arm-gen.c

Tiny C&C++,看看吧,也许用的着

      /* simple type (currently always same size) */
      /* XXX: implicit cast ? */
      size=4;
      if ((vtop->type.t & VT_BTYPE) == VT_LLONG) {
	lexpand_nr();
	s=RC_INT;
	if(nb_args-i<5 && plan[nb_args-i-1][1]!=-1) {
	  s=regmask(plan[nb_args-i-1][1]);
	  todo&=~(1<<plan[nb_args-i-1][1]);
	}
	if(s==RC_INT) {
	  r = gv(s);
	  o(0xE52D0004|(intr(r)<<12)); /* str r,[sp,#-4]! */
	  vtop--;
	} else {
	  plan2[keep]=s;
	  keep++;
          vswap();
	}
	size = 8;
      }
      s=RC_INT;
      if(nb_args-i<5 && plan[nb_args-i-1][0]!=-1) {
        s=regmask(plan[nb_args-i-1][0]);
	todo&=~(1<<plan[nb_args-i-1][0]);
      }
      if(s==RC_INT) {
	r = gv(s);
	o(0xE52D0004|(intr(r)<<12)); /* str r,[sp,#-4]! */
	vtop--;
      } else {
	plan2[keep]=s;
	keep++;
      }
      args_size += size;
    }
  }
  for(i=keep;i--;) {
    gv(plan2[i]);
    vrott(keep);
  }
  save_regs(keep); /* save used temporary registers */
  keep++;
  if(args_size) {
    int n;
    n=args_size/4;
    if(n>4)
      n=4;
    todo&=((1<<n)-1);
    if(todo) {
      int i;
      o(0xE8BD0000|todo);
      for(i=0;i<4;i++)
	if(todo&(1<<i)) {
	  vpushi(0);
	  vtop->r=i;
	  keep++;
	}
    }
    args_size-=n*4;
  }
  vnrott(keep);
  func_sym = vtop->type.ref;
  gcall_or_jmp(0);
  if (args_size)
      gadd_sp(args_size);
  vtop-=keep;
}

/* generate function prolog of type 't' */
void gfunc_prolog(CType *func_type)
{
  Sym *sym,*sym2;
  int n,addr,size,align;

  sym = func_type->ref;
  func_vt = sym->type;
  
  n=0;
  addr=12;
  if((func_vt.t & VT_BTYPE) == VT_STRUCT) {
    func_vc = addr;
    addr += 4;
    n++;
  }
  for(sym2=sym->next;sym2 && n<4;sym2=sym2->next) {
    size = type_size(&sym2->type, &align);
    size = (size + 3) & ~3;
    n+=size/4;
  }
  o(0xE1A0C00D); /* mov ip,sp */
  if(func_type->ref->c == FUNC_ELLIPSIS)
    n=4;
  if(n) {
    if(n>4)
      n=4;
    o(0xE92D0000|((1<<n)-1)); /* save r0-r4 on stack if needed */
  }
  o(0xE92D5800); /* save fp, ip, lr*/
  o(0xE1A0B00D); /* mov fp,sp */
  func_sub_sp_offset = ind;
  o(0xE1A00000); /* nop, leave space for stack adjustment */
  while ((sym = sym->next)) {
    CType *type;
    type = &sym->type;
    sym_push(sym->v & ~SYM_FIELD, type, VT_LOCAL | VT_LVAL, addr);
    size = type_size(type, &align);
    size = (size + 3) & ~3;
    addr += size;
  }
  last_itod_magic=0;
  loc = 0;
}

/* generate function epilog */
void gfunc_epilog(void)
{
  unsigned long x;
  o(0xE89BA800); /* restore fp, sp, pc */
  if(loc) {
    x=stuff_const(0xE24DD000, (-loc + 3) & -4); /* sub sp,sp,# */
    if(x)
      *(unsigned long *)(cur_text_section->data + func_sub_sp_offset) = x;
    else {
      unsigned long addr;
      addr=ind;
      o(0xE59FC004); /* ldr ip,[pc+4] */
      o(0xE04DD00C); /* sub sp,sp,ip  */
      o(0xE1A0F00E); /* mov pc,lr */
      o((-loc + 3) & -4);
      *(unsigned long *)(cur_text_section->data + func_sub_sp_offset) = 0xE1000000|encbranch(func_sub_sp_offset,addr,1);
    }
  }
}

/* generate a jump to a label */
int gjmp(int t)
{
  int r;
  r=ind;
  o(0xE0000000|encbranch(r,t,1));
  return r;
}

/* generate a jump to a fixed address */
void gjmp_addr(int a)
{
  gjmp(a);
}

/* generate a test. set 'inv' to invert test. Stack entry is popped */
int gtst(int inv, int t)
{
  int v, r;
  unsigned long op;
  v = vtop->r & VT_VALMASK;
  r=ind;
  if (v == VT_CMP) {
    op=mapcc(inv?negcc(vtop->c.i):vtop->c.i);
    op|=encbranch(r,t,1);
    o(op);
    t=r;
  } else if (v == VT_JMP || v == VT_JMPI) {
    if ((v & 1) == inv) {
      if(!vtop->c.i)
	vtop->c.i=t;
      else {
	unsigned long *x;
	int p,lp;
	if(t) {
          p = vtop->c.i;
          do {
	    p = decbranch(lp=p);
          } while(p);
	  x = (unsigned long *)(cur_text_section->data + lp);
	  *x &= 0xff000000;
	  *x |= encbranch(lp,t,1);
	}
	t = vtop->c.i;
      }
    } else {
      t = gjmp(t);
      gsym(vtop->c.i);
    }
  } else {
    if (is_float(vtop->type.t)) {
      r=gv(RC_FLOAT);
      o(0xEE90F118|fpr(r)<<16);
      vtop->r = VT_CMP;
      vtop->c.i = TOK_NE;
      return gtst(inv, t);
    } else if ((vtop->r & (VT_VALMASK | VT_LVAL | VT_SYM)) == VT_CONST) {
      /* constant jmp optimization */
      if ((vtop->c.i != 0) != inv) 
	t = gjmp(t);
    } else {
      v = gv(RC_INT);
      o(0xE3300000|(intr(v)<<16));
      vtop->r = VT_CMP;
      vtop->c.i = TOK_NE;
      return gtst(inv, t);
    }   
  }
  vtop--;
  return t;
}

/* generate an integer binary operation */
void gen_opi(int op)
{
  int c, func = 0;
  unsigned long opc = 0,r,fr;

  c=0;
  switch(op) {
    case '+':
      opc = 0x8;
      c=1;
      break;
    case TOK_ADDC1: /* add with carry generation */
      opc = 0x9;
      c=1;
      break;
    case '-':
      opc = 0x4;
      c=1;
      break;
    case TOK_SUBC1: /* sub with carry generation */
      opc = 0x5;
      c=1;
      break;
    case TOK_ADDC2: /* add with carry use */
      opc = 0xA;
      c=1;
      break;
    case TOK_SUBC2: /* sub with carry use */
      opc = 0xC;
      c=1;
      break;
    case '&':
      opc = 0x0;
      c=1;
      break;
    case '^':
      opc = 0x2;
      c=1;
      break;
    case '|':
      opc = 0x18;
      c=1;
      break;
    case '*':
      gv2(RC_INT, RC_INT);
      r = vtop[-1].r;
      fr = vtop[0].r;
      vtop--;
      o(0xE0000090|(intr(r)<<16)|(intr(r)<<8)|intr(fr));
      return;
    case TOK_SHL:
      opc = 0;
      c=2;
      break;
    case TOK_SHR:
      opc = 1;
      c=2;
      break;
    case TOK_SAR:
      opc = 2;
      c=2;
      break;
    case '/':
    case TOK_PDIV:
      func=TOK___divsi3;
      c=3;
      break;
    case TOK_UDIV:
      func=TOK___udivsi3;
      c=3;
      break;
    case '%':
      func=TOK___modsi3;
      c=3;
      break;
    case TOK_UMOD:
      func=TOK___umodsi3;
      c=3;
      break;
    case TOK_UMULL:
      gv2(RC_INT, RC_INT);
      r=intr(vtop[-1].r2=get_reg(RC_INT));
      c=vtop[-1].r;
      vtop[-1].r=get_reg_ex(RC_INT,regmask(c));
      vtop--;
      o(0xE0800090|(r<<16)|(intr(vtop->r)<<12)|(intr(c)<<8)|intr(vtop[1].r));
      return;
    default:
      opc = 0x15;
      c=1;
      break;
  }
  switch(c) {
    case 1:
      if((vtop[-1].r & (VT_VALMASK | VT_LVAL | VT_SYM)) == VT_CONST) {
	if(opc == 4 || opc == 5 || opc == 0xc) {
	  vswap();
	  opc|=2; // sub -> rsb
	}
      }
      if ((vtop->r & VT_VALMASK) == VT_CMP ||
          (vtop->r & (VT_VALMASK & ~1)) == VT_JMP)
        gv(RC_INT);
      vswap();
      c=intr(gv(RC_INT));
      vswap();
      opc=0xE0000000|(opc<<20)|(c<<16);
      if((vtop->r & (VT_VALMASK | VT_LVAL | VT_SYM)) == VT_CONST) {
	unsigned long x;
	x=stuff_const(opc|0x2000000,vtop->c.i);
	if(x) {
	  r=intr(vtop[-1].r=get_reg_ex(RC_INT,regmask(vtop[-1].r)));
	  o(x|(r<<12));
	  goto done;
	}
      }
      fr=intr(gv(RC_INT));
      r=intr(vtop[-1].r=get_reg_ex(RC_INT,two2mask(vtop->r,vtop[-1].r)));
      o(opc|(r<<12)|fr);
done:
      vtop--;
      if (op >= TOK_ULT && op <= TOK_GT) {
        vtop->r = VT_CMP;
        vtop->c.i = op;
      }
      break;
    case 2:
      opc=0xE1A00000|(opc<<5);
      if ((vtop->r & VT_VALMASK) == VT_CMP ||
          (vtop->r & (VT_VALMASK & ~1)) == VT_JMP)
        gv(RC_INT);
      vswap();
      r=intr(gv(RC_INT));
      vswap();
      opc|=r;
      if ((vtop->r & (VT_VALMASK | VT_LVAL | VT_SYM)) == VT_CONST) {
	fr=intr(vtop[-1].r=get_reg_ex(RC_INT,regmask(vtop[-1].r)));
	c = vtop->c.i & 0x1f;
	o(opc|(c<<7)|(fr<<12));
      } else {
        fr=intr(gv(RC_INT));
	c=intr(vtop[-1].r=get_reg_ex(RC_INT,two2mask(vtop->r,vtop[-1].r)));
	o(opc|(c<<12)|(fr<<8)|0x10);
      }
      vtop--;
      break;
    case 3:
      vpush_global_sym(&func_old_type, func);
      vrott(3);
      gfunc_call(2);
      vpushi(0);
      vtop->r = REG_IRET;
      break;
    default:
      error("gen_opi %i unimplemented!",op);
  }
}

static int is_fconst()
{
  long double f;
  int r;
  if((vtop->r & (VT_VALMASK | VT_LVAL | VT_SYM)) != VT_CONST)
    return 0;
  if (vtop->type.t == VT_FLOAT)
    f = vtop->c.f;
  else if (vtop->type.t == VT_DOUBLE)
    f = vtop->c.d;
  else
    f = vtop->c.ld;
  if(!ieee_finite(f))
    return 0;
  r=0x8;
  if(f<0.0) {
    r=0x18;
    f=-f;
  }
  if(f==0.0)
    return r;
  if(f==1.0)
    return r|1;
  if(f==2.0)
    return r|2;
  if(f==3.0)
    return r|3;
  if(f==4.0)
    return r|4;
  if(f==5.0)
    return r|5;
  if(f==0.5)
    return r|6;
  if(f==10.0)
    return r|7;
  return 0;
}

/* generate a floating point operation 'v = t1 op t2' instruction. The
   two operands are guaranted to have the same floating point type */
void gen_opf(int op)
{
  unsigned long x;
  int r,r2,c1,c2;
  //fputs("gen_opf\n",stderr);
  vswap();
  c1 = is_fconst();
  vswap();
  c2 = is_fconst();
  x=0xEE000100;
#if LDOUBLE_SIZE == 8
  if ((vtop->type.t & VT_BTYPE) != VT_FLOAT)
    x|=0x80;
#else
  if ((vtop->type.t & VT_BTYPE) == VT_DOUBLE)
    x|=0x80;
  else if ((vtop->type.t & VT_BTYPE) == VT_LDOUBLE)
    x|=0x80000;
#endif
  switch(op)
  {
    case '+':
      if(!c2) {
	vswap();
	c2=c1;
      }
      vswap();
      r=fpr(gv(RC_FLOAT));
      vswap();
      if(c2) {
	if(c2>0xf)
	  x|=0x200000; // suf
	r2=c2&0xf;
      } else {
	r2=fpr(gv(RC_FLOAT));
      }
      break;
    case '-':
      if(c2) {
	if(c2<=0xf)
	  x|=0x200000; // suf
	r2=c2&0xf;
	vswap();
	r=fpr(gv(RC_FLOAT));
	vswap();
      } else if(c1 && c1<=0xf) {
	x|=0x300000; // rsf
	r2=c1;
	r=fpr(gv(RC_FLOAT));
	vswap();
      } else {
	x|=0x200000; // suf
	vswap();
	r=fpr(gv(RC_FLOAT));
	vswap();
	r2=fpr(gv(RC_FLOAT));
      }
      break;
    case '*':
      if(!c2 || c2>0xf) {
	vswap();
	c2=c1;
      }
      vswap();
      r=fpr(gv(RC_FLOAT));
      vswap();
      if(c2 && c2<=0xf)
	r2=c2;
      else
	r2=fpr(gv(RC_FLOAT));
      x|=0x100000; // muf
      break;
    case '/':
      if(c2 && c2<=0xf) {
	x|=0x400000; // dvf
	r2=c2;
	vswap();
	r=fpr(gv(RC_FLOAT));
	vswap();
      } else if(c1 && c1<=0xf) {
	x|=0x500000; // rdf
	r2=c1;
	r=fpr(gv(RC_FLOAT));
	vswap();
      } else {
	x|=0x400000; // dvf
	vswap();
	r=fpr(gv(RC_FLOAT));
	vswap();
	r2=fpr(gv(RC_FLOAT));
      }     
      break;
    default:
      if(op >= TOK_ULT && op <= TOK_GT) {
	x|=0xd0f110; // cmfe
	switch(op) {
	  case TOK_ULT:
	  case TOK_UGE:
	  case TOK_ULE:
	  case TOK_UGT:
	    fputs("unsigned comparision on floats?\n",stderr);
	    break;
	  case TOK_LT:
	    op=TOK_ULT;
	    break;
	  case TOK_GE:
	    op=TOK_UGE;
	    break;
	  case TOK_LE:
	    op=TOK_ULE;
	    break;
	  case TOK_GT:
	    op=TOK_UGT;
	    break;
	  case TOK_EQ:
	  case TOK_NE:
	    x&=~0x400000; // cmfe -> cmf
	    break;
	}
	if(c1 && !c2) {
	  c2=c1;
	  vswap();
	  switch(op) {
	    case TOK_ULT:
	      op=TOK_UGT;
	      break;
	    case TOK_UGE:
	      op=TOK_ULE;
	      break;
	    case TOK_ULE:
	      op=TOK_UGE;
	      break;
	    case TOK_UGT:
	      op=TOK_ULT;
	      break;
	  }
	}
// bug (intention?) in Linux FPU emulator
// doesn't set carry if equal
	if(op==TOK_ULT)
	  op=TOK_LT;
	else if(op==TOK_UGE)
	  op=TOK_GE;
	vswap();
	r=fpr(gv(RC_FLOAT));
	vswap();
	if(c2) {
	  if(c2>0xf)
	    x|=0x200000;
	  r2=c2&0xf;
	} else {
	  r2=fpr(gv(RC_FLOAT));
	}
	vtop[-1].r = VT_CMP;
	vtop[-1].c.i = op;
      } else {
	error("unknown fp op %x!\n",op);
	return;
      }
  }
  if(vtop[-1].r == VT_CMP)
    c1=15;
  else {
    c1=vtop->r;
    if(r2&0x8)
      c1=vtop[-1].r;
    vtop[-1].r=get_reg_ex(RC_FLOAT,two2mask(vtop[-1].r,c1));
    c1=fpr(vtop[-1].r);
  }
  vtop--;
  o(x|(r<<16)|(c1<<12)|r2);
}

/* convert integers to fp 't' type. Must handle 'int', 'unsigned int'
   and 'long long' cases. */
void gen_cvt_itof(int t)
{
  int r,r2,bt;
  bt=vtop->type.t & VT_BTYPE;
  if(bt == VT_INT || bt == VT_SHORT || bt == VT_BYTE) {
    r=intr(gv(RC_INT));
    r2=fpr(vtop->r=get_reg(RC_FLOAT));
    o(0xEE000190|(r2<<16)|(r<<12));
    if((vtop->type.t & (VT_UNSIGNED|VT_BTYPE)) == (VT_UNSIGNED|VT_INT)) {
      unsigned int off=0;
      o(0xE3500000|(r<<12));
      r=fpr(get_reg(RC_FLOAT));
      if(last_itod_magic) {
	off=ind+8-last_itod_magic;
	off/=4;
	if(off>255)
	  off=0;
      }
      o(0xBD1F8100|(r<<12)|off);
      if(!off) {
        o(0xEA000001);
        last_itod_magic=ind;
        o(0x41F00000);
        o(0);
      }
      o(0xBE000180|(r2<<16)|(r2<<12)|r);
    }
    return;
  } else if(bt == VT_LLONG) {
    int func;
    if(vtop->type.t & VT_UNSIGNED)
      func=TOK___ulltold;
    else
      func=TOK___slltold;
    vpush_global_sym(&func_old_type, func);
    vswap();
    gfunc_call(1);
    vpushi(0);
    vtop->r=TREG_F0;
    return;
  }
  error("unimplemented gen_cvt_itof %x!",vtop->type.t);
}

/* convert fp to int 't' type */
void gen_cvt_ftoi(int t)
{
  int r,r2,u,func=0;
  u=t&VT_UNSIGNED;
  t&=VT_BTYPE;
  r2=vtop->type.t & VT_BTYPE;
  if(t==VT_INT) {
    if(u) {
      if(r2 == VT_FLOAT)
        func=TOK___fixunssfsi;
      else if(r2 == VT_DOUBLE)
	func=TOK___fixunsdfsi;
      else if(r2 == VT_LDOUBLE)
#if LDOUBLE_SIZE == 8
	func=TOK___fixunsdfsi;
#else
	func=TOK___fixunsxfsi;
#endif
    } else {
      r=fpr(gv(RC_FLOAT));
      r2=intr(vtop->r=get_reg(RC_INT));
      o(0xEE100170|(r2<<12)|r);
    return;
    }
  } else if(t == VT_LLONG) { // unsigned handled in gen_cvt_ftoi1
    if(r2 == VT_FLOAT)
      func=TOK___fixsfdi;
    else if(r2 == VT_DOUBLE)
      func=TOK___fixdfdi;
    else if(r2 == VT_LDOUBLE)
#if LDOUBLE_SIZE == 8
      func=TOK___fixdfdi;
#else
      func=TOK___fixxfdi;
#endif
    }
  if(func) {
    vpush_global_sym(&func_old_type, func);
    vswap();
    gfunc_call(1);
    vpushi(0);
    if(t == VT_LLONG)
      vtop->r2 = REG_LRET;
    vtop->r = REG_IRET;
    return;
  }
  error("unimplemented gen_cvt_ftoi!");
}

/* convert from one floating point type to another */
void gen_cvt_ftof(int t)
{
  /* all we have to do on i386 and ARM is to put the float in a register */
  gv(RC_FLOAT);
}

/* computed goto support */
void ggoto(void)
{
  gcall_or_jmp(1);
  vtop--;
}

/* end of ARM code generator */
/*************************************************************/