arm.c

   1 #include <string.h>
   2 #include "tok.h"
   3 #include "gen.h"
   4 #include "out.h"
   5
   6 #define MIN(a, b)               ((a) < (b) ? (a) : (b))
   7 #define ALIGN(x, a)             (((x) + (a) - 1) & ~((a) - 1))
   8 #define oi4(i)                  oi((i), 4)
   9
  10 #define REG_DP          10      /* data pointer register */
  11 #define REG_TMP         12      /* temporary register */
  12 #define REG_LR          14      /* link register */
  13 #define REG_PC          15      /* program counter */
  14
  15 #define I_AND           0x00
  16 #define I_EOR           0x01
  17 #define I_SUB           0x02
  18 #define I_RSB           0x03
  19 #define I_ADD           0x04
  20 #define I_TST           0x08
  21 #define I_CMP           0x0a
  22 #define I_ORR           0x0c
  23 #define I_MOV           0x0d
  24 #define I_MVN           0x0f
  25
  26 int tmpregs[] = {4, 5, 6, 7, 8, 9, 3, 2, 1, 0};
  27 int argregs[] = {0, 1, 2, 3};
  28
  29 /* compiled division functions; div.s contains the source */
  30 static int udivdi3[] = {
  31         0xe3a02000, 0xe3a03000, 0xe1110001, 0x0a00000a,
  32         0xe1b0c211, 0xe2822001, 0x5afffffc, 0xe3a0c001,
  33         0xe2522001, 0x4a000004, 0xe1500211, 0x3afffffb,
  34         0xe0400211, 0xe083321c, 0xeafffff8, 0xe1a01000,
  35         0xe1a00003, 0xe1a0f00e,
  36 };
  37 static int umoddi3[] = {
  38         0xe92d4000, 0xebffffeb, 0xe1a00001, 0xe8bd8000,
  39 };
  40 static int divdi3[] = {
  41         0xe92d4030, 0xe1a04000, 0xe1a05001, 0xe1100000,
  42         0x42600000, 0xe1110001, 0x42611000, 0xebffffe1,
  43         0xe1340005, 0x42600000, 0xe1140004, 0x42611000,
  44         0xe8bd8030,
  45 };
  46 static int moddi3[] = {
  47         0xe92d4000, 0xebfffff0, 0xe1a00001, 0xe8bd8000,
  48 };
  49
  50 /* output div/mod functions */
  51 static int putdiv = 0;
  52
  53 static void insert_spsub(void);
  54
  55 static void i_div(char *func)
  56 {
  57         putdiv = 1;
  58         insert_spsub();
  59         i_call(func, 0);
  60 }
  61
  62 void i_done(void)
  63 {
  64         if (putdiv) {
  65                 out_sym("__udivdi3", OUT_CS, cslen, 0);
  66                 os(udivdi3, sizeof(udivdi3));
  67                 out_sym("__umoddi3", OUT_CS, cslen, 0);
  68                 os(umoddi3, sizeof(umoddi3));
  69                 out_sym("__divdi3", OUT_CS, cslen, 0);
  70                 os(divdi3, sizeof(divdi3));
  71                 out_sym("__moddi3", OUT_CS, cslen, 0);
  72                 os(moddi3, sizeof(moddi3));
  73         }
  74 }
  75
  76 /* for optimizing cmp + bcc */
  77 #define OPT_ISCMP()             (last_cmp + 12 == cslen && last_set + 4 == cslen)
  78 #define OPT_CCOND()             (*(unsigned int *) ((void *) cs + last_set) >> 28)
  79
  80 static long last_cmp = -1;
  81 static long last_set = -1;
  82
  83 #define MAXNUMS         1024
  84
  85 /* data pool */
  86 static long num_offs[MAXNUMS];                  /* data immediate value */
  87 static char num_names[MAXNUMS][NAMELEN];        /* relocation data symbol name */
  88 static int nums;
  89
  90 static int pool_find(char *name, int off)
  91 {
  92         int i;
  93         for (i = 0; i < nums; i++)
  94                 if (!strcmp(name, num_names[i]) && off == num_offs[i])
  95                         return i;
  96         return -1;
  97 }
  98
  99 static int pool_num(long num)
 100 {
 101         int idx = pool_find("", num);
 102         if (idx < 0) {
 103                 idx = nums++;
 104                 num_offs[idx] = num;
 105                 num_names[idx][0] = '\0';
 106         }
 107         return idx << 2;
 108 }
 109
 110 static int pool_reloc(char *name, long off)
 111 {
 112         int idx = pool_find(name, off);
 113         if (idx < 0) {
 114                 idx = nums++;
 115                 num_offs[idx] = off;
 116                 strcpy(num_names[idx], name);
 117         }
 118         return idx << 2;
 119 }
 120
 121 static void pool_write(void)
 122 {
 123         int i;
 124         for (i = 0; i < nums; i++) {
 125                 if (num_names[i] && !pass1)
 126                         out_rel(num_names[i], OUT_CS, cslen);
 127                 oi4(num_offs[i]);
 128         }
 129 }
 130
 131 /*
 132  * data processing:
 133  * +---------------------------------------+
 134  * |COND|00|I| op |S| Rn | Rd |  operand2  |
 135  * +---------------------------------------+
 136  *
 137  * S: set condition code
 138  * Rn: first operand
 139  * Rd: destination operand
 140  *
 141  * I=0 operand2=| shift  | Rm |
 142  * I=1 operand2=|rota|  imm   |
 143  */
 144 #define ADD(op, rd, rn, s, i, cond)     \
 145         (((cond) << 28) | ((i) << 25) | ((s) << 20) | \
 146                 ((op) << 21) | ((rn) << 16) | ((rd) << 12))
 147
 148 static int add_encimm(unsigned n)
 149 {
 150         int i = 0;
 151         while (i < 12 && (n >> ((4 + i) << 1)))
 152                 i++;
 153         return (n >> (i << 1)) | (((16 - i) & 0x0f) << 8);
 154 }
 155
 156 static unsigned add_decimm(int n)
 157 {
 158         int rot = (16 - ((n >> 8) & 0x0f)) & 0x0f;
 159         return (n & 0xff) << (rot << 1);
 160 }
 161
 162 static int add_rndimm(unsigned n)
 163 {
 164         int rot = (n >> 8) & 0x0f;
 165         int num = n & 0xff;
 166         if (rot == 0)
 167                 return n;
 168         if (num == 0xff) {
 169                 num = 0;
 170                 rot = (rot + 12) & 0x0f;
 171         }
 172         return ((num + 1) & 0xff) | (rot << 8);
 173 }
 174
 175 static int opcode_add(int op)
 176 {
 177         /* opcode for O_ADD, O_SUB, O_AND, O_OR, O_XOR */
 178         static int rx[] = {I_ADD, I_SUB, I_AND, I_ORR, I_EOR};
 179         return rx[op & 0x0f];
 180 }
 181
 182 static void i_add(int op, int rd, int rn, int rm)
 183 {
 184         oi4(ADD(opcode_add(op), rd, rn, 0, 0, 14) | rm);
 185 }
 186
 187 int i_imm(int op, long imm)
 188 {
 189         return (op & 0xf0) != 0x20 && add_decimm(add_encimm(imm)) == imm;
 190 }
 191
 192 static void i_add_imm(int op, int rd, int rn, long n)
 193 {
 194         oi4(ADD(opcode_add(op), rd, rn, 0, 1, 14) | add_encimm(n));
 195 }
 196
 197 static void i_ldr(int l, int rd, int rn, int off, int bt);
 198
 199 void i_num(int rd, long n)
 200 {
 201         int enc = add_encimm(n);
 202         if (n == add_decimm(enc)) {
 203                 oi4(ADD(I_MOV, rd, 0, 0, 1, 14) | enc);
 204                 return;
 205         }
 206         enc = add_encimm(-n - 1);
 207         if (~n == add_decimm(enc)) {
 208                 oi4(ADD(I_MVN, rd, 0, 0, 1, 14) | enc);
 209                 return;
 210         }
 211         i_ldr(1, rd, REG_DP, pool_num(n), LONGSZ);
 212 }
 213
 214 static void i_add_anyimm(int rd, int rn, long n)
 215 {
 216         int neg = n < 0;
 217         int imm = add_encimm(neg ? -n : n);
 218         if (imm == add_decimm(neg ? -n : n)) {
 219                 oi4(ADD(neg ? I_SUB : I_ADD, rd, rn, 0, 1, 14) | imm);
 220         } else {
 221                 i_num(rd, n);
 222                 i_add(O_ADD, rd, rd, rn);
 223         }
 224 }
 225
 226 /*
 227  * multiply
 228  * +----------------------------------------+
 229  * |COND|000000|A|S| Rd | Rn | Rs |1001| Rm |
 230  * +----------------------------------------+
 231  *
 232  * Rd: destination
 233  * A: accumulate
 234  * C: set condition codes
 235  *
 236  * I=0 operand2=| shift  | Rm |
 237  * I=1 operand2=|rota|  imm   |
 238  */
 239 #define MUL(rd, rn, rs)         \
 240         ((14 << 28) | ((rd) << 16) | ((0) << 12) | ((rn) << 8) | ((9) << 4) | (rm))
 241
 242 static void i_mul(int rd, int rn, int rm)
 243 {
 244         oi4(MUL(rd, rn, rm));
 245 }
 246
 247 static int opcode_set(int op)
 248 {
 249         /* lt, gt, le, ge, eq, neq */
 250         static int ucond[] = {3, 8, 9, 2, 0, 1};
 251         static int scond[] = {11, 12, 13, 10, 0, 1};
 252         return op & O_SIGNED ? scond[op & 0x0f] : ucond[op & 0x0f];
 253 }
 254
 255 static void i_tst(int rn, int rm)
 256 {
 257         oi4(ADD(I_TST, 0, rn, 1, 0, 14) | rm);
 258 }
 259
 260 static void i_cmp(int rn, int rm)
 261 {
 262         last_cmp = cslen;
 263         oi4(ADD(I_CMP, 0, rn, 1, 0, 14) | rm);
 264 }
 265
 266 static void i_cmp_imm(int rn, long n)
 267 {
 268         last_cmp = cslen;
 269         oi4(ADD(I_CMP, 0, rn, 1, 1, 14) | add_encimm(n));
 270 }
 271
 272 static void i_set(int cond, int rd)
 273 {
 274         oi4(ADD(I_MOV, rd, 0, 0, 1, 14));
 275         last_set = cslen;
 276         oi4(ADD(I_MOV, rd, 0, 0, 1, opcode_set(cond)) | 1);
 277 }
 278
 279 #define SM_LSL          0
 280 #define SM_LSR          1
 281 #define SM_ASR          2
 282
 283 static int opcode_shl(int op)
 284 {
 285         if (op & 0x0f)
 286                 return op & O_SIGNED ? SM_ASR : SM_LSR;
 287         return SM_LSL;
 288 }
 289
 290 static void i_shl(int op, int rd, int rm, int rs)
 291 {
 292         int sm = opcode_shl(op);
 293         oi4(ADD(I_MOV, rd, 0, 0, 0, 14) | (rs << 8) | (sm << 5) | (1 << 4) | rm);
 294 }
 295
 296 static void i_shl_imm(int op, int rd, int rn, long n)
 297 {
 298         int sm = opcode_shl(op);
 299         oi4(ADD(I_MOV, rd, 0, 0, 0, 14) | (n << 7) | (sm << 5) | rn);
 300 }
 301
 302 void i_mov(int rd, int rn)
 303 {
 304         oi4(ADD(I_MOV, rd, 0, 0, 0, 14) | rn);
 305 }
 306
 307 /*
 308  * single data transfer:
 309  * +------------------------------------------+
 310  * |COND|01|I|P|U|B|W|L| Rn | Rd |   offset   |
 311  * +------------------------------------------+
 312  *
 313  * I: immediate/offset
 314  * P: post/pre indexing
 315  * U: down/up
 316  * B: byte/word
 317  * W: writeback
 318  * L: store/load
 319  * Rn: base register
 320  * Rd: source/destination register
 321  *
 322  * I=0 offset=| immediate |
 323  * I=1 offset=| shift  | Rm |
 324  *
 325  * halfword and signed data transfer
 326  * +----------------------------------------------+
 327  * |COND|000|P|U|0|W|L| Rn | Rd |0000|1|S|H|1| Rm |
 328  * +----------------------------------------------+
 329  *
 330  * +----------------------------------------------+
 331  * |COND|000|P|U|1|W|L| Rn | Rd |off1|1|S|H|1|off2|
 332  * +----------------------------------------------+
 333  *
 334  * S: singed
 335  * H: halfword
 336  */
 337 #define LDR(l, rd, rn, b, u, p, w)              \
 338         ((14 << 28) | (1 << 26) | ((p) << 24) | ((b) << 22) | ((u) << 23) | \
 339         ((w) << 21) | ((l) << 20) | ((rn) << 16) | ((rd) << 12))
 340 #define LDRH(l, rd, rn, s, h, u, i)     \
 341         ((14 << 28) | (1 << 24) | ((u) << 23) | ((i) << 22) | ((l) << 20) | \
 342         ((rn) << 16) | ((rd) << 12) | ((s) << 6) | ((h) << 5) | (9 << 4))
 343
 344 static void i_ldr(int l, int rd, int rn, int off, int bt)
 345 {
 346         int b = BT_SZ(bt) == 1;
 347         int h = BT_SZ(bt) == 2;
 348         int s = l && (bt & BT_SIGNED);
 349         int half = h || (b && s);
 350         int maximm = half ? 0x100 : 0x1000;
 351         int neg = off < 0;
 352         if (neg)
 353                 off = -off;
 354         while (off >= maximm) {
 355                 int imm = add_encimm(off);
 356                 oi4(ADD(neg ? I_SUB : I_ADD, REG_TMP, rn, 0, 1, 14) | imm);
 357                 rn = REG_TMP;
 358                 off -= add_decimm(imm);
 359         }
 360         if (!half)
 361                 oi4(LDR(l, rd, rn, b, !neg, 1, 0) | off);
 362         else
 363                 oi4(LDRH(l, rd, rn, s, h, !neg, 1) |
 364                         ((off & 0xf0) << 4) | (off & 0x0f));
 365 }
 366
 367 void i_load(int rd, int rn, int off, int bt)
 368 {
 369         i_ldr(1, rd, rn, off, bt);
 370 }
 371
 372 void i_save(int rd, int rn, int off, int bt)
 373 {
 374         i_ldr(0, rd, rn, off, bt);
 375 }
 376
 377 void i_sym(int rd, char *sym, int off)
 378 {
 379         int doff = pool_reloc(sym, off);
 380         i_ldr(1, rd, REG_DP, doff, LONGSZ);
 381 }
 382
 383 static void i_neg(int rd, int r1)
 384 {
 385         oi4(ADD(I_RSB, rd, r1, 0, 1, 14));
 386 }
 387
 388 static void i_not(int rd, int r1)
 389 {
 390         oi4(ADD(I_MVN, rd, 0, 0, 0, 14) | r1);
 391 }
 392
 393 static int cond_nots[] = {1, 0, 3, 2, -1, -1, -1, -1, 9, 8, 11, 10, 13, 12, -1};
 394
 395 static void i_lnot(int rd, int r1)
 396 {
 397         if (OPT_ISCMP()) {
 398                 unsigned int *lset = (void *) cs + last_set;
 399                 int cond = cond_nots[OPT_CCOND()];
 400                 *lset = (*lset & 0x0fffffff) | (cond << 28);
 401                 return;
 402         }
 403         i_tst(r1, r1);
 404         i_set(O_EQ, rd);
 405 }
 406
 407 /* rd = rd & ((1 << bits) - 1) */
 408 static void i_zx(int rd, int r1, int bits)
 409 {
 410         if (bits <= 8) {
 411                 oi4(ADD(I_AND, rd, r1, 0, 1, 14) | add_encimm((1 << bits) - 1));
 412         } else {
 413                 i_shl_imm(O_SHL, rd, r1, 32 - bits);
 414                 i_shl_imm(O_SHR, rd, rd, 32 - bits);
 415         }
 416 }
 417
 418 static void i_sx(int rd, int r1, int bits)
 419 {
 420         i_shl_imm(O_SHL, rd, r1, 32 - bits);
 421         i_shl_imm(O_SIGNED | O_SHR, rd, rd, 32 - bits);
 422 }
 423
 424 /*
 425  * branch:
 426  * +-----------------------------------+
 427  * |COND|101|L|         offset         |
 428  * +-----------------------------------+
 429  *
 430  * L: link
 431  */
 432 #define BL(cond, l, o)  (((cond) << 28) | (5 << 25) | ((l) << 24) | \
 433                                 ((((o) - 8) >> 2) & 0x00ffffff))
 434 void i_jmp(int rn, int jc, int nbytes)
 435 {
 436         if (!nbytes)
 437                 return;
 438         if (rn < 0) {
 439                 oi4(BL(14, 0, 0));
 440                 return;
 441         }
 442         if (OPT_ISCMP()) {
 443                 int cond = OPT_CCOND();
 444                 cslen = last_cmp + 4;
 445                 last_set = -1;
 446                 oi4(BL(jc ? cond_nots[cond] : cond, 0, 0));
 447                 return;
 448         }
 449         i_tst(rn, rn);
 450         oi4(BL(jc ? 0 : 1, 0, 0));
 451 }
 452
 453 long i_fill(long src, long dst, int nbytes)
 454 {
 455         long *d = (void *) cs + src - 4;
 456         if (!nbytes)
 457                 return 0;
 458         *d = (*d & 0xff000000) | (((dst - src - 4) >> 2) & 0x00ffffff);
 459         return dst - src;
 460 }
 461
 462 void i_memcpy(int rd, int rs, int rn)
 463 {
 464         oi4(ADD(I_SUB, rn, rn, 1, 1, 14) | 1);
 465         oi4(BL(4, 0, 16));
 466         oi4(LDR(1, REG_TMP, rs, 1, 1, 0, 0) | 1);
 467         oi4(LDR(0, REG_TMP, rd, 1, 1, 0, 0) | 1);
 468         oi4(BL(14, 0, -16));
 469 }
 470
 471 void i_memset(int rd, int rs, int rn)
 472 {
 473         oi4(ADD(I_SUB, rn, rn, 1, 1, 14) | 1);
 474         oi4(BL(4, 0, 12));
 475         oi4(LDR(0, rs, rd, 1, 1, 0, 0) | 1);
 476         oi4(BL(14, 0, -12));
 477 }
 478
 479 void i_call_reg(int rd)
 480 {
 481         i_mov(REG_LR, REG_PC);
 482         i_mov(REG_PC, rd);
 483 }
 484
 485 void i_call(char *sym, int off)
 486 {
 487         if (!pass1)
 488                 out_rel(sym, OUT_CS | OUT_RLREL | OUT_RL24, cslen);
 489         oi4(BL(14, 1, off));
 490 }
 491
 492 void i_reg(int op, int *rd, int *r1, int *r2, int *tmp)
 493 {
 494         *rd = R_TMPS;
 495         *r1 = R_TMPS;
 496         *r2 = (op & O_IMM || (op & 0xf0) == 0x40) ? 0 : R_TMPS;
 497         *tmp = 0;
 498         if ((op & 0xff) == O_DIV || (op & 0xff) == O_MOD) {
 499                 *rd = 1 << REG_RET;
 500                 *r1 = 1 << argregs[0];
 501                 *r2 = 1 << argregs[1];
 502                 *tmp = R_TMPS & ~R_SAVED;
 503         }
 504 }
 505
 506 void i_op(int op, int rd, int r1, int r2)
 507 {
 508         if ((op & 0xf0) == 0x00)
 509                 i_add(op, rd, r1, r2);
 510         if ((op & 0xf0) == 0x10)
 511                 i_shl(op, rd, r1, r2);
 512         if ((op & 0xf0) == 0x20) {
 513                 if ((op & 0xff) == O_MUL)
 514                         i_mul(rd, r1, r2);
 515                 if ((op & 0xff) == O_DIV)
 516                         i_div(op & O_SIGNED ? "__divdi3" : "__udivdi3");
 517                 if ((op & 0xff) == O_MOD)
 518                         i_div(op & O_SIGNED ? "__moddi3" : "__umoddi3");
 519                 return;
 520         }
 521         if ((op & 0xf0) == 0x30) {
 522                 i_cmp(r1, r2);
 523                 i_set(op, rd);
 524                 return;
 525         }
 526         if ((op & 0xf0) == 0x40) {      /* uop */
 527                 if ((op & 0xff) == O_NEG)
 528                         i_neg(rd, r1);
 529                 if ((op & 0xff) == O_NOT)
 530                         i_not(rd, r1);
 531                 if ((op & 0xff) == O_LNOT)
 532                         i_lnot(rd, r1);
 533                 return;
 534         }
 535 }
 536
 537 void i_op_imm(int op, int rd, int r1, long n)
 538 {
 539         if ((op & 0xf0) == 0x00) {
 540                 if (i_imm(O_ADD, n))
 541                         i_add_imm(op, rd, r1, n);
 542                 else
 543                         i_add_anyimm(rd, r1, n);
 544         }
 545         if ((op & 0xf0) == 0x10)        /* shl */
 546                 i_shl_imm(op, rd, r1, n);
 547         if ((op & 0xf0) == 0x30) {      /* imm */
 548                 i_cmp_imm(r1, n);
 549                 i_set(op, rd);
 550         }
 551         if ((op & 0xf0) == 0x50) {      /* etc */
 552                 if ((op & 0xff) == O_ZX)
 553                         i_zx(rd, r1, n);
 554                 if ((op & 0xff) == O_SX)
 555                         i_sx(rd, r1, n);
 556                 if ((op & 0xff) == O_MOV)
 557                         i_mov(rd, r1);
 558         }
 559 }
 560
 561 static int func_argc;
 562 static int func_varg;
 563 static int func_spsub;
 564 static int func_sargs;
 565 static int func_sregs;
 566 static int func_initfp;
 567 static int func_initdp = 1;
 568 static int spsub_addr;
 569 static int dpadd_addr;
 570
 571 static int saved_regs(int args)
 572 {
 573         int n = 2;
 574         int i;
 575         for (i = 0; i < N_REGS; i++) {
 576                 if ((1 << i) & func_sregs)
 577                         n++;
 578                 if (args && (1 << i) & func_sargs)
 579                         n++;
 580         }
 581         return n;
 582 }
 583
 584 int i_args(void)
 585 {
 586         return saved_regs(0) * LONGSZ;
 587 }
 588
 589 int i_sp(void)
 590 {
 591         return 0;
 592 }
 593
 594 static int plain_function(void)
 595 {
 596         return !func_initfp && !func_spsub && !func_initdp && !func_varg &&
 597                 !func_sargs && !func_sregs && func_argc <= N_ARGS;
 598 }
 599
 600 static void insert_spsub(void)
 601 {
 602         if (!func_spsub) {
 603                 func_spsub = 1;
 604                 spsub_addr = cslen;
 605                 oi4(0xe24dd000);        /* sub   sp, sp, xx */
 606         }
 607 }
 608
 609 void i_prolog(int argc, int varg, int sargs, int sregs, int initfp, int spsub)
 610 {
 611         last_set = -1;
 612         nums = 0;
 613         func_argc = argc;
 614         func_varg = varg;
 615         func_sargs = sargs;
 616         func_sregs = sregs;
 617         func_initfp = initfp;
 618         func_spsub = 0;
 619         if (plain_function())
 620                 return;
 621         if (initfp)
 622                 func_sregs |= 1 << REG_FP;
 623         if (func_initdp)
 624                 func_sregs |= 1 << REG_DP;
 625         /* stack should remain 8-aligned */
 626         if (saved_regs(1) & 0x1)
 627                 func_sregs |= 8;
 628         oi4(0xe1a0c00d);                        /* mov   r12, sp */
 629         if (func_sargs)
 630                 oi4(0xe92d0000 | func_sargs);   /* stmfd sp!, {r0-r3} */
 631         oi4(0xe92d5000 | func_sregs);           /* stmfd sp!, {r0-r11, r12, lr} */
 632         if (func_initfp)
 633                 oi4(0xe1a0b00d);                /* mov   fp, sp */
 634         if (spsub)
 635                 insert_spsub();
 636         if (func_initdp) {
 637                 dpadd_addr = cslen;
 638                 oi4(0xe28fa000);                /* add   dp, pc, xx */
 639         }
 640 }
 641
 642 void i_epilog(int sp_max)
 643 {
 644         sp_max = -sp_max;
 645         if (plain_function()) {
 646                 oi4(0xe1a0f00e);                /* mov   pc, lr */
 647                 return;
 648         }
 649         if (func_initfp)
 650                 oi4(0xe89ba000 | func_sregs);/* ldmfd fp, {r4-r11, sp, pc} */
 651         if (!func_initfp)
 652                 oi4(0xe89da000 | func_sregs);/* ldmfd sp, {r4-r11, sp, pc} */
 653         if (func_initdp) {
 654                 int dpoff = cslen - dpadd_addr - 8;
 655                 dpoff = add_decimm(add_rndimm(add_encimm(dpoff)));
 656                 cslen = dpadd_addr + dpoff + 8;
 657                 /* fill data ptr addition: dp = pc + xx */
 658                 *(long *) (cs + dpadd_addr) |= add_encimm(dpoff);
 659         }
 660         if (func_initfp && func_spsub) {
 661                 sp_max = ALIGN(sp_max, 8);
 662                 sp_max = add_decimm(add_rndimm(add_encimm(sp_max)));
 663                 /* fill stack sub: sp = sp - xx */
 664                 *(long *) (cs + spsub_addr) |= add_encimm(sp_max);
 665         }
 666         pool_write();
 667 }