2 * X86 code generator for TCC
4 * Copyright (c) 2001, 2002, 2003 Fabrice Bellard
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 /* number of available registers */
24 /* a register can belong to several classes. The classes must be
25 sorted from more general to more precise (see gv2() code which does
26 assumptions on it). */
27 #define RC_INT 0x0001 /* generic integer register */
28 #define RC_FLOAT 0x0002 /* generic float register */
33 #define RC_IRET RC_EAX /* function return: integer register */
34 #define RC_LRET RC_EDX /* function return: second integer register */
35 #define RC_FRET RC_ST0 /* function return: float register */
37 /* pretty names for the registers */
45 int reg_classes
[NB_REGS
] = {
46 /* eax */ RC_INT
| RC_EAX
,
47 /* ecx */ RC_INT
| RC_ECX
,
48 /* edx */ RC_INT
| RC_EDX
,
49 /* st0 */ RC_FLOAT
| RC_ST0
,
52 /* return registers for function */
53 #define REG_IRET TREG_EAX /* single word int return register */
54 #define REG_LRET TREG_EDX /* second word return register (for long long) */
55 #define REG_FRET TREG_ST0 /* float return register */
57 /* defined if function parameters must be evaluated in reverse order */
58 #define INVERT_FUNC_PARAMS
60 /* defined if structures are passed as pointers. Otherwise structures
61 are directly pushed on stack. */
62 //#define FUNC_STRUCT_PARAM_AS_PTR
64 /* pointer size, in bytes */
67 /* long double size and alignment, in bytes */
68 #define LDOUBLE_SIZE 12
69 #define LDOUBLE_ALIGN 4
70 /* maximum alignment (for aligned attribute support) */
73 /******************************************************/
76 #define EM_TCC_TARGET EM_386
78 /* relocation type for 32 bit data relocation */
79 #define R_DATA_32 R_386_32
80 #define R_JMP_SLOT R_386_JMP_SLOT
81 #define R_COPY R_386_COPY
83 #define ELF_START_ADDR 0x08048000
84 #define ELF_PAGE_SIZE 0x1000
86 /******************************************************/
88 static unsigned long func_sub_sp_offset
;
89 static unsigned long func_bound_offset
;
90 static int func_ret_sub
;
92 /* XXX: make it faster ? */
97 if (ind1
> cur_text_section
->data_allocated
)
98 section_realloc(cur_text_section
, ind1
);
99 cur_text_section
->data
[ind
] = c
;
119 /* output a symbol and patch all calls to it */
120 void gsym_addr(int t
, int a
)
124 ptr
= (int *)(cur_text_section
->data
+ t
);
125 n
= *ptr
; /* next value */
136 /* psym is used to put an instruction with a data field which is a
137 reference to a symbol. It is in fact the same as oad ! */
140 /* instruction + 4 bytes data. Return the address of the data */
141 static int oad(int c
, int s
)
147 if (ind1
> cur_text_section
->data_allocated
)
148 section_realloc(cur_text_section
, ind1
);
149 *(int *)(cur_text_section
->data
+ ind
) = s
;
155 /* output constant with relocation if 'r & VT_SYM' is true */
156 static void gen_addr32(int r
, Sym
*sym
, int c
)
159 greloc(cur_text_section
, sym
, ind
, R_386_32
);
163 /* generate a modrm reference. 'op_reg' contains the addtionnal 3
165 static void gen_modrm(int op_reg
, int r
, Sym
*sym
, int c
)
167 op_reg
= op_reg
<< 3;
168 if ((r
& VT_VALMASK
) == VT_CONST
) {
169 /* constant memory reference */
171 gen_addr32(r
, sym
, c
);
172 } else if ((r
& VT_VALMASK
) == VT_LOCAL
) {
173 /* currently, we use only ebp as base */
175 /* short reference */
179 oad(0x85 | op_reg
, c
);
182 g(0x00 | op_reg
| (r
& VT_VALMASK
));
187 /* load 'r' from value 'sv' */
188 void load(int r
, SValue
*sv
)
190 int v
, t
, ft
, fc
, fr
;
199 if (v
== VT_LLOCAL
) {
201 v1
.r
= VT_LOCAL
| VT_LVAL
;
206 if ((ft
& VT_BTYPE
) == VT_FLOAT
) {
209 } else if ((ft
& VT_BTYPE
) == VT_DOUBLE
) {
212 } else if ((ft
& VT_BTYPE
) == VT_LDOUBLE
) {
215 } else if ((ft
& VT_TYPE
) == VT_BYTE
) {
216 o(0xbe0f); /* movsbl */
217 } else if ((ft
& VT_TYPE
) == (VT_BYTE
| VT_UNSIGNED
)) {
218 o(0xb60f); /* movzbl */
219 } else if ((ft
& VT_TYPE
) == VT_SHORT
) {
220 o(0xbf0f); /* movswl */
221 } else if ((ft
& VT_TYPE
) == (VT_SHORT
| VT_UNSIGNED
)) {
222 o(0xb70f); /* movzwl */
226 gen_modrm(r
, fr
, sv
->sym
, fc
);
229 o(0xb8 + r
); /* mov $xx, r */
230 gen_addr32(fr
, sv
->sym
, fc
);
231 } else if (v
== VT_LOCAL
) {
232 o(0x8d); /* lea xxx(%ebp), r */
233 gen_modrm(r
, VT_LOCAL
, sv
->sym
, fc
);
234 } else if (v
== VT_CMP
) {
235 oad(0xb8 + r
, 0); /* mov $0, r */
236 o(0x0f); /* setxx %br */
239 } else if (v
== VT_JMP
|| v
== VT_JMPI
) {
241 oad(0xb8 + r
, t
); /* mov $1, r */
242 o(0x05eb); /* jmp after */
244 oad(0xb8 + r
, t
^ 1); /* mov $0, r */
247 o(0xc0 + r
+ v
* 8); /* mov v, r */
252 /* store register 'r' in lvalue 'v' */
253 void store(int r
, SValue
*v
)
259 fr
= v
->r
& VT_VALMASK
;
261 /* XXX: incorrect if float reg to reg */
262 if (bt
== VT_FLOAT
) {
265 } else if (bt
== VT_DOUBLE
) {
268 } else if (bt
== VT_LDOUBLE
) {
269 o(0xc0d9); /* fld %st(0) */
280 if (fr
== VT_CONST
||
283 gen_modrm(r
, v
->r
, v
->sym
, fc
);
284 } else if (fr
!= r
) {
285 o(0xc0 + fr
+ r
* 8); /* mov r, fr */
289 static void gadd_sp(int val
)
291 if (val
== (char)val
) {
295 oad(0xc481, val
); /* add $xxx, %esp */
299 /* 'is_jmp' is '1' if it is a jump */
300 static void gcall_or_jmp(int is_jmp
)
303 if ((vtop
->r
& (VT_VALMASK
| VT_LVAL
)) == VT_CONST
) {
305 if (vtop
->r
& VT_SYM
) {
306 /* relocation case */
307 greloc(cur_text_section
, vtop
->sym
,
308 ind
+ 1, R_386_PC32
);
310 /* put an empty PC32 relocation */
311 put_elf_reloc(symtab_section
, cur_text_section
,
312 ind
+ 1, R_386_PC32
, 0);
314 oad(0xe8 + is_jmp
, vtop
->c
.ul
- 4); /* call/jmp im */
316 /* otherwise, indirect call */
318 o(0xff); /* call/jmp *r */
319 o(0xd0 + r
+ (is_jmp
<< 4));
323 /* Generate function call. The function address is pushed first, then
324 all the parameters in call order. This functions pops all the
325 parameters and the function address. */
326 void gfunc_call(int nb_args
)
328 int size
, align
, r
, args_size
, i
;
332 for(i
= 0;i
< nb_args
; i
++) {
333 if ((vtop
->type
.t
& VT_BTYPE
) == VT_STRUCT
) {
334 size
= type_size(&vtop
->type
, &align
);
335 /* align to stack align size */
336 size
= (size
+ 3) & ~3;
337 /* allocate the necessary size on stack */
338 oad(0xec81, size
); /* sub $xxx, %esp */
339 /* generate structure store */
341 o(0x89); /* mov %esp, r */
343 vset(&vtop
->type
, r
| VT_LVAL
, 0);
347 } else if (is_float(vtop
->type
.t
)) {
348 gv(RC_FLOAT
); /* only one float register */
349 if ((vtop
->type
.t
& VT_BTYPE
) == VT_FLOAT
)
351 else if ((vtop
->type
.t
& VT_BTYPE
) == VT_DOUBLE
)
355 oad(0xec81, size
); /* sub $xxx, %esp */
359 o(0x5cd9 + size
- 4); /* fstp[s|l] 0(%esp) */
364 /* simple type (currently always same size) */
365 /* XXX: implicit cast ? */
367 if ((vtop
->type
.t
& VT_BTYPE
) == VT_LLONG
) {
369 o(0x50 + vtop
->r2
); /* push r */
373 o(0x50 + r
); /* push r */
378 save_regs(0); /* save used temporary registers */
379 func_sym
= vtop
->type
.ref
;
381 if (args_size
&& func_sym
->r
== FUNC_CDECL
)
386 /* generate function prolog of type 't' */
387 void gfunc_prolog(CType
*func_type
)
389 int addr
, align
, size
, func_call
;
393 sym
= func_type
->ref
;
396 /* if the function returns a structure, then add an
397 implicit pointer parameter */
399 if ((func_vt
.t
& VT_BTYPE
) == VT_STRUCT
) {
403 /* define parameters */
404 while ((sym
= sym
->next
) != NULL
) {
406 sym_push(sym
->v
& ~SYM_FIELD
, type
,
407 VT_LOCAL
| VT_LVAL
, addr
);
408 size
= type_size(type
, &align
);
409 size
= (size
+ 3) & ~3;
410 #ifdef FUNC_STRUCT_PARAM_AS_PTR
411 /* structs are passed as pointer */
412 if ((type
->t
& VT_BTYPE
) == VT_STRUCT
) {
419 /* pascal type call ? */
420 if (func_call
== FUNC_STDCALL
)
421 func_ret_sub
= addr
- 8;
422 o(0xe58955); /* push %ebp, mov %esp, %ebp */
423 func_sub_sp_offset
= oad(0xec81, 0); /* sub $xxx, %esp */
424 /* leave some room for bound checking code */
425 if (do_bounds_check
) {
426 oad(0xb8, 0); /* lbound section pointer */
427 oad(0xb8, 0); /* call to function */
428 func_bound_offset
= lbounds_section
->data_offset
;
432 /* generate function epilog */
433 void gfunc_epilog(void)
435 #ifdef CONFIG_TCC_BCHECK
436 if (do_bounds_check
&& func_bound_offset
!= lbounds_section
->data_offset
) {
440 /* add end of table info */
441 bounds_ptr
= section_ptr_add(lbounds_section
, sizeof(int));
443 /* generate bound local allocation */
445 ind
= func_sub_sp_offset
+ 4;
446 sym_data
= get_sym_ref(&char_pointer_type
, lbounds_section
,
447 func_bound_offset
, lbounds_section
->data_offset
);
448 greloc(cur_text_section
, sym_data
,
450 oad(0xb8, 0); /* mov %eax, xxx */
451 sym
= external_global_sym(TOK___bound_local_new
, &func_old_type
, 0);
452 greloc(cur_text_section
, sym
,
453 ind
+ 1, R_386_PC32
);
456 /* generate bound check local freeing */
457 o(0x5250); /* save returned value, if any */
458 greloc(cur_text_section
, sym_data
,
460 oad(0xb8, 0); /* mov %eax, xxx */
461 sym
= external_global_sym(TOK___bound_local_delete
, &func_old_type
, 0);
462 greloc(cur_text_section
, sym
,
463 ind
+ 1, R_386_PC32
);
465 o(0x585a); /* restore returned value, if any */
469 if (func_ret_sub
== 0) {
474 g(func_ret_sub
>> 8);
476 /* align local size to word & save local variables */
477 *(int *)(cur_text_section
->data
+ func_sub_sp_offset
) = (-loc
+ 3) & -4;
480 /* generate a jump to a label */
483 return psym(0xe9, t
);
486 /* generate a jump to a fixed address */
487 void gjmp_addr(int a
)
495 oad(0xe9, a
- ind
- 5);
499 /* generate a test. set 'inv' to invert test. Stack entry is popped */
500 int gtst(int inv
, int t
)
504 v
= vtop
->r
& VT_VALMASK
;
506 /* fast case : can jump directly since flags are set */
508 t
= psym((vtop
->c
.i
- 16) ^ inv
, t
);
509 } else if (v
== VT_JMP
|| v
== VT_JMPI
) {
510 /* && or || optimization */
511 if ((v
& 1) == inv
) {
512 /* insert vtop->c jump list in t */
515 p
= (int *)(cur_text_section
->data
+ *p
);
523 if (is_float(vtop
->type
.t
)) {
527 if ((vtop
->r
& (VT_VALMASK
| VT_LVAL
| VT_SYM
)) == VT_CONST
) {
528 /* constant jmp optimization */
529 if ((vtop
->c
.i
!= 0) != inv
)
536 t
= psym(0x85 ^ inv
, t
);
543 /* generate an integer binary operation */
550 case TOK_ADDC1
: /* add with carry generation */
553 if ((vtop
->r
& (VT_VALMASK
| VT_LVAL
| VT_SYM
)) == VT_CONST
) {
560 /* XXX: generate inc and dec for smaller code ? */
562 o(0xc0 | (opc
<< 3) | r
);
566 oad(0xc0 | (opc
<< 3) | r
, c
);
572 o((opc
<< 3) | 0x01);
573 o(0xc0 + r
+ fr
* 8);
576 if (op
>= TOK_ULT
&& op
<= TOK_GT
) {
582 case TOK_SUBC1
: /* sub with carry generation */
585 case TOK_ADDC2
: /* add with carry use */
588 case TOK_SUBC2
: /* sub with carry use */
605 o(0xaf0f); /* imul fr, r */
606 o(0xc0 + fr
+ r
* 8);
617 opc
= 0xc0 | (opc
<< 3);
618 if ((vtop
->r
& (VT_VALMASK
| VT_LVAL
| VT_SYM
)) == VT_CONST
) {
623 c
= vtop
->c
.i
& 0x1f;
624 o(0xc1); /* shl/shr/sar $xxx, r */
628 /* we generate the shift in ecx */
631 o(0xd3); /* shl/shr/sar %cl, r */
642 /* first operand must be in eax */
643 /* XXX: need better constraint for second operand */
649 if (op
== TOK_UMULL
) {
650 o(0xf7); /* mul fr */
655 if (op
== TOK_UDIV
|| op
== TOK_UMOD
) {
656 o(0xf7d231); /* xor %edx, %edx, div fr, %eax */
659 o(0xf799); /* cltd, idiv fr, %eax */
662 if (op
== '%' || op
== TOK_UMOD
)
675 /* generate a floating point operation 'v = t1 op t2' instruction. The
676 two operands are guaranted to have the same floating point type */
677 /* XXX: need to use ST1 too */
680 int a
, ft
, fc
, swapped
, r
;
682 /* convert constants to memory references */
683 if ((vtop
[-1].r
& (VT_VALMASK
| VT_LVAL
)) == VT_CONST
) {
688 if ((vtop
[0].r
& (VT_VALMASK
| VT_LVAL
)) == VT_CONST
)
691 /* must put at least one value in the floating point register */
692 if ((vtop
[-1].r
& VT_LVAL
) &&
693 (vtop
[0].r
& VT_LVAL
)) {
699 /* swap the stack if needed so that t1 is the register and t2 is
700 the memory reference */
701 if (vtop
[-1].r
& VT_LVAL
) {
705 if (op
>= TOK_ULT
&& op
<= TOK_GT
) {
706 /* load on stack second operand */
707 load(TREG_ST0
, vtop
);
708 save_reg(TREG_EAX
); /* eax is used by FP comparison code */
709 if (op
== TOK_GE
|| op
== TOK_GT
)
711 else if (op
== TOK_EQ
|| op
== TOK_NE
)
714 o(0xc9d9); /* fxch %st(1) */
715 o(0xe9da); /* fucompp */
716 o(0xe0df); /* fnstsw %ax */
718 o(0x45e480); /* and $0x45, %ah */
719 o(0x40fC80); /* cmp $0x40, %ah */
720 } else if (op
== TOK_NE
) {
721 o(0x45e480); /* and $0x45, %ah */
722 o(0x40f480); /* xor $0x40, %ah */
724 } else if (op
== TOK_GE
|| op
== TOK_LE
) {
725 o(0x05c4f6); /* test $0x05, %ah */
728 o(0x45c4f6); /* test $0x45, %ah */
735 /* no memory reference possible for long double operations */
736 if ((vtop
->type
.t
& VT_BTYPE
) == VT_LDOUBLE
) {
737 load(TREG_ST0
, vtop
);
762 if ((ft
& VT_BTYPE
) == VT_LDOUBLE
) {
763 o(0xde); /* fxxxp %st, %st(1) */
766 /* if saved lvalue, then we must reload it */
768 if ((r
& VT_VALMASK
) == VT_LLOCAL
) {
772 v1
.r
= VT_LOCAL
| VT_LVAL
;
778 if ((ft
& VT_BTYPE
) == VT_DOUBLE
)
782 gen_modrm(a
, r
, vtop
->sym
, fc
);
788 /* convert integers to fp 't' type. Must handle 'int', 'unsigned int'
789 and 'long long' cases. */
790 void gen_cvt_itof(int t
)
794 if ((vtop
->type
.t
& VT_BTYPE
) == VT_LLONG
) {
795 /* signed long long to float/double/long double (unsigned case
796 is handled generically) */
797 o(0x50 + vtop
->r2
); /* push r2 */
798 o(0x50 + (vtop
->r
& VT_VALMASK
)); /* push r */
799 o(0x242cdf); /* fildll (%esp) */
800 o(0x08c483); /* add $8, %esp */
801 } else if ((vtop
->type
.t
& (VT_BTYPE
| VT_UNSIGNED
)) ==
802 (VT_INT
| VT_UNSIGNED
)) {
803 /* unsigned int to float/double/long double */
804 o(0x6a); /* push $0 */
806 o(0x50 + (vtop
->r
& VT_VALMASK
)); /* push r */
807 o(0x242cdf); /* fildll (%esp) */
808 o(0x08c483); /* add $8, %esp */
810 /* int to float/double/long double */
811 o(0x50 + (vtop
->r
& VT_VALMASK
)); /* push r */
812 o(0x2404db); /* fildl (%esp) */
813 o(0x04c483); /* add $4, %esp */
818 /* convert fp to int 't' type */
819 /* XXX: handle long long case */
820 void gen_cvt_ftoi(int t
)
826 ushort_type
.t
= VT_SHORT
| VT_UNSIGNED
;
834 o(0x2dd9); /* ldcw xxx */
835 sym
= external_global_sym(TOK___tcc_int_fpu_control
,
836 &ushort_type
, VT_LVAL
);
837 greloc(cur_text_section
, sym
,
841 oad(0xec81, size
); /* sub $xxx, %esp */
843 o(0x1cdb); /* fistpl */
845 o(0x3cdf); /* fistpll */
847 o(0x2dd9); /* ldcw xxx */
848 sym
= external_global_sym(TOK___tcc_fpu_control
,
849 &ushort_type
, VT_LVAL
);
850 greloc(cur_text_section
, sym
,
855 o(0x58 + r
); /* pop r */
858 vtop
->r
= r
; /* mark reg as used */
859 r2
= get_reg(RC_INT
);
860 o(0x58 + r2
); /* pop r2 */
863 o(0x04c483); /* add $4, %esp */
869 /* convert from one floating point type to another */
870 void gen_cvt_ftof(int t
)
872 /* all we have to do on i386 is to put the float in a register */
876 /* computed goto support */
883 /* bound check support functions */
884 #ifdef CONFIG_TCC_BCHECK
886 /* generate a bounded pointer addition */
887 void gen_bounded_ptr_add(void)
891 /* prepare fast i386 function call (args in eax and edx) */
893 /* save all temporary registers */
896 /* do a fast function call */
897 sym
= external_global_sym(TOK___bound_ptr_add
, &func_old_type
, 0);
898 greloc(cur_text_section
, sym
,
899 ind
+ 1, R_386_PC32
);
901 /* returned pointer is in eax */
903 vtop
->r
= TREG_EAX
| VT_BOUNDED
;
904 /* address of bounding function call point */
905 vtop
->c
.ul
= (cur_text_section
->reloc
->data_offset
- sizeof(Elf32_Rel
));
908 /* patch pointer addition in vtop so that pointer dereferencing is
910 void gen_bounded_ptr_deref(void)
918 /* XXX: put that code in generic part of tcc */
919 if (!is_float(vtop
->type
.t
)) {
920 if (vtop
->r
& VT_LVAL_BYTE
)
922 else if (vtop
->r
& VT_LVAL_SHORT
)
926 size
= type_size(&vtop
->type
, &align
);
928 case 1: func
= TOK___bound_ptr_indir1
; break;
929 case 2: func
= TOK___bound_ptr_indir2
; break;
930 case 4: func
= TOK___bound_ptr_indir4
; break;
931 case 8: func
= TOK___bound_ptr_indir8
; break;
932 case 12: func
= TOK___bound_ptr_indir12
; break;
933 case 16: func
= TOK___bound_ptr_indir16
; break;
935 error("unhandled size when derefencing bounded pointer");
940 /* patch relocation */
941 /* XXX: find a better solution ? */
942 rel
= (Elf32_Rel
*)(cur_text_section
->reloc
->data
+ vtop
->c
.ul
);
943 sym
= external_global_sym(func
, &func_old_type
, 0);
945 put_extern_sym(sym
, NULL
, 0, 0);
946 rel
->r_info
= ELF32_R_INFO(sym
->c
, ELF32_R_TYPE(rel
->r_info
));
950 /* end of X86 code generator */
951 /*************************************************************/