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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 #include "tcg-runtime.h"
27 
28 #if TCG_TARGET_REG_BITS == 32
29 typedef int32_t tcg_target_long;
30 typedef uint32_t tcg_target_ulong;
31 #define TCG_PRIlx PRIx32
32 #define TCG_PRIld PRId32
33 #elif TCG_TARGET_REG_BITS == 64
34 typedef int64_t tcg_target_long;
35 typedef uint64_t tcg_target_ulong;
36 #define TCG_PRIlx PRIx64
37 #define TCG_PRIld PRId64
38 #else
39 #error unsupported
40 #endif
41 
42 #if TCG_TARGET_NB_REGS <= 32
43 typedef uint32_t TCGRegSet;
44 #elif TCG_TARGET_NB_REGS <= 64
45 typedef uint64_t TCGRegSet;
46 #else
47 #error unsupported
48 #endif
49 
50 typedef enum TCGOpcode {
51 #define DEF(name, oargs, iargs, cargs, flags) INDEX_op_ ## name,
52 #include "tcg-opc.h"
53 #undef DEF
54     NB_OPS,
55 } TCGOpcode;
56 
57 #define tcg_regset_clear(d) (d) = 0
58 #define tcg_regset_set(d, s) (d) = (s)
59 #define tcg_regset_set32(d, reg, val32) (d) |= (val32) << (reg)
60 #define tcg_regset_set_reg(d, r) (d) |= 1L << (r)
61 #define tcg_regset_reset_reg(d, r) (d) &= ~(1L << (r))
62 #define tcg_regset_test_reg(d, r) (((d) >> (r)) & 1)
63 #define tcg_regset_or(d, a, b) (d) = (a) | (b)
64 #define tcg_regset_and(d, a, b) (d) = (a) & (b)
65 #define tcg_regset_andnot(d, a, b) (d) = (a) & ~(b)
66 #define tcg_regset_not(d, a) (d) = ~(a)
67 
68 typedef struct TCGRelocation {
69     struct TCGRelocation *next;
70     int type;
71     uint8_t *ptr;
72     tcg_target_long addend;
73 } TCGRelocation;
74 
75 typedef struct TCGLabel {
76     int has_value;
77     union {
78         tcg_target_ulong value;
79         TCGRelocation *first_reloc;
80     } u;
81 } TCGLabel;
82 
83 typedef struct TCGPool {
84     struct TCGPool *next;
85     int size;
86     uint8_t data[0] __attribute__ ((aligned));
87 } TCGPool;
88 
89 #define TCG_POOL_CHUNK_SIZE 32768
90 
91 #define TCG_MAX_LABELS 512
92 
93 #define TCG_MAX_TEMPS 512
94 
95 /* when the size of the arguments of a called function is smaller than
96    this value, they are statically allocated in the TB stack frame */
97 #define TCG_STATIC_CALL_ARGS_SIZE 128
98 
99 typedef enum TCGType {
100     TCG_TYPE_I32,
101     TCG_TYPE_I64,
102     TCG_TYPE_COUNT, /* number of different types */
103 
104     /* An alias for the size of the host register.  */
105 #if TCG_TARGET_REG_BITS == 32
106     TCG_TYPE_REG = TCG_TYPE_I32,
107 #else
108     TCG_TYPE_REG = TCG_TYPE_I64,
109 #endif
110 
111     /* An alias for the size of the native pointer.  We don't currently
112        support any hosts with 64-bit registers and 32-bit pointers.  */
113     TCG_TYPE_PTR = TCG_TYPE_REG,
114 
115     /* An alias for the size of the target "long", aka register.  */
116 #if TARGET_LONG_BITS == 64
117     TCG_TYPE_TL = TCG_TYPE_I64,
118 #else
119     TCG_TYPE_TL = TCG_TYPE_I32,
120 #endif
121 } TCGType;
122 
123 typedef tcg_target_ulong TCGArg;
124 
125 /* Define a type and accessor macros for varables.  Using a struct is
126    nice because it gives some level of type safely.  Ideally the compiler
127    be able to see through all this.  However in practice this is not true,
128    expecially on targets with braindamaged ABIs (e.g. i386).
129    We use plain int by default to avoid this runtime overhead.
130    Users of tcg_gen_* don't need to know about any of this, and should
131    treat TCGv as an opaque type.
132    In additon we do typechecking for different types of variables.  TCGv_i32
133    and TCGv_i64 are 32/64-bit variables respectively.  TCGv and TCGv_ptr
134    are aliases for target_ulong and host pointer sized values respectively.
135  */
136 
137 #ifdef CONFIG_DEBUG_TCG
138 #define DEBUG_TCGV 1
139 #endif
140 
141 #ifdef DEBUG_TCGV
142 
143 typedef struct
144 {
145     int i32;
146 } TCGv_i32;
147 
148 typedef struct
149 {
150     int i64;
151 } TCGv_i64;
152 
153 #define MAKE_TCGV_I32(i) __extension__                  \
154     ({ TCGv_i32 make_tcgv_tmp = {i}; make_tcgv_tmp;})
155 #define MAKE_TCGV_I64(i) __extension__                  \
156     ({ TCGv_i64 make_tcgv_tmp = {i}; make_tcgv_tmp;})
157 #define GET_TCGV_I32(t) ((t).i32)
158 #define GET_TCGV_I64(t) ((t).i64)
159 #if TCG_TARGET_REG_BITS == 32
160 #define TCGV_LOW(t) MAKE_TCGV_I32(GET_TCGV_I64(t))
161 #define TCGV_HIGH(t) MAKE_TCGV_I32(GET_TCGV_I64(t) + 1)
162 #endif
163 
164 #else /* !DEBUG_TCGV */
165 
166 typedef int TCGv_i32;
167 typedef int TCGv_i64;
168 #define MAKE_TCGV_I32(x) (x)
169 #define MAKE_TCGV_I64(x) (x)
170 #define GET_TCGV_I32(t) (t)
171 #define GET_TCGV_I64(t) (t)
172 
173 #if TCG_TARGET_REG_BITS == 32
174 #define TCGV_LOW(t) (t)
175 #define TCGV_HIGH(t) ((t) + 1)
176 #endif
177 
178 #endif /* DEBUG_TCGV */
179 
180 #define TCGV_EQUAL_I32(a, b) (GET_TCGV_I32(a) == GET_TCGV_I32(b))
181 #define TCGV_EQUAL_I64(a, b) (GET_TCGV_I64(a) == GET_TCGV_I64(b))
182 
183 /* Dummy definition to avoid compiler warnings.  */
184 #define TCGV_UNUSED_I32(x) x = MAKE_TCGV_I32(-1)
185 #define TCGV_UNUSED_I64(x) x = MAKE_TCGV_I64(-1)
186 
187 /* call flags */
188 #define TCG_CALL_TYPE_MASK      0x000f
189 #define TCG_CALL_TYPE_STD       0x0000 /* standard C call */
190 #define TCG_CALL_TYPE_REGPARM_1 0x0001 /* i386 style regparm call (1 reg) */
191 #define TCG_CALL_TYPE_REGPARM_2 0x0002 /* i386 style regparm call (2 regs) */
192 #define TCG_CALL_TYPE_REGPARM   0x0003 /* i386 style regparm call (3 regs) */
193 /* A pure function only reads its arguments and TCG global variables
194    and cannot raise exceptions. Hence a call to a pure function can be
195    safely suppressed if the return value is not used. */
196 #define TCG_CALL_PURE           0x0010
197 /* A const function only reads its arguments and does not use TCG
198    global variables. Hence a call to such a function does not
199    save TCG global variables back to their canonical location. */
200 #define TCG_CALL_CONST          0x0020
201 
202 /* used to align parameters */
203 #define TCG_CALL_DUMMY_TCGV     MAKE_TCGV_I32(-1)
204 #define TCG_CALL_DUMMY_ARG      ((TCGArg)(-1))
205 
206 typedef enum {
207     TCG_COND_EQ,
208     TCG_COND_NE,
209     TCG_COND_LT,
210     TCG_COND_GE,
211     TCG_COND_LE,
212     TCG_COND_GT,
213     /* unsigned */
214     TCG_COND_LTU,
215     TCG_COND_GEU,
216     TCG_COND_LEU,
217     TCG_COND_GTU,
218 } TCGCond;
219 
220 /* Invert the sense of the comparison.  */
tcg_invert_cond(TCGCond c)221 static inline TCGCond tcg_invert_cond(TCGCond c)
222 {
223     return (TCGCond)(c ^ 1);
224 }
225 
226 /* Swap the operands in a comparison.  */
tcg_swap_cond(TCGCond c)227 static inline TCGCond tcg_swap_cond(TCGCond c)
228 {
229     int mask = (c < TCG_COND_LT ? 0 : c < TCG_COND_LTU ? 7 : 15);
230     return (TCGCond)(c ^ mask);
231 }
232 
tcg_unsigned_cond(TCGCond c)233 static inline TCGCond tcg_unsigned_cond(TCGCond c)
234 {
235     return (c >= TCG_COND_LT && c <= TCG_COND_GT ? c + 4 : c);
236 }
237 
238 #define TEMP_VAL_DEAD  0
239 #define TEMP_VAL_REG   1
240 #define TEMP_VAL_MEM   2
241 #define TEMP_VAL_CONST 3
242 
243 /* XXX: optimize memory layout */
244 typedef struct TCGTemp {
245     TCGType base_type;
246     TCGType type;
247     int val_type;
248     int reg;
249     tcg_target_long val;
250     int mem_reg;
251     tcg_target_long mem_offset;
252     unsigned int fixed_reg:1;
253     unsigned int mem_coherent:1;
254     unsigned int mem_allocated:1;
255     unsigned int temp_local:1; /* If true, the temp is saved accross
256                                   basic blocks. Otherwise, it is not
257                                   preserved accross basic blocks. */
258     unsigned int temp_allocated:1; /* never used for code gen */
259     /* index of next free temp of same base type, -1 if end */
260     int next_free_temp;
261     const char *name;
262 } TCGTemp;
263 
264 typedef struct TCGHelperInfo {
265     tcg_target_ulong func;
266     const char *name;
267 } TCGHelperInfo;
268 
269 typedef struct TCGContext TCGContext;
270 
271 struct TCGContext {
272     uint8_t *pool_cur, *pool_end;
273     TCGPool *pool_first, *pool_current;
274     TCGLabel *labels;
275     int nb_labels;
276     TCGTemp *temps; /* globals first, temps after */
277     int nb_globals;
278     int nb_temps;
279     /* index of free temps, -1 if none */
280     int first_free_temp[TCG_TYPE_COUNT * 2];
281 
282     /* goto_tb support */
283     uint8_t *code_buf;
284     unsigned long *tb_next;
285     uint16_t *tb_next_offset;
286     uint16_t *tb_jmp_offset; /* != NULL if USE_DIRECT_JUMP */
287 
288     /* liveness analysis */
289     uint16_t *op_dead_iargs; /* for each operation, each bit tells if the
290                                 corresponding input argument is dead */
291 
292     /* tells in which temporary a given register is. It does not take
293        into account fixed registers */
294     int reg_to_temp[TCG_TARGET_NB_REGS];
295     TCGRegSet reserved_regs;
296     tcg_target_long current_frame_offset;
297     tcg_target_long frame_start;
298     tcg_target_long frame_end;
299     int frame_reg;
300 
301     uint8_t *code_ptr;
302     TCGTemp static_temps[TCG_MAX_TEMPS];
303 
304     TCGHelperInfo *helpers;
305     int nb_helpers;
306     int allocated_helpers;
307     int helpers_sorted;
308 
309 #ifdef CONFIG_PROFILER
310     /* profiling info */
311     int64_t tb_count1;
312     int64_t tb_count;
313     int64_t op_count; /* total insn count */
314     int op_count_max; /* max insn per TB */
315     int64_t temp_count;
316     int temp_count_max;
317     int64_t del_op_count;
318     int64_t code_in_len;
319     int64_t code_out_len;
320     int64_t interm_time;
321     int64_t code_time;
322     int64_t la_time;
323     int64_t restore_count;
324     int64_t restore_time;
325 #endif
326 
327 #ifdef CONFIG_DEBUG_TCG
328     int temps_in_use;
329 #endif
330 };
331 
332 extern TCGContext tcg_ctx;
333 extern uint16_t *gen_opc_ptr;
334 extern TCGArg *gen_opparam_ptr;
335 extern uint16_t gen_opc_buf[];
336 extern TCGArg gen_opparam_buf[];
337 
338 /* pool based memory allocation */
339 
340 void *tcg_malloc_internal(TCGContext *s, int size);
341 void tcg_pool_reset(TCGContext *s);
342 void tcg_pool_delete(TCGContext *s);
343 
tcg_malloc(int size)344 static inline void *tcg_malloc(int size)
345 {
346     TCGContext *s = &tcg_ctx;
347     uint8_t *ptr, *ptr_end;
348     size = (size + sizeof(long) - 1) & ~(sizeof(long) - 1);
349     ptr = s->pool_cur;
350     ptr_end = ptr + size;
351     if (unlikely(ptr_end > s->pool_end)) {
352         return tcg_malloc_internal(&tcg_ctx, size);
353     } else {
354         s->pool_cur = ptr_end;
355         return ptr;
356     }
357 }
358 
359 void tcg_context_init(TCGContext *s);
360 void tcg_prologue_init(TCGContext *s);
361 void tcg_func_start(TCGContext *s);
362 
363 int tcg_gen_code(TCGContext *s, uint8_t *gen_code_buf);
364 int tcg_gen_code_search_pc(TCGContext *s, uint8_t *gen_code_buf, long offset);
365 
366 void tcg_set_frame(TCGContext *s, int reg,
367                    tcg_target_long start, tcg_target_long size);
368 
369 TCGv_i32 tcg_global_reg_new_i32(int reg, const char *name);
370 TCGv_i32 tcg_global_mem_new_i32(int reg, tcg_target_long offset,
371                                 const char *name);
372 TCGv_i32 tcg_temp_new_internal_i32(int temp_local);
tcg_temp_new_i32(void)373 static inline TCGv_i32 tcg_temp_new_i32(void)
374 {
375     return tcg_temp_new_internal_i32(0);
376 }
tcg_temp_local_new_i32(void)377 static inline TCGv_i32 tcg_temp_local_new_i32(void)
378 {
379     return tcg_temp_new_internal_i32(1);
380 }
381 void tcg_temp_free_i32(TCGv_i32 arg);
382 char *tcg_get_arg_str_i32(TCGContext *s, char *buf, int buf_size, TCGv_i32 arg);
383 
384 TCGv_i64 tcg_global_reg_new_i64(int reg, const char *name);
385 TCGv_i64 tcg_global_mem_new_i64(int reg, tcg_target_long offset,
386                                 const char *name);
387 TCGv_i64 tcg_temp_new_internal_i64(int temp_local);
tcg_temp_new_i64(void)388 static inline TCGv_i64 tcg_temp_new_i64(void)
389 {
390     return tcg_temp_new_internal_i64(0);
391 }
tcg_temp_local_new_i64(void)392 static inline TCGv_i64 tcg_temp_local_new_i64(void)
393 {
394     return tcg_temp_new_internal_i64(1);
395 }
396 void tcg_temp_free_i64(TCGv_i64 arg);
397 char *tcg_get_arg_str_i64(TCGContext *s, char *buf, int buf_size, TCGv_i64 arg);
398 
399 #if defined(CONFIG_DEBUG_TCG)
400 /* If you call tcg_clear_temp_count() at the start of a section of
401  * code which is not supposed to leak any TCG temporaries, then
402  * calling tcg_check_temp_count() at the end of the section will
403  * return 1 if the section did in fact leak a temporary.
404  */
405 void tcg_clear_temp_count(void);
406 int tcg_check_temp_count(void);
407 #else
408 #define tcg_clear_temp_count() do { } while (0)
409 #define tcg_check_temp_count() 0
410 #endif
411 
412 void tcg_dump_info(FILE *f, fprintf_function cpu_fprintf);
413 
414 #define TCG_CT_ALIAS  0x80
415 #define TCG_CT_IALIAS 0x40
416 #define TCG_CT_REG    0x01
417 #define TCG_CT_CONST  0x02 /* any constant of register size */
418 
419 typedef struct TCGArgConstraint {
420     uint16_t ct;
421     uint8_t alias_index;
422     union {
423         TCGRegSet regs;
424     } u;
425 } TCGArgConstraint;
426 
427 #define TCG_MAX_OP_ARGS 16
428 
429 #define TCG_OPF_BB_END     0x01 /* instruction defines the end of a basic
430                                    block */
431 #define TCG_OPF_CALL_CLOBBER 0x02 /* instruction clobbers call registers
432                                    and potentially update globals. */
433 #define TCG_OPF_SIDE_EFFECTS 0x04 /* instruction has side effects : it
434                                      cannot be removed if its output
435                                      are not used */
436 
437 typedef struct TCGOpDef {
438     const char *name;
439     uint8_t nb_oargs, nb_iargs, nb_cargs, nb_args;
440     uint8_t flags;
441     TCGArgConstraint *args_ct;
442     int *sorted_args;
443 #if defined(CONFIG_DEBUG_TCG)
444     int used;
445 #endif
446 } TCGOpDef;
447 
448 typedef struct TCGTargetOpDef {
449     TCGOpcode op;
450     const char *args_ct_str[TCG_MAX_OP_ARGS];
451 } TCGTargetOpDef;
452 
453 #define tcg_abort() \
454 do {\
455     fprintf(stderr, "%s:%d: tcg fatal error\n", __FILE__, __LINE__);\
456     abort();\
457 } while (0)
458 
459 void tcg_add_target_add_op_defs(const TCGTargetOpDef *tdefs);
460 
461 #if TCG_TARGET_REG_BITS == 32
462 #define tcg_const_ptr tcg_const_i32
463 #define tcg_add_ptr tcg_add_i32
464 #define tcg_sub_ptr tcg_sub_i32
465 #define TCGv_ptr TCGv_i32
466 #define GET_TCGV_PTR GET_TCGV_I32
467 #define tcg_global_reg_new_ptr tcg_global_reg_new_i32
468 #define tcg_global_mem_new_ptr tcg_global_mem_new_i32
469 #define tcg_temp_new_ptr tcg_temp_new_i32
470 #define tcg_temp_free_ptr tcg_temp_free_i32
471 #else
472 #define tcg_const_ptr tcg_const_i64
473 #define tcg_add_ptr tcg_add_i64
474 #define tcg_sub_ptr tcg_sub_i64
475 #define TCGv_ptr TCGv_i64
476 #define GET_TCGV_PTR GET_TCGV_I64
477 #define tcg_global_reg_new_ptr tcg_global_reg_new_i64
478 #define tcg_global_mem_new_ptr tcg_global_mem_new_i64
479 #define tcg_temp_new_ptr tcg_temp_new_i64
480 #define tcg_temp_free_ptr tcg_temp_free_i64
481 #endif
482 
483 void tcg_gen_callN(TCGContext *s, TCGv_ptr func, unsigned int flags,
484                    int sizemask, TCGArg ret, int nargs, TCGArg *args);
485 
486 void tcg_gen_shifti_i64(TCGv_i64 ret, TCGv_i64 arg1,
487                         int c, int right, int arith);
488 
489 /* only used for debugging purposes */
490 void tcg_register_helper(void *func, const char *name);
491 const char *tcg_helper_get_name(TCGContext *s, void *func);
492 void tcg_dump_ops(TCGContext *s, FILE *outfile);
493 
494 void dump_ops(const uint16_t *opc_buf, const TCGArg *opparam_buf);
495 TCGv_i32 tcg_const_i32(int32_t val);
496 TCGv_i64 tcg_const_i64(int64_t val);
497 TCGv_i32 tcg_const_local_i32(int32_t val);
498 TCGv_i64 tcg_const_local_i64(int64_t val);
499 
500 extern uint8_t code_gen_prologue[];
501 #if defined(_ARCH_PPC) && !defined(_ARCH_PPC64)
502 #define tcg_qemu_tb_exec(tb_ptr) \
503     ((long REGPARM __attribute__ ((longcall)) (*)(void *))code_gen_prologue)(tb_ptr)
504 #else
505 #define tcg_qemu_tb_exec(tb_ptr) ((long REGPARM (*)(void *))code_gen_prologue)(tb_ptr)
506 #endif
507