Home | History | Annotate | Download | only in tcg
      1 /*
      2  * Tiny Code Generator for QEMU
      3  *
      4  * Copyright (c) 2008 Fabrice Bellard
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining a copy
      7  * of this software and associated documentation files (the "Software"), to deal
      8  * in the Software without restriction, including without limitation the rights
      9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     10  * copies of the Software, and to permit persons to whom the Software is
     11  * furnished to do so, subject to the following conditions:
     12  *
     13  * The above copyright notice and this permission notice shall be included in
     14  * all copies or substantial portions of the Software.
     15  *
     16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
     19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
     22  * THE SOFTWARE.
     23  */
     24 #include "qemu-common.h"
     25 #include "tcg-target.h"
     26 
     27 #if TCG_TARGET_REG_BITS == 32
     28 typedef int32_t tcg_target_long;
     29 typedef uint32_t tcg_target_ulong;
     30 #define TCG_PRIlx PRIx32
     31 #define TCG_PRIld PRId32
     32 #elif TCG_TARGET_REG_BITS == 64
     33 typedef int64_t tcg_target_long;
     34 typedef uint64_t tcg_target_ulong;
     35 #define TCG_PRIlx PRIx64
     36 #define TCG_PRIld PRId64
     37 #else
     38 #error unsupported
     39 #endif
     40 
     41 #if TCG_TARGET_NB_REGS <= 32
     42 typedef uint32_t TCGRegSet;
     43 #elif TCG_TARGET_NB_REGS <= 64
     44 typedef uint64_t TCGRegSet;
     45 #else
     46 #error unsupported
     47 #endif
     48 
     49 enum {
     50 #define DEF(s, n, copy_size) INDEX_op_ ## s,
     51 #include "tcg-opc.h"
     52 #undef DEF
     53     NB_OPS,
     54 };
     55 
     56 #define tcg_regset_clear(d) (d) = 0
     57 #define tcg_regset_set(d, s) (d) = (s)
     58 #define tcg_regset_set32(d, reg, val32) (d) |= (val32) << (reg)
     59 #define tcg_regset_set_reg(d, r) (d) |= 1 << (r)
     60 #define tcg_regset_reset_reg(d, r) (d) &= ~(1 << (r))
     61 #define tcg_regset_test_reg(d, r) (((d) >> (r)) & 1)
     62 #define tcg_regset_or(d, a, b) (d) = (a) | (b)
     63 #define tcg_regset_and(d, a, b) (d) = (a) & (b)
     64 #define tcg_regset_andnot(d, a, b) (d) = (a) & ~(b)
     65 #define tcg_regset_not(d, a) (d) = ~(a)
     66 
     67 typedef struct TCGRelocation {
     68     struct TCGRelocation *next;
     69     int type;
     70     uint8_t *ptr;
     71     tcg_target_long addend;
     72 } TCGRelocation;
     73 
     74 typedef struct TCGLabel {
     75     int has_value;
     76     union {
     77         tcg_target_ulong value;
     78         TCGRelocation *first_reloc;
     79     } u;
     80 } TCGLabel;
     81 
     82 typedef struct TCGPool {
     83     struct TCGPool *next;
     84     int size;
     85     uint8_t data[0] __attribute__ ((aligned));
     86 } TCGPool;
     87 
     88 #define TCG_POOL_CHUNK_SIZE 32768
     89 
     90 #define TCG_MAX_LABELS 512
     91 
     92 #define TCG_MAX_TEMPS 512
     93 
     94 /* when the size of the arguments of a called function is smaller than
     95    this value, they are statically allocated in the TB stack frame */
     96 #define TCG_STATIC_CALL_ARGS_SIZE 128
     97 
     98 typedef int TCGType;
     99 
    100 #define TCG_TYPE_I32 0
    101 #define TCG_TYPE_I64 1
    102 #define TCG_TYPE_COUNT 2 /* number of different types */
    103 
    104 #if TCG_TARGET_REG_BITS == 32
    105 #define TCG_TYPE_PTR TCG_TYPE_I32
    106 #else
    107 #define TCG_TYPE_PTR TCG_TYPE_I64
    108 #endif
    109 
    110 typedef tcg_target_ulong TCGArg;
    111 
    112 /* Define a type and accessor macros for varables.  Using a struct is
    113    nice because it gives some level of type safely.  Ideally the compiler
    114    be able to see through all this.  However in practice this is not true,
    115    expecially on targets with braindamaged ABIs (e.g. i386).
    116    We use plain int by default to avoid this runtime overhead.
    117    Users of tcg_gen_* don't need to know about any of this, and should
    118    treat TCGv as an opaque type.
    119    In additon we do typechecking for different types of variables.  TCGv_i32
    120    and TCGv_i64 are 32/64-bit variables respectively.  TCGv and TCGv_ptr
    121    are aliases for target_ulong and host pointer sized values respectively.
    122  */
    123 
    124 #ifdef DEBUG_TCG
    125 #define DEBUG_TCGV 1
    126 #endif
    127 
    128 #ifdef DEBUG_TCGV
    129 
    130 typedef struct
    131 {
    132     int i32;
    133 } TCGv_i32;
    134 
    135 typedef struct
    136 {
    137     int i64;
    138 } TCGv_i64;
    139 
    140 #define MAKE_TCGV_I32(i) __extension__                  \
    141     ({ TCGv_i32 make_tcgv_tmp = {i}; make_tcgv_tmp;})
    142 #define MAKE_TCGV_I64(i) __extension__                  \
    143     ({ TCGv_i64 make_tcgv_tmp = {i}; make_tcgv_tmp;})
    144 #define GET_TCGV_I32(t) ((t).i32)
    145 #define GET_TCGV_I64(t) ((t).i64)
    146 #if TCG_TARGET_REG_BITS == 32
    147 #define TCGV_LOW(t) MAKE_TCGV_I32(GET_TCGV_I64(t))
    148 #define TCGV_HIGH(t) MAKE_TCGV_I32(GET_TCGV_I64(t) + 1)
    149 #endif
    150 
    151 #else /* !DEBUG_TCGV */
    152 
    153 typedef int TCGv_i32;
    154 typedef int TCGv_i64;
    155 #define MAKE_TCGV_I32(x) (x)
    156 #define MAKE_TCGV_I64(x) (x)
    157 #define GET_TCGV_I32(t) (t)
    158 #define GET_TCGV_I64(t) (t)
    159 
    160 #if TCG_TARGET_REG_BITS == 32
    161 #define TCGV_LOW(t) (t)
    162 #define TCGV_HIGH(t) ((t) + 1)
    163 #endif
    164 
    165 #endif /* DEBUG_TCGV */
    166 
    167 #define TCGV_EQUAL_I32(a, b) (GET_TCGV_I32(a) == GET_TCGV_I32(b))
    168 #define TCGV_EQUAL_I64(a, b) (GET_TCGV_I64(a) == GET_TCGV_I64(b))
    169 
    170 /* Dummy definition to avoid compiler warnings.  */
    171 #define TCGV_UNUSED_I32(x) x = MAKE_TCGV_I32(-1)
    172 #define TCGV_UNUSED_I64(x) x = MAKE_TCGV_I64(-1)
    173 
    174 /* call flags */
    175 #define TCG_CALL_TYPE_MASK      0x000f
    176 #define TCG_CALL_TYPE_STD       0x0000 /* standard C call */
    177 #define TCG_CALL_TYPE_REGPARM_1 0x0001 /* i386 style regparm call (1 reg) */
    178 #define TCG_CALL_TYPE_REGPARM_2 0x0002 /* i386 style regparm call (2 regs) */
    179 #define TCG_CALL_TYPE_REGPARM   0x0003 /* i386 style regparm call (3 regs) */
    180 /* A pure function only reads its arguments and TCG global variables
    181    and cannot raise exceptions. Hence a call to a pure function can be
    182    safely suppressed if the return value is not used. */
    183 #define TCG_CALL_PURE           0x0010
    184 /* A const function only reads its arguments and does not use TCG
    185    global variables. Hence a call to such a function does not
    186    save TCG global variables back to their canonical location. */
    187 #define TCG_CALL_CONST          0x0020
    188 
    189 /* used to align parameters */
    190 #define TCG_CALL_DUMMY_TCGV     MAKE_TCGV_I32(-1)
    191 #define TCG_CALL_DUMMY_ARG      ((TCGArg)(-1))
    192 
    193 typedef enum {
    194     TCG_COND_EQ,
    195     TCG_COND_NE,
    196     TCG_COND_LT,
    197     TCG_COND_GE,
    198     TCG_COND_LE,
    199     TCG_COND_GT,
    200     /* unsigned */
    201     TCG_COND_LTU,
    202     TCG_COND_GEU,
    203     TCG_COND_LEU,
    204     TCG_COND_GTU,
    205 } TCGCond;
    206 
    207 #define TEMP_VAL_DEAD  0
    208 #define TEMP_VAL_REG   1
    209 #define TEMP_VAL_MEM   2
    210 #define TEMP_VAL_CONST 3
    211 
    212 /* XXX: optimize memory layout */
    213 typedef struct TCGTemp {
    214     TCGType base_type;
    215     TCGType type;
    216     int val_type;
    217     int reg;
    218     tcg_target_long val;
    219     int mem_reg;
    220     tcg_target_long mem_offset;
    221     unsigned int fixed_reg:1;
    222     unsigned int mem_coherent:1;
    223     unsigned int mem_allocated:1;
    224     unsigned int temp_local:1; /* If true, the temp is saved accross
    225                                   basic blocks. Otherwise, it is not
    226                                   preserved accross basic blocks. */
    227     unsigned int temp_allocated:1; /* never used for code gen */
    228     /* index of next free temp of same base type, -1 if end */
    229     int next_free_temp;
    230     const char *name;
    231 } TCGTemp;
    232 
    233 typedef struct TCGHelperInfo {
    234     tcg_target_ulong func;
    235     const char *name;
    236 } TCGHelperInfo;
    237 
    238 typedef struct TCGContext TCGContext;
    239 
    240 struct TCGContext {
    241     uint8_t *pool_cur, *pool_end;
    242     TCGPool *pool_first, *pool_current;
    243     TCGLabel *labels;
    244     int nb_labels;
    245     TCGTemp *temps; /* globals first, temps after */
    246     int nb_globals;
    247     int nb_temps;
    248     /* index of free temps, -1 if none */
    249     int first_free_temp[TCG_TYPE_COUNT * 2];
    250 
    251     /* goto_tb support */
    252     uint8_t *code_buf;
    253     unsigned long *tb_next;
    254     uint16_t *tb_next_offset;
    255     uint16_t *tb_jmp_offset; /* != NULL if USE_DIRECT_JUMP */
    256 
    257     /* liveness analysis */
    258     uint16_t *op_dead_iargs; /* for each operation, each bit tells if the
    259                                 corresponding input argument is dead */
    260 
    261     /* tells in which temporary a given register is. It does not take
    262        into account fixed registers */
    263     int reg_to_temp[TCG_TARGET_NB_REGS];
    264     TCGRegSet reserved_regs;
    265     tcg_target_long current_frame_offset;
    266     tcg_target_long frame_start;
    267     tcg_target_long frame_end;
    268     int frame_reg;
    269 
    270     uint8_t *code_ptr;
    271     TCGTemp static_temps[TCG_MAX_TEMPS];
    272 
    273     TCGHelperInfo *helpers;
    274     int nb_helpers;
    275     int allocated_helpers;
    276     int helpers_sorted;
    277 
    278 #ifdef CONFIG_PROFILER
    279     /* profiling info */
    280     int64_t tb_count1;
    281     int64_t tb_count;
    282     int64_t op_count; /* total insn count */
    283     int op_count_max; /* max insn per TB */
    284     int64_t temp_count;
    285     int temp_count_max;
    286     int64_t del_op_count;
    287     int64_t code_in_len;
    288     int64_t code_out_len;
    289     int64_t interm_time;
    290     int64_t code_time;
    291     int64_t la_time;
    292     int64_t restore_count;
    293     int64_t restore_time;
    294 #endif
    295 };
    296 
    297 extern TCGContext tcg_ctx;
    298 extern uint16_t *gen_opc_ptr;
    299 extern TCGArg *gen_opparam_ptr;
    300 extern uint16_t gen_opc_buf[];
    301 extern TCGArg gen_opparam_buf[];
    302 
    303 /* pool based memory allocation */
    304 
    305 void *tcg_malloc_internal(TCGContext *s, int size);
    306 void tcg_pool_reset(TCGContext *s);
    307 void tcg_pool_delete(TCGContext *s);
    308 
    309 static inline void *tcg_malloc(int size)
    310 {
    311     TCGContext *s = &tcg_ctx;
    312     uint8_t *ptr, *ptr_end;
    313     size = (size + sizeof(long) - 1) & ~(sizeof(long) - 1);
    314     ptr = s->pool_cur;
    315     ptr_end = ptr + size;
    316     if (unlikely(ptr_end > s->pool_end)) {
    317         return tcg_malloc_internal(&tcg_ctx, size);
    318     } else {
    319         s->pool_cur = ptr_end;
    320         return ptr;
    321     }
    322 }
    323 
    324 void tcg_context_init(TCGContext *s);
    325 void tcg_func_start(TCGContext *s);
    326 
    327 int tcg_gen_code(TCGContext *s, uint8_t *gen_code_buf);
    328 int tcg_gen_code_search_pc(TCGContext *s, uint8_t *gen_code_buf, long offset);
    329 
    330 void tcg_set_frame(TCGContext *s, int reg,
    331                    tcg_target_long start, tcg_target_long size);
    332 
    333 TCGv_i32 tcg_global_reg_new_i32(int reg, const char *name);
    334 TCGv_i32 tcg_global_mem_new_i32(int reg, tcg_target_long offset,
    335                                 const char *name);
    336 TCGv_i32 tcg_temp_new_internal_i32(int temp_local);
    337 static inline TCGv_i32 tcg_temp_new_i32(void)
    338 {
    339     return tcg_temp_new_internal_i32(0);
    340 }
    341 static inline TCGv_i32 tcg_temp_local_new_i32(void)
    342 {
    343     return tcg_temp_new_internal_i32(1);
    344 }
    345 void tcg_temp_free_i32(TCGv_i32 arg);
    346 char *tcg_get_arg_str_i32(TCGContext *s, char *buf, int buf_size, TCGv_i32 arg);
    347 
    348 TCGv_i64 tcg_global_reg_new_i64(int reg, const char *name);
    349 TCGv_i64 tcg_global_mem_new_i64(int reg, tcg_target_long offset,
    350                                 const char *name);
    351 TCGv_i64 tcg_temp_new_internal_i64(int temp_local);
    352 static inline TCGv_i64 tcg_temp_new_i64(void)
    353 {
    354     return tcg_temp_new_internal_i64(0);
    355 }
    356 static inline TCGv_i64 tcg_temp_local_new_i64(void)
    357 {
    358     return tcg_temp_new_internal_i64(1);
    359 }
    360 void tcg_temp_free_i64(TCGv_i64 arg);
    361 char *tcg_get_arg_str_i64(TCGContext *s, char *buf, int buf_size, TCGv_i64 arg);
    362 
    363 void tcg_dump_info(FILE *f,
    364                    int (*cpu_fprintf)(FILE *f, const char *fmt, ...));
    365 
    366 #define TCG_CT_ALIAS  0x80
    367 #define TCG_CT_IALIAS 0x40
    368 #define TCG_CT_REG    0x01
    369 #define TCG_CT_CONST  0x02 /* any constant of register size */
    370 
    371 typedef struct TCGArgConstraint {
    372     uint16_t ct;
    373     uint8_t alias_index;
    374     union {
    375         TCGRegSet regs;
    376     } u;
    377 } TCGArgConstraint;
    378 
    379 #define TCG_MAX_OP_ARGS 16
    380 
    381 #define TCG_OPF_BB_END     0x01 /* instruction defines the end of a basic
    382                                    block */
    383 #define TCG_OPF_CALL_CLOBBER 0x02 /* instruction clobbers call registers
    384                                    and potentially update globals. */
    385 #define TCG_OPF_SIDE_EFFECTS 0x04 /* instruction has side effects : it
    386                                      cannot be removed if its output
    387                                      are not used */
    388 
    389 typedef struct TCGOpDef {
    390     const char *name;
    391     uint8_t nb_oargs, nb_iargs, nb_cargs, nb_args;
    392     uint8_t flags;
    393     uint16_t copy_size;
    394     TCGArgConstraint *args_ct;
    395     int *sorted_args;
    396 } TCGOpDef;
    397 
    398 typedef struct TCGTargetOpDef {
    399     int op;
    400     const char *args_ct_str[TCG_MAX_OP_ARGS];
    401 } TCGTargetOpDef;
    402 
    403 void tcg_target_init(TCGContext *s);
    404 void tcg_target_qemu_prologue(TCGContext *s);
    405 
    406 #define tcg_abort() \
    407 do {\
    408     fprintf(stderr, "%s:%d: tcg fatal error\n", __FILE__, __LINE__);\
    409     abort();\
    410 } while (0)
    411 
    412 void tcg_add_target_add_op_defs(const TCGTargetOpDef *tdefs);
    413 
    414 #if TCG_TARGET_REG_BITS == 32
    415 #define tcg_const_ptr tcg_const_i32
    416 #define tcg_add_ptr tcg_add_i32
    417 #define tcg_sub_ptr tcg_sub_i32
    418 #define TCGv_ptr TCGv_i32
    419 #define GET_TCGV_PTR GET_TCGV_I32
    420 #define tcg_global_reg_new_ptr tcg_global_reg_new_i32
    421 #define tcg_global_mem_new_ptr tcg_global_mem_new_i32
    422 #define tcg_temp_new_ptr tcg_temp_new_i32
    423 #define tcg_temp_free_ptr tcg_temp_free_i32
    424 #else
    425 #define tcg_const_ptr tcg_const_i64
    426 #define tcg_add_ptr tcg_add_i64
    427 #define tcg_sub_ptr tcg_sub_i64
    428 #define TCGv_ptr TCGv_i64
    429 #define GET_TCGV_PTR GET_TCGV_I64
    430 #define tcg_global_reg_new_ptr tcg_global_reg_new_i64
    431 #define tcg_global_mem_new_ptr tcg_global_mem_new_i64
    432 #define tcg_temp_new_ptr tcg_temp_new_i64
    433 #define tcg_temp_free_ptr tcg_temp_free_i64
    434 #endif
    435 
    436 void tcg_gen_callN(TCGContext *s, TCGv_ptr func, unsigned int flags,
    437                    int sizemask, TCGArg ret, int nargs, TCGArg *args);
    438 
    439 void tcg_gen_shifti_i64(TCGv_i64 ret, TCGv_i64 arg1,
    440                         int c, int right, int arith);
    441 
    442 /* only used for debugging purposes */
    443 void tcg_register_helper(void *func, const char *name);
    444 const char *tcg_helper_get_name(TCGContext *s, void *func);
    445 void tcg_dump_ops(TCGContext *s, FILE *outfile);
    446 
    447 void dump_ops(const uint16_t *opc_buf, const TCGArg *opparam_buf);
    448 TCGv_i32 tcg_const_i32(int32_t val);
    449 TCGv_i64 tcg_const_i64(int64_t val);
    450 TCGv_i32 tcg_const_local_i32(int32_t val);
    451 TCGv_i64 tcg_const_local_i64(int64_t val);
    452 
    453 void tcg_out_reloc(TCGContext *s, uint8_t *code_ptr, int type,
    454                    int label_index, long addend);
    455 const TCGArg *tcg_gen_code_op(TCGContext *s, int opc, const TCGArg *args1,
    456                               unsigned int dead_iargs);
    457 
    458 /* tcg-runtime.c */
    459 int64_t tcg_helper_shl_i64(int64_t arg1, int64_t arg2);
    460 int64_t tcg_helper_shr_i64(int64_t arg1, int64_t arg2);
    461 int64_t tcg_helper_sar_i64(int64_t arg1, int64_t arg2);
    462 int64_t tcg_helper_div_i64(int64_t arg1, int64_t arg2);
    463 int64_t tcg_helper_rem_i64(int64_t arg1, int64_t arg2);
    464 uint64_t tcg_helper_divu_i64(uint64_t arg1, uint64_t arg2);
    465 uint64_t tcg_helper_remu_i64(uint64_t arg1, uint64_t arg2);
    466 
    467 extern uint8_t code_gen_prologue[];
    468 #if defined(_ARCH_PPC) && !defined(_ARCH_PPC64)
    469 #define tcg_qemu_tb_exec(tb_ptr) \
    470     ((long REGPARM __attribute__ ((longcall)) (*)(void *))code_gen_prologue)(tb_ptr)
    471 #else
    472 #define tcg_qemu_tb_exec(tb_ptr) ((long REGPARM (*)(void *))code_gen_prologue)(tb_ptr)
    473 #endif
    474