segment up higher in 6l for all GOOS.
    38  // At the same time, can raise StackBig in ../../pkg/runtime/stack.h.
    39  vlong unmappedzero = 4096;
    40  
    41  void
    42  clearp(Prog *p)
    43  {
    44  	p->as = AEND;
    45  	p->from.type = D_NONE;
    46  	p->from.index = D_NONE;
    47  	p->to.type = D_NONE;
    48  	p->to.index = D_NONE;
    49  	p->loc = pcloc;
    50  	pcloc++;
    51  }
    52  
    53  static int ddumped;
    54  static Prog *dfirst;
    55  static Prog *dpc;
    56  
    57  /*
    58   * generate and return proc with p->as = as,
    59   * linked into program. pc is next instruction.
    60   */
    61  Prog*
    62  prog(int as)
    63  {
    64  	Prog *p;
    65  
    66  	if(as == ADATA || as == AGLOBL) {
    67  		if(ddumped)
    68  			fatal("already dumped data");
    69  		if(dpc == nil) {
    70  			dpc = mal(sizeof(*dpc));
    71  			dfirst = dpc;
    72  		}
    73  		p = dpc;
    74  		dpc = mal(sizeof(*dpc));
    75  		p->link = dpc;
    76  	} else {
    77  		p = pc;
    78  		pc = mal(sizeof(*pc));
    79  		clearp(pc);
    80  		p->link = pc;
    81  	}
    82  
    83  	if(lineno == 0) {
    84  		if(debug['K'])
    85  			warn("prog: line 0");
    86  	}
    87  
    88  	p->as = as;
    89  	p->lineno = lineno;
    90  	return p;
    91  }
    92  
    93  void
    94  dumpdata(void)
    95  {
    96  	ddumped = 1;
    97  	if(dfirst == nil)
    98  		return;
    99  	newplist();
   100  	*pc = *dfirst;
   101  	pc = dpc;
   102  	clearp(pc);
   103  }
   104  
   105  /*
   106   * generate a branch.
   107   * t is ignored.
   108   * likely values are for branch prediction:
   109   *	-1 unlikely
   110   *	0 no opinion
   111   *	+1 likely
   112   */
   113  Prog*
   114  gbranch(int as, Type *t, int likely)
   115  {
   116  	Prog *p;
   117  	
   118  	USED(t);
   119  
   120  	p = prog(as);
   121  	p->to.type = D_BRANCH;
   122  	p->to.u.branch = P;
   123  	if(as != AJMP && likely != 0) {
   124  		p->from.type = D_CONST;
   125  		p->from.offset = likely > 0;
   126  	}
   127  	return p;
   128  }
   129  
   130  /*
   131   * patch previous branch to jump to to.
   132   */
   133  void
   134  patch(Prog *p, Prog *to)
   135  {
   136  	if(p->to.type != D_BRANCH)
   137  		fatal("patch: not a branch");
   138  	p->to.u.branch = to;
   139  	p->to.offset = to->loc;
   140  }
   141  
   142  Prog*
   143  unpatch(Prog *p)
   144  {
   145  	Prog *q;
   146  
   147  	if(p->to.type != D_BRANCH)
   148  		fatal("unpatch: not a branch");
   149  	q = p->to.u.branch;
   150  	p->to.u.branch = P;
   151  	p->to.offset = 0;
   152  	return q;
   153  }
   154  
   155  /*
   156   * start a new Prog list.
   157   */
   158  Plist*
   159  newplist(void)
   160  {
   161  	Plist *pl;
   162  
   163  	pl = mal(sizeof(*pl));
   164  	if(plist == nil)
   165  		plist = pl;
   166  	else
   167  		plast->link = pl;
   168  	plast = pl;
   169  
   170  	pc = mal(sizeof(*pc));
   171  	clearp(pc);
   172  	pl->firstpc = pc;
   173  
   174  	return pl;
   175  }
   176  
   177  void
   178  gused(Node *n)
   179  {
   180  	gins(ANOP, n, N);	// used
   181  }
   182  
   183  Prog*
   184  gjmp(Prog *to)
   185  {
   186  	Prog *p;
   187  
   188  	p = gbranch(AJMP, T, 0);
   189  	if(to != P)
   190  		patch(p, to);
   191  	return p;
   192  }
   193  
   194  void
   195  ggloblnod(Node *nam)
   196  {
   197  	Prog *p;
   198  
   199  	p = gins(AGLOBL, nam, N);
   200  	p->lineno = nam->lineno;
   201  	p->from.gotype = ngotype(nam);
   202  	p->to.sym = S;
   203  	p->to.type = D_CONST;
   204  	p->to.offset = nam->type->width;
   205  	if(nam->readonly)
   206  		p->from.scale = RODATA;
   207  	if(nam->type != T && !haspointers(nam->type))
   208  		p->from.scale |= NOPTR;
   209  }
   210  
   211  void
   212  gtrack(Sym *s)
   213  {
   214  	Prog *p;
   215  	
   216  	p = gins(AUSEFIELD, N, N);
   217  	p->from.type = D_EXTERN;
   218  	p->from.index = D_NONE;
   219  	p->from.sym = s;
   220  }
   221  
   222  void
   223  gargsize(vlong size)
   224  {
   225  	Node n1, n2;
   226  	
   227  	nodconst(&n1, types[TINT32], PCDATA_ArgSize);
   228  	nodconst(&n2, types[TINT32], size);
   229  	gins(APCDATA, &n1, &n2);
   230  }
   231  
   232  void
   233  ggloblsym(Sym *s, int32 width, int dupok, int rodata)
   234  {
   235  	Prog *p;
   236  
   237  	p = gins(AGLOBL, N, N);
   238  	p->from.type = D_EXTERN;
   239  	p->from.index = D_NONE;
   240  	p->from.sym = s;
   241  	p->to.type = D_CONST;
   242  	p->to.index = D_NONE;
   243  	p->to.offset = width;
   244  	if(dupok)
   245  		p->from.scale |= DUPOK;
   246  	if(rodata)
   247  		p->from.scale |= RODATA;
   248  }
   249  
   250  int
   251  isfat(Type *t)
   252  {
   253  	if(t != T)
   254  	switch(t->etype) {
   255  	case TSTRUCT:
   256  	case TARRAY:
   257  	case TSTRING:
   258  	case TINTER:	// maybe remove later
   259  		return 1;
   260  	}
   261  	return 0;
   262  }
   263  
   264  /*
   265   * naddr of func generates code for address of func.
   266   * if using opcode that can take address implicitly,
   267   * call afunclit to fix up the argument.
   268   */
   269  void
   270  afunclit(Addr *a, Node *n)
   271  {
   272  	if(a->type == D_ADDR && a->index == D_EXTERN) {
   273  		a->type = D_EXTERN;
   274  		a->index = D_NONE;
   275  		a->sym = n->sym;
   276  	}
   277  }
   278  
   279  static	int	resvd[] =
   280  {
   281  	D_DI,	// for movstring
   282  	D_SI,	// for movstring
   283  
   284  	D_AX,	// for divide
   285  	D_CX,	// for shift
   286  	D_DX,	// for divide
   287  	D_SP,	// for stack
   288  };
   289  
   290  void
   291  ginit(void)
   292  {
   293  	int i;
   294  
   295  	for(i=0; i<nelem(reg); i++)
   296  		reg[i] = 1;
   297  	for(i=D_AX; i<=D_R15; i++)
   298  		reg[i] = 0;
   299  	for(i=D_X0; i<=D_X15; i++)
   300  		reg[i] = 0;
   301  
   302  	for(i=0; i<nelem(resvd); i++)
   303  		reg[resvd[i]]++;
   304  }
   305  
   306  void
   307  gclean(void)
   308  {
   309  	int i;
   310  
   311  	for(i=0; i<nelem(resvd); i++)
   312  		reg[resvd[i]]--;
   313  
   314  	for(i=D_AX; i<=D_R15; i++)
   315  		if(reg[i])
   316  			yyerror("reg %R left allocated\n", i);
   317  	for(i=D_X0; i<=D_X15; i++)
   318  		if(reg[i])
   319  			yyerror("reg %R left allocated\n", i);
   320  }
   321  
   322  int32
   323  anyregalloc(void)
   324  {
   325  	int i, j;
   326  
   327  	for(i=D_AX; i<=D_R15; i++) {
   328  		if(reg[i] == 0)
   329  			goto ok;
   330  		for(j=0; j<nelem(resvd); j++)
   331  			if(resvd[j] == i)
   332  				goto ok;
   333  		return 1;
   334  	ok:;
   335  	}
   336  	return 0;
   337  }
   338  
   339  static	uintptr	regpc[D_R15+1 - D_AX];
   340  
   341  /*
   342   * allocate register of type t, leave in n.
   343   * if o != N, o is desired fixed register.
   344   * caller must regfree(n).
   345   */
   346  void
   347  regalloc(Node *n, Type *t, Node *o)
   348  {
   349  	int i, et;
   350  
   351  	if(t == T)
   352  		fatal("regalloc: t nil");
   353  	et = simtype[t->etype];
   354  
   355  	switch(et) {
   356  	case TINT8:
   357  	case TUINT8:
   358  	case TINT16:
   359  	case TUINT16:
   360  	case TINT32:
   361  	case TUINT32:
   362  	case TINT64:
   363  	case TUINT64:
   364  	case TPTR32:
   365  	case TPTR64:
   366  	case TBOOL:
   367  		if(o != N && o->op == OREGISTER) {
   368  			i = o->val.u.reg;
   369  			if(i >= D_AX && i <= D_R15)
   370  				goto out;
   371  		}
   372  		for(i=D_AX; i<=D_R15; i++)
   373  			if(reg[i] == 0) {
   374  				regpc[i-D_AX] = (uintptr)getcallerpc(&n);
   375  				goto out;
   376  			}
   377  
   378  		flusherrors();
   379  		for(i=0; i+D_AX<=D_R15; i++)
   380  			print("%d %p\n", i, regpc[i]);
   381  		fatal("out of fixed registers");
   382  
   383  	case TFLOAT32:
   384  	case TFLOAT64:
   385  		if(o != N && o->op == OREGISTER) {
   386  			i = o->val.u.reg;
   387  			if(i >= D_X0 && i <= D_X15)
   388  				goto out;
   389  		}
   390  		for(i=D_X0; i<=D_X15; i++)
   391  			if(reg[i] == 0)
   392  				goto out;
   393  		fatal("out of floating registers");
   394  
   395  	case TCOMPLEX64:
   396  	case TCOMPLEX128:
   397  		tempname(n, t);
   398  		return;
   399  	}
   400  	fatal("regalloc: unknown type %T", t);
   401  	return;
   402  
   403  out:
   404  	reg[i]++;
   405  	nodreg(n, t, i);
   406  }
   407  
   408  void
   409  regfree(Node *n)
   410  {
   411  	int i;
   412  
   413  	if(n->op == ONAME)
   414  		return;
   415  	if(n->op != OREGISTER && n->op != OINDREG)
   416  		fatal("regfree: not a register");
   417  	i = n->val.u.reg;
   418  	if(i == D_SP)
   419  		return;
   420  	if(i < 0 || i >= nelem(reg))
   421  		fatal("regfree: reg out of range");
   422  	if(reg[i] <= 0)
   423  		fatal("regfree: reg not allocated");
   424  	reg[i]--;
   425  	if(reg[i] == 0 && D_AX <= i && i <= D_R15)
   426  		regpc[i - D_AX] = 0;
   427  }
   428  
   429  /*
   430   * initialize n to be register r of type t.
   431   */
   432  void
   433  nodreg(Node *n, Type *t, int r)
   434  {
   435  	if(t == T)
   436  		fatal("nodreg: t nil");
   437  
   438  	memset(n, 0, sizeof(*n));
   439  	n->op = OREGISTER;
   440  	n->addable = 1;
   441  	ullmancalc(n);
   442  	n->val.u.reg = r;
   443  	n->type = t;
   444  }
   445  
   446  /*
   447   * initialize n to be indirect of register r; n is type t.
   448   */
   449  void
   450  nodindreg(Node *n, Type *t, int r)
   451  {
   452  	nodreg(n, t, r);
   453  	n->op = OINDREG;
   454  }
   455  
   456  Node*
   457  nodarg(Type *t, int fp)
   458  {
   459  	Node *n;
   460  	Type *first;
   461  	Iter savet;
   462  
   463  	// entire argument struct, not just one arg
   464  	if(t->etype == TSTRUCT && t->funarg) {
   465  		n = nod(ONAME, N, N);
   466  		n->sym = lookup(".args");
   467  		n->type = t;
   468  		first = structfirst(&savet, &t);
   469  		if(first == nil)
   470  			fatal("nodarg: bad struct");
   471  		if(first->width == BADWIDTH)
   472  			fatal("nodarg: offset not computed for %T", t);
   473  		n->xoffset = first->width;
   474  		n->addable = 1;
   475  		goto fp;
   476  	}
   477  
   478  	if(t->etype != TFIELD)
   479  		fatal("nodarg: not field %T", t);
   480  
   481  	n = nod(ONAME, N, N);
   482  	n->type = t->type;
   483  	n->sym = t->sym;
   484  	
   485  	if(t->width == BADWIDTH)
   486  		fatal("nodarg: offset not computed for %T", t);
   487  	n->xoffset = t->width;
   488  	n->addable = 1;
   489  	n->orig = t->nname;
   490  
   491  fp:
   492  	// Rewrite argument named _ to __,
   493  	// or else the assignment to _ will be
   494  	// discarded during code generation.
   495  	if(isblank(n))
   496  		n->sym = lookup("__");
   497  
   498  	switch(fp) {
   499  	case 0:		// output arg
   500  		n->op = OINDREG;
   501  		n->val.u.reg = D_SP;
   502  		break;
   503  
   504  	case 1:		// input arg
   505  		n->class = PPARAM;
   506  		break;
   507  
   508  	case 2:		// offset output arg
   509  fatal("shouldn't be used");
   510  		n->op = OINDREG;
   511  		n->val.u.reg = D_SP;
   512  		n->xoffset += types[tptr]->width;
   513  		break;
   514  	}
   515  	n->typecheck = 1;
   516  	return n;
   517  }
   518  
   519  /*
   520   * generate
   521   *	as $c, reg
   522   */
   523  void
   524  gconreg(int as, vlong c, int reg)
   525  {
   526  	Node nr;
   527  
   528  	nodreg(&nr, types[TINT64], reg);
   529  	ginscon(as, c, &nr);
   530  }
   531  
   532  /*
   533   * generate
   534   *	as $c, n
   535   */
   536  void
   537  ginscon(int as, vlong c, Node *n2)
   538  {
   539  	Node n1, ntmp;
   540  
   541  	nodconst(&n1, types[TINT64], c);
   542  
   543  	if(as != AMOVQ && (c < -(1LL<<31) || c >= 1LL<<31)) {
   544  		// cannot have 64-bit immediokate in ADD, etc.
   545  		// instead, MOV into register first.
   546  		regalloc(&ntmp, types[TINT64], N);
   547  		gins(AMOVQ, &n1, &ntmp);
   548  		gins(as, &ntmp, n2);
   549  		regfree(&ntmp);
   550  		return;
   551  	}
   552  	gins(as, &n1, n2);
   553  }
   554  
   555  #define	CASE(a,b)	(((a)<<16)|((b)<<0))
   556  
   557  /*
   558   * Is this node a memory operand?
   559   */
   560  int
   561  ismem(Node *n)
   562  {
   563  	switch(n->op) {
   564  	case OITAB:
   565  	case OSPTR:
   566  	case OLEN:
   567  	case OCAP:
   568  	case OINDREG:
   569  	case ONAME:
   570  	case OPARAM:
   571  	case OCLOSUREVAR:
   572  		return 1;
   573  	case OADDR:
   574  		if(flag_largemodel)
   575  			return 1;
   576  		break;
   577  	}
   578  	return 0;
   579  }
   580  
   581  /*
   582   * set up nodes representing 2^63
   583   */
   584  Node bigi;
   585  Node bigf;
   586  
   587  void
   588  bignodes(void)
   589  {
   590  	static int did;
   591  
   592  	if(did)
   593  		return;
   594  	did = 1;
   595  
   596  	nodconst(&bigi, types[TUINT64], 1);
   597  	mpshiftfix(bigi.val.u.xval, 63);
   598  
   599  	bigf = bigi;
   600  	bigf.type = types[TFLOAT64];
   601  	bigf.val.ctype = CTFLT;
   602  	bigf.val.u.fval = mal(sizeof *bigf.val.u.fval);
   603  	mpmovefixflt(bigf.val.u.fval, bigi.val.u.xval);
   604  }
   605  
   606  /*
   607   * generate move:
   608   *	t = f
   609   * hard part is conversions.
   610   */
   611  // TODO: lost special constants for floating point.  XORPD for 0.0?
   612  void
   613  gmove(Node *f, Node *t)
   614  {
   615  	int a, ft, tt;
   616  	Type *cvt;
   617  	Node r1, r2, r3, r4, zero, one, con;
   618  	Prog *p1, *p2;
   619  
   620  	if(debug['M'])
   621  		print("gmove %lN -> %lN\n", f, t);
   622  
   623  	ft = simsimtype(f->type);
   624  	tt = simsimtype(t->type);
   625  	cvt = t->type;
   626  
   627  	if(iscomplex[ft] || iscomplex[tt]) {
   628  		complexmove(f, t);
   629  		return;
   630  	}
   631  
   632  	// cannot have two memory operands
   633  	if(ismem(f) && ismem(t))
   634  		goto hard;
   635  
   636  	// convert constant to desired type
   637  	if(f->op == OLITERAL) {
   638  		convconst(&con, t->type, &f->val);
   639  		f = &con;
   640  		ft = tt;	// so big switch will choose a simple mov
   641  
   642  		// some constants can't move directly to memory.
   643  		if(ismem(t)) {
   644  			// float constants come from memory.
   645  			if(isfloat[tt])
   646  				goto hard;
   647  
   648  			// 64-bit immediates are really 32-bit sign-extended
   649  			// unless moving into a register.
   650  			if(isint[tt]) {
   651  				if(mpcmpfixfix(con.val.u.xval, minintval[TINT32]) < 0)
   652  					goto hard;
   653  				if(mpcmpfixfix(con.val.u.xval, maxintval[TINT32]) > 0)
   654  					goto hard;
   655  			}
   656  		}
   657  	}
   658  
   659  	// value -> value copy, only one memory operand.
   660  	// figure out the instruction to use.
   661  	// break out of switch for one-instruction gins.
   662  	// goto rdst for "destination must be register".
   663  	// goto hard for "convert to cvt type first".
   664  	// otherwise handle and return.
   665  
   666  	switch(CASE(ft, tt)) {
   667  	default:
   668  		fatal("gmove %lT -> %lT", f->type, t->type);
   669  
   670  	/*
   671  	 * integer copy and truncate
   672  	 */
   673  	case CASE(TINT8, TINT8):	// same size
   674  	case CASE(TINT8, TUINT8):
   675  	case CASE(TUINT8, TINT8):
   676  	case CASE(TUINT8, TUINT8):
   677  	case CASE(TINT16, TINT8):	// truncate
   678  	case CASE(TUINT16, TINT8):
   679  	case CASE(TINT32, TINT8):
   680  	case CASE(TUINT32, TINT8):
   681  	case CASE(TINT64, TINT8):
   682  	case CASE(TUINT64, TINT8):
   683  	case CASE(TINT16, TUINT8):
   684  	case CASE(TUINT16, TUINT8):
   685  	case CASE(TINT32, TUINT8):
   686  	case CASE(TUINT32, TUINT8):
   687  	case CASE(TINT64, TUINT8):
   688  	case CASE(TUINT64, TUINT8):
   689  		a = AMOVB;
   690  		break;
   691  
   692  	case CASE(TINT16, TINT16):	// same size
   693  	case CASE(TINT16, TUINT16):
   694  	case CASE(TUINT16, TINT16):
   695  	case CASE(TUINT16, TUINT16):
   696  	case CASE(TINT32, TINT16):	// truncate
   697  	case CASE(TUINT32, TINT16):
   698  	case CASE(TINT64, TINT16):
   699  	case CASE(TUINT64, TINT16):
   700  	case CASE(TINT32, TUINT16):
   701  	case CASE(TUINT32, TUINT16):
   702  	case CASE(TINT64, TUINT16):
   703  	case CASE(TUINT64, TUINT16):
   704  		a = AMOVW;
   705  		break;
   706  
   707  	case CASE(TINT32, TINT32):	// same size
   708  	case CASE(TINT32, TUINT32):
   709  	case CASE(TUINT32, TINT32):
   710  	case CASE(TUINT32, TUINT32):
   711  		a = AMOVL;
   712  		break;
   713  
   714  	case CASE(TINT64, TINT32):	// truncate
   715  	case CASE(TUINT64, TINT32):
   716  	case CASE(TINT64, TUINT32):
   717  	case CASE(TUINT64, TUINT32):
   718  		a = AMOVQL;
   719  		break;
   720  
   721  	case CASE(TINT64, TINT64):	// same size
   722  	case CASE(TINT64, TUINT64):
   723  	case CASE(TUINT64, TINT64):
   724  	case CASE(TUINT64, TUINT64):
   725  		a = AMOVQ;
   726  		break;
   727  
   728  	/*
   729  	 * integer up-conversions
   730  	 */
   731  	case CASE(TINT8, TINT16):	// sign extend int8
   732  	case CASE(TINT8, TUINT16):
   733  		a = AMOVBWSX;
   734  		goto rdst;
   735  	case CASE(TINT8, TINT32):
   736  	case CASE(TINT8, TUINT32):
   737  		a = AMOVBLSX;
   738  		goto rdst;
   739  	case CASE(TINT8, TINT64):
   740  	case CASE(TINT8, TUINT64):
   741  		a = AMOVBQSX;
   742  		goto rdst;
   743  
   744  	case CASE(TUINT8, TINT16):	// zero extend uint8
   745  	case CASE(TUINT8, TUINT16):
   746  		a = AMOVBWZX;
   747  		goto rdst;
   748  	case CASE(TUINT8, TINT32):
   749  	case CASE(TUINT8, TUINT32):
   750  		a = AMOVBLZX;
   751  		goto rdst;
   752  	case CASE(TUINT8, TINT64):
   753  	case CASE(TUINT8, TUINT64):
   754  		a = AMOVBQZX;
   755  		goto rdst;
   756  
   757  	case CASE(TINT16, TINT32):	// sign extend int16
   758  	case CASE(TINT16, TUINT32):
   759  		a = AMOVWLSX;
   760  		goto rdst;
   761  	case CASE(TINT16, TINT64):
   762  	case CASE(TINT16, TUINT64):
   763  		a = AMOVWQSX;
   764  		goto rdst;
   765  
   766  	case CASE(TUINT16, TINT32):	// zero extend uint16
   767  	case CASE(TUINT16, TUINT32):
   768  		a = AMOVWLZX;
   769  		goto rdst;
   770  	case CASE(TUINT16, TINT64):
   771  	case CASE(TUINT16, TUINT64):
   772  		a = AMOVWQZX;
   773  		goto rdst;
   774  
   775  	case CASE(TINT32, TINT64):	// sign extend int32
   776  	case CASE(TINT32, TUINT64):
   777  		a = AMOVLQSX;
   778  		goto rdst;
   779  
   780  	case CASE(TUINT32, TINT64):	// zero extend uint32
   781  	case CASE(TUINT32, TUINT64):
   782  		// AMOVL into a register zeros the top of the register,
   783  		// so this is not always necessary, but if we rely on AMOVL
   784  		// the optimizer is almost certain to screw with us.
   785  		a = AMOVLQZX;
   786  		goto rdst;
   787  
   788  	/*
   789  	* float to integer
   790  	*/
   791  	case CASE(TFLOAT32, TINT32):
   792  		a = ACVTTSS2SL;
   793  		goto rdst;
   794  
   795  	case CASE(TFLOAT64, TINT32):
   796  		a = ACVTTSD2SL;
   797  		goto rdst;
   798  
   799  	case CASE(TFLOAT32, TINT64):
   800  		a = ACVTTSS2SQ;
   801  		goto rdst;
   802  
   803  	case CASE(TFLOAT64, TINT64):
   804  		a = ACVTTSD2SQ;
   805  		goto rdst;
   806  
   807  	case CASE(TFLOAT32, TINT16):
   808  	case CASE(TFLOAT32, TINT8):
   809  	case CASE(TFLOAT32, TUINT16):
   810  	case CASE(TFLOAT32, TUINT8):
   811  	case CASE(TFLOAT64, TINT16):
   812  	case CASE(TFLOAT64, TINT8):
   813  	case CASE(TFLOAT64, TUINT16):
   814  	case CASE(TFLOAT64, TUINT8):
   815  		// convert via int32.
   816  		cvt = types[TINT32];
   817  		goto hard;
   818  
   819  	case CASE(TFLOAT32, TUINT32):
   820  	case CASE(TFLOAT64, TUINT32):
   821  		// convert via int64.
   822  		cvt = types[TINT64];
   823  		goto hard;
   824  
   825  	case CASE(TFLOAT32, TUINT64):
   826  	case CASE(TFLOAT64, TUINT64):
   827  		// algorithm is:
   828  		//	if small enough, use native float64 -> int64 conversion.
   829  		//	otherwise, subtract 2^63, convert, and add it back.
   830  		a = ACVTTSS2SQ;
   831  		if(ft == TFLOAT64)
   832  			a = ACVTTSD2SQ;
   833  		bignodes();
   834  		regalloc(&r1, types[ft], N);
   835  		regalloc(&r2, types[tt], t);
   836  		regalloc(&r3, types[ft], N);
   837  		regalloc(&r4, types[tt], N);
   838  		gins(optoas(OAS, f->type), f, &r1);
   839  		gins(optoas(OCMP, f->type), &bigf, &r1);
   840  		p1 = gbranch(optoas(OLE, f->type), T, +1);
   841  		gins(a, &r1, &r2);
   842  		p2 = gbranch(AJMP, T, 0);
   843  		patch(p1, pc);
   844  		gins(optoas(OAS, f->type), &bigf, &r3);
   845  		gins(optoas(OSUB, f->type), &r3, &r1);
   846  		gins(a, &r1, &r2);
   847  		gins(AMOVQ, &bigi, &r4);
   848  		gins(AXORQ, &r4, &r2);
   849  		patch(p2, pc);
   850  		gmove(&r2, t);
   851  		regfree(&r4);
   852  		regfree(&r3);
   853  		regfree(&r2);
   854  		regfree(&r1);
   855  		return;
   856  
   857  	/*
   858  	 * integer to float
   859  	 */
   860  	case CASE(TINT32, TFLOAT32):
   861  		a = ACVTSL2SS;
   862  		goto rdst;
   863  
   864  
   865  	case CASE(TINT32, TFLOAT64):
   866  		a = ACVTSL2SD;
   867  		goto rdst;
   868  
   869  	case CASE(TINT64, TFLOAT32):
   870  		a = ACVTSQ2SS;
   871  		goto rdst;
   872  
   873  	case CASE(TINT64, TFLOAT64):
   874  		a = ACVTSQ2SD;
   875  		goto rdst;
   876  
   877  	case CASE(TINT16, TFLOAT32):
   878  	case CASE(TINT16, TFLOAT64):
   879  	case CASE(TINT8, TFLOAT32):
   880  	case CASE(TINT8, TFLOAT64):
   881  	case CASE(TUINT16, TFLOAT32):
   882  	case CASE(TUINT16, TFLOAT64):
   883  	case CASE(TUINT8, TFLOAT32):
   884  	case CASE(TUINT8, TFLOAT64):
   885  		// convert via int32
   886  		cvt = types[TINT32];
   887  		goto hard;
   888  
   889  	case CASE(TUINT32, TFLOAT32):
   890  	case CASE(TUINT32, TFLOAT64):
   891  		// convert via int64.
   892  		cvt = types[TINT64];
   893  		goto hard;
   894  
   895  	case CASE(TUINT64, TFLOAT32):
   896  	case CASE(TUINT64, TFLOAT64):
   897  		// algorithm is:
   898  		//	if small enough, use native int64 -> uint64 conversion.
   899  		//	otherwise, halve (rounding to odd?), convert, and double.
   900  		a = ACVTSQ2SS;
   901  		if(tt == TFLOAT64)
   902  			a = ACVTSQ2SD;
   903  		nodconst(&zero, types[TUINT64], 0);
   904  		nodconst(&one, types[TUINT64], 1);
   905  		regalloc(&r1, f->type, f);
   906  		regalloc(&r2, t->type, t);
   907  		regalloc(&r3, f->type, N);
   908  		regalloc(&r4, f->type, N);
   909  		gmove(f, &r1);
   910  		gins(ACMPQ, &r1, &zero);
   911  		p1 = gbranch(AJLT, T, +1);
   912  		gins(a, &r1, &r2);
   913  		p2 = gbranch(AJMP, T, 0);
   914  		patch(p1, pc);
   915  		gmove(&r1, &r3);
   916  		gins(ASHRQ, &one, &r3);
   917  		gmove(&r1, &r4);
   918  		gins(AANDL, &one, &r4);
   919  		gins(AORQ, &r4, &r3);
   920  		gins(a, &r3, &r2);
   921  		gins(optoas(OADD, t->type), &r2, &r2);
   922  		patch(p2, pc);
   923  		gmove(&r2, t);
   924  		regfree(&r4);
   925  		regfree(&r3);
   926  		regfree(&r2);
   927  		regfree(&r1);
   928  		return;
   929  
   930  	/*
   931  	 * float to float
   932  	 */
   933  	case CASE(TFLOAT32, TFLOAT32):
   934  		a = AMOVSS;
   935  		break;
   936  
   937  	case CASE(TFLOAT64, TFLOAT64):
   938  		a = AMOVSD;
   939  		break;
   940  
   941  	case CASE(TFLOAT32, TFLOAT64):
   942  		a = ACVTSS2SD;
   943  		goto rdst;
   944  
   945  	case CASE(TFLOAT64, TFLOAT32):
   946  		a = ACVTSD2SS;
   947  		goto rdst;
   948  	}
   949  
   950  	gins(a, f, t);
   951  	return;
   952  
   953  rdst:
   954  	// requires register destination
   955  	regalloc(&r1, t->type, t);
   956  	gins(a, f, &r1);
   957  	gmove(&r1, t);
   958  	regfree(&r1);
   959  	return;
   960  
   961  hard:
   962  	// requires register intermediate
   963  	regalloc(&r1, cvt, t);
   964  	gmove(f, &r1);
   965  	gmove(&r1, t);
   966  	regfree(&r1);
   967  	return;
   968  }
   969  
   970  int
   971  samaddr(Node *f, Node *t)
   972  {
   973  
   974  	if(f->op != t->op)
   975  		return 0;
   976  
   977  	switch(f->op) {
   978  	case OREGISTER:
   979  		if(f->val.u.reg != t->val.u.reg)
   980  			break;
   981  		return 1;
   982  	}
   983  	return 0;
   984  }
   985  
   986  /*
   987   * generate one instruction:
   988   *	as f, t
   989   */
   990  Prog*
   991  gins(int as, Node *f, Node *t)
   992  {
   993  //	Node nod;
   994  	int32 w;
   995  	Prog *p;
   996  	Addr af, at;
   997  
   998  //	if(f != N && f->op == OINDEX) {
   999  //		regalloc(&nod, &regnode, Z);
  1000  //		v = constnode.vconst;
  1001  //		cgen(f->right, &nod);
  1002  //		constnode.vconst = v;
  1003  //		idx.reg = nod.reg;
  1004  //		regfree(&nod);
  1005  //	}
  1006  //	if(t != N && t->op == OINDEX) {
  1007  //		regalloc(&nod, &regnode, Z);
  1008  //		v = constnode.vconst;
  1009  //		cgen(t->right, &nod);
  1010  //		constnode.vconst = v;
  1011  //		idx.reg = nod.reg;
  1012  //		regfree(&nod);
  1013  //	}
  1014  
  1015  	switch(as) {
  1016  	case AMOVB:
  1017  	case AMOVW:
  1018  	case AMOVL:
  1019  	case AMOVQ:
  1020  	case AMOVSS:
  1021  	case AMOVSD:
  1022  		if(f != N && t != N && samaddr(f, t))
  1023  			return nil;
  1024  		break;
  1025  	
  1026  	case ALEAQ:
  1027  		if(f != N && isconst(f, CTNIL)) {
  1028  			fatal("gins LEAQ nil %T", f->type);
  1029  		}
  1030  		break;
  1031  	}
  1032  
  1033  	memset(&af, 0, sizeof af);
  1034  	memset(&at, 0, sizeof at);
  1035  	if(f != N)
  1036  		naddr(f, &af, 1);
  1037  	if(t != N)
  1038  		naddr(t, &at, 1);
  1039  	p = prog(as);
  1040  	if(f != N)
  1041  		p->from = af;
  1042  	if(t != N)
  1043  		p->to = at;
  1044  	if(debug['g'])
  1045  		print("%P\n", p);
  1046  
  1047  	w = 0;
  1048  	switch(as) {
  1049  	case AMOVB:
  1050  		w = 1;
  1051  		break;
  1052  	case AMOVW:
  1053  		w = 2;
  1054  		break;
  1055  	case AMOVL:
  1056  		w = 4;
  1057  		break;
  1058  	case AMOVQ:
  1059  		w = 8;
  1060  		break;
  1061  	}
  1062  	if(w != 0 && ((f != N && af.width < w) || (t != N && at.width > w))) {
  1063  		dump("f", f);
  1064  		dump("t", t);
  1065  		fatal("bad width: %P (%d, %d)\n", p, af.width, at.width);
  1066  	}
  1067  
  1068  	return p;
  1069  }
  1070  
  1071  void
  1072  fixlargeoffset(Node *n)
  1073  {
  1074  	Node a;
  1075  
  1076  	if(n == N)
  1077  		return;
  1078  	if(n->op != OINDREG)
  1079  		return;
  1080  	if(n->val.u.reg == D_SP) // stack offset cannot be large
  1081  		return;
  1082  	if(n->xoffset != (int32)n->xoffset) {
  1083  		// offset too large, add to register instead.
  1084  		a = *n;
  1085  		a.op = OREGISTER;
  1086  		a.type = types[tptr];
  1087  		a.xoffset = 0;
  1088  		cgen_checknil(&a);
  1089  		ginscon(optoas(OADD, types[tptr]), n->xoffset, &a);
  1090  		n->xoffset = 0;
  1091  	}
  1092  }
  1093  
  1094  /*
  1095   * generate code to compute n;
  1096   * make a refer to result.
  1097   */
  1098  void
  1099  naddr(Node *n, Addr *a, int canemitcode)
  1100  {
  1101  	a->scale = 0;
  1102  	a->index = D_NONE;
  1103  	a->type = D_NONE;
  1104  	a->gotype = S;
  1105  	a->node = N;
  1106  	a->width = 0;
  1107  	if(n == N)
  1108  		return;
  1109  
  1110  	if(n->type != T && n->type->etype != TIDEAL) {
  1111  		dowidth(n->type);
  1112  		a->width = n->type->width;
  1113  	}
  1114  
  1115  	switch(n->op) {
  1116  	default:
  1117  		fatal("naddr: bad %O %D", n->op, a);
  1118  		break;
  1119  
  1120  	case OREGISTER:
  1121  		a->type = n->val.u.reg;
  1122  		a->sym = S;
  1123  		break;
  1124  
  1125  //	case OINDEX:
  1126  //	case OIND:
  1127  //		naddr(n->left, a);
  1128  //		if(a->type >= D_AX && a->type <= D_DI)
  1129  //			a->type += D_INDIR;
  1130  //		else
  1131  //		if(a->type == D_CONST)
  1132  //			a->type = D_NONE+D_INDIR;
  1133  //		else
  1134  //		if(a->type == D_ADDR) {
  1135  //			a->type = a->index;
  1136  //			a->index = D_NONE;
  1137  //		} else
  1138  //			goto bad;
  1139  //		if(n->op == OINDEX) {
  1140  //			a->index = idx.reg;
  1141  //			a->scale = n->scale;
  1142  //		}
  1143  //		break;
  1144  
  1145  	case OINDREG:
  1146  		a->type = n->val.u.reg+D_INDIR;
  1147  		a->sym = n->sym;
  1148  		a->offset = n->xoffset;
  1149  		if(a->offset != (int32)a->offset)
  1150  			yyerror("offset %lld too large for OINDREG", a->offset);
  1151  		break;
  1152  
  1153  	case OPARAM:
  1154  		// n->left is PHEAP ONAME for stack parameter.
  1155  		// compute address of actual parameter on stack.
  1156  		a->etype = simtype[n->left->type->etype];
  1157  		a->width = n->left->type->width;
  1158  		a->offset = n->xoffset;
  1159  		a->sym = n->left->sym;
  1160  		a->type = D_PARAM;
  1161  		a->node = n->left->orig;
  1162  		break;
  1163  	
  1164  	case OCLOSUREVAR:
  1165  		a->type = D_DX+D_INDIR;
  1166  		a->sym = S;
  1167  		a->offset = n->xoffset;
  1168  		break;
  1169  	
  1170  	case OCFUNC:
  1171  		naddr(n->left, a, canemitcode);
  1172  		a->sym = n->left->sym;
  1173  		break;
  1174  
  1175  	case ONAME:
  1176  		a->etype = 0;
  1177  		if(n->type != T)
  1178  			a->etype = simtype[n->type->etype];
  1179  		a->offset = n->xoffset;
  1180  		a->sym = n->sym;
  1181  		a->node = n->orig;
  1182  		//if(a->node >= (Node*)&n)
  1183  		//	fatal("stack node");
  1184  		if(a->sym == S)
  1185  			a->sym = lookup(".noname");
  1186  		if(n->method) {
  1187  			if(n->type != T)
  1188  			if(n->type->sym != S)
  1189  			if(n->type->sym->pkg != nil)
  1190  				a->sym = pkglookup(a->sym->name, n->type->sym->pkg);
  1191  		}
  1192  
  1193  		switch(n->class) {
  1194  		default:
  1195  			fatal("naddr: ONAME class %S %d\n", n->sym, n->class);
  1196  		case PEXTERN:
  1197  			a->type = D_EXTERN;
  1198  			break;
  1199  		case PAUTO:
  1200  			a->type = D_AUTO;
  1201  			break;
  1202  		case PPARAM:
  1203  		case PPARAMOUT:
  1204  			a->type = D_PARAM;
  1205  			break;
  1206  		case PFUNC:
  1207  			a->index = D_EXTERN;
  1208  			a->type = D_ADDR;
  1209  			a->width = widthptr;
  1210  			a->sym = funcsym(a->sym);
  1211  			break;
  1212  		}
  1213  		break;
  1214  
  1215  	case OLITERAL:
  1216  		switch(n->val.ctype) {
  1217  		default:
  1218  			fatal("naddr: const %lT", n->type);
  1219  			break;
  1220  		case CTFLT:
  1221  			a->type = D_FCONST;
  1222  			a->u.dval = mpgetflt(n->val.u.fval);
  1223  			break;
  1224  		case CTINT:
  1225  		case CTRUNE:
  1226  			a->sym = S;
  1227  			a->type = D_CONST;
  1228  			a->offset = mpgetfix(n->val.u.xval);
  1229  			break;
  1230  		case CTSTR:
  1231  			datagostring(n->val.u.sval, a);
  1232  			break;
  1233  		case CTBOOL:
  1234  			a->sym = S;
  1235  			a->type = D_CONST;
  1236  			a->offset = n->val.u.bval;
  1237  			break;
  1238  		case CTNIL:
  1239  			a->sym = S;
  1240  			a->type = D_CONST;
  1241  			a->offset = 0;
  1242  			break;
  1243  		}
  1244  		break;
  1245  
  1246  	case OADDR:
  1247  		naddr(n->left, a, canemitcode);
  1248  		a->width = widthptr;
  1249  		if(a->type >= D_INDIR) {
  1250  			a->type -= D_INDIR;
  1251  			break;
  1252  		}
  1253  		if(a->type == D_EXTERN || a->type == D_STATIC ||
  1254  		   a->type == D_AUTO || a->type == D_PARAM)
  1255  			if(a->index == D_NONE) {
  1256  				a->index = a->type;
  1257  				a->type = D_ADDR;
  1258  				break;
  1259  			}
  1260  		fatal("naddr: OADDR\n");
  1261  	
  1262  	case OITAB:
  1263  		// itable of interface value
  1264  		naddr(n->left, a, canemitcode);
  1265  		if(a->type == D_CONST && a->offset == 0)
  1266  			break;  // itab(nil)
  1267  		a->etype = tptr;
  1268  		a->width = widthptr;
  1269  		break;
  1270  
  1271  	case OSPTR:
  1272  		// pointer in a string or slice
  1273  		naddr(n->left, a, canemitcode);
  1274  		if(a->type == D_CONST && a->offset == 0)
  1275  			break;	// ptr(nil)
  1276  		a->etype = simtype[TUINTPTR];
  1277  		a->offset += Array_array;
  1278  		a->width = widthptr;
  1279  		break;
  1280  
  1281  	case OLEN:
  1282  		// len of string or slice
  1283  		naddr(n->left, a, canemitcode);
  1284  		if(a->type == D_CONST && a->offset == 0)
  1285  			break;	// len(nil)
  1286  		a->etype = simtype[TUINT];
  1287  		a->offset += Array_nel;
  1288  		a->width = widthint;
  1289  		break;
  1290  
  1291  	case OCAP:
  1292  		// cap of string or slice
  1293  		naddr(n->left, a, canemitcode);
  1294  		if(a->type == D_CONST && a->offset == 0)
  1295  			break;	// cap(nil)
  1296  		a->etype = simtype[TUINT];
  1297  		a->offset += Array_cap;
  1298  		a->width = widthint;
  1299  		break;
  1300  
  1301  //	case OADD:
  1302  //		if(n->right->op == OLITERAL) {
  1303  //			v = n->right->vconst;
  1304  //			naddr(n->left, a, canemitcode);
  1305  //		} else
  1306  //		if(n->left->op == OLITERAL) {
  1307  //			v = n->left->vconst;
  1308  //			naddr(n->right, a, canemitcode);
  1309  //		} else
  1310  //			goto bad;
  1311  //		a->offset += v;
  1312  //		break;
  1313  
  1314  	}
  1315  }
  1316  
  1317  /*
  1318   * return Axxx for Oxxx on type t.
  1319   */
  1320  int
  1321  optoas(int op, Type *t)
  1322  {
  1323  	int a;
  1324  
  1325  	if(t == T)
  1326  		fatal("optoas: t is nil");
  1327  
  1328  	a = AGOK;
  1329  	switch(CASE(op, simtype[t->etype])) {
  1330  	default:
  1331  		fatal("optoas: no entry %O-%T", op, t);
  1332  		break;
  1333  
  1334  	case CASE(OADDR, TPTR32):
  1335  		a = ALEAL;
  1336  		break;
  1337  
  1338  	case CASE(OADDR, TPTR64):
  1339  		a = ALEAQ;
  1340  		break;
  1341  
  1342  	case CASE(OEQ, TBOOL):
  1343  	case CASE(OEQ, TINT8):
  1344  	case CASE(OEQ, TUINT8):
  1345  	case CASE(OEQ, TINT16):
  1346  	case CASE(OEQ, TUINT16):
  1347  	case CASE(OEQ, TINT32):
  1348  	case CASE(OEQ, TUINT32):
  1349  	case CASE(OEQ, TINT64):
  1350  	case CASE(OEQ, TUINT64):
  1351  	case CASE(OEQ, TPTR32):
  1352  	case CASE(OEQ, TPTR64):
  1353  	case CASE(OEQ, TFLOAT32):
  1354  	case CASE(OEQ, TFLOAT64):
  1355  		a = AJEQ;
  1356  		break;
  1357  
  1358  	case CASE(ONE, TBOOL):
  1359  	case CASE(ONE, TINT8):
  1360  	case CASE(ONE, TUINT8):
  1361  	case CASE(ONE, TINT16):
  1362  	case CASE(ONE, TUINT16):
  1363  	case CASE(ONE, TINT32):
  1364  	case CASE(ONE, TUINT32):
  1365  	case CASE(ONE, TINT64):
  1366  	case CASE(ONE, TUINT64):
  1367  	case CASE(ONE, TPTR32):
  1368  	case CASE(ONE, TPTR64):
  1369  	case CASE(ONE, TFLOAT32):
  1370  	case CASE(ONE, TFLOAT64):
  1371  		a = AJNE;
  1372  		break;
  1373  
  1374  	case CASE(OLT, TINT8):
  1375  	case CASE(OLT, TINT16):
  1376  	case CASE(OLT, TINT32):
  1377  	case CASE(OLT, TINT64):
  1378  		a = AJLT;
  1379  		break;
  1380  
  1381  	case CASE(OLT, TUINT8):
  1382  	case CASE(OLT, TUINT16):
  1383  	case CASE(OLT, TUINT32):
  1384  	case CASE(OLT, TUINT64):
  1385  		a = AJCS;
  1386  		break;
  1387  
  1388  	case CASE(OLE, TINT8):
  1389  	case CASE(OLE, TINT16):
  1390  	case CASE(OLE, TINT32):
  1391  	case CASE(OLE, TINT64):
  1392  		a = AJLE;
  1393  		break;
  1394  
  1395  	case CASE(OLE, TUINT8):
  1396  	case CASE(OLE, TUINT16):
  1397  	case CASE(OLE, TUINT32):
  1398  	case CASE(OLE, TUINT64):
  1399  		a = AJLS;
  1400  		break;
  1401  
  1402  	case CASE(OGT, TINT8):
  1403  	case CASE(OGT, TINT16):
  1404  	case CASE(OGT, TINT32):
  1405  	case CASE(OGT, TINT64):
  1406  		a = AJGT;
  1407  		break;
  1408  
  1409  	case CASE(OGT, TUINT8):
  1410  	case CASE(OGT, TUINT16):
  1411  	case CASE(OGT, TUINT32):
  1412  	case CASE(OGT, TUINT64):
  1413  	case CASE(OLT, TFLOAT32):
  1414  	case CASE(OLT, TFLOAT64):
  1415  		a = AJHI;
  1416  		break;
  1417  
  1418  	case CASE(OGE, TINT8):
  1419  	case CASE(OGE, TINT16):
  1420  	case CASE(OGE, TINT32):
  1421  	case CASE(OGE, TINT64):
  1422  		a = AJGE;
  1423  		break;
  1424  
  1425  	case CASE(OGE, TUINT8):
  1426  	case CASE(OGE, TUINT16):
  1427  	case CASE(OGE, TUINT32):
  1428  	case CASE(OGE, TUINT64):
  1429  	case CASE(OLE, TFLOAT32):
  1430  	case CASE(OLE, TFLOAT64):
  1431  		a = AJCC;
  1432  		break;
  1433  
  1434  	case CASE(OCMP, TBOOL):
  1435  	case CASE(OCMP, TINT8):
  1436  	case CASE(OCMP, TUINT8):
  1437  		a = ACMPB;
  1438  		break;
  1439  
  1440  	case CASE(OCMP, TINT16):
  1441  	case CASE(OCMP, TUINT16):
  1442  		a = ACMPW;
  1443  		break;
  1444  
  1445  	case CASE(OCMP, TINT32):
  1446  	case CASE(OCMP, TUINT32):
  1447  	case CASE(OCMP, TPTR32):
  1448  		a = ACMPL;
  1449  		break;
  1450  
  1451  	case CASE(OCMP, TINT64):
  1452  	case CASE(OCMP, TUINT64):
  1453  	case CASE(OCMP, TPTR64):
  1454  		a = ACMPQ;
  1455  		break;
  1456  
  1457  	case CASE(OCMP, TFLOAT32):
  1458  		a = AUCOMISS;
  1459  		break;
  1460  
  1461  	case CASE(OCMP, TFLOAT64):
  1462  		a = AUCOMISD;
  1463  		break;
  1464  
  1465  	case CASE(OAS, TBOOL):
  1466  	case CASE(OAS, TINT8):
  1467  	case CASE(OAS, TUINT8):
  1468  		a = AMOVB;
  1469  		break;
  1470  
  1471  	case CASE(OAS, TINT16):
  1472  	case CASE(OAS, TUINT16):
  1473  		a = AMOVW;
  1474  		break;
  1475  
  1476  	case CASE(OAS, TINT32):
  1477  	case CASE(OAS, TUINT32):
  1478  	case CASE(OAS, TPTR32):
  1479  		a = AMOVL;
  1480  		break;
  1481  
  1482  	case CASE(OAS, TINT64):
  1483  	case CASE(OAS, TUINT64):
  1484  	case CASE(OAS, TPTR64):
  1485  		a = AMOVQ;
  1486  		break;
  1487  
  1488  	case CASE(OAS, TFLOAT32):
  1489  		a = AMOVSS;
  1490  		break;
  1491  
  1492  	case CASE(OAS, TFLOAT64):
  1493  		a = AMOVSD;
  1494  		break;
  1495  
  1496  	case CASE(OADD, TINT8):
  1497  	case CASE(OADD, TUINT8):
  1498  		a = AADDB;
  1499  		break;
  1500  
  1501  	case CASE(OADD, TINT16):
  1502  	case CASE(OADD, TUINT16):
  1503  		a = AADDW;
  1504  		break;
  1505  
  1506  	case CASE(OADD, TINT32):
  1507  	case CASE(OADD, TUINT32):
  1508  	case CASE(OADD, TPTR32):
  1509  		a = AADDL;
  1510  		break;
  1511  
  1512  	case CASE(OADD, TINT64):
  1513  	case CASE(OADD, TUINT64):
  1514  	case CASE(OADD, TPTR64):
  1515  		a = AADDQ;
  1516  		break;
  1517  
  1518  	case CASE(OADD, TFLOAT32):
  1519  		a = AADDSS;
  1520  		break;
  1521  
  1522  	case CASE(OADD, TFLOAT64):
  1523  		a = AADDSD;
  1524  		break;
  1525  
  1526  	case CASE(OSUB, TINT8):
  1527  	case CASE(OSUB, TUINT8):
  1528  		a = ASUBB;
  1529  		break;
  1530  
  1531  	case CASE(OSUB, TINT16):
  1532  	case CASE(OSUB, TUINT16):
  1533  		a = ASUBW;
  1534  		break;
  1535  
  1536  	case CASE(OSUB, TINT32):
  1537  	case CASE(OSUB, TUINT32):
  1538  	case CASE(OSUB, TPTR32):
  1539  		a = ASUBL;
  1540  		break;
  1541  
  1542  	case CASE(OSUB, TINT64):
  1543  	case CASE(OSUB, TUINT64):
  1544  	case CASE(OSUB, TPTR64):
  1545  		a = ASUBQ;
  1546  		break;
  1547  
  1548  	case CASE(OSUB, TFLOAT32):
  1549  		a = ASUBSS;
  1550  		break;
  1551  
  1552  	case CASE(OSUB, TFLOAT64):
  1553  		a = ASUBSD;
  1554  		break;
  1555  
  1556  	case CASE(OINC, TINT8):
  1557  	case CASE(OINC, TUINT8):
  1558  		a = AINCB;
  1559  		break;
  1560  
  1561  	case CASE(OINC, TINT16):
  1562  	case CASE(OINC, TUINT16):
  1563  		a = AINCW;
  1564  		break;
  1565  
  1566  	case CASE(OINC, TINT32):
  1567  	case CASE(OINC, TUINT32):
  1568  	case CASE(OINC, TPTR32):
  1569  		a = AINCL;
  1570  		break;
  1571  
  1572  	case CASE(OINC, TINT64):
  1573  	case CASE(OINC, TUINT64):
  1574  	case CASE(OINC, TPTR64):
  1575  		a = AINCQ;
  1576  		break;
  1577  
  1578  	case CASE(ODEC, TINT8):
  1579  	case CASE(ODEC, TUINT8):
  1580  		a = ADECB;
  1581  		break;
  1582  
  1583  	case CASE(ODEC, TINT16):
  1584  	case CASE(ODEC, TUINT16):
  1585  		a = ADECW;
  1586  		break;
  1587  
  1588  	case CASE(ODEC, TINT32):
  1589  	case CASE(ODEC, TUINT32):
  1590  	case CASE(ODEC, TPTR32):
  1591  		a = ADECL;
  1592  		break;
  1593  
  1594  	case CASE(ODEC, TINT64):
  1595  	case CASE(ODEC, TUINT64):
  1596  	case CASE(ODEC, TPTR64):
  1597  		a = ADECQ;
  1598  		break;
  1599  
  1600  	case CASE(OMINUS, TINT8):
  1601  	case CASE(OMINUS, TUINT8):
  1602  		a = ANEGB;
  1603  		break;
  1604  
  1605  	case CASE(OMINUS, TINT16):
  1606  	case CASE(OMINUS, TUINT16):
  1607  		a = ANEGW;
  1608  		break;
  1609  
  1610  	case CASE(OMINUS, TINT32):
  1611  	case CASE(OMINUS, TUINT32):
  1612  	case CASE(OMINUS, TPTR32):
  1613  		a = ANEGL;
  1614  		break;
  1615  
  1616  	case CASE(OMINUS, TINT64):
  1617  	case CASE(OMINUS, TUINT64):
  1618  	case CASE(OMINUS, TPTR64):
  1619  		a = ANEGQ;
  1620  		break;
  1621  
  1622  	case CASE(OAND, TINT8):
  1623  	case CASE(OAND, TUINT8):
  1624  		a = AANDB;
  1625  		break;
  1626  
  1627  	case CASE(OAND, TINT16):
  1628  	case CASE(OAND, TUINT16):
  1629  		a = AANDW;
  1630  		break;
  1631  
  1632  	case CASE(OAND, TINT32):
  1633  	case CASE(OAND, TUINT32):
  1634  	case CASE(OAND, TPTR32):
  1635  		a = AANDL;
  1636  		break;
  1637  
  1638  	case CASE(OAND, TINT64):
  1639  	case CASE(OAND, TUINT64):
  1640  	case CASE(OAND, TPTR64):
  1641  		a = AANDQ;
  1642  		break;
  1643  
  1644  	case CASE(OOR, TINT8):
  1645  	case CASE(OOR, TUINT8):
  1646  		a = AORB;
  1647  		break;
  1648  
  1649  	case CASE(OOR, TINT16):
  1650  	case CASE(OOR, TUINT16):
  1651  		a = AORW;
  1652  		break;
  1653  
  1654  	case CASE(OOR, TINT32):
  1655  	case CASE(OOR, TUINT32):
  1656  	case CASE(OOR, TPTR32):
  1657  		a = AORL;
  1658  		break;
  1659  
  1660  	case CASE(OOR, TINT64):
  1661  	case CASE(OOR, TUINT64):
  1662  	case CASE(OOR, TPTR64):
  1663  		a = AORQ;
  1664  		break;
  1665  
  1666  	case CASE(OXOR, TINT8):
  1667  	case CASE(OXOR, TUINT8):
  1668  		a = AXORB;
  1669  		break;
  1670  
  1671  	case CASE(OXOR, TINT16):
  1672  	case CASE(OXOR, TUINT16):
  1673  		a = AXORW;
  1674  		break;
  1675  
  1676  	case CASE(OXOR, TINT32):
  1677  	case CASE(OXOR, TUINT32):
  1678  	case CASE(OXOR, TPTR32):
  1679  		a = AXORL;
  1680  		break;
  1681  
  1682  	case CASE(OXOR, TINT64):
  1683  	case CASE(OXOR, TUINT64):
  1684  	case CASE(OXOR, TPTR64):
  1685  		a = AXORQ;
  1686  		break;
  1687  
  1688  	case CASE(OLROT, TINT8):
  1689  	case CASE(OLROT, TUINT8):
  1690  		a = AROLB;
  1691  		break;
  1692  
  1693  	case CASE(OLROT, TINT16):
  1694  	case CASE(OLROT, TUINT16):
  1695  		a = AROLW;
  1696  		break;
  1697  
  1698  	case CASE(OLROT, TINT32):
  1699  	case CASE(OLROT, TUINT32):
  1700  	case CASE(OLROT, TPTR32):
  1701  		a = AROLL;
  1702  		break;
  1703  
  1704  	case CASE(OLROT, TINT64):
  1705  	case CASE(OLROT, TUINT64):
  1706  	case CASE(OLROT, TPTR64):
  1707  		a = AROLQ;
  1708  		break;
  1709  
  1710  	case CASE(OLSH, TINT8):
  1711  	case CASE(OLSH, TUINT8):
  1712  		a = ASHLB;
  1713  		break;
  1714  
  1715  	case CASE(OLSH, TINT16):
  1716  	case CASE(OLSH, TUINT16):
  1717  		a = ASHLW;
  1718  		break;
  1719  
  1720  	case CASE(OLSH, TINT32):
  1721  	case CASE(OLSH, TUINT32):
  1722  	case CASE(OLSH, TPTR32):
  1723  		a = ASHLL;
  1724  		break;
  1725  
  1726  	case CASE(OLSH, TINT64):
  1727  	case CASE(OLSH, TUINT64):
  1728  	case CASE(OLSH, TPTR64):
  1729  		a = ASHLQ;
  1730  		break;
  1731  
  1732  	case CASE(ORSH, TUINT8):
  1733  		a = ASHRB;
  1734  		break;
  1735  
  1736  	case CASE(ORSH, TUINT16):
  1737  		a = ASHRW;
  1738  		break;
  1739  
  1740  	case CASE(ORSH, TUINT32):
  1741  	case CASE(ORSH, TPTR32):
  1742  		a = ASHRL;
  1743  		break;
  1744  
  1745  	case CASE(ORSH, TUINT64):
  1746  	case CASE(ORSH, TPTR64):
  1747  		a = ASHRQ;
  1748  		break;
  1749  
  1750  	case CASE(ORSH, TINT8):
  1751  		a = ASARB;
  1752  		break;
  1753  
  1754  	case CASE(ORSH, TINT16):
  1755  		a = ASARW;
  1756  		break;
  1757  
  1758  	case CASE(ORSH, TINT32):
  1759  		a = ASARL;
  1760  		break;
  1761  
  1762  	case CASE(ORSH, TINT64):
  1763  		a = ASARQ;
  1764  		break;
  1765  
  1766  	case CASE(ORROTC, TINT8):
  1767  	case CASE(ORROTC, TUINT8):
  1768  		a = ARCRB;
  1769  		break;
  1770  
  1771  	case CASE(ORROTC, TINT16):
  1772  	case CASE(ORROTC, TUINT16):
  1773  		a = ARCRW;
  1774  		break;
  1775  
  1776  	case CASE(ORROTC, TINT32):
  1777  	case CASE(ORROTC, TUINT32):
  1778  		a = ARCRL;
  1779  		break;
  1780  
  1781  	case CASE(ORROTC, TINT64):
  1782  	case CASE(ORROTC, TUINT64):
  1783  		a = ARCRQ;
  1784  		break;
  1785  
  1786  	case CASE(OHMUL, TINT8):
  1787  	case CASE(OMUL, TINT8):
  1788  	case CASE(OMUL, TUINT8):
  1789  		a = AIMULB;
  1790  		break;
  1791  
  1792  	case CASE(OHMUL, TINT16):
  1793  	case CASE(OMUL, TINT16):
  1794  	case CASE(OMUL, TUINT16):
  1795  		a = AIMULW;
  1796  		break;
  1797  
  1798  	case CASE(OHMUL, TINT32):
  1799  	case CASE(OMUL, TINT32):
  1800  	case CASE(OMUL, TUINT32):
  1801  	case CASE(OMUL, TPTR32):
  1802  		a = AIMULL;
  1803  		break;
  1804  
  1805  	case CASE(OHMUL, TINT64):
  1806  	case CASE(OMUL, TINT64):
  1807  	case CASE(OMUL, TUINT64):
  1808  	case CASE(OMUL, TPTR64):
  1809  		a = AIMULQ;
  1810  		break;
  1811  
  1812  	case CASE(OHMUL, TUINT8):
  1813  		a = AMULB;
  1814  		break;
  1815  
  1816  	case CASE(OHMUL, TUINT16):
  1817  		a = AMULW;
  1818  		break;
  1819  
  1820  	case CASE(OHMUL, TUINT32):
  1821  	case CASE(OHMUL, TPTR32):
  1822  		a = AMULL;
  1823  		break;
  1824  
  1825  	case CASE(OHMUL, TUINT64):
  1826  	case CASE(OHMUL, TPTR64):
  1827  		a = AMULQ;
  1828  		break;
  1829  
  1830  	case CASE(OMUL, TFLOAT32):
  1831  		a = AMULSS;
  1832  		break;
  1833  
  1834  	case CASE(OMUL, TFLOAT64):
  1835  		a = AMULSD;
  1836  		break;
  1837  
  1838  	case CASE(ODIV, TINT8):
  1839  	case CASE(OMOD, TINT8):
  1840  		a = AIDIVB;
  1841  		break;
  1842  
  1843  	case CASE(ODIV, TUINT8):
  1844  	case CASE(OMOD, TUINT8):
  1845  		a = ADIVB;
  1846  		break;
  1847  
  1848  	case CASE(ODIV, TINT16):
  1849  	case CASE(OMOD, TINT16):
  1850  		a = AIDIVW;
  1851  		break;
  1852  
  1853  	case CASE(ODIV, TUINT16):
  1854  	case CASE(OMOD, TUINT16):
  1855  		a = ADIVW;
  1856  		break;
  1857  
  1858  	case CASE(ODIV, TINT32):
  1859  	case CASE(OMOD, TINT32):
  1860  		a = AIDIVL;
  1861  		break;
  1862  
  1863  	case CASE(ODIV, TUINT32):
  1864  	case CASE(ODIV, TPTR32):
  1865  	case CASE(OMOD, TUINT32):
  1866  	case CASE(OMOD, TPTR32):
  1867  		a = ADIVL;
  1868  		break;
  1869  
  1870  	case CASE(ODIV, TINT64):
  1871  	case CASE(OMOD, TINT64):
  1872  		a = AIDIVQ;
  1873  		break;
  1874  
  1875  	case CASE(ODIV, TUINT64):
  1876  	case CASE(ODIV, TPTR64):
  1877  	case CASE(OMOD, TUINT64):
  1878  	case CASE(OMOD, TPTR64):
  1879  		a = ADIVQ;
  1880  		break;
  1881  
  1882  	case CASE(OEXTEND, TINT16):
  1883  		a = ACWD;
  1884  		break;
  1885  
  1886  	case CASE(OEXTEND, TINT32):
  1887  		a = ACDQ;
  1888  		break;
  1889  
  1890  	case CASE(OEXTEND, TINT64):
  1891  		a = ACQO;
  1892  		break;
  1893  
  1894  	case CASE(ODIV, TFLOAT32):
  1895  		a = ADIVSS;
  1896  		break;
  1897  
  1898  	case CASE(ODIV, TFLOAT64):
  1899  		a = ADIVSD;
  1900  		break;
  1901  
  1902  	}
  1903  	return a;
  1904  }
  1905  
  1906  enum
  1907  {
  1908  	ODynam		= 1<<0,
  1909  	OAddable	= 1<<1,
  1910  };
  1911  
  1912  static	Node	clean[20];
  1913  static	int	cleani = 0;
  1914  
  1915  int
  1916  xgen(Node *n, Node *a, int o)
  1917  {
  1918  	regalloc(a, types[tptr], N);
  1919  
  1920  	if(o & ODynam)
  1921  	if(n->addable)
  1922  	if(n->op != OINDREG)
  1923  	if(n->op != OREGISTER)
  1924  		return 1;
  1925  
  1926  	agen(n, a);
  1927  	return 0;
  1928  }
  1929  
  1930  void
  1931  sudoclean(void)
  1932  {
  1933  	if(clean[cleani-1].op != OEMPTY)
  1934  		regfree(&clean[cleani-1]);
  1935  	if(clean[cleani-2].op != OEMPTY)
  1936  		regfree(&clean[cleani-2]);
  1937  	cleani -= 2;
  1938  }
  1939  
  1940  /*
  1941   * generate code to compute address of n,
  1942   * a reference to a (perhaps nested) field inside
  1943   * an array or struct.
  1944   * return 0 on failure, 1 on success.
  1945   * on success, leaves usable address in a.
  1946   *
  1947   * caller is responsible for calling sudoclean
  1948   * after successful sudoaddable,
  1949   * to release the register used for a.
  1950   */
  1951  int
  1952  sudoaddable(int as, Node *n, Addr *a)
  1953  {
  1954  	int o, i;
  1955  	int64 oary[10];
  1956  	int64 v, w;
  1957  	Node n1, n2, n3, n4, *nn, *l, *r;
  1958  	Node *reg, *reg1;
  1959  	Prog *p1;
  1960  	Type *t;
  1961  
  1962  	if(n->type == T)
  1963  		return 0;
  1964  
  1965  	switch(n->op) {
  1966  	case OLITERAL:
  1967  		if(!isconst(n, CTINT))
  1968  			break;
  1969  		v = mpgetfix(n->val.u.xval);
  1970  		if(v >= 32000 || v <= -32000)
  1971  			break;
  1972  		goto lit;
  1973  
  1974  	case ODOT:
  1975  	case ODOTPTR:
  1976  		cleani += 2;
  1977  		reg = &clean[cleani-1];
  1978  		reg1 = &clean[cleani-2];
  1979  		reg->op = OEMPTY;
  1980  		reg1->op = OEMPTY;
  1981  		goto odot;
  1982  
  1983  	case OINDEX:
  1984  		return 0;
  1985  		// disabled: OINDEX case is now covered by agenr
  1986  		// for a more suitable register allocation pattern.
  1987  		if(n->left->type->etype == TSTRING)
  1988  			return 0;
  1989  		goto oindex;
  1990  	}
  1991  	return 0;
  1992  
  1993  lit:
  1994  	switch(as) {
  1995  	default:
  1996  		return 0;
  1997  	case AADDB: case AADDW: case AADDL: case AADDQ:
  1998  	case ASUBB: case ASUBW: case ASUBL: case ASUBQ:
  1999  	case AANDB: case AANDW: case AANDL: case AANDQ:
  2000  	case AORB:  case AORW:  case AORL:  case AORQ:
  2001  	case AXORB: case AXORW: case AXORL: case AXORQ:
  2002  	case AINCB: case AINCW: case AINCL: case AINCQ:
  2003  	case ADECB: case ADECW: case ADECL: case ADECQ:
  2004  	case AMOVB: case AMOVW: case AMOVL: case AMOVQ:
  2005  		break;
  2006  	}
  2007  
  2008  	cleani += 2;
  2009  	reg = &clean[cleani-1];
  2010  	reg1 = &clean[cleani-2];
  2011  	reg->op = OEMPTY;
  2012  	reg1->op = OEMPTY;
  2013  	naddr(n, a, 1);
  2014  	goto yes;
  2015  
  2016  odot:
  2017  	o = dotoffset(n, oary, &nn);
  2018  	if(nn == N)
  2019  		goto no;
  2020  
  2021  	if(nn->addable && o == 1 && oary[0] >= 0) {
  2022  		// directly addressable set of DOTs
  2023  		n1 = *nn;
  2024  		n1.type = n->type;
  2025  		n1.xoffset += oary[0];
  2026  		naddr(&n1, a, 1);
  2027  		goto yes;
  2028  	}
  2029  
  2030  	regalloc(reg, types[tptr], N);
  2031  	n1 = *reg;
  2032  	n1.op = OINDREG;
  2033  	if(oary[0] >= 0) {
  2034  		agen(nn, reg);
  2035  		n1.xoffset = oary[0];
  2036  	} else {
  2037  		cgen(nn, reg);
  2038  		cgen_checknil(reg);
  2039  		n1.xoffset = -(oary[0]+1);
  2040  	}
  2041  
  2042  	for(i=1; i<o; i++) {
  2043  		if(oary[i] >= 0)
  2044  			fatal("can't happen");
  2045  		gins(AMOVQ, &n1, reg);
  2046  		cgen_checknil(reg);
  2047  		n1.xoffset = -(oary[i]+1);
  2048  	}
  2049  
  2050  	a->type = D_NONE;
  2051  	a->index = D_NONE;
  2052  	fixlargeoffset(&n1);
  2053  	naddr(&n1, a, 1);
  2054  	goto yes;
  2055  
  2056  oindex:
  2057  	l = n->left;
  2058  	r = n->right;
  2059  	if(l->ullman >= UINF && r->ullman >= UINF)
  2060  		return 0;
  2061  
  2062  	// set o to type of array
  2063  	o = 0;
  2064  	if(isptr[l->type->etype])
  2065  		fatal("ptr ary");
  2066  	if(l->type->etype != TARRAY)
  2067  		fatal("not ary");
  2068  	if(l->type->bound < 0)
  2069  		o |= ODynam;
  2070  
  2071  	w = n->type->width;
  2072  	if(isconst(r, CTINT))
  2073  		goto oindex_const;
  2074  
  2075  	switch(w) {
  2076  	default:
  2077  		return 0;
  2078  	case 1:
  2079  	case 2:
  2080  	case 4:
  2081  	case 8:
  2082  		break;
  2083  	}
  2084  
  2085  	cleani += 2;
  2086  	reg = &clean[cleani-1];
  2087  	reg1 = &clean[cleani-2];
  2088  	reg->op = OEMPTY;
  2089  	reg1->op = OEMPTY;
  2090  
  2091  	// load the array (reg)
  2092  	if(l->ullman > r->ullman) {
  2093  		if(xgen(l, reg, o))
  2094  			o |= OAddable;
  2095  	}
  2096  
  2097  	// load the index (reg1)
  2098  	t = types[TUINT64];
  2099  	if(issigned[r->type->etype])
  2100  		t = types[TINT64];
  2101  	regalloc(reg1, t, N);
  2102  	regalloc(&n3, r->type, reg1);
  2103  	cgen(r, &n3);
  2104  	gmove(&n3, reg1);
  2105  	regfree(&n3);
  2106  
  2107  	// load the array (reg)
  2108  	if(l->ullman <= r->ullman) {
  2109  		if(xgen(l, reg, o))
  2110  			o |= OAddable;
  2111  	}
  2112  
  2113  	// check bounds
  2114  	if(!debug['B'] && !n->bounded) {
  2115  		// check bounds
  2116  		n4.op = OXXX;
  2117  		t = types[simtype[TUINT]];
  2118  		if(o & ODynam) {
  2119  			if(o & OAddable) {
  2120  				n2 = *l;
  2121  				n2.xoffset += Array_nel;
  2122  				n2.type = types[simtype[TUINT]];
  2123  			} else {
  2124  				n2 = *reg;
  2125  				n2.xoffset = Array_nel;
  2126  				n2.op = OINDREG;
  2127  				n2.type = types[simtype[TUINT]];
  2128  			}
  2129  		} else {
  2130  			if(is64(r->type))
  2131  				t = types[TUINT64];
  2132  			nodconst(&n2, types[TUINT64], l->type->bound);
  2133  		}
  2134  		gins(optoas(OCMP, t), reg1, &n2);
  2135  		p1 = gbranch(optoas(OLT, t), T, +1);
  2136  		if(n4.op != OXXX)
  2137  			regfree(&n4);
  2138  		ginscall(panicindex, -1);
  2139  		patch(p1, pc);
  2140  	}
  2141  
  2142  	if(o & ODynam) {
  2143  		if(o & OAddable) {
  2144  			n2 = *l;
  2145  			n2.xoffset += Array_array;
  2146  			n2.type = types[tptr];
  2147  			gmove(&n2, reg);
  2148  		} else {
  2149  			n2 = *reg;
  2150  			n2.op = OINDREG;
  2151  			n2.xoffset = Array_array;
  2152  			n2.type = types[tptr];
  2153  			gmove(&n2, reg);
  2154  		}
  2155  	}
  2156  
  2157  	if(o & OAddable) {
  2158  		naddr(reg1, a, 1);
  2159  		a->offset = 0;
  2160  		a->scale = w;
  2161  		a->index = a->type;
  2162  		a->type = reg->val.u.reg + D_INDIR;
  2163  	} else {
  2164  		naddr(reg1, a, 1);
  2165  		a->offset = 0;
  2166  		a->scale = w;
  2167  		a->index = a->type;
  2168  		a->type = reg->val.u.reg + D_INDIR;
  2169  	}
  2170  
  2171  	goto yes;
  2172  
  2173  oindex_const:
  2174  	// index is constant
  2175  	// can check statically and
  2176  	// can multiply by width statically
  2177  
  2178  	v = mpgetfix(r->val.u.xval);
  2179  
  2180  	if(sudoaddable(as, l, a))
  2181  		goto oindex_const_sudo;
  2182  
  2183  	cleani += 2;
  2184  	reg = &clean[cleani-1];
  2185  	reg1 = &clean[cleani-2];
  2186  	reg->op = OEMPTY;
  2187  	reg1->op = OEMPTY;
  2188  
  2189  	if(o & ODynam) {
  2190  		regalloc(reg, types[tptr], N);
  2191  		agen(l, reg);
  2192  	
  2193  		if(!debug['B'] && !n->bounded) {
  2194  			n1 = *reg;
  2195  			n1.op = OINDREG;
  2196  			n1.type = types[tptr];
  2197  			n1.xoffset = Array_nel;
  2198  			nodconst(&n2, types[TUINT64], v);
  2199  			gins(optoas(OCMP, types[simtype[TUINT]]), &n1, &n2);
  2200  			p1 = gbranch(optoas(OGT, types[simtype[TUINT]]), T, +1);
  2201  			ginscall(panicindex, -1);
  2202  			patch(p1, pc);
  2203  		}
  2204  
  2205  		n1 = *reg;
  2206  		n1.op = OINDREG;
  2207  		n1.type = types[tptr];
  2208  		n1.xoffset = Array_array;
  2209  		gmove(&n1, reg);
  2210  
  2211  		n2 = *reg;
  2212  		n2.op = OINDREG;
  2213  		n2.xoffset = v*w;
  2214  		fixlargeoffset(&n2);
  2215  		a->type = D_NONE;
  2216  		a->index = D_NONE;
  2217  		naddr(&n2, a, 1);
  2218  		goto yes;
  2219  	}
  2220  	
  2221  	igen(l, &n1, N);
  2222  	if(n1.op == OINDREG) {
  2223  		*reg = n1;
  2224  		reg->op = OREGISTER;
  2225  	}
  2226  	n1.xoffset += v*w;
  2227  	fixlargeoffset(&n1);
  2228  	a->type = D_NONE;
  2229  	a->index= D_NONE;
  2230  	naddr(&n1, a, 1);
  2231  	goto yes;
  2232  
  2233  oindex_const_sudo:
  2234  	if((o & ODynam) == 0) {
  2235  		// array indexed by a constant
  2236  		a->offset += v*w;
  2237  		goto yes;
  2238  	}
  2239  
  2240  	// slice indexed by a constant
  2241  	if(!debug['B'] && !n->bounded) {
  2242  		a->offset += Array_nel;
  2243  		nodconst(&n2, types[TUINT64], v);
  2244  		p1 = gins(optoas(OCMP, types[simtype[TUINT]]), N, &n2);
  2245  		p1->from = *a;
  2246  		p1 = gbranch(optoas(OGT, types[simtype[TUINT]]), T, +1);
  2247  		ginscall(panicindex, -1);
  2248  		patch(p1, pc);
  2249  		a->offset -= Array_nel;
  2250  	}
  2251  
  2252  	a->offset += Array_array;
  2253  	reg = &clean[cleani-1];
  2254  	if(reg->op == OEMPTY)
  2255  		regalloc(reg, types[tptr], N);
  2256  
  2257  	p1 = gins(AMOVQ, N, reg);
  2258  	p1->from = *a;
  2259  
  2260  	n2 = *reg;
  2261  	n2.op = OINDREG;
  2262  	n2.xoffset = v*w;
  2263  	fixlargeoffset(&n2);
  2264  	a->type = D_NONE;
  2265  	a->index = D_NONE;
  2266  	naddr(&n2, a, 1);
  2267  	goto yes;
  2268  
  2269  yes:
  2270  	return 1;
  2271  
  2272  no:
  2273  	sudoclean();
  2274  	return 0;
  2275  }