tinycc/arm-gen.c

/*
 *  ARMv4 code generator for TCC
 * 
 *  Copyright (c) 2003 Daniel Gl<EFBFBD>ckner
 *  Copyright (c) 2012 Thomas Preud'homme
 *
 *  Based on i386-gen.c by Fabrice Bellard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifdef TARGET_DEFS_ONLY

#ifdef TCC_ARM_EABI
#ifndef TCC_ARM_VFP // Avoid useless warning
#define TCC_ARM_VFP
#endif
#endif

/* number of available registers */
#ifdef TCC_ARM_VFP
#define NB_REGS            13
#else
#define NB_REGS             9
#endif

/* a register can belong to several classes. The classes must be
   sorted from more general to more precise (see gv2() code which does
   assumptions on it). */
#define RC_INT     0x0001 /* generic integer register */
#define RC_FLOAT   0x0002 /* generic float register */
#define RC_R0      0x0004
#define RC_R1      0x0008 
#define RC_R2      0x0010
#define RC_R3      0x0020
#define RC_R12     0x0040
#define RC_F0      0x0080
#define RC_F1      0x0100
#define RC_F2      0x0200
#define RC_F3      0x0400
#ifdef TCC_ARM_VFP
#define RC_F4      0x0800
#define RC_F5      0x1000
#define RC_F6      0x2000
#define RC_F7      0x4000
#endif
#define RC_IRET    RC_R0  /* function return: integer register */
#define RC_LRET    RC_R1  /* function return: second integer register */
#define RC_FRET    RC_F0  /* function return: float register */

/* pretty names for the registers */
enum {
    TREG_R0 = 0,
    TREG_R1,
    TREG_R2,
    TREG_R3,
    TREG_R12,
    TREG_F0,
    TREG_F1,
    TREG_F2,
    TREG_F3,
#ifdef TCC_ARM_VFP
    TREG_F4,
    TREG_F5,
    TREG_F6,
    TREG_F7,
#endif
};

#ifdef TCC_ARM_VFP
#define T2CPR(t) (((t) & VT_BTYPE) != VT_FLOAT ? 0x100 : 0)
#endif

/* return registers for function */
#define REG_IRET TREG_R0 /* single word int return register */
#define REG_LRET TREG_R1 /* second word return register (for long long) */
#define REG_FRET TREG_F0 /* float return register */

#ifdef TCC_ARM_EABI
#define TOK___divdi3 TOK___aeabi_ldivmod
#define TOK___moddi3 TOK___aeabi_ldivmod
#define TOK___udivdi3 TOK___aeabi_uldivmod
#define TOK___umoddi3 TOK___aeabi_uldivmod
#endif

/* defined if function parameters must be evaluated in reverse order */
#define INVERT_FUNC_PARAMS

/* defined if structures are passed as pointers. Otherwise structures
   are directly pushed on stack. */
//#define FUNC_STRUCT_PARAM_AS_PTR

#if defined(TCC_ARM_EABI) && defined(TCC_ARM_VFP)
ST_DATA CType float_type, double_type, func_float_type, func_double_type;
#define func_ldouble_type func_double_type
#else
#define func_float_type func_old_type
#define func_double_type func_old_type
#define func_ldouble_type func_old_type
#endif

/* pointer size, in bytes */
#define PTR_SIZE 4

/* long double size and alignment, in bytes */
#ifdef TCC_ARM_VFP
#define LDOUBLE_SIZE  8
#endif

#ifndef LDOUBLE_SIZE
#define LDOUBLE_SIZE  8
#endif

#ifdef TCC_ARM_EABI
#define LDOUBLE_ALIGN 8
#else
#define LDOUBLE_ALIGN 4
#endif

/* maximum alignment (for aligned attribute support) */
#define MAX_ALIGN     8

#define CHAR_IS_UNSIGNED

/******************************************************/
/* ELF defines */

#define EM_TCC_TARGET EM_ARM

/* relocation type for 32 bit data relocation */
#define R_DATA_32   R_ARM_ABS32
#define R_DATA_PTR  R_ARM_ABS32
#define R_JMP_SLOT  R_ARM_JUMP_SLOT
#define R_COPY      R_ARM_COPY

#define ELF_START_ADDR 0x00008000
#define ELF_PAGE_SIZE  0x1000

/******************************************************/
#else /* ! TARGET_DEFS_ONLY */
/******************************************************/
#include "tcc.h"

ST_DATA const int reg_classes[NB_REGS] = {
    /* r0 */ RC_INT | RC_R0,
    /* r1 */ RC_INT | RC_R1,
    /* r2 */ RC_INT | RC_R2,
    /* r3 */ RC_INT | RC_R3,
    /* r12 */ RC_INT | RC_R12,
    /* f0 */ RC_FLOAT | RC_F0,
    /* f1 */ RC_FLOAT | RC_F1,
    /* f2 */ RC_FLOAT | RC_F2,
    /* f3 */ RC_FLOAT | RC_F3,
#ifdef TCC_ARM_VFP
 /* d4/s8 */ RC_FLOAT | RC_F4,
/* d5/s10 */ RC_FLOAT | RC_F5,
/* d6/s12 */ RC_FLOAT | RC_F6,
/* d7/s14 */ RC_FLOAT | RC_F7,
#endif
};

/* keep in sync with line 104 above */
#if defined(TCC_ARM_EABI) && defined(TCC_ARM_VFP)
ST_DATA CType float_type, double_type, func_float_type, func_double_type;
#endif

static int func_sub_sp_offset, last_itod_magic;
static int leaffunc;

static int two2mask(int a,int b) {
  return (reg_classes[a]|reg_classes[b])&~(RC_INT|RC_FLOAT);
}

static int regmask(int r) {
  return reg_classes[r]&~(RC_INT|RC_FLOAT);
}

/******************************************************/

void o(uint32_t i)
{
  /* this is a good place to start adding big-endian support*/
  int ind1;

  ind1 = ind + 4;
  if (!cur_text_section)
    tcc_error("compiler error! This happens f.ex. if the compiler\n"
         "can't evaluate constant expressions outside of a function.");
  if (ind1 > cur_text_section->data_allocated)
    section_realloc(cur_text_section, ind1);
  cur_text_section->data[ind++] = i&255;
  i>>=8;
  cur_text_section->data[ind++] = i&255;
  i>>=8; 
  cur_text_section->data[ind++] = i&255;
  i>>=8;
  cur_text_section->data[ind++] = i;
}

static uint32_t stuff_const(uint32_t op, uint32_t c)
{
  int try_neg=0;
  uint32_t nc = 0, negop = 0;

  switch(op&0x1F00000)
  {
    case 0x800000: //add
    case 0x400000: //sub
      try_neg=1;
      negop=op^0xC00000;
      nc=-c;
      break;
    case 0x1A00000: //mov
    case 0x1E00000: //mvn
      try_neg=1;
      negop=op^0x400000;
      nc=~c;
      break;
    case 0x200000: //xor
      if(c==~0)
	return (op&0xF010F000)|((op>>16)&0xF)|0x1E00000;
      break;
    case 0x0: //and
      if(c==~0)
	return (op&0xF010F000)|((op>>16)&0xF)|0x1A00000;
    case 0x1C00000: //bic
      try_neg=1;
      negop=op^0x1C00000;
      nc=~c;
      break;
    case 0x1800000: //orr
      if(c==~0)
	return (op&0xFFF0FFFF)|0x1E00000;
      break;
  }
  do {
    uint32_t m;
    int i;
    if(c<256) /* catch undefined <<32 */
      return op|c;
    for(i=2;i<32;i+=2) {
      m=(0xff>>i)|(0xff<<(32-i));
      if(!(c&~m))
	return op|(i<<7)|(c<<i)|(c>>(32-i));
    }
    op=negop;
    c=nc;
  } while(try_neg--);
  return 0;
}


//only add,sub
void stuff_const_harder(uint32_t op, uint32_t v) {
  uint32_t x;
  x=stuff_const(op,v);
  if(x)
    o(x);
  else {
    uint32_t a[16], nv, no, o2, n2;
    int i,j,k;
    a[0]=0xff;
    o2=(op&0xfff0ffff)|((op&0xf000)<<4);;
    for(i=1;i<16;i++)
      a[i]=(a[i-1]>>2)|(a[i-1]<<30);
    for(i=0;i<12;i++)
      for(j=i<4?i+12:15;j>=i+4;j--)
	if((v&(a[i]|a[j]))==v) {
	  o(stuff_const(op,v&a[i]));
	  o(stuff_const(o2,v&a[j]));
	  return;
	}
    no=op^0xC00000;
    n2=o2^0xC00000;
    nv=-v;
    for(i=0;i<12;i++)
      for(j=i<4?i+12:15;j>=i+4;j--)
	if((nv&(a[i]|a[j]))==nv) {
	  o(stuff_const(no,nv&a[i]));
	  o(stuff_const(n2,nv&a[j]));
	  return;
	}
    for(i=0;i<8;i++)
      for(j=i+4;j<12;j++)
	for(k=i<4?i+12:15;k>=j+4;k--)
	  if((v&(a[i]|a[j]|a[k]))==v) {
	    o(stuff_const(op,v&a[i]));
	    o(stuff_const(o2,v&a[j]));
	    o(stuff_const(o2,v&a[k]));
	    return;
	  }
    no=op^0xC00000;
    nv=-v;
    for(i=0;i<8;i++)
      for(j=i+4;j<12;j++)
	for(k=i<4?i+12:15;k>=j+4;k--)
	  if((nv&(a[i]|a[j]|a[k]))==nv) {
	    o(stuff_const(no,nv&a[i]));
	    o(stuff_const(n2,nv&a[j]));
	    o(stuff_const(n2,nv&a[k]));
	    return;
	  }
    o(stuff_const(op,v&a[0]));
    o(stuff_const(o2,v&a[4]));
    o(stuff_const(o2,v&a[8]));
    o(stuff_const(o2,v&a[12]));
  }
}

ST_FUNC uint32_t encbranch(int pos, int addr, int fail)
{
  addr-=pos+8;
  addr/=4;
  if(addr>=0x1000000 || addr<-0x1000000) {
    if(fail)
      tcc_error("FIXME: function bigger than 32MB");
    return 0;
  }
  return 0x0A000000|(addr&0xffffff);
}

int decbranch(int pos)
{
  int x;
  x=*(uint32_t *)(cur_text_section->data + pos);
  x&=0x00ffffff;
  if(x&0x800000)
    x-=0x1000000;
  return x*4+pos+8;
}

/* output a symbol and patch all calls to it */
void gsym_addr(int t, int a)
{
  uint32_t *x;
  int lt;
  while(t) {
    x=(uint32_t *)(cur_text_section->data + t);
    t=decbranch(lt=t);
    if(a==lt+4)
      *x=0xE1A00000; // nop
    else {
      *x &= 0xff000000;
      *x |= encbranch(lt,a,1);
    }
  }
}

void gsym(int t)
{
  gsym_addr(t, ind);
}

#ifdef TCC_ARM_VFP
static uint32_t vfpr(int r)
{
  if(r<TREG_F0 || r>TREG_F7)
    tcc_error("compiler error! register %i is no vfp register",r);
  return r-5;
}
#else
static uint32_t fpr(int r)
{
  if(r<TREG_F0 || r>TREG_F3)
    tcc_error("compiler error! register %i is no fpa register",r);
  return r-5;
}
#endif

static uint32_t intr(int r)
{
  if(r==4)
    return 12;
  if((r<0 || r>4) && r!=14)
    tcc_error("compiler error! register %i is no int register",r);
  return r;
}

static void calcaddr(uint32_t *base, int *off, int *sgn, int maxoff, unsigned shift)
{
  if(*off>maxoff || *off&((1<<shift)-1)) {
    uint32_t x, y;
    x=0xE280E000;
    if(*sgn)
      x=0xE240E000;
    x|=(*base)<<16;
    *base=14; // lr
    y=stuff_const(x,*off&~maxoff);
    if(y) {
      o(y);
      *off&=maxoff;
      return;
    }
    y=stuff_const(x,(*off+maxoff)&~maxoff);
    if(y) {
      o(y);
      *sgn=!*sgn;
      *off=((*off+maxoff)&~maxoff)-*off;
      return;
    }
    stuff_const_harder(x,*off&~maxoff);
    *off&=maxoff;
  }
}

static uint32_t mapcc(int cc)
{
  switch(cc)
  {
    case TOK_ULT:
      return 0x30000000; /* CC/LO */
    case TOK_UGE:
      return 0x20000000; /* CS/HS */
    case TOK_EQ:
      return 0x00000000; /* EQ */
    case TOK_NE:
      return 0x10000000; /* NE */
    case TOK_ULE:
      return 0x90000000; /* LS */
    case TOK_UGT:
      return 0x80000000; /* HI */
    case TOK_Nset:
      return 0x40000000; /* MI */
    case TOK_Nclear:
      return 0x50000000; /* PL */
    case TOK_LT:
      return 0xB0000000; /* LT */
    case TOK_GE:
      return 0xA0000000; /* GE */
    case TOK_LE:
      return 0xD0000000; /* LE */
    case TOK_GT:
      return 0xC0000000; /* GT */
  }
  tcc_error("unexpected condition code");
  return 0xE0000000; /* AL */
}

static int negcc(int cc)
{
  switch(cc)
  {
    case TOK_ULT:
      return TOK_UGE;
    case TOK_UGE:
      return TOK_ULT;
    case TOK_EQ:
      return TOK_NE;
    case TOK_NE:
      return TOK_EQ;
    case TOK_ULE:
      return TOK_UGT;
    case TOK_UGT:
      return TOK_ULE;
    case TOK_Nset:
      return TOK_Nclear;
    case TOK_Nclear:
      return TOK_Nset;
    case TOK_LT:
      return TOK_GE;
    case TOK_GE:
      return TOK_LT;
    case TOK_LE:
      return TOK_GT;
    case TOK_GT:
      return TOK_LE;
  }
  tcc_error("unexpected condition code");
  return TOK_NE;
}

/* load 'r' from value 'sv' */
void load(int r, SValue *sv)
{
  int v, ft, fc, fr, sign;
  uint32_t op;
  SValue v1;

  fr = sv->r;
  ft = sv->type.t;
  fc = sv->c.ul;

  if(fc>=0)
    sign=0;
  else {
    sign=1;
    fc=-fc;
  }
  
  v = fr & VT_VALMASK;
  if (fr & VT_LVAL) {
    uint32_t base = 0xB; // fp
    if(v == VT_LLOCAL) {
      v1.type.t = VT_PTR;
      v1.r = VT_LOCAL | VT_LVAL;
      v1.c.ul = sv->c.ul;
      load(base=14 /* lr */, &v1);
      fc=sign=0;
      v=VT_LOCAL;
    } else if(v == VT_CONST) {
      v1.type.t = VT_PTR;
      v1.r = fr&~VT_LVAL;
      v1.c.ul = sv->c.ul;
      v1.sym=sv->sym;
      load(base=14, &v1);
      fc=sign=0;
      v=VT_LOCAL;
    } else if(v < VT_CONST) {
      base=intr(v);
      fc=sign=0;
      v=VT_LOCAL;
    }
    if(v == VT_LOCAL) {
      if(is_float(ft)) {
	calcaddr(&base,&fc,&sign,1020,2);
#ifdef TCC_ARM_VFP
        op=0xED100A00; /* flds */
        if(!sign)
          op|=0x800000;
        if ((ft & VT_BTYPE) != VT_FLOAT)
          op|=0x100;   /* flds -> fldd */
        o(op|(vfpr(r)<<12)|(fc>>2)|(base<<16));
#else
	op=0xED100100;
	if(!sign)
	  op|=0x800000;
#if LDOUBLE_SIZE == 8
	if ((ft & VT_BTYPE) != VT_FLOAT)
	  op|=0x8000;
#else
	if ((ft & VT_BTYPE) == VT_DOUBLE)
	  op|=0x8000;
	else if ((ft & VT_BTYPE) == VT_LDOUBLE)
	  op|=0x400000;
#endif
	o(op|(fpr(r)<<12)|(fc>>2)|(base<<16));
#endif
      } else if((ft & (VT_BTYPE|VT_UNSIGNED)) == VT_BYTE
                || (ft & VT_BTYPE) == VT_SHORT) {
	calcaddr(&base,&fc,&sign,255,0);
	op=0xE1500090;
	if ((ft & VT_BTYPE) == VT_SHORT)
	  op|=0x20;
	if ((ft & VT_UNSIGNED) == 0)
	  op|=0x40;
	if(!sign)
	  op|=0x800000;
	o(op|(intr(r)<<12)|(base<<16)|((fc&0xf0)<<4)|(fc&0xf));
      } else {
	calcaddr(&base,&fc,&sign,4095,0);
	op=0xE5100000;
	if(!sign)
	  op|=0x800000;
        if ((ft & VT_BTYPE) == VT_BYTE)
          op|=0x400000;
        o(op|(intr(r)<<12)|fc|(base<<16));
      }
      return;
    }
  } else {
    if (v == VT_CONST) {
      op=stuff_const(0xE3A00000|(intr(r)<<12),sv->c.ul);
      if (fr & VT_SYM || !op) {
        o(0xE59F0000|(intr(r)<<12));
        o(0xEA000000);
        if(fr & VT_SYM)
	  greloc(cur_text_section, sv->sym, ind, R_ARM_ABS32);
        o(sv->c.ul);
      } else
        o(op);
      return;
    } else if (v == VT_LOCAL) {
      op=stuff_const(0xE28B0000|(intr(r)<<12),sv->c.ul);
      if (fr & VT_SYM || !op) {
	o(0xE59F0000|(intr(r)<<12));
	o(0xEA000000);
	if(fr & VT_SYM) // needed ?
	  greloc(cur_text_section, sv->sym, ind, R_ARM_ABS32);
	o(sv->c.ul);
	o(0xE08B0000|(intr(r)<<12)|intr(r));
      } else
	o(op);
      return;
    } else if(v == VT_CMP) {
      o(mapcc(sv->c.ul)|0x3A00001|(intr(r)<<12));
      o(mapcc(negcc(sv->c.ul))|0x3A00000|(intr(r)<<12));
      return;
    } else if (v == VT_JMP || v == VT_JMPI) {
      int t;
      t = v & 1;
      o(0xE3A00000|(intr(r)<<12)|t);
      o(0xEA000000);
      gsym(sv->c.ul);
      o(0xE3A00000|(intr(r)<<12)|(t^1));
      return;
    } else if (v < VT_CONST) {
      if(is_float(ft))
#ifdef TCC_ARM_VFP
        o(0xEEB00A40|(vfpr(r)<<12)|vfpr(v)|T2CPR(ft)); /* fcpyX */
#else
	o(0xEE008180|(fpr(r)<<12)|fpr(v));
#endif
      else
	o(0xE1A00000|(intr(r)<<12)|intr(v));
      return;
    }
  }
  tcc_error("load unimplemented!");
}

/* store register 'r' in lvalue 'v' */
void store(int r, SValue *sv)
{
  SValue v1;
  int v, ft, fc, fr, sign;
  uint32_t op;

  fr = sv->r;
  ft = sv->type.t;
  fc = sv->c.ul;

  if(fc>=0)
    sign=0;
  else {
    sign=1;
    fc=-fc;
  }
  
  v = fr & VT_VALMASK; 
  if (fr & VT_LVAL || fr == VT_LOCAL) {
    uint32_t base = 0xb;
    if(v < VT_CONST) {
      base=intr(v);
      v=VT_LOCAL;
      fc=sign=0;
    } else if(v == VT_CONST) {
      v1.type.t = ft;
      v1.r = fr&~VT_LVAL;
      v1.c.ul = sv->c.ul;
      v1.sym=sv->sym;
      load(base=14, &v1);
      fc=sign=0;
      v=VT_LOCAL;   
    }
    if(v == VT_LOCAL) {
       if(is_float(ft)) {
	calcaddr(&base,&fc,&sign,1020,2);
#ifdef TCC_ARM_VFP
        op=0xED000A00; /* fsts */
        if(!sign) 
          op|=0x800000; 
        if ((ft & VT_BTYPE) != VT_FLOAT) 
          op|=0x100;   /* fsts -> fstd */
        o(op|(vfpr(r)<<12)|(fc>>2)|(base<<16));
#else
	op=0xED000100;
	if(!sign)
	  op|=0x800000;
#if LDOUBLE_SIZE == 8
	if ((ft & VT_BTYPE) != VT_FLOAT)
	  op|=0x8000;
#else
	if ((ft & VT_BTYPE) == VT_DOUBLE)
	  op|=0x8000;
	if ((ft & VT_BTYPE) == VT_LDOUBLE)
	  op|=0x400000;
#endif
	o(op|(fpr(r)<<12)|(fc>>2)|(base<<16));
#endif
	return;
      } else if((ft & VT_BTYPE) == VT_SHORT) {
	calcaddr(&base,&fc,&sign,255,0);
	op=0xE14000B0;
	if(!sign)
	  op|=0x800000;
	o(op|(intr(r)<<12)|(base<<16)|((fc&0xf0)<<4)|(fc&0xf));
      } else {
	calcaddr(&base,&fc,&sign,4095,0);
	op=0xE5000000;
	if(!sign)
	  op|=0x800000;
        if ((ft & VT_BTYPE) == VT_BYTE)
          op|=0x400000;
        o(op|(intr(r)<<12)|fc|(base<<16));
      }
      return;
    }
  }
  tcc_error("store unimplemented");
}

static void gadd_sp(int val)
{
  stuff_const_harder(0xE28DD000,val);
}

/* 'is_jmp' is '1' if it is a jump */
static void gcall_or_jmp(int is_jmp)
{
  int r;
  if ((vtop->r & (VT_VALMASK | VT_LVAL)) == VT_CONST) {
    uint32_t x;
    /* constant case */
    x=encbranch(ind,ind+vtop->c.ul,0);
    if(x) {
      if (vtop->r & VT_SYM) {
	/* relocation case */
	greloc(cur_text_section, vtop->sym, ind, R_ARM_PC24);
      } else
	put_elf_reloc(symtab_section, cur_text_section, ind, R_ARM_PC24, 0);
      o(x|(is_jmp?0xE0000000:0xE1000000));
    } else {
      if(!is_jmp)
	o(0xE28FE004); // add lr,pc,#4
      o(0xE51FF004);   // ldr pc,[pc,#-4]
      if (vtop->r & VT_SYM)
	greloc(cur_text_section, vtop->sym, ind, R_ARM_ABS32);
      o(vtop->c.ul);
    }
  } else {
    /* otherwise, indirect call */
    r = gv(RC_INT);
    if(!is_jmp)
      o(0xE1A0E00F);       // mov lr,pc
    o(0xE1A0F000|intr(r)); // mov pc,r
  }
}

#ifdef TCC_ARM_HARDFLOAT
static int is_float_hgen_aggr(CType *type)
{
  if ((type->t & VT_BTYPE) == VT_STRUCT) {
    struct Sym *ref;
    int btype, nb_fields = 0;

    ref = type->ref;
    btype = ref->type.t & VT_BTYPE;
    if (btype == VT_FLOAT || btype == VT_DOUBLE) {
      for(; ref && btype == (ref->type.t & VT_BTYPE); ref = ref->next, nb_fields++);
      return !ref && nb_fields <= 4;
    }
  }
  return 0;
}

struct avail_regs {
  /* worst case: f(float, double, 3 float struct, double, 3 float struct, double) */
  signed char avail[3];
  int first_hole;
  int last_hole;
  int first_free_reg;
};

#define AVAIL_REGS_INITIALIZER (struct avail_regs) { { 0, 0, 0}, 0, 0, 0 }

/* Assign a register for a CPRC param with correct size and alignment
 * size and align are in bytes, as returned by type_size */
int assign_fpreg(struct avail_regs *avregs, int align, int size)
{
  int first_reg = 0;

  if (avregs->first_free_reg == -1)
    return -1;
  if (align >> 3) { // alignment needed (base type: double)
    first_reg = avregs->first_free_reg;
    if (first_reg & 1)
      avregs->avail[avregs->last_hole++] = first_reg++;
  } else {
    if (size == 4 && avregs->first_hole != avregs->last_hole)
      return avregs->avail[avregs->first_hole++];
    else
      first_reg = avregs->first_free_reg;
  }
  if (first_reg + size / 4 <= 16) {
    avregs->first_free_reg = first_reg + size / 4;
    return first_reg;
  }
  avregs->first_free_reg = -1;
  return -1;
}
#endif

/* Generate function call. The function address is pushed first, then
   all the parameters in call order. This functions pops all the
   parameters and the function address. */
void gfunc_call(int nb_args)
{
  int size, align, r, args_size, i, ncrn, ncprn, argno, vfp_argno;
  signed char plan[4][2]={{-1,-1},{-1,-1},{-1,-1},{-1,-1}};
  SValue *before_stack = NULL; /* SValue before first on stack argument */
  SValue *before_vfpreg_hfa = NULL; /* SValue before first in VFP reg hfa argument */
#ifdef TCC_ARM_HARDFLOAT
  struct avail_regs avregs = AVAIL_REGS_INITIALIZER;
  signed char vfp_plan[16];
  int plan2[4+16];
  int variadic;
#else
  int plan2[4]={0,0,0,0};
#endif
  int vfp_todo=0;
  int todo=0, keep;

#ifdef TCC_ARM_HARDFLOAT
  memset(vfp_plan, -1, sizeof(vfp_plan));
  memset(plan2, 0, sizeof(plan2));
  variadic = (vtop[-nb_args].type.ref->c == FUNC_ELLIPSIS);
#endif
  r = vtop->r & VT_VALMASK;
  if (r == VT_CMP || (r & ~1) == VT_JMP)
    gv(RC_INT);
#ifdef TCC_ARM_EABI
  if((vtop[-nb_args].type.ref->type.t & VT_BTYPE) == VT_STRUCT
     && type_size(&vtop[-nb_args].type.ref->type, &align) <= 4) {
    SValue tmp;
    tmp=vtop[-nb_args];
    vtop[-nb_args]=vtop[-nb_args+1];
    vtop[-nb_args+1]=tmp;
    --nb_args;
  }
  
  vpushi(0), nb_args++;
  vtop->type.t = VT_LLONG;
  args_size = 0;
#endif
  ncrn = ncprn = argno = vfp_argno = 0;
  /* Assign argument to registers and stack with alignment.
     If, considering alignment constraints, enough registers of the correct type
     (core or VFP) are free for the current argument, assign them to it, else
     allocate on stack with correct alignment. Whenever a structure is allocated
     in registers or on stack, it is always put on the stack at this stage. The
     stack is divided in 3 zones. The zone are, from low addresses to high
     addresses: structures to be loaded in core registers, structures to be
     loaded in VFP registers, argument allocated to stack. SValue's representing
     structures in the first zone are moved just after the SValue pointed by
     before_vfpreg_hfa. SValue's representing structures in the second zone are
     moved just after the SValue pointer by before_stack. */
  for(i = nb_args; i-- ;) {
    int j, assigned_vfpreg = 0;
    size = type_size(&vtop[-i].type, &align);
    switch(vtop[-i].type.t & VT_BTYPE) {
      case VT_STRUCT:
      case VT_FLOAT:
      case VT_DOUBLE:
      case VT_LDOUBLE:
#ifdef TCC_ARM_HARDFLOAT
      if (!variadic) {
        int hfa = 0; /* Homogeneous float aggregate */

        if (is_float(vtop[-i].type.t)
            || (hfa = is_float_hgen_aggr(&vtop[-i].type))) {
          int end_reg;

          assigned_vfpreg = assign_fpreg(&avregs, align, size);
          end_reg = assigned_vfpreg + (size - 1) / 4;
          if (assigned_vfpreg >= 0) {
            vfp_plan[vfp_argno++]=TREG_F0 + assigned_vfpreg/2;
            if (hfa) {
              /* before_stack can only have been set because all core registers
                 are assigned, so no need to care about before_vfpreg_hfa if
                 before_stack is set */
              if (before_stack) {
	        vrote(&vtop[-i], &vtop[-i] - before_stack);
                before_stack++;
              } else if (!before_vfpreg_hfa)
                before_vfpreg_hfa = &vtop[-i-1];
              for (j = assigned_vfpreg; j <= end_reg; j++)
                vfp_todo|=(1<<j);
            }
            continue;
          } else {
            if (!hfa)
              vfp_argno++;
            /* No need to update before_stack as no more hfa can be allocated in
               VFP regs */
            if (!before_vfpreg_hfa)
              before_vfpreg_hfa = &vtop[-i-1];
            break;
          }
        }
      }
#endif
      ncrn = (ncrn + (align-1)/4) & -(align/4);
      size = (size + 3) & -4;
      if (ncrn + size/4 <= 4 || (ncrn < 4 && assigned_vfpreg != -1)) {
        /* Either there is HFA in VFP registers, or there is arguments on stack,
           it cannot be both. Hence either before_stack already points after
           the slot where the vtop[-i] SValue is moved, or before_stack will not
           be used */
        if (before_vfpreg_hfa) {
	  vrote(&vtop[-i], &vtop[-i] - before_vfpreg_hfa);
          before_vfpreg_hfa++;
        }
        for (j = ncrn; j < 4 && j < ncrn + size / 4; j++)
          todo|=(1<<j);
        ncrn+=size/4;
        if (ncrn > 4) {
          args_size = (ncrn - 4) * 4;
          if (!before_stack)
            before_stack = &vtop[-i-1];
        }
      }
      else {
        ncrn = 4;
        /* No need to set before_vfpreg_hfa if not set since there will no
           longer be any structure assigned to core registers */
        if (!before_stack)
          before_stack = &vtop[-i-1];
        break;
      }
      continue;
      default:
#ifdef TCC_ARM_EABI
      if (!i) {
        break;
      }
#endif
      if (ncrn < 4) {
        int is_long = (vtop[-i].type.t & VT_BTYPE) == VT_LLONG;

        if (is_long) {
          ncrn = (ncrn + 1) & -2;
          if (ncrn == 4) {
            argno++;
            break;
          }
        }
        plan[argno++][0]=ncrn++;
        if (is_long) {
          plan[argno-1][1]=ncrn++;
        }
        continue;
      }
      argno++;
    }
#ifdef TCC_ARM_EABI
    if(args_size & (align-1)) {
      vpushi(0);
      vtop->type.t = VT_VOID; /* padding */
      vrott(i+2);
      args_size += 4;
      nb_args++;
      argno++;
    }
#endif
    args_size += (size + 3) & -4;
  }
#ifdef TCC_ARM_EABI
  vtop--, nb_args--;
#endif
  args_size = keep = 0;
  for(i = 0;i < nb_args; i++) {
    vrotb(keep+1);
    if ((vtop->type.t & VT_BTYPE) == VT_STRUCT) {
      size = type_size(&vtop->type, &align);
      /* align to stack align size */
      size = (size + 3) & -4;
      /* allocate the necessary size on stack */
      gadd_sp(-size);
      /* generate structure store */
      r = get_reg(RC_INT);
      o(0xE1A0000D|(intr(r)<<12));
      vset(&vtop->type, r | VT_LVAL, 0);
      vswap();
      vstore();
      vtop--;
      args_size += size;
    } else if (is_float(vtop->type.t)) {
#ifdef TCC_ARM_HARDFLOAT
      if (!variadic && --vfp_argno<16 && vfp_plan[vfp_argno]!=-1) {
        plan2[keep++]=vfp_plan[vfp_argno];
        continue;
      }
#endif
#ifdef TCC_ARM_VFP
      r=vfpr(gv(RC_FLOAT))<<12;
      size=4;
      if ((vtop->type.t & VT_BTYPE) != VT_FLOAT)
      {
        size=8;
        r|=0x101; /* fstms -> fstmd */
      }
      o(0xED2D0A01+r);
#else
      r=fpr(gv(RC_FLOAT))<<12;
      if ((vtop->type.t & VT_BTYPE) == VT_FLOAT)
        size = 4;
      else if ((vtop->type.t & VT_BTYPE) == VT_DOUBLE)
        size = 8;
      else
        size = LDOUBLE_SIZE;
      
      if (size == 12)
	r|=0x400000;
      else if(size == 8)
	r|=0x8000;

      o(0xED2D0100|r|(size>>2));
#endif
      vtop--;
      args_size += size;
    } else {
      int s;
      /* simple type (currently always same size) */
      /* XXX: implicit cast ? */
      size=4;
      if ((vtop->type.t & VT_BTYPE) == VT_LLONG) {
	lexpand_nr();
	s=-1;
	if(--argno<4 && plan[argno][1]!=-1)
	  s=plan[argno][1];
	argno++;
	size = 8;
	if(s==-1) {
	  r = gv(RC_INT);
	  o(0xE52D0004|(intr(r)<<12)); /* str r,[sp,#-4]! */
	  vtop--;
	} else {
	  size=0;
	  plan2[keep]=s;
	  keep++;
          vswap();
	}
      }
      s=-1;
      if(--argno<4 && plan[argno][0]!=-1)
        s=plan[argno][0];
#ifdef TCC_ARM_EABI
      if(vtop->type.t == VT_VOID) {
        if(s == -1)
          o(0xE24DD004); /* sub sp,sp,#4 */
        vtop--;
      } else
#endif
      if(s == -1) {
	r = gv(RC_INT);
	o(0xE52D0004|(intr(r)<<12)); /* str r,[sp,#-4]! */
	vtop--;
      } else {
        size=0;
	plan2[keep]=s;
	keep++;
      }
      args_size += size;
    }
  }
  for(i = 0; i < keep; i++) {
    vrotb(keep);
    gv(regmask(plan2[i]));
#ifdef TCC_ARM_HARDFLOAT
    /* arg is in s(2d+1): plan2[i]<plan2[i+1] => alignment occured (ex f,d,f) */
    if (i < keep - 1 && is_float(vtop->type.t) && (plan2[i] <= plan2[i + 1])) {
      o(0xEEF00A40|(vfpr(plan2[i])<<12)|vfpr(plan2[i]));
    }
#endif
  }
save_regs(keep); /* save used temporary registers */
  keep++;
  if(ncrn) {
    int nb_regs=0;
    if (ncrn>4)
      ncrn=4;
    todo&=((1<<ncrn)-1);
    if(todo) {
      int i;
      o(0xE8BD0000|todo);
      for(i=0;i<4;i++)
	if(todo&(1<<i)) {
	  vpushi(0);
	  vtop->r=i;
	  keep++;
	  nb_regs++;
	}
    }
    args_size-=nb_regs*4;
  }
  if(vfp_todo) {
    int nb_fregs=0;

    for(i=0;i<16;i++)
      if(vfp_todo&(1<<i)) {
        o(0xED9D0A00|(i&1)<<22|(i>>1)<<12|nb_fregs);
        vpushi(0);
        /* There might be 2 floats in a double VFP reg but that doesn't seem
           to matter */
        if (!(i%2))
          vtop->r=TREG_F0+i/2;
        keep++;
        nb_fregs++;
      }
    if (nb_fregs) {
      gadd_sp(nb_fregs*4);
      args_size-=nb_fregs*4;
    }
  }
  vrotb(keep);
  gcall_or_jmp(0);
  if (args_size)
      gadd_sp(args_size);
#ifdef TCC_ARM_EABI
  if((vtop->type.ref->type.t & VT_BTYPE) == VT_STRUCT
     && type_size(&vtop->type.ref->type, &align) <= 4)
  {
    store(REG_IRET,vtop-keep);
    ++keep;
  }
#ifdef TCC_ARM_VFP
#ifdef TCC_ARM_HARDFLOAT
  else if(variadic && is_float(vtop->type.ref->type.t)) {
#else
  else if(is_float(vtop->type.ref->type.t)) {
#endif
    if((vtop->type.ref->type.t & VT_BTYPE) == VT_FLOAT) {
      o(0xEE000A10); /* fmsr s0,r0 */
    } else {
      o(0xEE000B10); /* fmdlr d0,r0 */
      o(0xEE201B10); /* fmdhr d0,r1 */
    }
  }
#endif
#endif
  vtop-=keep;
  leaffunc = 0;
}

/* generate function prolog of type 't' */
void gfunc_prolog(CType *func_type)
{
  Sym *sym,*sym2;
  int n,nf,size,align, variadic, struct_ret = 0;
#ifdef TCC_ARM_HARDFLOAT
  struct avail_regs avregs = AVAIL_REGS_INITIALIZER;
#endif

  sym = func_type->ref;
  func_vt = sym->type;

  n = nf = 0;
  variadic = (func_type->ref->c == FUNC_ELLIPSIS);
  if((func_vt.t & VT_BTYPE) == VT_STRUCT
     && type_size(&func_vt,&align) > 4)
  {
    n++;
    struct_ret = 1;
    func_vc = 12; /* Offset from fp of the place to store the result */
  }
  for(sym2=sym->next;sym2 && (n<4 || nf<16);sym2=sym2->next) {
    size = type_size(&sym2->type, &align);
#ifdef TCC_ARM_HARDFLOAT
    if (!variadic && (is_float(sym2->type.t)
        || is_float_hgen_aggr(&sym2->type))) {
      int tmpnf = assign_fpreg(&avregs, align, size) + 1;
      nf = (tmpnf > nf) ? tmpnf : nf;
    } else
#endif
    if (n < 4)
      n += (size + 3) / 4;
  }
  o(0xE1A0C00D); /* mov ip,sp */
  if(variadic)
    n=4;
  if(n) {
    if(n>4)
      n=4;
#ifdef TCC_ARM_EABI
    n=(n+1)&-2;
#endif
    o(0xE92D0000|((1<<n)-1)); /* save r0-r4 on stack if needed */
  }
  if (nf) {
    if (nf>16)
      nf=16;
    nf=(nf+1)&-2; /* nf => HARDFLOAT => EABI */
    o(0xED2D0A00|nf); /* save s0-s15 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 in epilogue */
  {
    int addr, pn = struct_ret, sn = 0; /* pn=core, sn=stack */

#ifdef TCC_ARM_HARDFLOAT
    avregs = AVAIL_REGS_INITIALIZER;
#endif
    while ((sym = sym->next)) {
      CType *type;
      type = &sym->type;
      size = type_size(type, &align);
      size = (size + 3) >> 2;
#ifdef TCC_ARM_HARDFLOAT
      if (!variadic && (is_float(sym->type.t)
          || is_float_hgen_aggr(&sym->type))) {
        int fpn = assign_fpreg(&avregs, align, size << 2);
        if (fpn >= 0) {
          addr = fpn * 4;
        } else
          goto from_stack;
      } else
#endif
      if (pn < 4) {
#ifdef TCC_ARM_EABI
        pn = (pn + (align-1)/4) & -(align/4);
#endif
        addr = (nf + pn) * 4;
        pn += size;
        if (!sn && pn > 4)
          sn = (pn - 4);
      } else {
#ifdef TCC_ARM_HARDFLOAT
from_stack:
#endif
#ifdef TCC_ARM_EABI
        sn = (sn + (align-1)/4) & -(align/4);
#endif
        addr = (n + nf + sn) * 4;
        sn += size;
      }
      sym_push(sym->v & ~SYM_FIELD, type, VT_LOCAL | lvalue_type(type->t), addr+12);
    }
  }
  last_itod_magic=0;
  leaffunc = 1;
  loc = 0;
}

/* generate function epilog */
void gfunc_epilog(void)
{
  uint32_t x;
  int diff;
#ifdef TCC_ARM_EABI
  /* Useless but harmless copy of the float result into main register(s) in case
     of variadic function in the hardfloat variant */
  if(is_float(func_vt.t)) {
    if((func_vt.t & VT_BTYPE) == VT_FLOAT)
      o(0xEE100A10); /* fmrs r0, s0 */
    else {
      o(0xEE100B10); /* fmrdl r0, d0 */
      o(0xEE301B10); /* fmrdh r1, d0 */
    }
  }
#endif
  o(0xE89BA800); /* restore fp, sp, pc */
  diff = (-loc + 3) & -4;
#ifdef TCC_ARM_EABI
  if(!leaffunc)
    diff = ((diff + 11) & -8) - 4;
#endif
  if(diff > 0) {
    x=stuff_const(0xE24BD000, diff); /* sub sp,fp,# */
    if(x)
      *(uint32_t *)(cur_text_section->data + func_sub_sp_offset) = x;
    else {
      int addr;
      addr=ind;
      o(0xE59FC004); /* ldr ip,[pc+4] */
      o(0xE04BD00C); /* sub sp,fp,ip  */
      o(0xE1A0F00E); /* mov pc,lr */
      o(diff);
      *(uint32_t *)(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;
  uint32_t 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 {
	uint32_t *x;
	int p,lp;
	if(t) {
          p = vtop->c.i;
          do {
	    p = decbranch(lp=p);
          } while(p);
	  x = (uint32_t *)(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);
#ifdef TCC_ARM_VFP
      o(0xEEB50A40|(vfpr(r)<<12)|T2CPR(vtop->type.t)); /* fcmpzX */
      o(0xEEF1FA10); /* fmstat */
#else
      o(0xEE90F118|(fpr(r)<<16));
#endif
      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;
  uint32_t opc = 0, r, fr;
  unsigned short retreg = REG_IRET;

  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 '%':
#ifdef TCC_ARM_EABI
      func=TOK___aeabi_idivmod;
      retreg=REG_LRET;
#else
      func=TOK___modsi3;
#endif
      c=3;
      break;
    case TOK_UMOD:
#ifdef TCC_ARM_EABI
      func=TOK___aeabi_uidivmod;
      retreg=REG_LRET;
#else
      func=TOK___umodsi3;
#endif
      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) {
	uint32_t 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 = retreg;
      break;
    default:
      tcc_error("gen_opi %i unimplemented!",op);
  }
}

#ifdef TCC_ARM_VFP
static int is_zero(int i)
{
  if((vtop[i].r & (VT_VALMASK | VT_LVAL | VT_SYM)) != VT_CONST)
    return 0;
  if (vtop[i].type.t == VT_FLOAT)
    return (vtop[i].c.f == 0.f);
  else if (vtop[i].type.t == VT_DOUBLE)
    return (vtop[i].c.d == 0.0);
  return (vtop[i].c.ld == 0.l);
}

/* 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)
{
  uint32_t x;
  int fneg=0,r;
  x=0xEE000A00|T2CPR(vtop->type.t);
  switch(op) {
    case '+':
      if(is_zero(-1))
        vswap();
      if(is_zero(0)) {
        vtop--;
        return;
      }
      x|=0x300000;
      break;
    case '-':
      x|=0x300040;
      if(is_zero(0)) {
        vtop--;
        return;
      }
      if(is_zero(-1)) {
        x|=0x810000; /* fsubX -> fnegX */
        vswap();
        vtop--;
        fneg=1;
      }
      break;
    case '*':
      x|=0x200000;
      break;
    case '/':
      x|=0x800000;
      break;
    default:
      if(op < TOK_ULT || op > TOK_GT) {
        tcc_error("unknown fp op %x!",op);
        return;
      }
      if(is_zero(-1)) {
        vswap();
        switch(op) {
          case TOK_LT: op=TOK_GT; break;
          case TOK_GE: op=TOK_ULE; break;
          case TOK_LE: op=TOK_GE; break;
          case TOK_GT: op=TOK_ULT; break;
        }
      }
      x|=0xB40040; /* fcmpX */
      if(op!=TOK_EQ && op!=TOK_NE)
        x|=0x80; /* fcmpX -> fcmpeX */
      if(is_zero(0)) {
        vtop--;
        o(x|0x10000|(vfpr(gv(RC_FLOAT))<<12)); /* fcmp(e)X -> fcmp(e)zX */
      } else {
        x|=vfpr(gv(RC_FLOAT));
        vswap();
        o(x|(vfpr(gv(RC_FLOAT))<<12));
        vtop--;
      }
      o(0xEEF1FA10); /* fmstat */

      switch(op) {
        case TOK_LE: op=TOK_ULE; break;
        case TOK_LT: op=TOK_ULT; break;
        case TOK_UGE: op=TOK_GE; break;
        case TOK_UGT: op=TOK_GT; break;
      }
      
      vtop->r = VT_CMP;
      vtop->c.i = op;
      return;
  }
  r=gv(RC_FLOAT);
  x|=vfpr(r);
  r=regmask(r);
  if(!fneg) {
    int r2;
    vswap();
    r2=gv(RC_FLOAT);
    x|=vfpr(r2)<<16;
    r|=regmask(r2);
  }
  vtop->r=get_reg_ex(RC_FLOAT,r);
  if(!fneg)
    vtop--;
  o(x|(vfpr(vtop->r)<<12));
}

#else
static uint32_t is_fconst()
{
  long double f;
  uint32_t 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)
{
  uint32_t x, 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
/* bug (intention?) in Linux FPU emulator
   doesn't set carry if equal */
	switch(op) {
	  case TOK_ULT:
	  case TOK_UGE:
	  case TOK_ULE:
	  case TOK_UGT:
            tcc_error("unsigned comparision on floats?");
	    break;
	  case TOK_LT:
            op=TOK_Nset;
	    break;
	  case TOK_LE:
            op=TOK_ULE; /* correct in unordered case only if AC bit in FPSR set */
	    break;
	  case TOK_EQ:
	  case TOK_NE:
	    x&=~0x400000; // cmfe -> cmf
	    break;
	}
	if(c1 && !c2) {
	  c2=c1;
	  vswap();
	  switch(op) {
            case TOK_Nset:
              op=TOK_GT;
	      break;
            case TOK_GE:
	      op=TOK_ULE;
	      break;
	    case TOK_ULE:
              op=TOK_GE;
	      break;
            case TOK_GT:
              op=TOK_Nset;
	      break;
	  }
	}
	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 {
        tcc_error("unknown fp op %x!",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);
}
#endif

/* convert integers to fp 't' type. Must handle 'int', 'unsigned int'
   and 'long long' cases. */
ST_FUNC void gen_cvt_itof1(int t)
{
  uint32_t r, r2;
  int bt;
  bt=vtop->type.t & VT_BTYPE;
  if(bt == VT_INT || bt == VT_SHORT || bt == VT_BYTE) {
#ifndef TCC_ARM_VFP
    uint32_t dsize = 0;
#endif
    r=intr(gv(RC_INT));
#ifdef TCC_ARM_VFP
    r2=vfpr(vtop->r=get_reg(RC_FLOAT));
    o(0xEE000A10|(r<<12)|(r2<<16)); /* fmsr */
    r2<<=12;
    if(!(vtop->type.t & VT_UNSIGNED))
      r2|=0x80;                /* fuitoX -> fsituX */
    o(0xEEB80A40|r2|T2CPR(t)); /* fYitoX*/
#else
    r2=fpr(vtop->r=get_reg(RC_FLOAT));
    if((t & VT_BTYPE) != VT_FLOAT)
      dsize=0x80;    /* flts -> fltd */
    o(0xEE000110|dsize|(r2<<16)|(r<<12)); /* flts */
    if((vtop->type.t & (VT_UNSIGNED|VT_BTYPE)) == (VT_UNSIGNED|VT_INT)) {
      uint32_t off = 0;
      o(0xE3500000|(r<<12));        /* cmp */
      r=fpr(get_reg(RC_FLOAT));
      if(last_itod_magic) {
	off=ind+8-last_itod_magic;
	off/=4;
	if(off>255)
	  off=0;
      }
      o(0xBD1F0100|(r<<12)|off);    /* ldflts */
      if(!off) {
        o(0xEA000000);              /* b */
        last_itod_magic=ind;
        o(0x4F800000);              /* 4294967296.0f */
      }
      o(0xBE000100|dsize|(r2<<16)|(r2<<12)|r); /* adflt */
    }
#endif
    return;
  } else if(bt == VT_LLONG) {
    int func;
    CType *func_type = 0;
    if((t & VT_BTYPE) == VT_FLOAT) {
      func_type = &func_float_type;
      if(vtop->type.t & VT_UNSIGNED)
        func=TOK___floatundisf;
      else
        func=TOK___floatdisf;
#if LDOUBLE_SIZE != 8
    } else if((t & VT_BTYPE) == VT_LDOUBLE) {
      func_type = &func_ldouble_type;
      if(vtop->type.t & VT_UNSIGNED)
        func=TOK___floatundixf;
      else
        func=TOK___floatdixf;
    } else if((t & VT_BTYPE) == VT_DOUBLE) {
#else
    } else if((t & VT_BTYPE) == VT_DOUBLE || (t & VT_BTYPE) == VT_LDOUBLE) {
#endif
      func_type = &func_double_type;
      if(vtop->type.t & VT_UNSIGNED)
        func=TOK___floatundidf;
      else
        func=TOK___floatdidf;
    }
    if(func_type) {
      vpush_global_sym(func_type, func);
      vswap();
      gfunc_call(1);
      vpushi(0);
      vtop->r=TREG_F0;
      return;
    }
  }
  tcc_error("unimplemented gen_cvt_itof %x!",vtop->type.t);
}

/* convert fp to int 't' type */
void gen_cvt_ftoi(int t)
{
  uint32_t r, r2;
  int u, func = 0;
  u=t&VT_UNSIGNED;
  t&=VT_BTYPE;
  r2=vtop->type.t & VT_BTYPE;
  if(t==VT_INT) {
#ifdef TCC_ARM_VFP
    r=vfpr(gv(RC_FLOAT));
    u=u?0:0x10000;
    o(0xEEBC0A40|(r<<12)|r|T2CPR(r2)); /* ftoXiY */
    r2=intr(vtop->r=get_reg(RC_INT));
    o(0xEE100A10|(r<<16)|(r2<<12));
    return;
#else
    if(u) {
      if(r2 == VT_FLOAT)
        func=TOK___fixunssfsi;
#if LDOUBLE_SIZE != 8
      else if(r2 == VT_LDOUBLE)
	func=TOK___fixunsxfsi;
      else if(r2 == VT_DOUBLE)
#else
      else if(r2 == VT_LDOUBLE || r2 == VT_DOUBLE)
#endif
	func=TOK___fixunsdfsi;
    } else {
      r=fpr(gv(RC_FLOAT));
      r2=intr(vtop->r=get_reg(RC_INT));
      o(0xEE100170|(r2<<12)|r);
      return;
    }
#endif
  } else if(t == VT_LLONG) { // unsigned handled in gen_cvt_ftoi1
    if(r2 == VT_FLOAT)
      func=TOK___fixsfdi;
#if LDOUBLE_SIZE != 8
    else if(r2 == VT_LDOUBLE)
      func=TOK___fixxfdi;
    else if(r2 == VT_DOUBLE)
#else
    else if(r2 == VT_LDOUBLE || r2 == VT_DOUBLE)
#endif
      func=TOK___fixdfdi;
  }
  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;
  }
  tcc_error("unimplemented gen_cvt_ftoi!");
}

/* convert from one floating point type to another */
void gen_cvt_ftof(int t)
{
#ifdef TCC_ARM_VFP
  if(((vtop->type.t & VT_BTYPE) == VT_FLOAT) != ((t & VT_BTYPE) == VT_FLOAT)) {
    uint32_t r = vfpr(gv(RC_FLOAT));
    o(0xEEB70AC0|(r<<12)|r|T2CPR(vtop->type.t));
  }
#else
  /* all we have to do on i386 and FPA ARM is to put the float in a register */
  gv(RC_FLOAT);
#endif
}

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

/* end of ARM code generator */
/*************************************************************/
#endif
/*************************************************************/