xref: /illumos-gate/usr/src/lib/libdtrace/common/dt_cg.c (revision 1a1df1dbef1b5c57672433301a296dfe4311e6db)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
25  * Use is subject to license terms.
26  */
27 
28 /*
29  * Copyright (c) 2012 by Delphix. All rights reserved.
30  */
31 
32 #include <sys/types.h>
33 #include <sys/sysmacros.h>
34 #include <sys/isa_defs.h>
35 
36 #include <strings.h>
37 #include <stdlib.h>
38 #include <setjmp.h>
39 #include <assert.h>
40 #include <errno.h>
41 
42 #include <dt_impl.h>
43 #include <dt_grammar.h>
44 #include <dt_parser.h>
45 #include <dt_provider.h>
46 
47 static void dt_cg_node(dt_node_t *, dt_irlist_t *, dt_regset_t *);
48 
49 static dt_irnode_t *
50 dt_cg_node_alloc(uint_t label, dif_instr_t instr)
51 {
52 	dt_irnode_t *dip = malloc(sizeof (dt_irnode_t));
53 
54 	if (dip == NULL)
55 		longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
56 
57 	dip->di_label = label;
58 	dip->di_instr = instr;
59 	dip->di_extern = NULL;
60 	dip->di_next = NULL;
61 
62 	return (dip);
63 }
64 
65 /*
66  * Code generator wrapper function for ctf_member_info.  If we are given a
67  * reference to a forward declaration tag, search the entire type space for
68  * the actual definition and then call ctf_member_info on the result.
69  */
70 static ctf_file_t *
71 dt_cg_membinfo(ctf_file_t *fp, ctf_id_t type, const char *s, ctf_membinfo_t *mp)
72 {
73 	while (ctf_type_kind(fp, type) == CTF_K_FORWARD) {
74 		char n[DT_TYPE_NAMELEN];
75 		dtrace_typeinfo_t dtt;
76 
77 		if (ctf_type_name(fp, type, n, sizeof (n)) == NULL ||
78 		    dt_type_lookup(n, &dtt) == -1 || (
79 		    dtt.dtt_ctfp == fp && dtt.dtt_type == type))
80 			break; /* unable to improve our position */
81 
82 		fp = dtt.dtt_ctfp;
83 		type = ctf_type_resolve(fp, dtt.dtt_type);
84 	}
85 
86 	if (ctf_member_info(fp, type, s, mp) == CTF_ERR)
87 		return (NULL); /* ctf_errno is set for us */
88 
89 	return (fp);
90 }
91 
92 static void
93 dt_cg_xsetx(dt_irlist_t *dlp, dt_ident_t *idp, uint_t lbl, int reg, uint64_t x)
94 {
95 	int flag = idp != NULL ? DT_INT_PRIVATE : DT_INT_SHARED;
96 	int intoff = dt_inttab_insert(yypcb->pcb_inttab, x, flag);
97 	dif_instr_t instr = DIF_INSTR_SETX((uint_t)intoff, reg);
98 
99 	if (intoff == -1)
100 		longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
101 
102 	if (intoff > DIF_INTOFF_MAX)
103 		longjmp(yypcb->pcb_jmpbuf, EDT_INT2BIG);
104 
105 	dt_irlist_append(dlp, dt_cg_node_alloc(lbl, instr));
106 
107 	if (idp != NULL)
108 		dlp->dl_last->di_extern = idp;
109 }
110 
111 static void
112 dt_cg_setx(dt_irlist_t *dlp, int reg, uint64_t x)
113 {
114 	dt_cg_xsetx(dlp, NULL, DT_LBL_NONE, reg, x);
115 }
116 
117 /*
118  * When loading bit-fields, we want to convert a byte count in the range
119  * 1-8 to the closest power of 2 (e.g. 3->4, 5->8, etc).  The clp2() function
120  * is a clever implementation from "Hacker's Delight" by Henry Warren, Jr.
121  */
122 static size_t
123 clp2(size_t x)
124 {
125 	x--;
126 
127 	x |= (x >> 1);
128 	x |= (x >> 2);
129 	x |= (x >> 4);
130 	x |= (x >> 8);
131 	x |= (x >> 16);
132 
133 	return (x + 1);
134 }
135 
136 /*
137  * Lookup the correct load opcode to use for the specified node and CTF type.
138  * We determine the size and convert it to a 3-bit index.  Our lookup table
139  * is constructed to use a 5-bit index, consisting of the 3-bit size 0-7, a
140  * bit for the sign, and a bit for userland address.  For example, a 4-byte
141  * signed load from userland would be at the following table index:
142  * user=1 sign=1 size=4 => binary index 11011 = decimal index 27
143  */
144 static uint_t
145 dt_cg_load(dt_node_t *dnp, ctf_file_t *ctfp, ctf_id_t type)
146 {
147 	static const uint_t ops[] = {
148 		DIF_OP_LDUB,	DIF_OP_LDUH,	0,	DIF_OP_LDUW,
149 		0,		0,		0,	DIF_OP_LDX,
150 		DIF_OP_LDSB,	DIF_OP_LDSH,	0,	DIF_OP_LDSW,
151 		0,		0,		0,	DIF_OP_LDX,
152 		DIF_OP_ULDUB,	DIF_OP_ULDUH,	0,	DIF_OP_ULDUW,
153 		0,		0,		0,	DIF_OP_ULDX,
154 		DIF_OP_ULDSB,	DIF_OP_ULDSH,	0,	DIF_OP_ULDSW,
155 		0,		0,		0,	DIF_OP_ULDX,
156 	};
157 
158 	ctf_encoding_t e;
159 	ssize_t size;
160 
161 	/*
162 	 * If we're loading a bit-field, the size of our load is found by
163 	 * rounding cte_bits up to a byte boundary and then finding the
164 	 * nearest power of two to this value (see clp2(), above).
165 	 */
166 	if ((dnp->dn_flags & DT_NF_BITFIELD) &&
167 	    ctf_type_encoding(ctfp, type, &e) != CTF_ERR)
168 		size = clp2(P2ROUNDUP(e.cte_bits, NBBY) / NBBY);
169 	else
170 		size = ctf_type_size(ctfp, type);
171 
172 	if (size < 1 || size > 8 || (size & (size - 1)) != 0) {
173 		xyerror(D_UNKNOWN, "internal error -- cg cannot load "
174 		    "size %ld when passed by value\n", (long)size);
175 	}
176 
177 	size--; /* convert size to 3-bit index */
178 
179 	if (dnp->dn_flags & DT_NF_SIGNED)
180 		size |= 0x08;
181 	if (dnp->dn_flags & DT_NF_USERLAND)
182 		size |= 0x10;
183 
184 	return (ops[size]);
185 }
186 
187 static void
188 dt_cg_ptrsize(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
189     uint_t op, int dreg)
190 {
191 	ctf_file_t *ctfp = dnp->dn_ctfp;
192 	ctf_arinfo_t r;
193 	dif_instr_t instr;
194 	ctf_id_t type;
195 	uint_t kind;
196 	ssize_t size;
197 	int sreg;
198 
199 	type = ctf_type_resolve(ctfp, dnp->dn_type);
200 	kind = ctf_type_kind(ctfp, type);
201 	assert(kind == CTF_K_POINTER || kind == CTF_K_ARRAY);
202 
203 	if (kind == CTF_K_ARRAY) {
204 		if (ctf_array_info(ctfp, type, &r) != 0) {
205 			yypcb->pcb_hdl->dt_ctferr = ctf_errno(ctfp);
206 			longjmp(yypcb->pcb_jmpbuf, EDT_CTF);
207 		}
208 		type = r.ctr_contents;
209 	} else
210 		type = ctf_type_reference(ctfp, type);
211 
212 	if ((size = ctf_type_size(ctfp, type)) == 1)
213 		return; /* multiply or divide by one can be omitted */
214 
215 	sreg = dt_regset_alloc(drp);
216 	dt_cg_setx(dlp, sreg, size);
217 	instr = DIF_INSTR_FMT(op, dreg, sreg, dreg);
218 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
219 	dt_regset_free(drp, sreg);
220 }
221 
222 /*
223  * If the result of a "." or "->" operation is a bit-field, we use this routine
224  * to generate an epilogue to the load instruction that extracts the value.  In
225  * the diagrams below the "ld??" is the load instruction that is generated to
226  * load the containing word that is generating prior to calling this function.
227  *
228  * Epilogue for unsigned fields:	Epilogue for signed fields:
229  *
230  * ldu?	[r1], r1			lds? [r1], r1
231  * setx	USHIFT, r2			setx 64 - SSHIFT, r2
232  * srl	r1, r2, r1			sll  r1, r2, r1
233  * setx	(1 << bits) - 1, r2		setx 64 - bits, r2
234  * and	r1, r2, r1			sra  r1, r2, r1
235  *
236  * The *SHIFT constants above changes value depending on the endian-ness of our
237  * target architecture.  Refer to the comments below for more details.
238  */
239 static void
240 dt_cg_field_get(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
241     ctf_file_t *fp, const ctf_membinfo_t *mp)
242 {
243 	ctf_encoding_t e;
244 	dif_instr_t instr;
245 	uint64_t shift;
246 	int r1, r2;
247 
248 	if (ctf_type_encoding(fp, mp->ctm_type, &e) != 0 || e.cte_bits > 64) {
249 		xyerror(D_UNKNOWN, "cg: bad field: off %lu type <%ld> "
250 		    "bits %u\n", mp->ctm_offset, mp->ctm_type, e.cte_bits);
251 	}
252 
253 	assert(dnp->dn_op == DT_TOK_PTR || dnp->dn_op == DT_TOK_DOT);
254 	r1 = dnp->dn_left->dn_reg;
255 	r2 = dt_regset_alloc(drp);
256 
257 	/*
258 	 * On little-endian architectures, ctm_offset counts from the right so
259 	 * ctm_offset % NBBY itself is the amount we want to shift right to
260 	 * move the value bits to the little end of the register to mask them.
261 	 * On big-endian architectures, ctm_offset counts from the left so we
262 	 * must subtract (ctm_offset % NBBY + cte_bits) from the size in bits
263 	 * we used for the load.  The size of our load in turn is found by
264 	 * rounding cte_bits up to a byte boundary and then finding the
265 	 * nearest power of two to this value (see clp2(), above).  These
266 	 * properties are used to compute shift as USHIFT or SSHIFT, below.
267 	 */
268 	if (dnp->dn_flags & DT_NF_SIGNED) {
269 #ifdef _BIG_ENDIAN
270 		shift = clp2(P2ROUNDUP(e.cte_bits, NBBY) / NBBY) * NBBY -
271 		    mp->ctm_offset % NBBY;
272 #else
273 		shift = mp->ctm_offset % NBBY + e.cte_bits;
274 #endif
275 		dt_cg_setx(dlp, r2, 64 - shift);
276 		instr = DIF_INSTR_FMT(DIF_OP_SLL, r1, r2, r1);
277 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
278 
279 		dt_cg_setx(dlp, r2, 64 - e.cte_bits);
280 		instr = DIF_INSTR_FMT(DIF_OP_SRA, r1, r2, r1);
281 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
282 	} else {
283 #ifdef _BIG_ENDIAN
284 		shift = clp2(P2ROUNDUP(e.cte_bits, NBBY) / NBBY) * NBBY -
285 		    (mp->ctm_offset % NBBY + e.cte_bits);
286 #else
287 		shift = mp->ctm_offset % NBBY;
288 #endif
289 		dt_cg_setx(dlp, r2, shift);
290 		instr = DIF_INSTR_FMT(DIF_OP_SRL, r1, r2, r1);
291 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
292 
293 		dt_cg_setx(dlp, r2, (1ULL << e.cte_bits) - 1);
294 		instr = DIF_INSTR_FMT(DIF_OP_AND, r1, r2, r1);
295 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
296 	}
297 
298 	dt_regset_free(drp, r2);
299 }
300 
301 /*
302  * If the destination of a store operation is a bit-field, we use this routine
303  * to generate a prologue to the store instruction that loads the surrounding
304  * bits, clears the destination field, and ORs in the new value of the field.
305  * In the diagram below the "st?" is the store instruction that is generated to
306  * store the containing word that is generating after calling this function.
307  *
308  * ld	[dst->dn_reg], r1
309  * setx	~(((1 << cte_bits) - 1) << (ctm_offset % NBBY)), r2
310  * and	r1, r2, r1
311  *
312  * setx	(1 << cte_bits) - 1, r2
313  * and	src->dn_reg, r2, r2
314  * setx ctm_offset % NBBY, r3
315  * sll	r2, r3, r2
316  *
317  * or	r1, r2, r1
318  * st?	r1, [dst->dn_reg]
319  *
320  * This routine allocates a new register to hold the value to be stored and
321  * returns it.  The caller is responsible for freeing this register later.
322  */
323 static int
324 dt_cg_field_set(dt_node_t *src, dt_irlist_t *dlp,
325     dt_regset_t *drp, dt_node_t *dst)
326 {
327 	uint64_t cmask, fmask, shift;
328 	dif_instr_t instr;
329 	int r1, r2, r3;
330 
331 	ctf_membinfo_t m;
332 	ctf_encoding_t e;
333 	ctf_file_t *fp, *ofp;
334 	ctf_id_t type;
335 
336 	assert(dst->dn_op == DT_TOK_PTR || dst->dn_op == DT_TOK_DOT);
337 	assert(dst->dn_right->dn_kind == DT_NODE_IDENT);
338 
339 	fp = dst->dn_left->dn_ctfp;
340 	type = ctf_type_resolve(fp, dst->dn_left->dn_type);
341 
342 	if (dst->dn_op == DT_TOK_PTR) {
343 		type = ctf_type_reference(fp, type);
344 		type = ctf_type_resolve(fp, type);
345 	}
346 
347 	if ((fp = dt_cg_membinfo(ofp = fp, type,
348 	    dst->dn_right->dn_string, &m)) == NULL) {
349 		yypcb->pcb_hdl->dt_ctferr = ctf_errno(ofp);
350 		longjmp(yypcb->pcb_jmpbuf, EDT_CTF);
351 	}
352 
353 	if (ctf_type_encoding(fp, m.ctm_type, &e) != 0 || e.cte_bits > 64) {
354 		xyerror(D_UNKNOWN, "cg: bad field: off %lu type <%ld> "
355 		    "bits %u\n", m.ctm_offset, m.ctm_type, e.cte_bits);
356 	}
357 
358 	r1 = dt_regset_alloc(drp);
359 	r2 = dt_regset_alloc(drp);
360 	r3 = dt_regset_alloc(drp);
361 
362 	/*
363 	 * Compute shifts and masks.  We need to compute "shift" as the amount
364 	 * we need to shift left to position our field in the containing word.
365 	 * Refer to the comments in dt_cg_field_get(), above, for more info.
366 	 * We then compute fmask as the mask that truncates the value in the
367 	 * input register to width cte_bits, and cmask as the mask used to
368 	 * pass through the containing bits and zero the field bits.
369 	 */
370 #ifdef _BIG_ENDIAN
371 	shift = clp2(P2ROUNDUP(e.cte_bits, NBBY) / NBBY) * NBBY -
372 	    (m.ctm_offset % NBBY + e.cte_bits);
373 #else
374 	shift = m.ctm_offset % NBBY;
375 #endif
376 	fmask = (1ULL << e.cte_bits) - 1;
377 	cmask = ~(fmask << shift);
378 
379 	instr = DIF_INSTR_LOAD(
380 	    dt_cg_load(dst, fp, m.ctm_type), dst->dn_reg, r1);
381 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
382 
383 	dt_cg_setx(dlp, r2, cmask);
384 	instr = DIF_INSTR_FMT(DIF_OP_AND, r1, r2, r1);
385 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
386 
387 	dt_cg_setx(dlp, r2, fmask);
388 	instr = DIF_INSTR_FMT(DIF_OP_AND, src->dn_reg, r2, r2);
389 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
390 
391 	dt_cg_setx(dlp, r3, shift);
392 	instr = DIF_INSTR_FMT(DIF_OP_SLL, r2, r3, r2);
393 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
394 
395 	instr = DIF_INSTR_FMT(DIF_OP_OR, r1, r2, r1);
396 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
397 
398 	dt_regset_free(drp, r3);
399 	dt_regset_free(drp, r2);
400 
401 	return (r1);
402 }
403 
404 static void
405 dt_cg_store(dt_node_t *src, dt_irlist_t *dlp, dt_regset_t *drp, dt_node_t *dst)
406 {
407 	ctf_encoding_t e;
408 	dif_instr_t instr;
409 	size_t size;
410 	int reg;
411 
412 	/*
413 	 * If we're loading a bit-field, the size of our store is found by
414 	 * rounding dst's cte_bits up to a byte boundary and then finding the
415 	 * nearest power of two to this value (see clp2(), above).
416 	 */
417 	if ((dst->dn_flags & DT_NF_BITFIELD) &&
418 	    ctf_type_encoding(dst->dn_ctfp, dst->dn_type, &e) != CTF_ERR)
419 		size = clp2(P2ROUNDUP(e.cte_bits, NBBY) / NBBY);
420 	else
421 		size = dt_node_type_size(src);
422 
423 	if (src->dn_flags & DT_NF_REF) {
424 		reg = dt_regset_alloc(drp);
425 		dt_cg_setx(dlp, reg, size);
426 		instr = DIF_INSTR_COPYS(src->dn_reg, reg, dst->dn_reg);
427 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
428 		dt_regset_free(drp, reg);
429 	} else {
430 		if (dst->dn_flags & DT_NF_BITFIELD)
431 			reg = dt_cg_field_set(src, dlp, drp, dst);
432 		else
433 			reg = src->dn_reg;
434 
435 		switch (size) {
436 		case 1:
437 			instr = DIF_INSTR_STORE(DIF_OP_STB, reg, dst->dn_reg);
438 			break;
439 		case 2:
440 			instr = DIF_INSTR_STORE(DIF_OP_STH, reg, dst->dn_reg);
441 			break;
442 		case 4:
443 			instr = DIF_INSTR_STORE(DIF_OP_STW, reg, dst->dn_reg);
444 			break;
445 		case 8:
446 			instr = DIF_INSTR_STORE(DIF_OP_STX, reg, dst->dn_reg);
447 			break;
448 		default:
449 			xyerror(D_UNKNOWN, "internal error -- cg cannot store "
450 			    "size %lu when passed by value\n", (ulong_t)size);
451 		}
452 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
453 
454 		if (dst->dn_flags & DT_NF_BITFIELD)
455 			dt_regset_free(drp, reg);
456 	}
457 }
458 
459 /*
460  * Generate code for a typecast or for argument promotion from the type of the
461  * actual to the type of the formal.  We need to generate code for casts when
462  * a scalar type is being narrowed or changing signed-ness.  We first shift the
463  * desired bits high (losing excess bits if narrowing) and then shift them down
464  * using logical shift (unsigned result) or arithmetic shift (signed result).
465  */
466 static void
467 dt_cg_typecast(const dt_node_t *src, const dt_node_t *dst,
468     dt_irlist_t *dlp, dt_regset_t *drp)
469 {
470 	size_t srcsize = dt_node_type_size(src);
471 	size_t dstsize = dt_node_type_size(dst);
472 
473 	dif_instr_t instr;
474 	int rg;
475 
476 	if (!dt_node_is_scalar(dst))
477 		return; /* not a scalar */
478 	if (dstsize == srcsize &&
479 	    ((src->dn_flags ^ dst->dn_flags) & DT_NF_SIGNED) == 0)
480 		return; /* not narrowing or changing signed-ness */
481 	if (dstsize > srcsize && (src->dn_flags & DT_NF_SIGNED) == 0)
482 		return; /* nothing to do in this case */
483 
484 	rg = dt_regset_alloc(drp);
485 
486 	if (dstsize > srcsize) {
487 		int n = sizeof (uint64_t) * NBBY - srcsize * NBBY;
488 		int s = (dstsize - srcsize) * NBBY;
489 
490 		dt_cg_setx(dlp, rg, n);
491 
492 		instr = DIF_INSTR_FMT(DIF_OP_SLL, src->dn_reg, rg, dst->dn_reg);
493 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
494 
495 		if ((dst->dn_flags & DT_NF_SIGNED) || n == s) {
496 			instr = DIF_INSTR_FMT(DIF_OP_SRA,
497 			    dst->dn_reg, rg, dst->dn_reg);
498 			dt_irlist_append(dlp,
499 			    dt_cg_node_alloc(DT_LBL_NONE, instr));
500 		} else {
501 			dt_cg_setx(dlp, rg, s);
502 			instr = DIF_INSTR_FMT(DIF_OP_SRA,
503 			    dst->dn_reg, rg, dst->dn_reg);
504 			dt_irlist_append(dlp,
505 			    dt_cg_node_alloc(DT_LBL_NONE, instr));
506 			dt_cg_setx(dlp, rg, n - s);
507 			instr = DIF_INSTR_FMT(DIF_OP_SRL,
508 			    dst->dn_reg, rg, dst->dn_reg);
509 			dt_irlist_append(dlp,
510 			    dt_cg_node_alloc(DT_LBL_NONE, instr));
511 		}
512 	} else if (dstsize != sizeof (uint64_t)) {
513 		int n = sizeof (uint64_t) * NBBY - dstsize * NBBY;
514 
515 		dt_cg_setx(dlp, rg, n);
516 
517 		instr = DIF_INSTR_FMT(DIF_OP_SLL, src->dn_reg, rg, dst->dn_reg);
518 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
519 
520 		instr = DIF_INSTR_FMT((dst->dn_flags & DT_NF_SIGNED) ?
521 		    DIF_OP_SRA : DIF_OP_SRL, dst->dn_reg, rg, dst->dn_reg);
522 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
523 	}
524 
525 	dt_regset_free(drp, rg);
526 }
527 
528 /*
529  * Generate code to push the specified argument list on to the tuple stack.
530  * We use this routine for handling subroutine calls and associative arrays.
531  * We must first generate code for all subexpressions before loading the stack
532  * because any subexpression could itself require the use of the tuple stack.
533  * This holds a number of registers equal to the number of arguments, but this
534  * is not a huge problem because the number of arguments can't exceed the
535  * number of tuple register stack elements anyway.  At most one extra register
536  * is required (either by dt_cg_typecast() or for dtdt_size, below).  This
537  * implies that a DIF implementation should offer a number of general purpose
538  * registers at least one greater than the number of tuple registers.
539  */
540 static void
541 dt_cg_arglist(dt_ident_t *idp, dt_node_t *args,
542     dt_irlist_t *dlp, dt_regset_t *drp)
543 {
544 	const dt_idsig_t *isp = idp->di_data;
545 	dt_node_t *dnp;
546 	int i = 0;
547 
548 	for (dnp = args; dnp != NULL; dnp = dnp->dn_list)
549 		dt_cg_node(dnp, dlp, drp);
550 
551 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, DIF_INSTR_FLUSHTS));
552 
553 	for (dnp = args; dnp != NULL; dnp = dnp->dn_list, i++) {
554 		dtrace_diftype_t t;
555 		dif_instr_t instr;
556 		uint_t op;
557 		int reg;
558 
559 		dt_node_diftype(yypcb->pcb_hdl, dnp, &t);
560 
561 		isp->dis_args[i].dn_reg = dnp->dn_reg; /* re-use register */
562 		dt_cg_typecast(dnp, &isp->dis_args[i], dlp, drp);
563 		isp->dis_args[i].dn_reg = -1;
564 
565 		if (t.dtdt_flags & DIF_TF_BYREF) {
566 			op = DIF_OP_PUSHTR;
567 			if (t.dtdt_size != 0) {
568 				reg = dt_regset_alloc(drp);
569 				dt_cg_setx(dlp, reg, t.dtdt_size);
570 			} else {
571 				reg = DIF_REG_R0;
572 			}
573 		} else {
574 			op = DIF_OP_PUSHTV;
575 			reg = DIF_REG_R0;
576 		}
577 
578 		instr = DIF_INSTR_PUSHTS(op, t.dtdt_kind, reg, dnp->dn_reg);
579 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
580 		dt_regset_free(drp, dnp->dn_reg);
581 
582 		if (reg != DIF_REG_R0)
583 			dt_regset_free(drp, reg);
584 	}
585 
586 	if (i > yypcb->pcb_hdl->dt_conf.dtc_diftupregs)
587 		longjmp(yypcb->pcb_jmpbuf, EDT_NOTUPREG);
588 }
589 
590 static void
591 dt_cg_arithmetic_op(dt_node_t *dnp, dt_irlist_t *dlp,
592     dt_regset_t *drp, uint_t op)
593 {
594 	int is_ptr_op = (dnp->dn_op == DT_TOK_ADD || dnp->dn_op == DT_TOK_SUB ||
595 	    dnp->dn_op == DT_TOK_ADD_EQ || dnp->dn_op == DT_TOK_SUB_EQ);
596 
597 	int lp_is_ptr = dt_node_is_pointer(dnp->dn_left);
598 	int rp_is_ptr = dt_node_is_pointer(dnp->dn_right);
599 
600 	dif_instr_t instr;
601 
602 	if (lp_is_ptr && rp_is_ptr) {
603 		assert(dnp->dn_op == DT_TOK_SUB);
604 		is_ptr_op = 0;
605 	}
606 
607 	dt_cg_node(dnp->dn_left, dlp, drp);
608 	if (is_ptr_op && rp_is_ptr)
609 		dt_cg_ptrsize(dnp, dlp, drp, DIF_OP_MUL, dnp->dn_left->dn_reg);
610 
611 	dt_cg_node(dnp->dn_right, dlp, drp);
612 	if (is_ptr_op && lp_is_ptr)
613 		dt_cg_ptrsize(dnp, dlp, drp, DIF_OP_MUL, dnp->dn_right->dn_reg);
614 
615 	instr = DIF_INSTR_FMT(op, dnp->dn_left->dn_reg,
616 	    dnp->dn_right->dn_reg, dnp->dn_left->dn_reg);
617 
618 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
619 	dt_regset_free(drp, dnp->dn_right->dn_reg);
620 	dnp->dn_reg = dnp->dn_left->dn_reg;
621 
622 	if (lp_is_ptr && rp_is_ptr)
623 		dt_cg_ptrsize(dnp->dn_right,
624 		    dlp, drp, DIF_OP_UDIV, dnp->dn_reg);
625 }
626 
627 static uint_t
628 dt_cg_stvar(const dt_ident_t *idp)
629 {
630 	static const uint_t aops[] = { DIF_OP_STGAA, DIF_OP_STTAA, DIF_OP_NOP };
631 	static const uint_t sops[] = { DIF_OP_STGS, DIF_OP_STTS, DIF_OP_STLS };
632 
633 	uint_t i = (((idp->di_flags & DT_IDFLG_LOCAL) != 0) << 1) |
634 	    ((idp->di_flags & DT_IDFLG_TLS) != 0);
635 
636 	return (idp->di_kind == DT_IDENT_ARRAY ? aops[i] : sops[i]);
637 }
638 
639 static void
640 dt_cg_prearith_op(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp, uint_t op)
641 {
642 	ctf_file_t *ctfp = dnp->dn_ctfp;
643 	dif_instr_t instr;
644 	ctf_id_t type;
645 	ssize_t size = 1;
646 	int reg;
647 
648 	if (dt_node_is_pointer(dnp)) {
649 		type = ctf_type_resolve(ctfp, dnp->dn_type);
650 		assert(ctf_type_kind(ctfp, type) == CTF_K_POINTER);
651 		size = ctf_type_size(ctfp, ctf_type_reference(ctfp, type));
652 	}
653 
654 	dt_cg_node(dnp->dn_child, dlp, drp);
655 	dnp->dn_reg = dnp->dn_child->dn_reg;
656 
657 	reg = dt_regset_alloc(drp);
658 	dt_cg_setx(dlp, reg, size);
659 
660 	instr = DIF_INSTR_FMT(op, dnp->dn_reg, reg, dnp->dn_reg);
661 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
662 	dt_regset_free(drp, reg);
663 
664 	/*
665 	 * If we are modifying a variable, generate an stv instruction from
666 	 * the variable specified by the identifier.  If we are storing to a
667 	 * memory address, generate code again for the left-hand side using
668 	 * DT_NF_REF to get the address, and then generate a store to it.
669 	 * In both paths, we store the value in dnp->dn_reg (the new value).
670 	 */
671 	if (dnp->dn_child->dn_kind == DT_NODE_VAR) {
672 		dt_ident_t *idp = dt_ident_resolve(dnp->dn_child->dn_ident);
673 
674 		idp->di_flags |= DT_IDFLG_DIFW;
675 		instr = DIF_INSTR_STV(dt_cg_stvar(idp),
676 		    idp->di_id, dnp->dn_reg);
677 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
678 	} else {
679 		uint_t rbit = dnp->dn_child->dn_flags & DT_NF_REF;
680 
681 		assert(dnp->dn_child->dn_flags & DT_NF_WRITABLE);
682 		assert(dnp->dn_child->dn_flags & DT_NF_LVALUE);
683 
684 		dnp->dn_child->dn_flags |= DT_NF_REF; /* force pass-by-ref */
685 		dt_cg_node(dnp->dn_child, dlp, drp);
686 
687 		dt_cg_store(dnp, dlp, drp, dnp->dn_child);
688 		dt_regset_free(drp, dnp->dn_child->dn_reg);
689 
690 		dnp->dn_left->dn_flags &= ~DT_NF_REF;
691 		dnp->dn_left->dn_flags |= rbit;
692 	}
693 }
694 
695 static void
696 dt_cg_postarith_op(dt_node_t *dnp, dt_irlist_t *dlp,
697     dt_regset_t *drp, uint_t op)
698 {
699 	ctf_file_t *ctfp = dnp->dn_ctfp;
700 	dif_instr_t instr;
701 	ctf_id_t type;
702 	ssize_t size = 1;
703 	int nreg;
704 
705 	if (dt_node_is_pointer(dnp)) {
706 		type = ctf_type_resolve(ctfp, dnp->dn_type);
707 		assert(ctf_type_kind(ctfp, type) == CTF_K_POINTER);
708 		size = ctf_type_size(ctfp, ctf_type_reference(ctfp, type));
709 	}
710 
711 	dt_cg_node(dnp->dn_child, dlp, drp);
712 	dnp->dn_reg = dnp->dn_child->dn_reg;
713 
714 	nreg = dt_regset_alloc(drp);
715 	dt_cg_setx(dlp, nreg, size);
716 	instr = DIF_INSTR_FMT(op, dnp->dn_reg, nreg, nreg);
717 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
718 
719 	/*
720 	 * If we are modifying a variable, generate an stv instruction from
721 	 * the variable specified by the identifier.  If we are storing to a
722 	 * memory address, generate code again for the left-hand side using
723 	 * DT_NF_REF to get the address, and then generate a store to it.
724 	 * In both paths, we store the value from 'nreg' (the new value).
725 	 */
726 	if (dnp->dn_child->dn_kind == DT_NODE_VAR) {
727 		dt_ident_t *idp = dt_ident_resolve(dnp->dn_child->dn_ident);
728 
729 		idp->di_flags |= DT_IDFLG_DIFW;
730 		instr = DIF_INSTR_STV(dt_cg_stvar(idp), idp->di_id, nreg);
731 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
732 	} else {
733 		uint_t rbit = dnp->dn_child->dn_flags & DT_NF_REF;
734 		int oreg = dnp->dn_reg;
735 
736 		assert(dnp->dn_child->dn_flags & DT_NF_WRITABLE);
737 		assert(dnp->dn_child->dn_flags & DT_NF_LVALUE);
738 
739 		dnp->dn_child->dn_flags |= DT_NF_REF; /* force pass-by-ref */
740 		dt_cg_node(dnp->dn_child, dlp, drp);
741 
742 		dnp->dn_reg = nreg;
743 		dt_cg_store(dnp, dlp, drp, dnp->dn_child);
744 		dnp->dn_reg = oreg;
745 
746 		dt_regset_free(drp, dnp->dn_child->dn_reg);
747 		dnp->dn_left->dn_flags &= ~DT_NF_REF;
748 		dnp->dn_left->dn_flags |= rbit;
749 	}
750 
751 	dt_regset_free(drp, nreg);
752 }
753 
754 /*
755  * Determine if we should perform signed or unsigned comparison for an OP2.
756  * If both operands are of arithmetic type, perform the usual arithmetic
757  * conversions to determine the common real type for comparison [ISOC 6.5.8.3].
758  */
759 static int
760 dt_cg_compare_signed(dt_node_t *dnp)
761 {
762 	dt_node_t dn;
763 
764 	if (dt_node_is_string(dnp->dn_left) ||
765 	    dt_node_is_string(dnp->dn_right))
766 		return (1); /* strings always compare signed */
767 	else if (!dt_node_is_arith(dnp->dn_left) ||
768 	    !dt_node_is_arith(dnp->dn_right))
769 		return (0); /* non-arithmetic types always compare unsigned */
770 
771 	bzero(&dn, sizeof (dn));
772 	dt_node_promote(dnp->dn_left, dnp->dn_right, &dn);
773 	return (dn.dn_flags & DT_NF_SIGNED);
774 }
775 
776 static void
777 dt_cg_compare_op(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp, uint_t op)
778 {
779 	uint_t lbl_true = dt_irlist_label(dlp);
780 	uint_t lbl_post = dt_irlist_label(dlp);
781 
782 	dif_instr_t instr;
783 	uint_t opc;
784 
785 	dt_cg_node(dnp->dn_left, dlp, drp);
786 	dt_cg_node(dnp->dn_right, dlp, drp);
787 
788 	if (dt_node_is_string(dnp->dn_left) || dt_node_is_string(dnp->dn_right))
789 		opc = DIF_OP_SCMP;
790 	else
791 		opc = DIF_OP_CMP;
792 
793 	instr = DIF_INSTR_CMP(opc, dnp->dn_left->dn_reg, dnp->dn_right->dn_reg);
794 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
795 	dt_regset_free(drp, dnp->dn_right->dn_reg);
796 	dnp->dn_reg = dnp->dn_left->dn_reg;
797 
798 	instr = DIF_INSTR_BRANCH(op, lbl_true);
799 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
800 
801 	instr = DIF_INSTR_MOV(DIF_REG_R0, dnp->dn_reg);
802 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
803 
804 	instr = DIF_INSTR_BRANCH(DIF_OP_BA, lbl_post);
805 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
806 
807 	dt_cg_xsetx(dlp, NULL, lbl_true, dnp->dn_reg, 1);
808 	dt_irlist_append(dlp, dt_cg_node_alloc(lbl_post, DIF_INSTR_NOP));
809 }
810 
811 /*
812  * Code generation for the ternary op requires some trickery with the assembler
813  * in order to conserve registers.  We generate code for dn_expr and dn_left
814  * and free their registers so they do not have be consumed across codegen for
815  * dn_right.  We insert a dummy MOV at the end of dn_left into the destination
816  * register, which is not yet known because we haven't done dn_right yet, and
817  * save the pointer to this instruction node.  We then generate code for
818  * dn_right and use its register as our output.  Finally, we reach back and
819  * patch the instruction for dn_left to move its output into this register.
820  */
821 static void
822 dt_cg_ternary_op(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
823 {
824 	uint_t lbl_false = dt_irlist_label(dlp);
825 	uint_t lbl_post = dt_irlist_label(dlp);
826 
827 	dif_instr_t instr;
828 	dt_irnode_t *dip;
829 
830 	dt_cg_node(dnp->dn_expr, dlp, drp);
831 	instr = DIF_INSTR_TST(dnp->dn_expr->dn_reg);
832 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
833 	dt_regset_free(drp, dnp->dn_expr->dn_reg);
834 
835 	instr = DIF_INSTR_BRANCH(DIF_OP_BE, lbl_false);
836 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
837 
838 	dt_cg_node(dnp->dn_left, dlp, drp);
839 	instr = DIF_INSTR_MOV(dnp->dn_left->dn_reg, DIF_REG_R0);
840 	dip = dt_cg_node_alloc(DT_LBL_NONE, instr); /* save dip for below */
841 	dt_irlist_append(dlp, dip);
842 	dt_regset_free(drp, dnp->dn_left->dn_reg);
843 
844 	instr = DIF_INSTR_BRANCH(DIF_OP_BA, lbl_post);
845 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
846 
847 	dt_irlist_append(dlp, dt_cg_node_alloc(lbl_false, DIF_INSTR_NOP));
848 	dt_cg_node(dnp->dn_right, dlp, drp);
849 	dnp->dn_reg = dnp->dn_right->dn_reg;
850 
851 	/*
852 	 * Now that dn_reg is assigned, reach back and patch the correct MOV
853 	 * instruction into the tail of dn_left.  We know dn_reg was unused
854 	 * at that point because otherwise dn_right couldn't have allocated it.
855 	 */
856 	dip->di_instr = DIF_INSTR_MOV(dnp->dn_left->dn_reg, dnp->dn_reg);
857 	dt_irlist_append(dlp, dt_cg_node_alloc(lbl_post, DIF_INSTR_NOP));
858 }
859 
860 static void
861 dt_cg_logical_and(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
862 {
863 	uint_t lbl_false = dt_irlist_label(dlp);
864 	uint_t lbl_post = dt_irlist_label(dlp);
865 
866 	dif_instr_t instr;
867 
868 	dt_cg_node(dnp->dn_left, dlp, drp);
869 	instr = DIF_INSTR_TST(dnp->dn_left->dn_reg);
870 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
871 	dt_regset_free(drp, dnp->dn_left->dn_reg);
872 
873 	instr = DIF_INSTR_BRANCH(DIF_OP_BE, lbl_false);
874 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
875 
876 	dt_cg_node(dnp->dn_right, dlp, drp);
877 	instr = DIF_INSTR_TST(dnp->dn_right->dn_reg);
878 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
879 	dnp->dn_reg = dnp->dn_right->dn_reg;
880 
881 	instr = DIF_INSTR_BRANCH(DIF_OP_BE, lbl_false);
882 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
883 
884 	dt_cg_setx(dlp, dnp->dn_reg, 1);
885 
886 	instr = DIF_INSTR_BRANCH(DIF_OP_BA, lbl_post);
887 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
888 
889 	instr = DIF_INSTR_MOV(DIF_REG_R0, dnp->dn_reg);
890 	dt_irlist_append(dlp, dt_cg_node_alloc(lbl_false, instr));
891 
892 	dt_irlist_append(dlp, dt_cg_node_alloc(lbl_post, DIF_INSTR_NOP));
893 }
894 
895 static void
896 dt_cg_logical_xor(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
897 {
898 	uint_t lbl_next = dt_irlist_label(dlp);
899 	uint_t lbl_tail = dt_irlist_label(dlp);
900 
901 	dif_instr_t instr;
902 
903 	dt_cg_node(dnp->dn_left, dlp, drp);
904 	instr = DIF_INSTR_TST(dnp->dn_left->dn_reg);
905 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
906 
907 	instr = DIF_INSTR_BRANCH(DIF_OP_BE, lbl_next);
908 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
909 	dt_cg_setx(dlp, dnp->dn_left->dn_reg, 1);
910 
911 	dt_irlist_append(dlp, dt_cg_node_alloc(lbl_next, DIF_INSTR_NOP));
912 	dt_cg_node(dnp->dn_right, dlp, drp);
913 
914 	instr = DIF_INSTR_TST(dnp->dn_right->dn_reg);
915 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
916 
917 	instr = DIF_INSTR_BRANCH(DIF_OP_BE, lbl_tail);
918 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
919 	dt_cg_setx(dlp, dnp->dn_right->dn_reg, 1);
920 
921 	instr = DIF_INSTR_FMT(DIF_OP_XOR, dnp->dn_left->dn_reg,
922 	    dnp->dn_right->dn_reg, dnp->dn_left->dn_reg);
923 
924 	dt_irlist_append(dlp, dt_cg_node_alloc(lbl_tail, instr));
925 
926 	dt_regset_free(drp, dnp->dn_right->dn_reg);
927 	dnp->dn_reg = dnp->dn_left->dn_reg;
928 }
929 
930 static void
931 dt_cg_logical_or(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
932 {
933 	uint_t lbl_true = dt_irlist_label(dlp);
934 	uint_t lbl_false = dt_irlist_label(dlp);
935 	uint_t lbl_post = dt_irlist_label(dlp);
936 
937 	dif_instr_t instr;
938 
939 	dt_cg_node(dnp->dn_left, dlp, drp);
940 	instr = DIF_INSTR_TST(dnp->dn_left->dn_reg);
941 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
942 	dt_regset_free(drp, dnp->dn_left->dn_reg);
943 
944 	instr = DIF_INSTR_BRANCH(DIF_OP_BNE, lbl_true);
945 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
946 
947 	dt_cg_node(dnp->dn_right, dlp, drp);
948 	instr = DIF_INSTR_TST(dnp->dn_right->dn_reg);
949 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
950 	dnp->dn_reg = dnp->dn_right->dn_reg;
951 
952 	instr = DIF_INSTR_BRANCH(DIF_OP_BE, lbl_false);
953 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
954 
955 	dt_cg_xsetx(dlp, NULL, lbl_true, dnp->dn_reg, 1);
956 
957 	instr = DIF_INSTR_BRANCH(DIF_OP_BA, lbl_post);
958 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
959 
960 	instr = DIF_INSTR_MOV(DIF_REG_R0, dnp->dn_reg);
961 	dt_irlist_append(dlp, dt_cg_node_alloc(lbl_false, instr));
962 
963 	dt_irlist_append(dlp, dt_cg_node_alloc(lbl_post, DIF_INSTR_NOP));
964 }
965 
966 static void
967 dt_cg_logical_neg(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
968 {
969 	uint_t lbl_zero = dt_irlist_label(dlp);
970 	uint_t lbl_post = dt_irlist_label(dlp);
971 
972 	dif_instr_t instr;
973 
974 	dt_cg_node(dnp->dn_child, dlp, drp);
975 	dnp->dn_reg = dnp->dn_child->dn_reg;
976 
977 	instr = DIF_INSTR_TST(dnp->dn_reg);
978 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
979 
980 	instr = DIF_INSTR_BRANCH(DIF_OP_BE, lbl_zero);
981 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
982 
983 	instr = DIF_INSTR_MOV(DIF_REG_R0, dnp->dn_reg);
984 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
985 
986 	instr = DIF_INSTR_BRANCH(DIF_OP_BA, lbl_post);
987 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
988 
989 	dt_cg_xsetx(dlp, NULL, lbl_zero, dnp->dn_reg, 1);
990 	dt_irlist_append(dlp, dt_cg_node_alloc(lbl_post, DIF_INSTR_NOP));
991 }
992 
993 static void
994 dt_cg_asgn_op(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
995 {
996 	dif_instr_t instr;
997 	dt_ident_t *idp;
998 
999 	/*
1000 	 * If we are performing a structure assignment of a translated type,
1001 	 * we must instantiate all members and create a snapshot of the object
1002 	 * in scratch space.  We allocs a chunk of memory, generate code for
1003 	 * each member, and then set dnp->dn_reg to the scratch object address.
1004 	 */
1005 	if ((idp = dt_node_resolve(dnp->dn_right, DT_IDENT_XLSOU)) != NULL) {
1006 		ctf_membinfo_t ctm;
1007 		dt_xlator_t *dxp = idp->di_data;
1008 		dt_node_t *mnp, dn, mn;
1009 		int r1, r2;
1010 
1011 		/*
1012 		 * Create two fake dt_node_t's representing operator "." and a
1013 		 * right-hand identifier child node.  These will be repeatedly
1014 		 * modified according to each instantiated member so that we
1015 		 * can pass them to dt_cg_store() and effect a member store.
1016 		 */
1017 		bzero(&dn, sizeof (dt_node_t));
1018 		dn.dn_kind = DT_NODE_OP2;
1019 		dn.dn_op = DT_TOK_DOT;
1020 		dn.dn_left = dnp;
1021 		dn.dn_right = &mn;
1022 
1023 		bzero(&mn, sizeof (dt_node_t));
1024 		mn.dn_kind = DT_NODE_IDENT;
1025 		mn.dn_op = DT_TOK_IDENT;
1026 
1027 		/*
1028 		 * Allocate a register for our scratch data pointer.  First we
1029 		 * set it to the size of our data structure, and then replace
1030 		 * it with the result of an allocs of the specified size.
1031 		 */
1032 		r1 = dt_regset_alloc(drp);
1033 		dt_cg_setx(dlp, r1,
1034 		    ctf_type_size(dxp->dx_dst_ctfp, dxp->dx_dst_base));
1035 
1036 		instr = DIF_INSTR_ALLOCS(r1, r1);
1037 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1038 
1039 		/*
1040 		 * When dt_cg_asgn_op() is called, we have already generated
1041 		 * code for dnp->dn_right, which is the translator input.  We
1042 		 * now associate this register with the translator's input
1043 		 * identifier so it can be referenced during our member loop.
1044 		 */
1045 		dxp->dx_ident->di_flags |= DT_IDFLG_CGREG;
1046 		dxp->dx_ident->di_id = dnp->dn_right->dn_reg;
1047 
1048 		for (mnp = dxp->dx_members; mnp != NULL; mnp = mnp->dn_list) {
1049 			/*
1050 			 * Generate code for the translator member expression,
1051 			 * and then cast the result to the member type.
1052 			 */
1053 			dt_cg_node(mnp->dn_membexpr, dlp, drp);
1054 			mnp->dn_reg = mnp->dn_membexpr->dn_reg;
1055 			dt_cg_typecast(mnp->dn_membexpr, mnp, dlp, drp);
1056 
1057 			/*
1058 			 * Ask CTF for the offset of the member so we can store
1059 			 * to the appropriate offset.  This call has already
1060 			 * been done once by the parser, so it should succeed.
1061 			 */
1062 			if (ctf_member_info(dxp->dx_dst_ctfp, dxp->dx_dst_base,
1063 			    mnp->dn_membname, &ctm) == CTF_ERR) {
1064 				yypcb->pcb_hdl->dt_ctferr =
1065 				    ctf_errno(dxp->dx_dst_ctfp);
1066 				longjmp(yypcb->pcb_jmpbuf, EDT_CTF);
1067 			}
1068 
1069 			/*
1070 			 * If the destination member is at offset 0, store the
1071 			 * result directly to r1 (the scratch buffer address).
1072 			 * Otherwise allocate another temporary for the offset
1073 			 * and add r1 to it before storing the result.
1074 			 */
1075 			if (ctm.ctm_offset != 0) {
1076 				r2 = dt_regset_alloc(drp);
1077 
1078 				/*
1079 				 * Add the member offset rounded down to the
1080 				 * nearest byte.  If the offset was not aligned
1081 				 * on a byte boundary, this member is a bit-
1082 				 * field and dt_cg_store() will handle masking.
1083 				 */
1084 				dt_cg_setx(dlp, r2, ctm.ctm_offset / NBBY);
1085 				instr = DIF_INSTR_FMT(DIF_OP_ADD, r1, r2, r2);
1086 				dt_irlist_append(dlp,
1087 				    dt_cg_node_alloc(DT_LBL_NONE, instr));
1088 
1089 				dt_node_type_propagate(mnp, &dn);
1090 				dn.dn_right->dn_string = mnp->dn_membname;
1091 				dn.dn_reg = r2;
1092 
1093 				dt_cg_store(mnp, dlp, drp, &dn);
1094 				dt_regset_free(drp, r2);
1095 
1096 			} else {
1097 				dt_node_type_propagate(mnp, &dn);
1098 				dn.dn_right->dn_string = mnp->dn_membname;
1099 				dn.dn_reg = r1;
1100 
1101 				dt_cg_store(mnp, dlp, drp, &dn);
1102 			}
1103 
1104 			dt_regset_free(drp, mnp->dn_reg);
1105 		}
1106 
1107 		dxp->dx_ident->di_flags &= ~DT_IDFLG_CGREG;
1108 		dxp->dx_ident->di_id = 0;
1109 
1110 		if (dnp->dn_right->dn_reg != -1)
1111 			dt_regset_free(drp, dnp->dn_right->dn_reg);
1112 
1113 		assert(dnp->dn_reg == dnp->dn_right->dn_reg);
1114 		dnp->dn_reg = r1;
1115 	}
1116 
1117 	/*
1118 	 * If we are storing to a variable, generate an stv instruction from
1119 	 * the variable specified by the identifier.  If we are storing to a
1120 	 * memory address, generate code again for the left-hand side using
1121 	 * DT_NF_REF to get the address, and then generate a store to it.
1122 	 * In both paths, we assume dnp->dn_reg already has the new value.
1123 	 */
1124 	if (dnp->dn_left->dn_kind == DT_NODE_VAR) {
1125 		idp = dt_ident_resolve(dnp->dn_left->dn_ident);
1126 
1127 		if (idp->di_kind == DT_IDENT_ARRAY)
1128 			dt_cg_arglist(idp, dnp->dn_left->dn_args, dlp, drp);
1129 
1130 		idp->di_flags |= DT_IDFLG_DIFW;
1131 		instr = DIF_INSTR_STV(dt_cg_stvar(idp),
1132 		    idp->di_id, dnp->dn_reg);
1133 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1134 	} else {
1135 		uint_t rbit = dnp->dn_left->dn_flags & DT_NF_REF;
1136 
1137 		assert(dnp->dn_left->dn_flags & DT_NF_WRITABLE);
1138 		assert(dnp->dn_left->dn_flags & DT_NF_LVALUE);
1139 
1140 		dnp->dn_left->dn_flags |= DT_NF_REF; /* force pass-by-ref */
1141 
1142 		dt_cg_node(dnp->dn_left, dlp, drp);
1143 		dt_cg_store(dnp, dlp, drp, dnp->dn_left);
1144 		dt_regset_free(drp, dnp->dn_left->dn_reg);
1145 
1146 		dnp->dn_left->dn_flags &= ~DT_NF_REF;
1147 		dnp->dn_left->dn_flags |= rbit;
1148 	}
1149 }
1150 
1151 static void
1152 dt_cg_assoc_op(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
1153 {
1154 	dif_instr_t instr;
1155 	uint_t op;
1156 
1157 	assert(dnp->dn_kind == DT_NODE_VAR);
1158 	assert(!(dnp->dn_ident->di_flags & DT_IDFLG_LOCAL));
1159 	assert(dnp->dn_args != NULL);
1160 
1161 	dt_cg_arglist(dnp->dn_ident, dnp->dn_args, dlp, drp);
1162 
1163 	dnp->dn_reg = dt_regset_alloc(drp);
1164 
1165 	if (dnp->dn_ident->di_flags & DT_IDFLG_TLS)
1166 		op = DIF_OP_LDTAA;
1167 	else
1168 		op = DIF_OP_LDGAA;
1169 
1170 	dnp->dn_ident->di_flags |= DT_IDFLG_DIFR;
1171 	instr = DIF_INSTR_LDV(op, dnp->dn_ident->di_id, dnp->dn_reg);
1172 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1173 
1174 	/*
1175 	 * If the associative array is a pass-by-reference type, then we are
1176 	 * loading its value as a pointer to either load or store through it.
1177 	 * The array element in question may not have been faulted in yet, in
1178 	 * which case DIF_OP_LD*AA will return zero.  We append an epilogue
1179 	 * of instructions similar to the following:
1180 	 *
1181 	 *	  ld?aa	 id, %r1	! base ld?aa instruction above
1182 	 *	  tst	 %r1		! start of epilogue
1183 	 *   +--- bne	 label
1184 	 *   |    setx	 size, %r1
1185 	 *   |    allocs %r1, %r1
1186 	 *   |    st?aa	 id, %r1
1187 	 *   |    ld?aa	 id, %r1
1188 	 *   v
1189 	 * label: < rest of code >
1190 	 *
1191 	 * The idea is that we allocs a zero-filled chunk of scratch space and
1192 	 * do a DIF_OP_ST*AA to fault in and initialize the array element, and
1193 	 * then reload it to get the faulted-in address of the new variable
1194 	 * storage.  This isn't cheap, but pass-by-ref associative array values
1195 	 * are (thus far) uncommon and the allocs cost only occurs once.  If
1196 	 * this path becomes important to DTrace users, we can improve things
1197 	 * by adding a new DIF opcode to fault in associative array elements.
1198 	 */
1199 	if (dnp->dn_flags & DT_NF_REF) {
1200 		uint_t stvop = op == DIF_OP_LDTAA ? DIF_OP_STTAA : DIF_OP_STGAA;
1201 		uint_t label = dt_irlist_label(dlp);
1202 
1203 		instr = DIF_INSTR_TST(dnp->dn_reg);
1204 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1205 
1206 		instr = DIF_INSTR_BRANCH(DIF_OP_BNE, label);
1207 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1208 
1209 		dt_cg_setx(dlp, dnp->dn_reg, dt_node_type_size(dnp));
1210 		instr = DIF_INSTR_ALLOCS(dnp->dn_reg, dnp->dn_reg);
1211 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1212 
1213 		dnp->dn_ident->di_flags |= DT_IDFLG_DIFW;
1214 		instr = DIF_INSTR_STV(stvop, dnp->dn_ident->di_id, dnp->dn_reg);
1215 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1216 
1217 		instr = DIF_INSTR_LDV(op, dnp->dn_ident->di_id, dnp->dn_reg);
1218 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1219 
1220 		dt_irlist_append(dlp, dt_cg_node_alloc(label, DIF_INSTR_NOP));
1221 	}
1222 }
1223 
1224 static void
1225 dt_cg_array_op(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
1226 {
1227 	dt_probe_t *prp = yypcb->pcb_probe;
1228 	uintmax_t saved = dnp->dn_args->dn_value;
1229 	dt_ident_t *idp = dnp->dn_ident;
1230 
1231 	dif_instr_t instr;
1232 	uint_t op;
1233 	size_t size;
1234 	int reg, n;
1235 
1236 	assert(dnp->dn_kind == DT_NODE_VAR);
1237 	assert(!(idp->di_flags & DT_IDFLG_LOCAL));
1238 
1239 	assert(dnp->dn_args->dn_kind == DT_NODE_INT);
1240 	assert(dnp->dn_args->dn_list == NULL);
1241 
1242 	/*
1243 	 * If this is a reference in the args[] array, temporarily modify the
1244 	 * array index according to the static argument mapping (if any),
1245 	 * unless the argument reference is provided by a dynamic translator.
1246 	 * If we're using a dynamic translator for args[], then just set dn_reg
1247 	 * to an invalid reg and return: DIF_OP_XLARG will fetch the arg later.
1248 	 */
1249 	if (idp->di_id == DIF_VAR_ARGS) {
1250 		if ((idp->di_kind == DT_IDENT_XLPTR ||
1251 		    idp->di_kind == DT_IDENT_XLSOU) &&
1252 		    dt_xlator_dynamic(idp->di_data)) {
1253 			dnp->dn_reg = -1;
1254 			return;
1255 		}
1256 		dnp->dn_args->dn_value = prp->pr_mapping[saved];
1257 	}
1258 
1259 	dt_cg_node(dnp->dn_args, dlp, drp);
1260 	dnp->dn_args->dn_value = saved;
1261 
1262 	dnp->dn_reg = dnp->dn_args->dn_reg;
1263 
1264 	if (idp->di_flags & DT_IDFLG_TLS)
1265 		op = DIF_OP_LDTA;
1266 	else
1267 		op = DIF_OP_LDGA;
1268 
1269 	idp->di_flags |= DT_IDFLG_DIFR;
1270 
1271 	instr = DIF_INSTR_LDA(op, idp->di_id,
1272 	    dnp->dn_args->dn_reg, dnp->dn_reg);
1273 
1274 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1275 
1276 	/*
1277 	 * If this is a reference to the args[] array, we need to take the
1278 	 * additional step of explicitly eliminating any bits larger than the
1279 	 * type size: the DIF interpreter in the kernel will always give us
1280 	 * the raw (64-bit) argument value, and any bits larger than the type
1281 	 * size may be junk.  As a practical matter, this arises only on 64-bit
1282 	 * architectures and only when the argument index is larger than the
1283 	 * number of arguments passed directly to DTrace: if a 8-, 16- or
1284 	 * 32-bit argument must be retrieved from the stack, it is possible
1285 	 * (and it some cases, likely) that the upper bits will be garbage.
1286 	 */
1287 	if (idp->di_id != DIF_VAR_ARGS || !dt_node_is_scalar(dnp))
1288 		return;
1289 
1290 	if ((size = dt_node_type_size(dnp)) == sizeof (uint64_t))
1291 		return;
1292 
1293 	reg = dt_regset_alloc(drp);
1294 	assert(size < sizeof (uint64_t));
1295 	n = sizeof (uint64_t) * NBBY - size * NBBY;
1296 
1297 	dt_cg_setx(dlp, reg, n);
1298 
1299 	instr = DIF_INSTR_FMT(DIF_OP_SLL, dnp->dn_reg, reg, dnp->dn_reg);
1300 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1301 
1302 	instr = DIF_INSTR_FMT((dnp->dn_flags & DT_NF_SIGNED) ?
1303 	    DIF_OP_SRA : DIF_OP_SRL, dnp->dn_reg, reg, dnp->dn_reg);
1304 
1305 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1306 	dt_regset_free(drp, reg);
1307 }
1308 
1309 /*
1310  * Generate code for an inlined variable reference.  Inlines can be used to
1311  * define either scalar or associative array substitutions.  For scalars, we
1312  * simply generate code for the parse tree saved in the identifier's din_root,
1313  * and then cast the resulting expression to the inline's declaration type.
1314  * For arrays, we take the input parameter subtrees from dnp->dn_args and
1315  * temporarily store them in the din_root of each din_argv[i] identifier,
1316  * which are themselves inlines and were set up for us by the parser.  The
1317  * result is that any reference to the inlined parameter inside the top-level
1318  * din_root will turn into a recursive call to dt_cg_inline() for a scalar
1319  * inline whose din_root will refer to the subtree pointed to by the argument.
1320  */
1321 static void
1322 dt_cg_inline(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
1323 {
1324 	dt_ident_t *idp = dnp->dn_ident;
1325 	dt_idnode_t *inp = idp->di_iarg;
1326 
1327 	dt_idnode_t *pinp;
1328 	dt_node_t *pnp;
1329 	int i;
1330 
1331 	assert(idp->di_flags & DT_IDFLG_INLINE);
1332 	assert(idp->di_ops == &dt_idops_inline);
1333 
1334 	if (idp->di_kind == DT_IDENT_ARRAY) {
1335 		for (i = 0, pnp = dnp->dn_args;
1336 		    pnp != NULL; pnp = pnp->dn_list, i++) {
1337 			if (inp->din_argv[i] != NULL) {
1338 				pinp = inp->din_argv[i]->di_iarg;
1339 				pinp->din_root = pnp;
1340 			}
1341 		}
1342 	}
1343 
1344 	dt_cg_node(inp->din_root, dlp, drp);
1345 	dnp->dn_reg = inp->din_root->dn_reg;
1346 	dt_cg_typecast(inp->din_root, dnp, dlp, drp);
1347 
1348 	if (idp->di_kind == DT_IDENT_ARRAY) {
1349 		for (i = 0; i < inp->din_argc; i++) {
1350 			pinp = inp->din_argv[i]->di_iarg;
1351 			pinp->din_root = NULL;
1352 		}
1353 	}
1354 }
1355 
1356 typedef struct dt_xlmemb {
1357 	dt_ident_t *dtxl_idp;		/* translated ident */
1358 	dt_irlist_t *dtxl_dlp;		/* instruction list */
1359 	dt_regset_t *dtxl_drp;		/* register set */
1360 	int dtxl_sreg;			/* location of the translation input */
1361 	int dtxl_dreg;			/* location of our allocated buffer */
1362 } dt_xlmemb_t;
1363 
1364 /*ARGSUSED*/
1365 static int
1366 dt_cg_xlate_member(const char *name, ctf_id_t type, ulong_t off, void *arg)
1367 {
1368 	dt_xlmemb_t *dx = arg;
1369 	dt_ident_t *idp = dx->dtxl_idp;
1370 	dt_irlist_t *dlp = dx->dtxl_dlp;
1371 	dt_regset_t *drp = dx->dtxl_drp;
1372 
1373 	dt_node_t *mnp;
1374 	dt_xlator_t *dxp;
1375 
1376 	int reg, treg;
1377 	uint32_t instr;
1378 	size_t size;
1379 
1380 	/* Generate code for the translation. */
1381 	dxp = idp->di_data;
1382 	mnp = dt_xlator_member(dxp, name);
1383 
1384 	/* If there's no translator for the given member, skip it. */
1385 	if (mnp == NULL)
1386 		return (0);
1387 
1388 	dxp->dx_ident->di_flags |= DT_IDFLG_CGREG;
1389 	dxp->dx_ident->di_id = dx->dtxl_sreg;
1390 
1391 	dt_cg_node(mnp->dn_membexpr, dlp, drp);
1392 
1393 	dxp->dx_ident->di_flags &= ~DT_IDFLG_CGREG;
1394 	dxp->dx_ident->di_id = 0;
1395 
1396 	treg = mnp->dn_membexpr->dn_reg;
1397 
1398 	/* Compute the offset into our buffer and store the result there. */
1399 	reg = dt_regset_alloc(drp);
1400 
1401 	dt_cg_setx(dlp, reg, off / NBBY);
1402 	instr = DIF_INSTR_FMT(DIF_OP_ADD, dx->dtxl_dreg, reg, reg);
1403 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1404 
1405 	size = ctf_type_size(mnp->dn_membexpr->dn_ctfp,
1406 	    mnp->dn_membexpr->dn_type);
1407 	if (dt_node_is_scalar(mnp->dn_membexpr)) {
1408 		/*
1409 		 * Copying scalars is simple.
1410 		 */
1411 		switch (size) {
1412 		case 1:
1413 			instr = DIF_INSTR_STORE(DIF_OP_STB, treg, reg);
1414 			break;
1415 		case 2:
1416 			instr = DIF_INSTR_STORE(DIF_OP_STH, treg, reg);
1417 			break;
1418 		case 4:
1419 			instr = DIF_INSTR_STORE(DIF_OP_STW, treg, reg);
1420 			break;
1421 		case 8:
1422 			instr = DIF_INSTR_STORE(DIF_OP_STX, treg, reg);
1423 			break;
1424 		default:
1425 			xyerror(D_UNKNOWN, "internal error -- unexpected "
1426 			    "size: %lu\n", (ulong_t)size);
1427 		}
1428 
1429 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1430 
1431 	} else if (dt_node_is_string(mnp->dn_membexpr)) {
1432 		int szreg;
1433 
1434 		/*
1435 		 * Use the copys instruction for strings.
1436 		 */
1437 		szreg = dt_regset_alloc(drp);
1438 		dt_cg_setx(dlp, szreg, size);
1439 		instr = DIF_INSTR_COPYS(treg, szreg, reg);
1440 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1441 		dt_regset_free(drp, szreg);
1442 	} else {
1443 		int szreg;
1444 
1445 		/*
1446 		 * If it's anything else then we'll just bcopy it.
1447 		 */
1448 		szreg = dt_regset_alloc(drp);
1449 		dt_cg_setx(dlp, szreg, size);
1450 		dt_irlist_append(dlp,
1451 		    dt_cg_node_alloc(DT_LBL_NONE, DIF_INSTR_FLUSHTS));
1452 		instr = DIF_INSTR_PUSHTS(DIF_OP_PUSHTV, DIF_TYPE_CTF,
1453 		    DIF_REG_R0, treg);
1454 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1455 		instr = DIF_INSTR_PUSHTS(DIF_OP_PUSHTV, DIF_TYPE_CTF,
1456 		    DIF_REG_R0, reg);
1457 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1458 		instr = DIF_INSTR_PUSHTS(DIF_OP_PUSHTV, DIF_TYPE_CTF,
1459 		    DIF_REG_R0, szreg);
1460 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1461 		instr = DIF_INSTR_CALL(DIF_SUBR_BCOPY, szreg);
1462 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1463 		dt_regset_free(drp, szreg);
1464 	}
1465 
1466 	dt_regset_free(drp, reg);
1467 	dt_regset_free(drp, treg);
1468 
1469 	return (0);
1470 }
1471 
1472 /*
1473  * If we're expanding a translated type, we create an appropriately sized
1474  * buffer with alloca() and then translate each member into it.
1475  */
1476 static int
1477 dt_cg_xlate_expand(dt_node_t *dnp, dt_ident_t *idp, dt_irlist_t *dlp,
1478     dt_regset_t *drp)
1479 {
1480 	dt_xlmemb_t dlm;
1481 	uint32_t instr;
1482 	int dreg;
1483 	size_t size;
1484 
1485 	dreg = dt_regset_alloc(drp);
1486 	size = ctf_type_size(dnp->dn_ident->di_ctfp, dnp->dn_ident->di_type);
1487 
1488 	/* Call alloca() to create the buffer. */
1489 	dt_cg_setx(dlp, dreg, size);
1490 
1491 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, DIF_INSTR_FLUSHTS));
1492 
1493 	instr = DIF_INSTR_PUSHTS(DIF_OP_PUSHTV, DIF_TYPE_CTF, DIF_REG_R0, dreg);
1494 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1495 
1496 	instr = DIF_INSTR_CALL(DIF_SUBR_ALLOCA, dreg);
1497 	dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1498 
1499 	/* Generate the translation for each member. */
1500 	dlm.dtxl_idp = idp;
1501 	dlm.dtxl_dlp = dlp;
1502 	dlm.dtxl_drp = drp;
1503 	dlm.dtxl_sreg = dnp->dn_reg;
1504 	dlm.dtxl_dreg = dreg;
1505 	(void) ctf_member_iter(dnp->dn_ident->di_ctfp,
1506 	    dnp->dn_ident->di_type, dt_cg_xlate_member,
1507 	    &dlm);
1508 
1509 	return (dreg);
1510 }
1511 
1512 static void
1513 dt_cg_node(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
1514 {
1515 	ctf_file_t *ctfp = dnp->dn_ctfp;
1516 	ctf_file_t *octfp;
1517 	ctf_membinfo_t m;
1518 	ctf_id_t type;
1519 
1520 	dif_instr_t instr;
1521 	dt_ident_t *idp;
1522 	ssize_t stroff;
1523 	uint_t op;
1524 
1525 	switch (dnp->dn_op) {
1526 	case DT_TOK_COMMA:
1527 		dt_cg_node(dnp->dn_left, dlp, drp);
1528 		dt_regset_free(drp, dnp->dn_left->dn_reg);
1529 		dt_cg_node(dnp->dn_right, dlp, drp);
1530 		dnp->dn_reg = dnp->dn_right->dn_reg;
1531 		break;
1532 
1533 	case DT_TOK_ASGN:
1534 		dt_cg_node(dnp->dn_right, dlp, drp);
1535 		dnp->dn_reg = dnp->dn_right->dn_reg;
1536 		dt_cg_asgn_op(dnp, dlp, drp);
1537 		break;
1538 
1539 	case DT_TOK_ADD_EQ:
1540 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_ADD);
1541 		dt_cg_asgn_op(dnp, dlp, drp);
1542 		break;
1543 
1544 	case DT_TOK_SUB_EQ:
1545 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_SUB);
1546 		dt_cg_asgn_op(dnp, dlp, drp);
1547 		break;
1548 
1549 	case DT_TOK_MUL_EQ:
1550 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_MUL);
1551 		dt_cg_asgn_op(dnp, dlp, drp);
1552 		break;
1553 
1554 	case DT_TOK_DIV_EQ:
1555 		dt_cg_arithmetic_op(dnp, dlp, drp,
1556 		    (dnp->dn_flags & DT_NF_SIGNED) ? DIF_OP_SDIV : DIF_OP_UDIV);
1557 		dt_cg_asgn_op(dnp, dlp, drp);
1558 		break;
1559 
1560 	case DT_TOK_MOD_EQ:
1561 		dt_cg_arithmetic_op(dnp, dlp, drp,
1562 		    (dnp->dn_flags & DT_NF_SIGNED) ? DIF_OP_SREM : DIF_OP_UREM);
1563 		dt_cg_asgn_op(dnp, dlp, drp);
1564 		break;
1565 
1566 	case DT_TOK_AND_EQ:
1567 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_AND);
1568 		dt_cg_asgn_op(dnp, dlp, drp);
1569 		break;
1570 
1571 	case DT_TOK_XOR_EQ:
1572 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_XOR);
1573 		dt_cg_asgn_op(dnp, dlp, drp);
1574 		break;
1575 
1576 	case DT_TOK_OR_EQ:
1577 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_OR);
1578 		dt_cg_asgn_op(dnp, dlp, drp);
1579 		break;
1580 
1581 	case DT_TOK_LSH_EQ:
1582 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_SLL);
1583 		dt_cg_asgn_op(dnp, dlp, drp);
1584 		break;
1585 
1586 	case DT_TOK_RSH_EQ:
1587 		dt_cg_arithmetic_op(dnp, dlp, drp,
1588 		    (dnp->dn_flags & DT_NF_SIGNED) ? DIF_OP_SRA : DIF_OP_SRL);
1589 		dt_cg_asgn_op(dnp, dlp, drp);
1590 		break;
1591 
1592 	case DT_TOK_QUESTION:
1593 		dt_cg_ternary_op(dnp, dlp, drp);
1594 		break;
1595 
1596 	case DT_TOK_LOR:
1597 		dt_cg_logical_or(dnp, dlp, drp);
1598 		break;
1599 
1600 	case DT_TOK_LXOR:
1601 		dt_cg_logical_xor(dnp, dlp, drp);
1602 		break;
1603 
1604 	case DT_TOK_LAND:
1605 		dt_cg_logical_and(dnp, dlp, drp);
1606 		break;
1607 
1608 	case DT_TOK_BOR:
1609 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_OR);
1610 		break;
1611 
1612 	case DT_TOK_XOR:
1613 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_XOR);
1614 		break;
1615 
1616 	case DT_TOK_BAND:
1617 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_AND);
1618 		break;
1619 
1620 	case DT_TOK_EQU:
1621 		dt_cg_compare_op(dnp, dlp, drp, DIF_OP_BE);
1622 		break;
1623 
1624 	case DT_TOK_NEQ:
1625 		dt_cg_compare_op(dnp, dlp, drp, DIF_OP_BNE);
1626 		break;
1627 
1628 	case DT_TOK_LT:
1629 		dt_cg_compare_op(dnp, dlp, drp,
1630 		    dt_cg_compare_signed(dnp) ? DIF_OP_BL : DIF_OP_BLU);
1631 		break;
1632 
1633 	case DT_TOK_LE:
1634 		dt_cg_compare_op(dnp, dlp, drp,
1635 		    dt_cg_compare_signed(dnp) ? DIF_OP_BLE : DIF_OP_BLEU);
1636 		break;
1637 
1638 	case DT_TOK_GT:
1639 		dt_cg_compare_op(dnp, dlp, drp,
1640 		    dt_cg_compare_signed(dnp) ? DIF_OP_BG : DIF_OP_BGU);
1641 		break;
1642 
1643 	case DT_TOK_GE:
1644 		dt_cg_compare_op(dnp, dlp, drp,
1645 		    dt_cg_compare_signed(dnp) ? DIF_OP_BGE : DIF_OP_BGEU);
1646 		break;
1647 
1648 	case DT_TOK_LSH:
1649 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_SLL);
1650 		break;
1651 
1652 	case DT_TOK_RSH:
1653 		dt_cg_arithmetic_op(dnp, dlp, drp,
1654 		    (dnp->dn_flags & DT_NF_SIGNED) ? DIF_OP_SRA : DIF_OP_SRL);
1655 		break;
1656 
1657 	case DT_TOK_ADD:
1658 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_ADD);
1659 		break;
1660 
1661 	case DT_TOK_SUB:
1662 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_SUB);
1663 		break;
1664 
1665 	case DT_TOK_MUL:
1666 		dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_MUL);
1667 		break;
1668 
1669 	case DT_TOK_DIV:
1670 		dt_cg_arithmetic_op(dnp, dlp, drp,
1671 		    (dnp->dn_flags & DT_NF_SIGNED) ? DIF_OP_SDIV : DIF_OP_UDIV);
1672 		break;
1673 
1674 	case DT_TOK_MOD:
1675 		dt_cg_arithmetic_op(dnp, dlp, drp,
1676 		    (dnp->dn_flags & DT_NF_SIGNED) ? DIF_OP_SREM : DIF_OP_UREM);
1677 		break;
1678 
1679 	case DT_TOK_LNEG:
1680 		dt_cg_logical_neg(dnp, dlp, drp);
1681 		break;
1682 
1683 	case DT_TOK_BNEG:
1684 		dt_cg_node(dnp->dn_child, dlp, drp);
1685 		dnp->dn_reg = dnp->dn_child->dn_reg;
1686 		instr = DIF_INSTR_NOT(dnp->dn_reg, dnp->dn_reg);
1687 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1688 		break;
1689 
1690 	case DT_TOK_PREINC:
1691 		dt_cg_prearith_op(dnp, dlp, drp, DIF_OP_ADD);
1692 		break;
1693 
1694 	case DT_TOK_POSTINC:
1695 		dt_cg_postarith_op(dnp, dlp, drp, DIF_OP_ADD);
1696 		break;
1697 
1698 	case DT_TOK_PREDEC:
1699 		dt_cg_prearith_op(dnp, dlp, drp, DIF_OP_SUB);
1700 		break;
1701 
1702 	case DT_TOK_POSTDEC:
1703 		dt_cg_postarith_op(dnp, dlp, drp, DIF_OP_SUB);
1704 		break;
1705 
1706 	case DT_TOK_IPOS:
1707 		dt_cg_node(dnp->dn_child, dlp, drp);
1708 		dnp->dn_reg = dnp->dn_child->dn_reg;
1709 		break;
1710 
1711 	case DT_TOK_INEG:
1712 		dt_cg_node(dnp->dn_child, dlp, drp);
1713 		dnp->dn_reg = dnp->dn_child->dn_reg;
1714 
1715 		instr = DIF_INSTR_FMT(DIF_OP_SUB, DIF_REG_R0,
1716 		    dnp->dn_reg, dnp->dn_reg);
1717 
1718 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1719 		break;
1720 
1721 	case DT_TOK_DEREF:
1722 		dt_cg_node(dnp->dn_child, dlp, drp);
1723 		dnp->dn_reg = dnp->dn_child->dn_reg;
1724 
1725 		if (dt_node_is_dynamic(dnp->dn_child)) {
1726 			int reg;
1727 			idp = dt_node_resolve(dnp->dn_child, DT_IDENT_XLPTR);
1728 			assert(idp != NULL);
1729 			reg = dt_cg_xlate_expand(dnp, idp, dlp, drp);
1730 
1731 			dt_regset_free(drp, dnp->dn_child->dn_reg);
1732 			dnp->dn_reg = reg;
1733 
1734 		} else if (!(dnp->dn_flags & DT_NF_REF)) {
1735 			uint_t ubit = dnp->dn_flags & DT_NF_USERLAND;
1736 
1737 			/*
1738 			 * Save and restore DT_NF_USERLAND across dt_cg_load():
1739 			 * we need the sign bit from dnp and the user bit from
1740 			 * dnp->dn_child in order to get the proper opcode.
1741 			 */
1742 			dnp->dn_flags |=
1743 			    (dnp->dn_child->dn_flags & DT_NF_USERLAND);
1744 
1745 			instr = DIF_INSTR_LOAD(dt_cg_load(dnp, ctfp,
1746 			    dnp->dn_type), dnp->dn_reg, dnp->dn_reg);
1747 
1748 			dnp->dn_flags &= ~DT_NF_USERLAND;
1749 			dnp->dn_flags |= ubit;
1750 
1751 			dt_irlist_append(dlp,
1752 			    dt_cg_node_alloc(DT_LBL_NONE, instr));
1753 		}
1754 		break;
1755 
1756 	case DT_TOK_ADDROF: {
1757 		uint_t rbit = dnp->dn_child->dn_flags & DT_NF_REF;
1758 
1759 		dnp->dn_child->dn_flags |= DT_NF_REF; /* force pass-by-ref */
1760 		dt_cg_node(dnp->dn_child, dlp, drp);
1761 		dnp->dn_reg = dnp->dn_child->dn_reg;
1762 
1763 		dnp->dn_child->dn_flags &= ~DT_NF_REF;
1764 		dnp->dn_child->dn_flags |= rbit;
1765 		break;
1766 	}
1767 
1768 	case DT_TOK_SIZEOF: {
1769 		size_t size = dt_node_sizeof(dnp->dn_child);
1770 		dnp->dn_reg = dt_regset_alloc(drp);
1771 		assert(size != 0);
1772 		dt_cg_setx(dlp, dnp->dn_reg, size);
1773 		break;
1774 	}
1775 
1776 	case DT_TOK_STRINGOF:
1777 		dt_cg_node(dnp->dn_child, dlp, drp);
1778 		dnp->dn_reg = dnp->dn_child->dn_reg;
1779 		break;
1780 
1781 	case DT_TOK_XLATE:
1782 		/*
1783 		 * An xlate operator appears in either an XLATOR, indicating a
1784 		 * reference to a dynamic translator, or an OP2, indicating
1785 		 * use of the xlate operator in the user's program.  For the
1786 		 * dynamic case, generate an xlate opcode with a reference to
1787 		 * the corresponding member, pre-computed for us in dn_members.
1788 		 */
1789 		if (dnp->dn_kind == DT_NODE_XLATOR) {
1790 			dt_xlator_t *dxp = dnp->dn_xlator;
1791 
1792 			assert(dxp->dx_ident->di_flags & DT_IDFLG_CGREG);
1793 			assert(dxp->dx_ident->di_id != 0);
1794 
1795 			dnp->dn_reg = dt_regset_alloc(drp);
1796 
1797 			if (dxp->dx_arg == -1) {
1798 				instr = DIF_INSTR_MOV(
1799 				    dxp->dx_ident->di_id, dnp->dn_reg);
1800 				dt_irlist_append(dlp,
1801 				    dt_cg_node_alloc(DT_LBL_NONE, instr));
1802 				op = DIF_OP_XLATE;
1803 			} else
1804 				op = DIF_OP_XLARG;
1805 
1806 			instr = DIF_INSTR_XLATE(op, 0, dnp->dn_reg);
1807 			dt_irlist_append(dlp,
1808 			    dt_cg_node_alloc(DT_LBL_NONE, instr));
1809 
1810 			dlp->dl_last->di_extern = dnp->dn_xmember;
1811 			break;
1812 		}
1813 
1814 		assert(dnp->dn_kind == DT_NODE_OP2);
1815 		dt_cg_node(dnp->dn_right, dlp, drp);
1816 		dnp->dn_reg = dnp->dn_right->dn_reg;
1817 		break;
1818 
1819 	case DT_TOK_LPAR:
1820 		dt_cg_node(dnp->dn_right, dlp, drp);
1821 		dnp->dn_reg = dnp->dn_right->dn_reg;
1822 		dt_cg_typecast(dnp->dn_right, dnp, dlp, drp);
1823 		break;
1824 
1825 	case DT_TOK_PTR:
1826 	case DT_TOK_DOT:
1827 		assert(dnp->dn_right->dn_kind == DT_NODE_IDENT);
1828 		dt_cg_node(dnp->dn_left, dlp, drp);
1829 
1830 		/*
1831 		 * If the left-hand side of PTR or DOT is a dynamic variable,
1832 		 * we expect it to be the output of a D translator.   In this
1833 		 * case, we look up the parse tree corresponding to the member
1834 		 * that is being accessed and run the code generator over it.
1835 		 * We then cast the result as if by the assignment operator.
1836 		 */
1837 		if ((idp = dt_node_resolve(
1838 		    dnp->dn_left, DT_IDENT_XLSOU)) != NULL ||
1839 		    (idp = dt_node_resolve(
1840 		    dnp->dn_left, DT_IDENT_XLPTR)) != NULL) {
1841 
1842 			dt_xlator_t *dxp;
1843 			dt_node_t *mnp;
1844 
1845 			dxp = idp->di_data;
1846 			mnp = dt_xlator_member(dxp, dnp->dn_right->dn_string);
1847 			assert(mnp != NULL);
1848 
1849 			dxp->dx_ident->di_flags |= DT_IDFLG_CGREG;
1850 			dxp->dx_ident->di_id = dnp->dn_left->dn_reg;
1851 
1852 			dt_cg_node(mnp->dn_membexpr, dlp, drp);
1853 			dnp->dn_reg = mnp->dn_membexpr->dn_reg;
1854 			dt_cg_typecast(mnp->dn_membexpr, dnp, dlp, drp);
1855 
1856 			dxp->dx_ident->di_flags &= ~DT_IDFLG_CGREG;
1857 			dxp->dx_ident->di_id = 0;
1858 
1859 			if (dnp->dn_left->dn_reg != -1)
1860 				dt_regset_free(drp, dnp->dn_left->dn_reg);
1861 			break;
1862 		}
1863 
1864 		ctfp = dnp->dn_left->dn_ctfp;
1865 		type = ctf_type_resolve(ctfp, dnp->dn_left->dn_type);
1866 
1867 		if (dnp->dn_op == DT_TOK_PTR) {
1868 			type = ctf_type_reference(ctfp, type);
1869 			type = ctf_type_resolve(ctfp, type);
1870 		}
1871 
1872 		if ((ctfp = dt_cg_membinfo(octfp = ctfp, type,
1873 		    dnp->dn_right->dn_string, &m)) == NULL) {
1874 			yypcb->pcb_hdl->dt_ctferr = ctf_errno(octfp);
1875 			longjmp(yypcb->pcb_jmpbuf, EDT_CTF);
1876 		}
1877 
1878 		if (m.ctm_offset != 0) {
1879 			int reg;
1880 
1881 			reg = dt_regset_alloc(drp);
1882 
1883 			/*
1884 			 * If the offset is not aligned on a byte boundary, it
1885 			 * is a bit-field member and we will extract the value
1886 			 * bits below after we generate the appropriate load.
1887 			 */
1888 			dt_cg_setx(dlp, reg, m.ctm_offset / NBBY);
1889 
1890 			instr = DIF_INSTR_FMT(DIF_OP_ADD,
1891 			    dnp->dn_left->dn_reg, reg, dnp->dn_left->dn_reg);
1892 
1893 			dt_irlist_append(dlp,
1894 			    dt_cg_node_alloc(DT_LBL_NONE, instr));
1895 			dt_regset_free(drp, reg);
1896 		}
1897 
1898 		if (!(dnp->dn_flags & DT_NF_REF)) {
1899 			uint_t ubit = dnp->dn_flags & DT_NF_USERLAND;
1900 
1901 			/*
1902 			 * Save and restore DT_NF_USERLAND across dt_cg_load():
1903 			 * we need the sign bit from dnp and the user bit from
1904 			 * dnp->dn_left in order to get the proper opcode.
1905 			 */
1906 			dnp->dn_flags |=
1907 			    (dnp->dn_left->dn_flags & DT_NF_USERLAND);
1908 
1909 			instr = DIF_INSTR_LOAD(dt_cg_load(dnp,
1910 			    ctfp, m.ctm_type), dnp->dn_left->dn_reg,
1911 			    dnp->dn_left->dn_reg);
1912 
1913 			dnp->dn_flags &= ~DT_NF_USERLAND;
1914 			dnp->dn_flags |= ubit;
1915 
1916 			dt_irlist_append(dlp,
1917 			    dt_cg_node_alloc(DT_LBL_NONE, instr));
1918 
1919 			if (dnp->dn_flags & DT_NF_BITFIELD)
1920 				dt_cg_field_get(dnp, dlp, drp, ctfp, &m);
1921 		}
1922 
1923 		dnp->dn_reg = dnp->dn_left->dn_reg;
1924 		break;
1925 
1926 	case DT_TOK_STRING:
1927 		dnp->dn_reg = dt_regset_alloc(drp);
1928 
1929 		assert(dnp->dn_kind == DT_NODE_STRING);
1930 		stroff = dt_strtab_insert(yypcb->pcb_strtab, dnp->dn_string);
1931 
1932 		if (stroff == -1L)
1933 			longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);
1934 		if (stroff > DIF_STROFF_MAX)
1935 			longjmp(yypcb->pcb_jmpbuf, EDT_STR2BIG);
1936 
1937 		instr = DIF_INSTR_SETS((ulong_t)stroff, dnp->dn_reg);
1938 		dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
1939 		break;
1940 
1941 	case DT_TOK_IDENT:
1942 		/*
1943 		 * If the specified identifier is a variable on which we have
1944 		 * set the code generator register flag, then this variable
1945 		 * has already had code generated for it and saved in di_id.
1946 		 * Allocate a new register and copy the existing value to it.
1947 		 */
1948 		if (dnp->dn_kind == DT_NODE_VAR &&
1949 		    (dnp->dn_ident->di_flags & DT_IDFLG_CGREG)) {
1950 			dnp->dn_reg = dt_regset_alloc(drp);
1951 			instr = DIF_INSTR_MOV(dnp->dn_ident->di_id,
1952 			    dnp->dn_reg);
1953 			dt_irlist_append(dlp,
1954 			    dt_cg_node_alloc(DT_LBL_NONE, instr));
1955 			break;
1956 		}
1957 
1958 		/*
1959 		 * Identifiers can represent function calls, variable refs, or
1960 		 * symbols.  First we check for inlined variables, and handle
1961 		 * them by generating code for the inline parse tree.
1962 		 */
1963 		if (dnp->dn_kind == DT_NODE_VAR &&
1964 		    (dnp->dn_ident->di_flags & DT_IDFLG_INLINE)) {
1965 			dt_cg_inline(dnp, dlp, drp);
1966 			break;
1967 		}
1968 
1969 		switch (dnp->dn_kind) {
1970 		case DT_NODE_FUNC:
1971 			if ((idp = dnp->dn_ident)->di_kind != DT_IDENT_FUNC) {
1972 				dnerror(dnp, D_CG_EXPR, "%s %s( ) may not be "
1973 				    "called from a D expression (D program "
1974 				    "context required)\n",
1975 				    dt_idkind_name(idp->di_kind), idp->di_name);
1976 			}
1977 
1978 			dt_cg_arglist(dnp->dn_ident, dnp->dn_args, dlp, drp);
1979 
1980 			dnp->dn_reg = dt_regset_alloc(drp);
1981 			instr = DIF_INSTR_CALL(dnp->dn_ident->di_id,
1982 			    dnp->dn_reg);
1983 
1984 			dt_irlist_append(dlp,
1985 			    dt_cg_node_alloc(DT_LBL_NONE, instr));
1986 
1987 			break;
1988 
1989 		case DT_NODE_VAR:
1990 			if (dnp->dn_ident->di_kind == DT_IDENT_XLSOU ||
1991 			    dnp->dn_ident->di_kind == DT_IDENT_XLPTR) {
1992 				/*
1993 				 * This can only happen if we have translated
1994 				 * args[].  See dt_idcook_args() for details.
1995 				 */
1996 				assert(dnp->dn_ident->di_id == DIF_VAR_ARGS);
1997 				dt_cg_array_op(dnp, dlp, drp);
1998 				break;
1999 			}
2000 
2001 			if (dnp->dn_ident->di_kind == DT_IDENT_ARRAY) {
2002 				if (dnp->dn_ident->di_id > DIF_VAR_ARRAY_MAX)
2003 					dt_cg_assoc_op(dnp, dlp, drp);
2004 				else
2005 					dt_cg_array_op(dnp, dlp, drp);
2006 				break;
2007 			}
2008 
2009 			dnp->dn_reg = dt_regset_alloc(drp);
2010 
2011 			if (dnp->dn_ident->di_flags & DT_IDFLG_LOCAL)
2012 				op = DIF_OP_LDLS;
2013 			else if (dnp->dn_ident->di_flags & DT_IDFLG_TLS)
2014 				op = DIF_OP_LDTS;
2015 			else
2016 				op = DIF_OP_LDGS;
2017 
2018 			dnp->dn_ident->di_flags |= DT_IDFLG_DIFR;
2019 
2020 			instr = DIF_INSTR_LDV(op,
2021 			    dnp->dn_ident->di_id, dnp->dn_reg);
2022 
2023 			dt_irlist_append(dlp,
2024 			    dt_cg_node_alloc(DT_LBL_NONE, instr));
2025 			break;
2026 
2027 		case DT_NODE_SYM: {
2028 			dtrace_hdl_t *dtp = yypcb->pcb_hdl;
2029 			dtrace_syminfo_t *sip = dnp->dn_ident->di_data;
2030 			GElf_Sym sym;
2031 
2032 			if (dtrace_lookup_by_name(dtp,
2033 			    sip->dts_object, sip->dts_name, &sym, NULL) == -1) {
2034 				xyerror(D_UNKNOWN, "cg failed for symbol %s`%s:"
2035 				    " %s\n", sip->dts_object, sip->dts_name,
2036 				    dtrace_errmsg(dtp, dtrace_errno(dtp)));
2037 			}
2038 
2039 			dnp->dn_reg = dt_regset_alloc(drp);
2040 			dt_cg_xsetx(dlp, dnp->dn_ident,
2041 			    DT_LBL_NONE, dnp->dn_reg, sym.st_value);
2042 
2043 			if (!(dnp->dn_flags & DT_NF_REF)) {
2044 				instr = DIF_INSTR_LOAD(dt_cg_load(dnp, ctfp,
2045 				    dnp->dn_type), dnp->dn_reg, dnp->dn_reg);
2046 				dt_irlist_append(dlp,
2047 				    dt_cg_node_alloc(DT_LBL_NONE, instr));
2048 			}
2049 			break;
2050 		}
2051 
2052 		default:
2053 			xyerror(D_UNKNOWN, "internal error -- node type %u is "
2054 			    "not valid for an identifier\n", dnp->dn_kind);
2055 		}
2056 		break;
2057 
2058 	case DT_TOK_INT:
2059 		dnp->dn_reg = dt_regset_alloc(drp);
2060 		dt_cg_setx(dlp, dnp->dn_reg, dnp->dn_value);
2061 		break;
2062 
2063 	default:
2064 		xyerror(D_UNKNOWN, "internal error -- token type %u is not a "
2065 		    "valid D compilation token\n", dnp->dn_op);
2066 	}
2067 }
2068 
2069 void
2070 dt_cg(dt_pcb_t *pcb, dt_node_t *dnp)
2071 {
2072 	dif_instr_t instr;
2073 	dt_xlator_t *dxp;
2074 	dt_ident_t *idp;
2075 
2076 	if (pcb->pcb_regs == NULL && (pcb->pcb_regs =
2077 	    dt_regset_create(pcb->pcb_hdl->dt_conf.dtc_difintregs)) == NULL)
2078 		longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
2079 
2080 	dt_regset_reset(pcb->pcb_regs);
2081 	(void) dt_regset_alloc(pcb->pcb_regs); /* allocate %r0 */
2082 
2083 	if (pcb->pcb_inttab != NULL)
2084 		dt_inttab_destroy(pcb->pcb_inttab);
2085 
2086 	if ((pcb->pcb_inttab = dt_inttab_create(yypcb->pcb_hdl)) == NULL)
2087 		longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
2088 
2089 	if (pcb->pcb_strtab != NULL)
2090 		dt_strtab_destroy(pcb->pcb_strtab);
2091 
2092 	if ((pcb->pcb_strtab = dt_strtab_create(BUFSIZ)) == NULL)
2093 		longjmp(pcb->pcb_jmpbuf, EDT_NOMEM);
2094 
2095 	dt_irlist_destroy(&pcb->pcb_ir);
2096 	dt_irlist_create(&pcb->pcb_ir);
2097 
2098 	assert(pcb->pcb_dret == NULL);
2099 	pcb->pcb_dret = dnp;
2100 
2101 	if (dt_node_resolve(dnp, DT_IDENT_XLPTR) != NULL) {
2102 		dnerror(dnp, D_CG_DYN, "expression cannot evaluate to result "
2103 		    "of a translated pointer\n");
2104 	}
2105 
2106 	/*
2107 	 * If we're generating code for a translator body, assign the input
2108 	 * parameter to the first available register (i.e. caller passes %r1).
2109 	 */
2110 	if (dnp->dn_kind == DT_NODE_MEMBER) {
2111 		dxp = dnp->dn_membxlator;
2112 		dnp = dnp->dn_membexpr;
2113 
2114 		dxp->dx_ident->di_flags |= DT_IDFLG_CGREG;
2115 		dxp->dx_ident->di_id = dt_regset_alloc(pcb->pcb_regs);
2116 	}
2117 
2118 	dt_cg_node(dnp, &pcb->pcb_ir, pcb->pcb_regs);
2119 
2120 	if ((idp = dt_node_resolve(dnp, DT_IDENT_XLSOU)) != NULL) {
2121 		int reg = dt_cg_xlate_expand(dnp, idp,
2122 		    &pcb->pcb_ir, pcb->pcb_regs);
2123 		dt_regset_free(pcb->pcb_regs, dnp->dn_reg);
2124 		dnp->dn_reg = reg;
2125 	}
2126 
2127 	instr = DIF_INSTR_RET(dnp->dn_reg);
2128 	dt_regset_free(pcb->pcb_regs, dnp->dn_reg);
2129 	dt_irlist_append(&pcb->pcb_ir, dt_cg_node_alloc(DT_LBL_NONE, instr));
2130 
2131 	if (dnp->dn_kind == DT_NODE_MEMBER) {
2132 		dt_regset_free(pcb->pcb_regs, dxp->dx_ident->di_id);
2133 		dxp->dx_ident->di_id = 0;
2134 		dxp->dx_ident->di_flags &= ~DT_IDFLG_CGREG;
2135 	}
2136 
2137 	dt_regset_free(pcb->pcb_regs, 0);
2138 	dt_regset_assert_free(pcb->pcb_regs);
2139 }
2140