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local.c

/*    $Id: local.c,v 1.29 2011/04/07 18:50:16 ragge Exp $   */
/*
 * Copyright (c) 2003 Anders Magnusson (ragge@ludd.luth.se).
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <assert.h>
#include "pass1.h"

#define IALLOC(sz) (isinlining ? permalloc(sz) : tmpalloc(sz))

extern int kflag;

static void simmod(NODE *p);

/*    this file contains code which is dependent on the target machine */

#if defined(MACHOABI)

/*
 *  Keep track of PIC stubs.
 */

void
addstub(struct stub *list, char *name)
{
        struct stub *s;

        DLIST_FOREACH(s, list, link) {
                if (strcmp(s->name, name) == 0)
                        return;
        }

        s = permalloc(sizeof(struct stub));
        s->name = permalloc(strlen(name) + 1);
        strcpy(s->name, name);
        DLIST_INSERT_BEFORE(list, s, link);
}

#endif


/*
 * Make a symtab entry for PIC use.
 */
static struct symtab *
picsymtab(char *p, char *s, char *s2)
{
      struct symtab *sp = IALLOC(sizeof(struct symtab));
      size_t len = strlen(p) + strlen(s) + strlen(s2) + 1;

      sp->sname = sp->soname = IALLOC(len);
      strlcpy(sp->soname, p, len);
      strlcat(sp->soname, s, len);
      strlcat(sp->soname, s2, len);
      sp->sclass = EXTERN;
      sp->sflags = sp->slevel = 0;

      return sp;
}

int gotnr;  /* tempnum for GOT register */

/*
 * Create a reference for an extern variable.
 */
static NODE *
picext(NODE *p)
{
      NODE *q;
      struct symtab *sp;
      char *name;

      name = p->n_sp->soname ? p->n_sp->soname : exname(p->n_sp->sname);

      if (strncmp(name, "__builtin", 9) == 0)
            return p;

#if defined(ELFABI)

      sp = picsymtab("", name, "@got(31)");
      q = xbcon(0, sp, PTR+VOID);
      q = block(UMUL, q, 0, PTR+VOID, 0, 0);

#elif defined(MACHOABI)

      char buf2[64];
      NODE *r;
      char *fname;

      fname = cftnsp->soname ? cftnsp->soname : cftnsp->sname;

      if (p->n_sp->sclass == EXTDEF) {
            snprintf(buf2, 64, "-L%s$pb", fname);
            sp = picsymtab("", name, buf2);
      } else {
            snprintf(buf2, 64, "$non_lazy_ptr-L%s$pb", fname);
            sp = picsymtab("L", name, buf2);
            addstub(&nlplist, name);
      }
#if USE_GOTNR
      q = tempnode(gotnr, PTR+VOID, 0, 0);
#else
      q = block(REG, NIL, NIL, PTR+VOID, 0, 0);
      regno(q) = GOTREG;
#endif
      r = xbcon(0, sp, INT);
      q = buildtree(PLUS, q, r);

      if (p->n_sp->sclass != EXTDEF)
            q = block(UMUL, q, 0, PTR+VOID, 0, 0);

#endif

      q = block(UMUL, q, 0, p->n_type, p->n_df, p->n_ap);
      q->n_sp = p->n_sp; /* for init */
      nfree(p);

      return q;
}

/*
 * Create a reference for a static variable
 */

static NODE *
picstatic(NODE *p)
{
      NODE *q;
      struct symtab *sp;

#if defined(ELFABI)
      char *n;

      if (p->n_sp->slevel > 0) {
            char buf[64];
            snprintf(buf, 64, LABFMT, (int)p->n_sp->soffset);
            sp = picsymtab("", buf, "@got(31)");
      } else  {
            n = p->n_sp->soname ? p->n_sp->soname : p->n_sp->sname;
            sp = picsymtab("", exname(n), "@got(31)");
      }
      sp->sclass = STATIC;
      sp->stype = p->n_sp->stype;
      q = xbcon(0, sp, PTR+VOID);
      q = block(UMUL, q, 0, p->n_type, p->n_df, p->n_ap);
      q->n_sp = p->n_sp;
      nfree(p);

#elif defined(MACHOABI)

      char buf2[64];
      NODE *r;

      snprintf(buf2, 64, "-L%s$pb",
          cftnsp->soname ? cftnsp->soname : cftnsp->sname);

      if (p->n_sp->slevel > 0) {
            char buf1[64];
            snprintf(buf1, 64, LABFMT, (int)p->n_sp->soffset);
            sp = picsymtab("", buf1, buf2);
      } else  {
            char *name = p->n_sp->soname ? p->n_sp->soname : exname(p->n_sp->sname);
            sp = picsymtab("", name, buf2);
      }
      sp->sclass = STATIC;
      sp->stype = p->n_sp->stype;
#if USE_GOTNR
      q = tempnode(gotnr, PTR+VOID, 0, 0);
#else
      q = block(REG, NIL, NIL, PTR+VOID, 0, 0);
      regno(q) = GOTREG;
#endif
      r = xbcon(0, sp, INT);
      q = buildtree(PLUS, q, r);
      q = block(UMUL, q, 0, p->n_type, p->n_df, p->n_ap);
      q->n_sp = p->n_sp;
      nfree(p);

#endif

      return q;
}

static NODE *
convert_ulltof(NODE *p)
{
      NODE *q, *r, *l, *t;
      int ty;
      int tmpnr;

      ty = p->n_type;
      l = p->n_left;
      nfree(p);

      q = tempnode(0, ULONGLONG, 0, 0);
      tmpnr = regno(q);
      t = buildtree(ASSIGN, q, l);
      ecomp(t);

#if 0
      q = tempnode(tmpnr, ULONGLONG, 0, 0);
      q = block(SCONV, q, NIL, LONGLONG, 0, 0);
#endif
      q = tempnode(tmpnr, LONGLONG, 0, 0);
      r = block(SCONV, q, NIL, ty, 0, 0);

      q = tempnode(tmpnr, ULONGLONG, 0, 0);
      q = block(RS, q, bcon(1), ULONGLONG, 0, 0);
      q = block(SCONV, q, NIL, LONGLONG, 0, 0);
      q = block(SCONV, q, NIL, ty, 0, 0);
      t = block(FCON, NIL, NIL, ty, 0, 0);
      t->n_dcon = 2;
      l = block(MUL, q, t, ty, 0, 0);

      r = buildtree(COLON, l, r);

      q = tempnode(tmpnr, ULONGLONG, 0, 0);
      q = block(SCONV, q, NIL, LONGLONG, 0, 0);
      l = block(LE, q, xbcon(0, NULL, LONGLONG), INT, 0, 0);

      return clocal(buildtree(QUEST, l, r));

}


/* clocal() is called to do local transformations on
 * an expression tree preparitory to its being
 * written out in intermediate code.
 *
 * the major essential job is rewriting the
 * automatic variables and arguments in terms of
 * REG and OREG nodes
 * conversion ops which are not necessary are also clobbered here
 * in addition, any special features (such as rewriting
 * exclusive or) are easily handled here as well
 */
NODE *
clocal(NODE *p)
{

      struct symtab *q;
      NODE *r, *l;
      int o;
      int m;
      TWORD t;
      int isptrvoid = 0;
      int tmpnr;

#ifdef PCC_DEBUG
      if (xdebug) {
            printf("clocal: %p\n", p);
            fwalk(p, eprint, 0);
      }
#endif
      switch (o = p->n_op) {

      case ADDROF:
#ifdef PCC_DEBUG
            if (xdebug) {
                  printf("clocal(): ADDROF\n");
                  printf("type: 0x%x\n", p->n_type);
            }
#endif
            /* XXX cannot takes addresses of PARAMs */

            if (kflag == 0 || blevel == 0)
                  break;
            /* char arrays may end up here */
            l = p->n_left;
            if (l->n_op != NAME ||
                (l->n_type != ARY+CHAR && l->n_type != ARY+WCHAR_TYPE))
                  break;
            l = p;
            p = picstatic(p->n_left);
            nfree(l);
            if (p->n_op != UMUL)
                  cerror("ADDROF error");
            l = p;
            p = p->n_left;
            nfree(l);
            break;

      case NAME:
            if ((q = p->n_sp) == NULL)
                  return p; /* Nothing to care about */

            switch (q->sclass) {

            case PARAM:
            case AUTO:
                  /* fake up a structure reference */
                  r = block(REG, NIL, NIL, PTR+STRTY, 0, 0);
                  r->n_lval = 0;
                  r->n_rval = FPREG;
                  p = stref(block(STREF, r, p, 0, 0, 0));
                  break;

            case USTATIC:
                  if (kflag == 0)
                        break;
                  /* FALLTHROUGH */

            case STATIC:
                  if (kflag == 0) {
                        if (q->slevel == 0)
                              break;
                        p->n_lval = 0;
                  } else if (blevel > 0) {
                        p = picstatic(p);
                  }
                  break;

            case REGISTER:
                  p->n_op = REG;
                  p->n_lval = 0;
                  p->n_rval = q->soffset;
                  break;

            case EXTERN: 
            case EXTDEF:
                  if (kflag == 0)
                        break;
                  if (blevel > 0)
                        p = picext(p);
                  break;
            }
            break;

      case UCALL:
      case CALL:
      case USTCALL:
      case STCALL:
                if (p->n_type == VOID)
                        break;
                /*
                 * if the function returns void*, ecode() invokes
                 * delvoid() to convert it to uchar*.
                 * We just let this happen on the ASSIGN to the temp,
                 * and cast the pointer back to void* on access
                 * from the temp.
                 */
                if (p->n_type == PTR+VOID)
                        isptrvoid = 1;
                r = tempnode(0, p->n_type, p->n_df, p->n_ap);
                tmpnr = regno(r);
            r = buildtree(ASSIGN, r, p);

                p = tempnode(tmpnr, r->n_type, r->n_df, r->n_ap);
                if (isptrvoid) {
                        p = block(PCONV, p, NIL, PTR+VOID,
                            p->n_df, 0);
                }
#if 1
                p = buildtree(COMOP, r, p);
#else
            /* XXX this doesn't work if the call is already in a COMOP */
            r = clocal(r);
            ecomp(r);
#endif
                break;
            
      case CBRANCH:
            l = p->n_left;

            /*
             * Remove unnecessary conversion ops.
             */
            if (clogop(l->n_op) && l->n_left->n_op == SCONV) {
                  if (coptype(l->n_op) != BITYPE)
                        break;
                  if (l->n_right->n_op == ICON) {
                        r = l->n_left->n_left;
                        if (r->n_type >= FLOAT && r->n_type <= LDOUBLE)
                              break;
                        /* Type must be correct */
                        t = r->n_type;
                        nfree(l->n_left);
                        l->n_left = r;
                        l->n_type = t;
                        l->n_right->n_type = t;
                  }
            }
            break;

      case PCONV:
            /* Remove redundant PCONV's. Be careful */
            l = p->n_left;
            if (l->n_op == ICON) {
                  l->n_lval = (unsigned)l->n_lval;
                  goto delp;
            }
            if (l->n_type < INT || DEUNSIGN(l->n_type) == LONGLONG) {
                  /* float etc? */
                  p->n_left = block(SCONV, l, NIL,
                      UNSIGNED, 0, 0);
                  break;
            }
            /* if left is SCONV, cannot remove */
            if (l->n_op == SCONV)
                  break;

            /* avoid ADDROF TEMP */
            if (l->n_op == ADDROF && l->n_left->n_op == TEMP)
                  break;

            /* if conversion to another pointer type, just remove */
            if (p->n_type > BTMASK && l->n_type > BTMASK)
                  goto delp;
            break;

      delp: l->n_type = p->n_type;
            l->n_qual = p->n_qual;
            l->n_df = p->n_df;
            l->n_ap = p->n_ap;
            nfree(p);
            p = l;
            break;
            
      case SCONV:
            l = p->n_left;

            if (p->n_type == l->n_type) {
                  nfree(p);
                  return l;
            }

            if ((p->n_type & TMASK) == 0 && (l->n_type & TMASK) == 0 &&
                btattr[p->n_type].atypsz == btattr[l->n_type].atypsz) {
                  if (p->n_type != FLOAT && p->n_type != DOUBLE &&
                      l->n_type != FLOAT && l->n_type != DOUBLE &&
                      l->n_type != LDOUBLE && p->n_type != LDOUBLE) {
                        if (l->n_op == NAME || l->n_op == UMUL ||
                            l->n_op == TEMP) {
                              l->n_type = p->n_type;
                              nfree(p);
                              return l;
                        }
                  }
            }

            if (DEUNSIGN(p->n_type) == INT && DEUNSIGN(l->n_type) == INT &&
                coptype(l->n_op) == BITYPE) {
                  l->n_type = p->n_type;
                  nfree(p);
                  return l;
            }

            /*
             * if converting ULONGLONG to FLOAT/(L)DOUBLE,
             * replace ___floatunsdidf() with ___floatdidf()
             */
            if (l->n_type == ULONGLONG && p->n_type >= FLOAT &&
                p->n_type <= LDOUBLE) {
                  return convert_ulltof(p);
            }

            o = l->n_op;
            m = p->n_type;

            if (o == ICON) {
                  CONSZ val = l->n_lval;

                  if (!ISPTR(m)) /* Pointers don't need to be conv'd */
                      switch (m) {
                  case BOOL:
                        l->n_lval = l->n_lval != 0;
                        break;
                  case CHAR:
                        l->n_lval = (char)val;
                        break;
                  case UCHAR:
                        l->n_lval = val & 0377;
                        break;
                  case SHORT:
                        l->n_lval = (short)val;
                        break;
                  case USHORT:
                        l->n_lval = val & 0177777;
                        break;
                  case ULONG:
                  case UNSIGNED:
                        l->n_lval = val & 0xffffffff;
                        break;
                  case LONG:
                  case INT:
                        l->n_lval = (int)val;
                        break;
                  case LONGLONG:
                        l->n_lval = (long long)val;
                        break;
                  case ULONGLONG:
                        l->n_lval = val;
                        break;
                  case VOID:
                        break;
                  case LDOUBLE:
                  case DOUBLE:
                  case FLOAT:
                        l->n_op = FCON;
                        l->n_dcon = val;
                        break;
                  default:
                        cerror("unknown type %d", m);
                  }
                  l->n_type = m;
                  l->n_ap = 0;
                  nfree(p);
                  return l;
            } else if (o == FCON) {
                  l->n_lval = l->n_dcon;
                  l->n_sp = NULL;
                  l->n_op = ICON;
                  l->n_type = m;
                  l->n_ap = 0;
                  nfree(p);
                  return clocal(l);
            }
            if (DEUNSIGN(p->n_type) == SHORT &&
                DEUNSIGN(l->n_type) == SHORT) {
                  nfree(p);
                  p = l;
            }
            if ((DEUNSIGN(p->n_type) == CHAR ||
                DEUNSIGN(p->n_type) == SHORT) &&
                (l->n_type == FLOAT || l->n_type == DOUBLE ||
                l->n_type == LDOUBLE)) {
                  p = block(SCONV, p, NIL, p->n_type, p->n_df, p->n_ap);
                  p->n_left->n_type = INT;
                  return p;
            }
            if ((DEUNSIGN(l->n_type) == CHAR ||
                DEUNSIGN(l->n_type) == SHORT) &&
                (p->n_type == FLOAT || p->n_type == DOUBLE ||
                p->n_type == LDOUBLE)) {
                  p = block(SCONV, p, NIL, p->n_type, p->n_df, p->n_ap);
                  p->n_left->n_type = INT;
                  return p;
            }
            break;

      case MOD:
            simmod(p);
            break;

      case DIV:
            if (o == DIV && p->n_type != CHAR && p->n_type != SHORT)
                  break;
            /* make it an int division by inserting conversions */
            p->n_left = block(SCONV, p->n_left, NIL, INT, 0, 0);
            p->n_right = block(SCONV, p->n_right, NIL, INT, 0, 0);
            p = block(SCONV, p, NIL, p->n_type, 0, 0);
            p->n_left->n_type = INT;
            break;

      case PMCONV:
      case PVCONV:
                
                nfree(p);
                return(buildtree(o==PMCONV?MUL:DIV, p->n_left, p->n_right));

      case STNAME:
            if ((q = p->n_sp) == NULL)
                  return p;
            if (q->sclass != STNAME)
                  return p;
            t = p->n_type;
            p = block(ADDROF, p, NIL, INCREF(t), p->n_df, p->n_ap);
            p = block(UMUL, p, NIL, t, p->n_df, p->n_ap);
            break;

      case FORCE:
            /* put return value in return reg */
            p->n_op = ASSIGN;
            p->n_right = p->n_left;
            p->n_left = block(REG, NIL, NIL, p->n_type, 0, 0);
            p->n_left->n_rval = p->n_left->n_type == BOOL ? 
                RETREG(BOOL_TYPE) : RETREG(p->n_type);
            break;

      case LS:
      case RS:
            if (p->n_right->n_op == ICON)
                  break; /* do not do anything */
            if (DEUNSIGN(p->n_right->n_type) == INT)
                  break;
            p->n_right = block(SCONV, p->n_right, NIL, INT, 0, 0);
            break;
      }

#ifdef PCC_DEBUG
      if (xdebug) {
            printf("clocal end: %p\n", p);
            fwalk(p, eprint, 0);
      }
#endif
      return(p);
}

/*
 * Change CALL references to either direct (static) or PLT.
 */
static void
fixnames(NODE *p, void *arg)
{
        struct symtab *sp;
        struct attr *ap;
        NODE *q;
        char *c;
        int isu;

        if ((cdope(p->n_op) & CALLFLG) == 0)
                return;

        isu = 0;
        q = p->n_left;
        ap = q->n_ap;
        if (q->n_op == UMUL)
                q = q->n_left, isu = 1;

#if defined(ELFABI)

        if (q->n_op == ICON) {
                sp = q->n_sp;

#elif defined(MACHOABI)

#ifdef USE_GOTNR
      if (q->n_op == PLUS && q->n_left->n_op == TEMP &&
#else
      if (q->n_op == PLUS && q->n_left->n_op == REG &&
#endif
          q->n_right->n_op == ICON) {
                sp = q->n_right->n_sp;
#endif

                if (sp == NULL)
                        return; /* nothing to do */
                if (sp->sclass == STATIC && !ISFTN(sp->stype))
                        return; /* function pointer */

                if (sp->sclass != STATIC && sp->sclass != EXTERN &&
                    sp->sclass != EXTDEF)
                        cerror("fixnames");
            c = NULL;
#if defined(ELFABI)

            if (sp->soname == NULL ||
                    (c = strstr(sp->soname, "@got(31)")) == NULL)
                        cerror("fixnames2");
                if (isu) {
                        strcpy(c, "@plt");
                } else
                        *c = 0;

#elif defined(MACHOABI)

            if (sp->soname == NULL ||
                ((c = strstr(sp->soname, "$non_lazy_ptr")) == NULL &&
                (c = strstr(sp->soname, "-L")) == NULL))
                        cerror("fixnames2");
            if (isu) {
                  *c = 0;
                  addstub(&stublist, sp->soname+1);
                  strcpy(c, "$stub");
            } else 
                  *c = 0;

            nfree(q->n_left);
            q = q->n_right;
            if (isu)
                  nfree(p->n_left->n_left);
            nfree(p->n_left);
            p->n_left = q;
            q->n_ap = ap;

#endif
        }
}

void
myp2tree(NODE *p)
{
      int o = p->n_op;
      struct symtab *sp;

      if (kflag)
            walkf(p, fixnames, 0);
      if (o != FCON) 
            return;

      /* Write float constants to memory */
      /* Should be voluntary per architecture */
 
      sp = IALLOC(sizeof(struct symtab));
      sp->sclass = STATIC;
      sp->sap = 0;
      sp->slevel = 1; /* fake numeric label */
      sp->soffset = getlab();
      sp->sflags = 0;
      sp->stype = p->n_type;
      sp->squal = (CON >> TSHIFT);

      defloc(sp);
      ninval(0, tsize(sp->stype, sp->sdf, sp->sap), p);

      p->n_op = NAME;
      p->n_lval = 0;    
      p->n_sp = sp;
}

/*ARGSUSED*/
int
andable(NODE *p)
{
      return(1);  /* all names can have & taken on them */
}

/*
 * at the end of the arguments of a ftn, set the automatic offset
 */
void
cendarg()
{
#ifdef PCC_DEBUG
      if (xdebug)
            printf("cendarg: autooff=%d (was %d)\n", AUTOINIT, autooff);
#endif
      autooff = AUTOINIT;
}

/*
 * Return 1 if a variable of type type is OK to put in register.
 */
int
cisreg(TWORD t)
{
      return 1;
}

/*
 * return a node, for structure references, which is suitable for
 * being added to a pointer of type t, in order to be off bits offset
 * into a structure
 * t, d, and s are the type, dimension offset, and sizeoffset
 * Be careful about only handling first-level pointers, the following
 * indirections must be fullword.
 */
NODE *
offcon(OFFSZ off, TWORD t, union dimfun *d, struct attr *ap)
{
      register NODE *p;

#ifdef PCC_DEBUG
      if (xdebug)
            printf("offcon: OFFSZ %lld type %x dim %p siz %d\n",
                off, t, d, (int)tsize(t, d, ap));
#endif

      p = bcon(0);
      p->n_lval = off/SZCHAR; /* Default */
      return(p);
}

/*
 * Allocate bits on the stack.
 * 'off' is the number of bits to allocate
 * 'p' is a tree that when evaluated is the multiply count for 'off'
 * 't' is a storeable node where to write the allocated address
 */
void
spalloc(NODE *t, NODE *p, OFFSZ off)
{
      NODE *q, *r;
      int nbytes = off / SZCHAR;
      int stacksize = 24+40; /* this should be p2stacksize */

      /*
       * After we subtract the requisite bytes
       * off the stack, we need to step back over
       * the 40 bytes for the arguments registers
       * *and* any other parameters which will get
       * saved to the stack.  Unfortunately, we
       * don't have that information in pass1 and
       * the parameters will stomp on the allocated
       * space for alloca().
       *
       * No fix yet.
       */
      werror("parameters may stomp on alloca()");

      /* compute size */
      p = buildtree(MUL, p, bcon(nbytes));
      p = buildtree(PLUS, p, bcon(ALSTACK/SZCHAR));

      /* load the top-of-stack */
      q = block(REG, NIL, NIL, PTR+INT, 0, 0);
      regno(q) = SPREG;
      q = block(UMUL, q, NIL, INT, 0, 0);

      /* save old top-of-stack value to new top-of-stack position */
      r = block(REG, NIL, NIL, PTR+INT, 0, 0);
      regno(r) = SPREG;
      r = block(MINUSEQ, r, p, INT, 0, 0);
      r = block(UMUL, r, NIL, INT, 0, 0);
      ecomp(buildtree(ASSIGN, r, q));

      r = block(REG, NIL, NIL, PTR+INT, 0, 0);
      regno(r) = SPREG;

      /* skip over the arguments space and align to 16 bytes */
      r = block(PLUS, r, bcon(stacksize + 15), INT, 0, 0);
      r = block(RS, r, bcon(4), INT, 0, 0);
      r = block(LS, r, bcon(4), INT, 0, 0);

      t->n_type = p->n_type;
      ecomp(buildtree(ASSIGN, t, r));
}

/*
 * Print out a string of characters.
 * Unfortunately, this code assumes that the assembler understands
 * C-style escape sequences. (which it doesn't!)
 * Location is already set.
 */
void
instring(struct symtab *sp)
{
      char *s, *str = sp->sname;

#if defined(ELFABI)

      defloc(sp);

#elif defined(MACHOABI)

      extern int lastloc;
      if (lastloc != STRNG)
            printf("    .cstring\n");
      lastloc = STRNG;
      printf("\t.p2align 2\n");
      printf(LABFMT ":\n", sp->soffset);

#endif

      /* be kind to assemblers and avoid long strings */
      printf("\t.ascii \"");
      for (s = str; *s != 0; ) {
            if (*s++ == '\\') {
                  (void)esccon(&s);
            }
            if (s - str > 64) {
                  fwrite(str, 1, s - str, stdout);
                  printf("\"\n\t.ascii \"");
                  str = s;
            }
      }
      fwrite(str, 1, s - str, stdout);
      printf("\\0\"\n");
}

static int inbits, inval;

/*
 * set fsz bits in sequence to zero.
 */
void
zbits(OFFSZ off, int fsz)
{
      int m;

      if (idebug)
            printf("zbits off %lld, fsz %d inbits %d\n", off, fsz, inbits);

#if 0
      /* little-endian */
      if ((m = (inbits % SZCHAR))) {
            m = SZCHAR - m;
            if (fsz < m) {
                  inbits += fsz;
                  return;
            } else {
                  fsz -= m;
                  printf("\t.byte %d\n", inval);
                  inval = inbits = 0;
            }
      }
#endif
      /* big-endian */
      if (inbits) {
            m = SZCHAR - inbits;
            if (fsz < m) {
                  inbits += fsz;
                  inval <<= fsz;
            } else {
                  printf("\t.byte %d\n", inval << m);
                  fsz -= m;
                  inval = inbits = 0;
            }
      }

      if (fsz >= SZCHAR) {
            printf("\t.space %d\n", fsz/SZCHAR);
            fsz -= (fsz/SZCHAR) * SZCHAR;
      }
      if (fsz) {
            inval = 0;
            inbits = fsz;
      }
}

/*
 * Initialize a bitfield.
 */
void
infld(CONSZ off, int fsz, CONSZ val)
{
      if (idebug)
            printf("infld off %lld, fsz %d, val %lld inbits %d\n",
                off, fsz, val, inbits);

      val &= (1 << fsz)-1;

#if 0
      /* little-endian */
      while (fsz + inbits >= SZCHAR) {
            inval |= (val << inbits);
            printf("\t.byte %d\n", inval & 255);
            fsz -= (SZCHAR - inbits);
            val >>= (SZCHAR - inbits);
            inval = inbits = 0;
      }
      if (fsz) {
            inval |= (val << inbits);
            inbits += fsz;
      }
#endif

      /* big-endian */
      inval <<= fsz;
      inval |= val;
      inbits += fsz;
      while (inbits >= SZCHAR) {
            int pval = inval >> (inbits - SZCHAR);
            printf("\t.byte %d\n", pval & 255);
            inbits -= SZCHAR;
      }
}

/*
 * print out a constant node, may be associated with a label.
 * Do not free the node after use.
 * off is bit offset from the beginning of the aggregate
 * fsz is the number of bits this is referring to
 */
void
ninval(CONSZ off, int fsz, NODE *p)
{
      union { float f; double d; long double l; int i[3]; } u;
      struct symtab *q;
      char *c;
      TWORD t;
      int i;

      t = p->n_type;
      if (t > BTMASK)
            t = INT; /* pointer */

      while (p->n_op == SCONV || p->n_op == PCONV) {
            NODE *l = p->n_left;
            l->n_type = p->n_type;
            p = l;
      }

      if (kflag && (p->n_op == PLUS || p->n_op == UMUL)) {
            if (p->n_op == UMUL)
                  p = p->n_left;
            p = p->n_right;
            q = p->n_sp;

#if defined(ELFABI)

            if (q->soname && (c = strstr(q->soname, "@got(31)")) != NULL)
                  *c = 0; /* ignore GOT ref here */

#elif defined(MACHOABI)

            if  ((c = strstr(q->soname, "$non_lazy_ptr")) != NULL) {
                  q->soname++;      /* skip "L" */
                  *c = 0; /* ignore GOT ref here */
            }
            else if ((c = strstr(q->soname, "-L")) != NULL)
                  *c = 0; /* ignore GOT ref here */

#endif

      }

      if (p->n_op != ICON && p->n_op != FCON)
            cerror("ninval: init node not constant: node %p [%s]",
                 p, cftnsp->soname);

      if (p->n_op == ICON && p->n_sp != NULL && DEUNSIGN(t) != INT)
            uerror("element not constant");

      switch (t) {
      case LONGLONG:
      case ULONGLONG:
#if 0
            /* little-endian */
            i = (p->n_lval >> 32);
            p->n_lval &= 0xffffffff;
            p->n_type = INT;
            ninval(off, 32, p);
            p->n_lval = i;
            ninval(off+32, 32, p);
#endif
            /* big-endian */
            i = (p->n_lval & 0xffffffff);
            p->n_lval >>= 32;
            p->n_type = INT;
            ninval(off, 32, p);
            p->n_lval = i;
            ninval(off+32, 32, p);

            break;
      case INT:
      case UNSIGNED:
            printf("\t.long %d", (int)p->n_lval);
            if ((q = p->n_sp) != NULL) {
                  if ((q->sclass == STATIC && q->slevel > 0)) {
                        printf("+" LABFMT, q->soffset);
                  } else {
                        char *name = q->soname ? q->soname : exname(q->sname);
                        printf("+%s", name);
                  }
            }
            printf("\n");
            break;
      case SHORT:
      case USHORT:
            printf("\t.short %d\n", (int)p->n_lval & 0xffff);
            break;
      case BOOL:
            if (p->n_lval > 1)
                  p->n_lval = p->n_lval != 0;
            /* FALLTHROUGH */
      case CHAR:
      case UCHAR:
            printf("\t.byte %d\n", (int)p->n_lval & 0xff);
            break;
      case LDOUBLE:
            u.i[2] = 0;
            u.l = (long double)p->n_dcon;
#if 0
            /* little-endian */
            printf("\t.long 0x%x,0x%x,0x%x\n", u.i[0], u.i[1], u.i[2]);
#endif
            /* big-endian */
            printf("\t.long 0x%x,0x%x,0x%x\n", u.i[0], u.i[1], u.i[2]);
            break;
      case DOUBLE:
            u.d = (double)p->n_dcon;
            printf("\t.long 0x%x\n\t.long 0x%x\n", u.i[0], u.i[1]);
            break;
      case FLOAT:
            u.f = (float)p->n_dcon;
            printf("\t.long 0x%x\n", u.i[0]);
            break;
      default:
            cerror("ninval");
      }
}

/* make a name look like an external name in the local machine */
char *
exname(char *p)
{
#if defined(ELFABI)

      return (p == NULL ? "" : p);

#elif defined(MACHOABI)

#define NCHNAM    256
        static char text[NCHNAM+1];
      int i;

      if (p == NULL)
            return "";

        text[0] = '_';
        for (i=1; *p && i<NCHNAM; ++i)
                text[i] = *p++;

        text[i] = '\0';
        text[NCHNAM] = '\0';  /* truncate */

        return (text);

#endif
}

/*
 * map types which are not defined on the local machine
 */
TWORD
ctype(TWORD type)
{
      switch (BTYPE(type)) {
      case LONG:
            MODTYPE(type,INT);
            break;

      case ULONG:
            MODTYPE(type,UNSIGNED);

      }
      return (type);
}

void
calldec(NODE *p, NODE *q) 
{
#ifdef PCC_DEBUG
      if (xdebug)
            printf("calldec:\n");
#endif
}

void
extdec(struct symtab *q)
{
#ifdef PCC_DEBUG
      if (xdebug)
            printf("extdec:\n");
#endif
}

/* make a common declaration for id, if reasonable */
void
defzero(struct symtab *sp)
{
      char *n;
      int off;

      off = tsize(sp->stype, sp->sdf, sp->sap);
      off = (off+(SZCHAR-1))/SZCHAR;
      printf("\t.%scomm ", sp->sclass == STATIC ? "l" : "");
      n = sp->soname ? sp->soname : exname(sp->sname);
      if (sp->slevel == 0)
            printf("%s,%d\n", n, off);
      else
            printf(LABFMT ",%d\n", sp->soffset, off);
}


#ifdef notdef
/* make a common declaration for id, if reasonable */
void
commdec(struct symtab *q)
{
      int off;

      off = tsize(q->stype, q->sdf, q->ssue);
      off = (off+(SZCHAR-1))/SZCHAR;
      printf("\t.comm %s,0%o\n", q->soname ? q->soname : exname(q->sname), off);
}

/* make a local common declaration for id, if reasonable */
void
lcommdec(struct symtab *q)
{
      int off;

      off = tsize(q->stype, q->sdf, q->ssue);
      off = (off+(SZCHAR-1))/SZCHAR;
      if (q->slevel == 0)
            printf("\t.lcomm %s,%d\n", q->soname ? q->soname : exname(q->sname), off);
      else
            printf("\t.lcomm " LABFMT ",%d\n", q->soffset, off);
}

/*
 * print a (non-prog) label.
 */
void
deflab1(int label)
{
      printf(LABFMT ":\n", label);
}

#if defined(ELFABI)

static char *loctbl[] = { "text", "data", "section .rodata,",
    "section .rodata" };

#elif defined(MACHOABI)

static char *loctbl[] = { "text", "data", "section .rodata,", "cstring" };

#endif

void
setloc1(int locc)
{
#ifdef PCC_DEBUG
      if (xdebug)
            printf("setloc1: locc=%d, lastloc=%d\n", locc, lastloc);
#endif

      if (locc == lastloc)
            return;
      lastloc = locc;
      printf("    .%s\n", loctbl[locc]);
}
#endif

/* simulate and optimise the MOD opcode */
static void
simmod(NODE *p)
{
      NODE *r = p->n_right;

      assert(p->n_op == MOD);

      if (!ISUNSIGNED(p->n_type))
            return;

#define ISPOW2(n) ((n) && (((n)&((n)-1)) == 0))

      /* if the right is a constant power of two, then replace with AND */
      if (r->n_op == ICON && ISPOW2(r->n_lval)) {
            p->n_op = AND;
            r->n_lval--;
            return;
      }

#undef ISPOW2

      /* other optimizations can go here */
}

static int constructor;
static int destructor;

/*
 * Give target the opportunity of handling pragmas.
 */
int
mypragma(char *str)
{
      if (strcmp(str, "tls") == 0) {
            uerror("thread-local storage not supported for this target");
            return 1;
      }
      if (strcmp(str, "constructor") == 0 || strcmp(str, "init") == 0) {
            constructor = 1;
            return 1;
      }
      if (strcmp(str, "destructor") == 0 || strcmp(str, "fini") == 0) {
            destructor = 1;
            return 1;
      }

      return 0;
}

/*
 * Called when a identifier has been declared, to give target last word.
 */
void
fixdef(struct symtab *sp)
{
      /* may have sanity checks here */
      if ((constructor || destructor) && (sp->sclass != PARAM)) {
#ifdef MACHOABI
            if (kflag) {
                  if (constructor)
                        printf("\t.mod_init_func\n");
                  else
                        printf("\t.mod_term_func\n");
            } else {
                  if (constructor)
                        printf("\t.constructor\n");
                  else
                        printf("\t.destructor\n");
            }
            printf("\t.p2align 2\n");
            printf("\t.long %s\n", exname(sp->sname));
            printf("\t.text\n");
            constructor = destructor = 0;
#endif
      }
}

/*
 * There is very little different here to the standard builtins.
 * It basically handles promotion of types smaller than INT.
 */

NODE *
powerpc_builtin_stdarg_start(NODE *f, NODE *a, TWORD t)
{
        NODE *p, *q;
        int sz = 1;

        /* check num args and type */
        if (a == NULL || a->n_op != CM || a->n_left->n_op == CM ||
            !ISPTR(a->n_left->n_type))
                goto bad;

        /* must first deal with argument size; use int size */
        p = a->n_right;
        if (p->n_type < INT) {
                /* round up to word */
                sz = SZINT / tsize(p->n_type, p->n_df, p->n_ap);
        }

        p = buildtree(ADDROF, p, NIL);  /* address of last arg */
        p = optim(buildtree(PLUS, p, bcon(sz)));
        q = block(NAME, NIL, NIL, PTR+VOID, 0, 0);
        q = buildtree(CAST, q, p);
        p = q->n_right;
        nfree(q->n_left);
        nfree(q);
        p = buildtree(ASSIGN, a->n_left, p);
        tfree(f);
        nfree(a);

        return p;

bad:
        uerror("bad argument to __builtin_stdarg_start");
        return bcon(0);
}

NODE *
powerpc_builtin_va_arg(NODE *f, NODE *a, TWORD t)
{
        NODE *p, *q, *r;
        int sz, tmpnr;

        /* check num args and type */
        if (a == NULL || a->n_op != CM || a->n_left->n_op == CM ||
            !ISPTR(a->n_left->n_type) || a->n_right->n_op != TYPE)
                goto bad;

        r = a->n_right;

        /* get type size */
        sz = tsize(r->n_type, r->n_df, r->n_ap) / SZCHAR;
        if (sz < SZINT/SZCHAR) {
                werror("%s%s promoted to int when passed through ...",
                        ISUNSIGNED(r->n_type) ? "unsigned " : "",
                        DEUNSIGN(r->n_type) == SHORT ? "short" : "char");
                sz = SZINT/SZCHAR;
            r->n_type = INT;
            r->n_ap = 0;
        }

        p = tcopy(a->n_left);

#if defined(ELFABI)

        /* alignment */
        if (SZINT/SZCHAR && r->n_type != UNIONTY && r->n_type != STRTY) {
                p = buildtree(PLUS, p, bcon(ALSTACK/8 - 1));
                p = block(AND, p, bcon(-ALSTACK/8), p->n_type, p->n_df, p->n_ap);
        }

#endif

        /* create a copy to a temp node */
        q = tempnode(0, p->n_type, p->n_df, p->n_ap);
        tmpnr = regno(q);
        p = buildtree(ASSIGN, q, p);

        q = tempnode(tmpnr, p->n_type, p->n_df, p->n_ap);
        q = buildtree(PLUS, q, bcon(sz));
        q = buildtree(ASSIGN, a->n_left, q);

        q = buildtree(COMOP, p, q);

        nfree(a->n_right);
        nfree(a);
        nfree(f);

        p = tempnode(tmpnr, INCREF(r->n_type), r->n_df, r->n_ap);
        p = buildtree(UMUL, p, NIL);
        p = buildtree(COMOP, q, p);

        return p;

bad:
        uerror("bad argument to __builtin_va_arg");
        return bcon(0);
}

NODE *
powerpc_builtin_va_end(NODE *f, NODE *a, TWORD t)
{
        tfree(f);
        tfree(a);
 
        return bcon(0);
}

NODE *
powerpc_builtin_va_copy(NODE *f, NODE *a, TWORD t)
{
        if (a == NULL || a->n_op != CM || a->n_left->n_op == CM)
                goto bad;
        tfree(f);
        f = buildtree(ASSIGN, a->n_left, a->n_right);
        nfree(a);
        return f;

bad:
        uerror("bad argument to __buildtin_va_copy");
        return bcon(0);
}

NODE *
powerpc_builtin_return_address(NODE *f, NODE *a, TWORD t)
{
      int nframes;
      int i = 0;

      if (a == NULL || a->n_op != ICON)
            goto bad;

      nframes = a->n_lval;

      tfree(f);
      tfree(a);

      f = block(REG, NIL, NIL, PTR+VOID, 0, 0);
      regno(f) = SPREG;

      do {
            f = block(UMUL, f, NIL, PTR+VOID, 0, 0);
      } while (i++ < nframes);

      f = block(PLUS, f, bcon(8), INCREF(PTR+VOID), 0, 0);
      f = buildtree(UMUL, f, NIL);

      return f;
bad:
        uerror("bad argument to __builtin_return_address");
        return bcon(0);
}

NODE *
powerpc_builtin_frame_address(NODE *f, NODE *a, TWORD t)
{
      int nframes;
      int i = 0;

      if (a == NULL || a->n_op != ICON)
            goto bad;

      nframes = a->n_lval;

      tfree(f);
      tfree(a);

      if (nframes == 0) {
            f = block(REG, NIL, NIL, PTR+VOID, 0, 0);
            regno(f) = FPREG;
      } else {
            f = block(REG, NIL, NIL, PTR+VOID, 0, 0);
            regno(f) = SPREG;
            do {
                  f = block(UMUL, f, NIL, PTR+VOID, 0, 0);
            } while (i++ < nframes);
            f = block(PLUS, f, bcon(24), INCREF(PTR+VOID), 0, 0);
            f = buildtree(UMUL, f, NIL);
      }

      return f;
bad:
        uerror("bad argument to __builtin_frame_address");
        return bcon(0);
}

void
pass1_lastchance(struct interpass *ip)
{
}

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