tiny C support; cosmetic improvements for the docs

1 files changed, 1034 insertions, 0 deletions

diff --git a/tinyc/i386-gen.c b/tinyc/i386-gen.c
new file mode 100755
index 000000000..f958ab547
--- /dev/null
+++ b/tinyc/i386-gen.c
@@ -0,0 +1,1034 @@
+/*
+ *  X86 code generator for TCC
+ * 
+ *  Copyright (c) 2001-2004 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
+ */
+
+/* number of available registers */
+#define NB_REGS             4
+
+/* 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_EAX     0x0004
+#define RC_ST0     0x0008 
+#define RC_ECX     0x0010
+#define RC_EDX     0x0020
+#define RC_IRET    RC_EAX /* function return: integer register */
+#define RC_LRET    RC_EDX /* function return: second integer register */
+#define RC_FRET    RC_ST0 /* function return: float register */
+
+/* pretty names for the registers */
+enum {
+    TREG_EAX = 0,
+    TREG_ECX,
+    TREG_EDX,
+    TREG_ST0,
+};
+
+int reg_classes[NB_REGS] = {
+    /* eax */ RC_INT | RC_EAX,
+    /* ecx */ RC_INT | RC_ECX,
+    /* edx */ RC_INT | RC_EDX,
+    /* st0 */ RC_FLOAT | RC_ST0,
+};
+
+/* return registers for function */
+#define REG_IRET TREG_EAX /* single word int return register */
+#define REG_LRET TREG_EDX /* second word return register (for long long) */
+#define REG_FRET TREG_ST0 /* float return register */
+
+/* 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
+
+/* pointer size, in bytes */
+#define PTR_SIZE 4
+
+/* long double size and alignment, in bytes */
+#define LDOUBLE_SIZE  12
+#define LDOUBLE_ALIGN 4
+/* maximum alignment (for aligned attribute support) */
+#define MAX_ALIGN     8
+
+/******************************************************/
+/* ELF defines */
+
+#define EM_TCC_TARGET EM_386
+
+/* relocation type for 32 bit data relocation */
+#define R_DATA_32   R_386_32
+#define R_JMP_SLOT  R_386_JMP_SLOT
+#define R_COPY      R_386_COPY
+
+#define ELF_START_ADDR 0x08048000
+#define ELF_PAGE_SIZE  0x1000
+
+/******************************************************/
+
+static unsigned long func_sub_sp_offset;
+static unsigned long func_bound_offset;
+static int func_ret_sub;
+
+/* XXX: make it faster ? */
+void g(int c)
+{
+    int ind1;
+    ind1 = ind + 1;
+    if (ind1 > cur_text_section->data_allocated)
+        section_realloc(cur_text_section, ind1);
+    cur_text_section->data[ind] = c;
+    ind = ind1;
+}
+
+void o(unsigned int c)
+{
+    while (c) {
+        g(c);
+        c = c >> 8;
+    }
+}
+
+void gen_le32(int c)
+{
+    g(c);
+    g(c >> 8);
+    g(c >> 16);
+    g(c >> 24);
+}
+
+/* output a symbol and patch all calls to it */
+void gsym_addr(int t, int a)
+{
+    int n, *ptr;
+    while (t) {
+        ptr = (int *)(cur_text_section->data + t);
+        n = *ptr; /* next value */
+        *ptr = a - t - 4;
+        t = n;
+    }
+}
+
+void gsym(int t)
+{
+    gsym_addr(t, ind);
+}
+
+/* psym is used to put an instruction with a data field which is a
+   reference to a symbol. It is in fact the same as oad ! */
+#define psym oad
+
+/* instruction + 4 bytes data. Return the address of the data */
+static int oad(int c, int s)
+{
+    int ind1;
+
+    o(c);
+    ind1 = ind + 4;
+    if (ind1 > cur_text_section->data_allocated)
+        section_realloc(cur_text_section, ind1);
+    *(int *)(cur_text_section->data + ind) = s;
+    s = ind;
+    ind = ind1;
+    return s;
+}
+
+/* output constant with relocation if 'r & VT_SYM' is true */
+static void gen_addr32(int r, Sym *sym, int c)
+{
+    if (r & VT_SYM)
+        greloc(cur_text_section, sym, ind, R_386_32);
+    gen_le32(c);
+}
+
+/* generate a modrm reference. 'op_reg' contains the addtionnal 3
+   opcode bits */
+static void gen_modrm(int op_reg, int r, Sym *sym, int c)
+{
+    op_reg = op_reg << 3;
+    if ((r & VT_VALMASK) == VT_CONST) {
+        /* constant memory reference */
+        o(0x05 | op_reg);
+        gen_addr32(r, sym, c);
+    } else if ((r & VT_VALMASK) == VT_LOCAL) {
+        /* currently, we use only ebp as base */
+        if (c == (char)c) {
+            /* short reference */
+            o(0x45 | op_reg);
+            g(c);
+        } else {
+            oad(0x85 | op_reg, c);
+        }
+    } else {
+        g(0x00 | op_reg | (r & VT_VALMASK));
+    }
+}
+
+
+/* load 'r' from value 'sv' */
+void load(int r, SValue *sv)
+{
+    int v, t, ft, fc, fr;
+    SValue v1;
+
+    fr = sv->r;
+    ft = sv->type.t;
+    fc = sv->c.ul;
+
+    v = fr & VT_VALMASK;
+    if (fr & VT_LVAL) {
+        if (v == VT_LLOCAL) {
+            v1.type.t = VT_INT;
+            v1.r = VT_LOCAL | VT_LVAL;
+            v1.c.ul = fc;
+            load(r, &v1);
+            fr = r;
+        }
+        if ((ft & VT_BTYPE) == VT_FLOAT) {
+            o(0xd9); /* flds */
+            r = 0;
+        } else if ((ft & VT_BTYPE) == VT_DOUBLE) {
+            o(0xdd); /* fldl */
+            r = 0;
+        } else if ((ft & VT_BTYPE) == VT_LDOUBLE) {
+            o(0xdb); /* fldt */
+            r = 5;
+        } else if ((ft & VT_TYPE) == VT_BYTE) {
+            o(0xbe0f);   /* movsbl */
+        } else if ((ft & VT_TYPE) == (VT_BYTE | VT_UNSIGNED)) {
+            o(0xb60f);   /* movzbl */
+        } else if ((ft & VT_TYPE) == VT_SHORT) {
+            o(0xbf0f);   /* movswl */
+        } else if ((ft & VT_TYPE) == (VT_SHORT | VT_UNSIGNED)) {
+            o(0xb70f);   /* movzwl */
+        } else {
+            o(0x8b);     /* movl */
+        }
+        gen_modrm(r, fr, sv->sym, fc);
+    } else {
+        if (v == VT_CONST) {
+            o(0xb8 + r); /* mov $xx, r */
+            gen_addr32(fr, sv->sym, fc);
+        } else if (v == VT_LOCAL) {
+            o(0x8d); /* lea xxx(%ebp), r */
+            gen_modrm(r, VT_LOCAL, sv->sym, fc);
+        } else if (v == VT_CMP) {
+            oad(0xb8 + r, 0); /* mov $0, r */
+            o(0x0f); /* setxx %br */
+            o(fc);
+            o(0xc0 + r);
+        } else if (v == VT_JMP || v == VT_JMPI) {
+            t = v & 1;
+            oad(0xb8 + r, t); /* mov $1, r */
+            o(0x05eb); /* jmp after */
+            gsym(fc);
+            oad(0xb8 + r, t ^ 1); /* mov $0, r */
+        } else if (v != r) {
+            o(0x89);
+            o(0xc0 + r + v * 8); /* mov v, r */
+        }
+    }
+}
+
+/* store register 'r' in lvalue 'v' */
+void store(int r, SValue *v)
+{
+    int fr, bt, ft, fc;
+
+    ft = v->type.t;
+    fc = v->c.ul;
+    fr = v->r & VT_VALMASK;
+    bt = ft & VT_BTYPE;
+    /* XXX: incorrect if float reg to reg */
+    if (bt == VT_FLOAT) {
+        o(0xd9); /* fsts */
+        r = 2;
+    } else if (bt == VT_DOUBLE) {
+        o(0xdd); /* fstpl */
+        r = 2;
+    } else if (bt == VT_LDOUBLE) {
+        o(0xc0d9); /* fld %st(0) */
+        o(0xdb); /* fstpt */
+        r = 7;
+    } else {
+        if (bt == VT_SHORT)
+            o(0x66);
+        if (bt == VT_BYTE || bt == VT_BOOL)
+            o(0x88);
+        else
+            o(0x89);
+    }
+    if (fr == VT_CONST ||
+        fr == VT_LOCAL ||
+        (v->r & VT_LVAL)) {
+        gen_modrm(r, v->r, v->sym, fc);
+    } else if (fr != r) {
+        o(0xc0 + fr + r * 8); /* mov r, fr */
+    }
+}
+
+static void gadd_sp(int val)
+{
+    if (val == (char)val) {
+        o(0xc483);
+        g(val);
+    } else {
+        oad(0xc481, val); /* add $xxx, %esp */
+    }
+}
+
+/* '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) {
+        /* constant case */
+        if (vtop->r & VT_SYM) {
+            /* relocation case */
+            greloc(cur_text_section, vtop->sym, 
+                   ind + 1, R_386_PC32);
+        } else {
+            /* put an empty PC32 relocation */
+            put_elf_reloc(symtab_section, cur_text_section, 
+                          ind + 1, R_386_PC32, 0);
+        }
+        oad(0xe8 + is_jmp, vtop->c.ul - 4); /* call/jmp im */
+    } else {
+        /* otherwise, indirect call */
+        r = gv(RC_INT);
+        o(0xff); /* call/jmp *r */
+        o(0xd0 + r + (is_jmp << 4));
+    }
+}
+
+static uint8_t fastcall_regs[3] = { TREG_EAX, TREG_EDX, TREG_ECX };
+static uint8_t fastcallw_regs[2] = { TREG_ECX, TREG_EDX };
+
+/* 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, func_call;
+    Sym *func_sym;
+    
+    args_size = 0;
+    for(i = 0;i < nb_args; i++) {
+        if ((vtop->type.t & VT_BTYPE) == VT_STRUCT) {
+            size = type_size(&vtop->type, &align);
+            /* align to stack align size */
+            size = (size + 3) & ~3;
+            /* allocate the necessary size on stack */
+            oad(0xec81, size); /* sub $xxx, %esp */
+            /* generate structure store */
+            r = get_reg(RC_INT);
+            o(0x89); /* mov %esp, r */
+            o(0xe0 + r);
+            vset(&vtop->type, r | VT_LVAL, 0);
+            vswap();
+            vstore();
+            args_size += size;
+        } else if (is_float(vtop->type.t)) {
+            gv(RC_FLOAT); /* only one float register */
+            if ((vtop->type.t & VT_BTYPE) == VT_FLOAT)
+                size = 4;
+            else if ((vtop->type.t & VT_BTYPE) == VT_DOUBLE)
+                size = 8;
+            else
+                size = 12;
+            oad(0xec81, size); /* sub $xxx, %esp */
+            if (size == 12)
+                o(0x7cdb);
+            else
+                o(0x5cd9 + size - 4); /* fstp[s|l] 0(%esp) */
+            g(0x24);
+            g(0x00);
+            args_size += size;
+        } else {
+            /* simple type (currently always same size) */
+            /* XXX: implicit cast ? */
+            r = gv(RC_INT);
+            if ((vtop->type.t & VT_BTYPE) == VT_LLONG) {
+                size = 8;
+                o(0x50 + vtop->r2); /* push r */
+            } else {
+                size = 4;
+            }
+            o(0x50 + r); /* push r */
+            args_size += size;
+        }
+        vtop--;
+    }
+    save_regs(0); /* save used temporary registers */
+    func_sym = vtop->type.ref;
+    func_call = FUNC_CALL(func_sym->r);
+    /* fast call case */
+    if ((func_call >= FUNC_FASTCALL1 && func_call <= FUNC_FASTCALL3) ||
+        func_call == FUNC_FASTCALLW) {
+        int fastcall_nb_regs;
+        uint8_t *fastcall_regs_ptr;
+        if (func_call == FUNC_FASTCALLW) {
+            fastcall_regs_ptr = fastcallw_regs;
+            fastcall_nb_regs = 2;
+        } else {
+            fastcall_regs_ptr = fastcall_regs;
+            fastcall_nb_regs = func_call - FUNC_FASTCALL1 + 1;
+        }
+        for(i = 0;i < fastcall_nb_regs; i++) {
+            if (args_size <= 0)
+                break;
+            o(0x58 + fastcall_regs_ptr[i]); /* pop r */
+            /* XXX: incorrect for struct/floats */
+            args_size -= 4;
+        }
+    }
+    gcall_or_jmp(0);
+    if (args_size && func_call != FUNC_STDCALL)
+        gadd_sp(args_size);
+    vtop--;
+}
+
+#ifdef TCC_TARGET_PE
+#define FUNC_PROLOG_SIZE 10
+#else
+#define FUNC_PROLOG_SIZE 9
+#endif
+
+/* generate function prolog of type 't' */
+void gfunc_prolog(CType *func_type)
+{
+    int addr, align, size, func_call, fastcall_nb_regs;
+    int param_index, param_addr;
+    uint8_t *fastcall_regs_ptr;
+    Sym *sym;
+    CType *type;
+
+    sym = func_type->ref;
+    func_call = FUNC_CALL(sym->r);
+    addr = 8;
+    loc = 0;
+    if (func_call >= FUNC_FASTCALL1 && func_call <= FUNC_FASTCALL3) {
+        fastcall_nb_regs = func_call - FUNC_FASTCALL1 + 1;
+        fastcall_regs_ptr = fastcall_regs;
+    } else if (func_call == FUNC_FASTCALLW) {
+        fastcall_nb_regs = 2;
+        fastcall_regs_ptr = fastcallw_regs;
+    } else {
+        fastcall_nb_regs = 0;
+        fastcall_regs_ptr = NULL;
+    }
+    param_index = 0;
+
+    ind += FUNC_PROLOG_SIZE;
+    func_sub_sp_offset = ind;
+    /* if the function returns a structure, then add an
+       implicit pointer parameter */
+    func_vt = sym->type;
+    if ((func_vt.t & VT_BTYPE) == VT_STRUCT) {
+        /* XXX: fastcall case ? */
+        func_vc = addr;
+        addr += 4;
+        param_index++;
+    }
+    /* define parameters */
+    while ((sym = sym->next) != NULL) {
+        type = &sym->type;
+        size = type_size(type, &align);
+        size = (size + 3) & ~3;
+#ifdef FUNC_STRUCT_PARAM_AS_PTR
+        /* structs are passed as pointer */
+        if ((type->t & VT_BTYPE) == VT_STRUCT) {
+            size = 4;
+        }
+#endif
+        if (param_index < fastcall_nb_regs) {
+            /* save FASTCALL register */
+            loc -= 4;
+            o(0x89);     /* movl */
+            gen_modrm(fastcall_regs_ptr[param_index], VT_LOCAL, NULL, loc);
+            param_addr = loc;
+        } else {
+            param_addr = addr;
+            addr += size;
+        }
+        sym_push(sym->v & ~SYM_FIELD, type,
+                 VT_LOCAL | lvalue_type(type->t), param_addr);
+        param_index++;
+    }
+    func_ret_sub = 0;
+    /* pascal type call ? */
+    if (func_call == FUNC_STDCALL)
+        func_ret_sub = addr - 8;
+
+    /* leave some room for bound checking code */
+    if (tcc_state->do_bounds_check) {
+        oad(0xb8, 0); /* lbound section pointer */
+        oad(0xb8, 0); /* call to function */
+        func_bound_offset = lbounds_section->data_offset;
+    }
+}
+
+/* generate function epilog */
+void gfunc_epilog(void)
+{
+    int v, saved_ind;
+
+#ifdef CONFIG_TCC_BCHECK
+    if (tcc_state->do_bounds_check
+     && func_bound_offset != lbounds_section->data_offset) {
+        int saved_ind;
+        int *bounds_ptr;
+        Sym *sym, *sym_data;
+        /* add end of table info */
+        bounds_ptr = section_ptr_add(lbounds_section, sizeof(int));
+        *bounds_ptr = 0;
+        /* generate bound local allocation */
+        saved_ind = ind;
+        ind = func_sub_sp_offset;
+        sym_data = get_sym_ref(&char_pointer_type, lbounds_section, 
+                               func_bound_offset, lbounds_section->data_offset);
+        greloc(cur_text_section, sym_data,
+               ind + 1, R_386_32);
+        oad(0xb8, 0); /* mov %eax, xxx */
+        sym = external_global_sym(TOK___bound_local_new, &func_old_type, 0);
+        greloc(cur_text_section, sym, 
+               ind + 1, R_386_PC32);
+        oad(0xe8, -4);
+        ind = saved_ind;
+        /* generate bound check local freeing */
+        o(0x5250); /* save returned value, if any */
+        greloc(cur_text_section, sym_data,
+               ind + 1, R_386_32);
+        oad(0xb8, 0); /* mov %eax, xxx */
+        sym = external_global_sym(TOK___bound_local_delete, &func_old_type, 0);
+        greloc(cur_text_section, sym, 
+               ind + 1, R_386_PC32);
+        oad(0xe8, -4);
+        o(0x585a); /* restore returned value, if any */
+    }
+#endif
+    o(0xc9); /* leave */
+    if (func_ret_sub == 0) {
+        o(0xc3); /* ret */
+    } else {
+        o(0xc2); /* ret n */
+        g(func_ret_sub);
+        g(func_ret_sub >> 8);
+    }
+    /* align local size to word & save local variables */
+    
+    v = (-loc + 3) & -4; 
+    saved_ind = ind;
+    ind = func_sub_sp_offset - FUNC_PROLOG_SIZE;
+#ifdef TCC_TARGET_PE
+    if (v >= 4096) {
+        Sym *sym = external_global_sym(TOK___chkstk, &func_old_type, 0);
+        oad(0xb8, v); /* mov stacksize, %eax */
+        oad(0xe8, -4); /* call __chkstk, (does the stackframe too) */
+        greloc(cur_text_section, sym, ind-4, R_386_PC32);
+    } else
+#endif
+    {
+        o(0xe58955);  /* push %ebp, mov %esp, %ebp */
+        o(0xec81);  /* sub esp, stacksize */
+        gen_le32(v);
+#if FUNC_PROLOG_SIZE == 10
+        o(0x90);  /* adjust to FUNC_PROLOG_SIZE */
+#endif
+    }
+    ind = saved_ind;
+}
+
+/* generate a jump to a label */
+int gjmp(int t)
+{
+    return psym(0xe9, t);
+}
+
+/* generate a jump to a fixed address */
+void gjmp_addr(int a)
+{
+    int r;
+    r = a - ind - 2;
+    if (r == (char)r) {
+        g(0xeb);
+        g(r);
+    } else {
+        oad(0xe9, a - ind - 5);
+    }
+}
+
+/* generate a test. set 'inv' to invert test. Stack entry is popped */
+int gtst(int inv, int t)
+{
+    int v, *p;
+
+    v = vtop->r & VT_VALMASK;
+    if (v == VT_CMP) {
+        /* fast case : can jump directly since flags are set */
+        g(0x0f);
+        t = psym((vtop->c.i - 16) ^ inv, t);
+    } else if (v == VT_JMP || v == VT_JMPI) {
+        /* && or || optimization */
+        if ((v & 1) == inv) {
+            /* insert vtop->c jump list in t */
+            p = &vtop->c.i;
+            while (*p != 0)
+                p = (int *)(cur_text_section->data + *p);
+            *p = t;
+            t = vtop->c.i;
+        } else {
+            t = gjmp(t);
+            gsym(vtop->c.i);
+        }
+    } else {
+        if (is_float(vtop->type.t) || 
+            (vtop->type.t & VT_BTYPE) == VT_LLONG) {
+            vpushi(0);
+            gen_op(TOK_NE);
+        }
+        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(0x85);
+            o(0xc0 + v * 9);
+            g(0x0f);
+            t = psym(0x85 ^ inv, t);
+        }
+    }
+    vtop--;
+    return t;
+}
+
+/* generate an integer binary operation */
+void gen_opi(int op)
+{
+    int r, fr, opc, c;
+
+    switch(op) {
+    case '+':
+    case TOK_ADDC1: /* add with carry generation */
+        opc = 0;
+    gen_op8:
+        if ((vtop->r & (VT_VALMASK | VT_LVAL | VT_SYM)) == VT_CONST) {
+            /* constant case */
+            vswap();
+            r = gv(RC_INT);
+            vswap();
+            c = vtop->c.i;
+            if (c == (char)c) {
+                /* XXX: generate inc and dec for smaller code ? */
+                o(0x83);
+                o(0xc0 | (opc << 3) | r);
+                g(c);
+            } else {
+                o(0x81);
+                oad(0xc0 | (opc << 3) | r, c);
+            }
+        } else {
+            gv2(RC_INT, RC_INT);
+            r = vtop[-1].r;
+            fr = vtop[0].r;
+            o((opc << 3) | 0x01);
+            o(0xc0 + r + fr * 8); 
+        }
+        vtop--;
+        if (op >= TOK_ULT && op <= TOK_GT) {
+            vtop->r = VT_CMP;
+            vtop->c.i = op;
+        }
+        break;
+    case '-':
+    case TOK_SUBC1: /* sub with carry generation */
+        opc = 5;
+        goto gen_op8;
+    case TOK_ADDC2: /* add with carry use */
+        opc = 2;
+        goto gen_op8;
+    case TOK_SUBC2: /* sub with carry use */
+        opc = 3;
+        goto gen_op8;
+    case '&':
+        opc = 4;
+        goto gen_op8;
+    case '^':
+        opc = 6;
+        goto gen_op8;
+    case '|':
+        opc = 1;
+        goto gen_op8;
+    case '*':
+        gv2(RC_INT, RC_INT);
+        r = vtop[-1].r;
+        fr = vtop[0].r;
+        vtop--;
+        o(0xaf0f); /* imul fr, r */
+        o(0xc0 + fr + r * 8);
+        break;
+    case TOK_SHL:
+        opc = 4;
+        goto gen_shift;
+    case TOK_SHR:
+        opc = 5;
+        goto gen_shift;
+    case TOK_SAR:
+        opc = 7;
+    gen_shift:
+        opc = 0xc0 | (opc << 3);
+        if ((vtop->r & (VT_VALMASK | VT_LVAL | VT_SYM)) == VT_CONST) {
+            /* constant case */
+            vswap();
+            r = gv(RC_INT);
+            vswap();
+            c = vtop->c.i & 0x1f;
+            o(0xc1); /* shl/shr/sar $xxx, r */
+            o(opc | r);
+            g(c);
+        } else {
+            /* we generate the shift in ecx */
+            gv2(RC_INT, RC_ECX);
+            r = vtop[-1].r;
+            o(0xd3); /* shl/shr/sar %cl, r */
+            o(opc | r);
+        }
+        vtop--;
+        break;
+    case '/':
+    case TOK_UDIV:
+    case TOK_PDIV:
+    case '%':
+    case TOK_UMOD:
+    case TOK_UMULL:
+        /* first operand must be in eax */
+        /* XXX: need better constraint for second operand */
+        gv2(RC_EAX, RC_ECX);
+        r = vtop[-1].r;
+        fr = vtop[0].r;
+        vtop--;
+        save_reg(TREG_EDX);
+        if (op == TOK_UMULL) {
+            o(0xf7); /* mul fr */
+            o(0xe0 + fr);
+            vtop->r2 = TREG_EDX;
+            r = TREG_EAX;
+        } else {
+            if (op == TOK_UDIV || op == TOK_UMOD) {
+                o(0xf7d231); /* xor %edx, %edx, div fr, %eax */
+                o(0xf0 + fr);
+            } else {
+                o(0xf799); /* cltd, idiv fr, %eax */
+                o(0xf8 + fr);
+            }
+            if (op == '%' || op == TOK_UMOD)
+                r = TREG_EDX;
+            else
+                r = TREG_EAX;
+        }
+        vtop->r = r;
+        break;
+    default:
+        opc = 7;
+        goto gen_op8;
+    }
+}
+
+/* generate a floating point operation 'v = t1 op t2' instruction. The
+   two operands are guaranted to have the same floating point type */
+/* XXX: need to use ST1 too */
+void gen_opf(int op)
+{
+    int a, ft, fc, swapped, r;
+
+    /* convert constants to memory references */
+    if ((vtop[-1].r & (VT_VALMASK | VT_LVAL)) == VT_CONST) {
+        vswap();
+        gv(RC_FLOAT);
+        vswap();
+    }
+    if ((vtop[0].r & (VT_VALMASK | VT_LVAL)) == VT_CONST)
+        gv(RC_FLOAT);
+
+    /* must put at least one value in the floating point register */
+    if ((vtop[-1].r & VT_LVAL) &&
+        (vtop[0].r & VT_LVAL)) {
+        vswap();
+        gv(RC_FLOAT);
+        vswap();
+    }
+    swapped = 0;
+    /* swap the stack if needed so that t1 is the register and t2 is
+       the memory reference */
+    if (vtop[-1].r & VT_LVAL) {
+        vswap();
+        swapped = 1;
+    }
+    if (op >= TOK_ULT && op <= TOK_GT) {
+        /* load on stack second operand */
+        load(TREG_ST0, vtop);
+        save_reg(TREG_EAX); /* eax is used by FP comparison code */
+        if (op == TOK_GE || op == TOK_GT)
+            swapped = !swapped;
+        else if (op == TOK_EQ || op == TOK_NE)
+            swapped = 0;
+        if (swapped)
+            o(0xc9d9); /* fxch %st(1) */
+        o(0xe9da); /* fucompp */
+        o(0xe0df); /* fnstsw %ax */
+        if (op == TOK_EQ) {
+            o(0x45e480); /* and $0x45, %ah */
+            o(0x40fC80); /* cmp $0x40, %ah */
+        } else if (op == TOK_NE) {
+            o(0x45e480); /* and $0x45, %ah */
+            o(0x40f480); /* xor $0x40, %ah */
+            op = TOK_NE;
+        } else if (op == TOK_GE || op == TOK_LE) {
+            o(0x05c4f6); /* test $0x05, %ah */
+            op = TOK_EQ;
+        } else {
+            o(0x45c4f6); /* test $0x45, %ah */
+            op = TOK_EQ;
+        }
+        vtop--;
+        vtop->r = VT_CMP;
+        vtop->c.i = op;
+    } else {
+        /* no memory reference possible for long double operations */
+        if ((vtop->type.t & VT_BTYPE) == VT_LDOUBLE) {
+            load(TREG_ST0, vtop);
+            swapped = !swapped;
+        }
+        
+        switch(op) {
+        default:
+        case '+':
+            a = 0;
+            break;
+        case '-':
+            a = 4;
+            if (swapped)
+                a++;
+            break;
+        case '*':
+            a = 1;
+            break;
+        case '/':
+            a = 6;
+            if (swapped)
+                a++;
+            break;
+        }
+        ft = vtop->type.t;
+        fc = vtop->c.ul;
+        if ((ft & VT_BTYPE) == VT_LDOUBLE) {
+            o(0xde); /* fxxxp %st, %st(1) */
+            o(0xc1 + (a << 3));
+        } else {
+            /* if saved lvalue, then we must reload it */
+            r = vtop->r;
+            if ((r & VT_VALMASK) == VT_LLOCAL) {
+                SValue v1;
+                r = get_reg(RC_INT);
+                v1.type.t = VT_INT;
+                v1.r = VT_LOCAL | VT_LVAL;
+                v1.c.ul = fc;
+                load(r, &v1);
+                fc = 0;
+            }
+
+            if ((ft & VT_BTYPE) == VT_DOUBLE)
+                o(0xdc);
+            else
+                o(0xd8);
+            gen_modrm(a, r, vtop->sym, fc);
+        }
+        vtop--;
+    }
+}
+
+/* convert integers to fp 't' type. Must handle 'int', 'unsigned int'
+   and 'long long' cases. */
+void gen_cvt_itof(int t)
+{
+    save_reg(TREG_ST0);
+    gv(RC_INT);
+    if ((vtop->type.t & VT_BTYPE) == VT_LLONG) {
+        /* signed long long to float/double/long double (unsigned case
+           is handled generically) */
+        o(0x50 + vtop->r2); /* push r2 */
+        o(0x50 + (vtop->r & VT_VALMASK)); /* push r */
+        o(0x242cdf); /* fildll (%esp) */
+        o(0x08c483); /* add $8, %esp */
+    } else if ((vtop->type.t & (VT_BTYPE | VT_UNSIGNED)) == 
+               (VT_INT | VT_UNSIGNED)) {
+        /* unsigned int to float/double/long double */
+        o(0x6a); /* push $0 */
+        g(0x00);
+        o(0x50 + (vtop->r & VT_VALMASK)); /* push r */
+        o(0x242cdf); /* fildll (%esp) */
+        o(0x08c483); /* add $8, %esp */
+    } else {
+        /* int to float/double/long double */
+        o(0x50 + (vtop->r & VT_VALMASK)); /* push r */
+        o(0x2404db); /* fildl (%esp) */
+        o(0x04c483); /* add $4, %esp */
+    }
+    vtop->r = TREG_ST0;
+}
+
+/* convert fp to int 't' type */
+/* XXX: handle long long case */
+void gen_cvt_ftoi(int t)
+{
+    int r, r2, size;
+    Sym *sym;
+    CType ushort_type;
+
+    ushort_type.t = VT_SHORT | VT_UNSIGNED;
+
+    gv(RC_FLOAT);
+    if (t != VT_INT)
+        size = 8;
+    else 
+        size = 4;
+    
+    o(0x2dd9); /* ldcw xxx */
+    sym = external_global_sym(TOK___tcc_int_fpu_control, 
+                              &ushort_type, VT_LVAL);
+    greloc(cur_text_section, sym, 
+           ind, R_386_32);
+    gen_le32(0);
+    
+    oad(0xec81, size); /* sub $xxx, %esp */
+    if (size == 4)
+        o(0x1cdb); /* fistpl */
+    else
+        o(0x3cdf); /* fistpll */
+    o(0x24);
+    o(0x2dd9); /* ldcw xxx */
+    sym = external_global_sym(TOK___tcc_fpu_control, 
+                              &ushort_type, VT_LVAL);
+    greloc(cur_text_section, sym, 
+           ind, R_386_32);
+    gen_le32(0);
+
+    r = get_reg(RC_INT);
+    o(0x58 + r); /* pop r */
+    if (size == 8) {
+        if (t == VT_LLONG) {
+            vtop->r = r; /* mark reg as used */
+            r2 = get_reg(RC_INT);
+            o(0x58 + r2); /* pop r2 */
+            vtop->r2 = r2;
+        } else {
+            o(0x04c483); /* add $4, %esp */
+        }
+    }
+    vtop->r = r;
+}
+
+/* convert from one floating point type to another */
+void gen_cvt_ftof(int t)
+{
+    /* all we have to do on i386 is to put the float in a register */
+    gv(RC_FLOAT);
+}
+
+/* computed goto support */
+void ggoto(void)
+{
+    gcall_or_jmp(1);
+    vtop--;
+}
+
+/* bound check support functions */
+#ifdef CONFIG_TCC_BCHECK
+
+/* generate a bounded pointer addition */
+void gen_bounded_ptr_add(void)
+{
+    Sym *sym;
+
+    /* prepare fast i386 function call (args in eax and edx) */
+    gv2(RC_EAX, RC_EDX);
+    /* save all temporary registers */
+    vtop -= 2;
+    save_regs(0);
+    /* do a fast function call */
+    sym = external_global_sym(TOK___bound_ptr_add, &func_old_type, 0);
+    greloc(cur_text_section, sym, 
+           ind + 1, R_386_PC32);
+    oad(0xe8, -4);
+    /* returned pointer is in eax */
+    vtop++;
+    vtop->r = TREG_EAX | VT_BOUNDED;
+    /* address of bounding function call point */
+    vtop->c.ul = (cur_text_section->reloc->data_offset - sizeof(Elf32_Rel)); 
+}
+
+/* patch pointer addition in vtop so that pointer dereferencing is
+   also tested */
+void gen_bounded_ptr_deref(void)
+{
+    int func;
+    int size, align;
+    Elf32_Rel *rel;
+    Sym *sym;
+
+    size = 0;
+    /* XXX: put that code in generic part of tcc */
+    if (!is_float(vtop->type.t)) {
+        if (vtop->r & VT_LVAL_BYTE)
+            size = 1;
+        else if (vtop->r & VT_LVAL_SHORT)
+            size = 2;
+    }
+    if (!size)
+        size = type_size(&vtop->type, &align);
+    switch(size) {
+    case  1: func = TOK___bound_ptr_indir1; break;
+    case  2: func = TOK___bound_ptr_indir2; break;
+    case  4: func = TOK___bound_ptr_indir4; break;
+    case  8: func = TOK___bound_ptr_indir8; break;
+    case 12: func = TOK___bound_ptr_indir12; break;
+    case 16: func = TOK___bound_ptr_indir16; break;
+    default:
+        error("unhandled size when derefencing bounded pointer");
+        func = 0;
+        break;
+    }
+
+    /* patch relocation */
+    /* XXX: find a better solution ? */
+    rel = (Elf32_Rel *)(cur_text_section->reloc->data + vtop->c.ul);
+    sym = external_global_sym(func, &func_old_type, 0);
+    if (!sym->c)
+        put_extern_sym(sym, NULL, 0, 0);
+    rel->r_info = ELF32_R_INFO(sym->c, ELF32_R_TYPE(rel->r_info));
+}
+#endif
+
+/* end of X86 code generator */
+/*************************************************************/
+