Remove remnants of NAMES_HAVE_UNDERSCORE.
[binutils-gdb.git] / gdb / tm-rs6000.h
1 /* Parameters for target execution on an RS6000, for GDB, the GNU debugger.
2 Copyright 1986, 1987, 1989, 1991, 1992, 1993 Free Software Foundation, Inc.
3 Contributed by IBM Corporation.
4
5 This file is part of GDB.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
20
21 extern int symtab_relocated;
22
23 /* Minimum possible text address in AIX */
24
25 #define TEXT_SEGMENT_BASE 0x10000000
26
27
28 /* text addresses in a core file does not necessarily match to symbol table,
29 if symbol table relocation wasn't done yet. */
30
31 #define CORE_NEEDS_RELOCATION(PC) \
32 if (!symtab_relocated && !inferior_pid && (PC) > TEXT_SEGMENT_BASE) \
33 (PC) -= ( TEXT_SEGMENT_BASE + text_adjustment (exec_bfd));
34
35 /* Load segment of a given pc value. */
36
37 #define PC_LOAD_SEGMENT(PC) pc_load_segment_name(PC)
38
39 /* AIX cc seems to get this right. */
40
41 #define BELIEVE_PCC_PROMOTION 1
42
43 /* Conversion between a register number in stab string to actual register num. */
44
45 #define STAB_REG_TO_REGNUM(value) (value)
46
47 /* return true if a given `pc' value is in `call dummy' function. */
48
49 #define PC_IN_CALL_DUMMY(STOP_PC, STOP_SP, STOP_FRAME_ADDR) \
50 (STOP_SP < STOP_PC && STOP_PC < STACK_END_ADDR)
51
52 /* For each symtab, we keep track of which BFD it came from. */
53 #define EXTRA_SYMTAB_INFO \
54 unsigned nonreloc:1; /* TRUE if non relocatable */
55
56 #define INIT_EXTRA_SYMTAB_INFO(symtab) \
57 symtab->nonreloc = 0; \
58
59 extern unsigned int text_start, data_start;
60 extern int inferior_pid;
61 extern char *corefile;
62
63 /* setpgrp() messes up controling terminal. The other version of it
64 requires libbsd.a. */
65 #define setpgrp(XX,YY) setpgid (XX, YY)
66
67 /* We are missing register descriptions in the system header files. Sigh! */
68
69 struct regs {
70 int gregs [32]; /* general purpose registers */
71 int pc; /* program conter */
72 int ps; /* processor status, or machine state */
73 };
74
75 struct fp_status {
76 double fpregs [32]; /* floating GP registers */
77 };
78
79
80 /* To be used by function_frame_info. */
81
82 struct aix_framedata {
83 int offset; /* # of bytes in gpr's and fpr's are saved */
84 int saved_gpr; /* smallest # of saved gpr */
85 int saved_fpr; /* smallest # of saved fpr */
86 int alloca_reg; /* alloca register number (frame ptr) */
87 char frameless; /* true if frameless functions. */
88 char nosavedpc; /* true if pc not saved. */
89 };
90
91 void
92 function_frame_info PARAMS ((CORE_ADDR, struct aix_framedata *));
93
94 /* Define the byte order of the machine. */
95
96 #define TARGET_BYTE_ORDER BIG_ENDIAN
97
98 /* AIX's assembler doesn't grok dollar signs in identifiers.
99 So we use dots instead. This item must be coordinated with G++. */
100 #undef CPLUS_MARKER
101 #define CPLUS_MARKER '.'
102
103 /* Offset from address of function to start of its code.
104 Zero on most machines. */
105
106 #define FUNCTION_START_OFFSET 0
107
108 /* Advance PC across any function entry prologue instructions
109 to reach some "real" code. */
110
111 #define SKIP_PROLOGUE(pc) pc = skip_prologue (pc)
112
113 /* If PC is in some function-call trampoline code, return the PC
114 where the function itself actually starts. If not, return NULL. */
115
116 #define SKIP_TRAMPOLINE_CODE(pc) skip_trampoline_code (pc)
117
118 /* When a child process is just starting, we sneak in and relocate
119 the symbol table (and other stuff) after the dynamic linker has
120 figured out where they go. But we want to do this relocation just
121 once. */
122
123 extern int loadinfotextindex;
124
125 #define SOLIB_CREATE_INFERIOR_HOOK(PID) \
126 do { \
127 if (loadinfotextindex == 0) \
128 xcoff_relocate_symtab (PID); \
129 } while (0)
130
131
132 /* Number of trap signals we need to skip over, once the inferior process
133 starts running. */
134
135 #define START_INFERIOR_TRAPS_EXPECTED 2
136
137 /* AIX might return a sigtrap, with a "stop after load" status. It should
138 be ignored by gdb, shouldn't be mixed up with breakpoint traps. */
139
140 /* Another little glitch in AIX is signal 0. I have no idea why wait(2)
141 returns with this status word. It looks harmless. */
142
143 #define SIGTRAP_STOP_AFTER_LOAD(W) \
144 if ( (W) == 0x57c || (W) == 0x7f) { \
145 if ((W)==0x57c && breakpoints_inserted) { \
146 mark_breakpoints_out (); \
147 insert_breakpoints (); \
148 insert_step_breakpoint (); \
149 } \
150 resume (0, 0); \
151 continue; \
152 }
153
154 /* In xcoff, we cannot process line numbers when we see them. This is
155 mainly because we don't know the boundaries of the include files. So,
156 we postpone that, and then enter and sort(?) the whole line table at
157 once, when we are closing the current symbol table in end_symtab(). */
158
159 #define PROCESS_LINENUMBER_HOOK() aix_process_linenos ()
160
161
162 /* When a target process or core-file has been attached, we sneak in
163 and figure out where the shared libraries have got to. In case there
164 is no inferior_process exists (e.g. bringing up a core file), we can't
165 attemtp to relocate symbol table, since we don't have information about
166 load segments. */
167
168 #define SOLIB_ADD(a, b, c) \
169 if (inferior_pid) xcoff_relocate_symtab (inferior_pid)
170
171 /* Immediately after a function call, return the saved pc.
172 Can't go through the frames for this because on some machines
173 the new frame is not set up until the new function executes
174 some instructions. */
175
176 #define SAVED_PC_AFTER_CALL(frame) read_register (LR_REGNUM)
177
178 /* Address of end of stack space. */
179
180 #define STACK_END_ADDR 0x2ff80000
181
182 /* Stack grows downward. */
183
184 #define INNER_THAN <
185
186 #if 0
187 /* No, we shouldn't use this. push_arguments() should leave stack in a
188 proper alignment! */
189 /* Stack has strict alignment. */
190
191 #define STACK_ALIGN(ADDR) (((ADDR)+7)&-8)
192 #endif
193
194 /* This is how argumets pushed onto stack or passed in registers. */
195
196 #define PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \
197 sp = push_arguments(nargs, args, sp, struct_return, struct_addr)
198
199 /* Sequence of bytes for breakpoint instruction. */
200
201 #define BREAKPOINT {0x7d, 0x82, 0x10, 0x08}
202
203 /* Amount PC must be decremented by after a breakpoint.
204 This is often the number of bytes in BREAKPOINT
205 but not always. */
206
207 #define DECR_PC_AFTER_BREAK 0
208
209 /* Nonzero if instruction at PC is a return instruction. */
210 /* Allow any of the return instructions, including a trapv and a return
211 from interrupt. */
212
213 #define ABOUT_TO_RETURN(pc) \
214 ((read_memory_integer (pc, 4) & 0xfe8007ff) == 0x4e800020)
215
216 /* Return 1 if P points to an invalid floating point value. */
217
218 #define INVALID_FLOAT(p, len) 0 /* Just a first guess; not checked */
219
220 /* Largest integer type */
221
222 #define LONGEST long
223
224 /* Name of the builtin type for the LONGEST type above. */
225
226 #define BUILTIN_TYPE_LONGEST builtin_type_long
227
228 /* Say how long (ordinary) registers are. */
229
230 #define REGISTER_TYPE long
231
232 /* Number of machine registers */
233
234 #define NUM_REGS 71
235
236 /* Initializer for an array of names of registers.
237 There should be NUM_REGS strings in this initializer. */
238
239 #define REGISTER_NAMES \
240 {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
241 "r8", "r9", "r10","r11","r12","r13","r14","r15", \
242 "r16","r17","r18","r19","r20","r21","r22","r23", \
243 "r24","r25","r26","r27","r28","r29","r30","r31", \
244 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
245 "f8", "f9", "f10","f11","f12","f13","f14","f15", \
246 "f16","f17","f18","f19","f20","f21","f22","f23", \
247 "f24","f25","f26","f27","f28","f29","f30","f31", \
248 "pc", "ps", "cnd", "lr", "cnt", "xer", "mq" }
249
250 /* Register numbers of various important registers.
251 Note that some of these values are "real" register numbers,
252 and correspond to the general registers of the machine,
253 and some are "phony" register numbers which are too large
254 to be actual register numbers as far as the user is concerned
255 but do serve to get the desired values when passed to read_register. */
256
257 #define FP_REGNUM 1 /* Contains address of executing stack frame */
258 #define SP_REGNUM 1 /* Contains address of top of stack */
259 #define TOC_REGNUM 2 /* TOC register */
260 #define FP0_REGNUM 32 /* Floating point register 0 */
261 #define GP0_REGNUM 0 /* GPR register 0 */
262 #define FP0_REGNUM 32 /* FPR (Floating point) register 0 */
263 #define FPLAST_REGNUM 63 /* Last floating point register */
264
265 /* Special purpose registers... */
266 /* P.S. keep these in the same order as in /usr/mstsave.h `mstsave' structure, for
267 easier processing */
268
269 #define PC_REGNUM 64 /* Program counter (instruction address %iar) */
270 #define PS_REGNUM 65 /* Processor (or machine) status (%msr) */
271 #define CR_REGNUM 66 /* Condition register */
272 #define LR_REGNUM 67 /* Link register */
273 #define CTR_REGNUM 68 /* Count register */
274 #define XER_REGNUM 69 /* Fixed point exception registers */
275 #define MQ_REGNUM 70 /* Multiply/quotient register */
276
277 #define FIRST_SP_REGNUM 64 /* first special register number */
278 #define LAST_SP_REGNUM 70 /* last special register number */
279
280 /* Total amount of space needed to store our copies of the machine's
281 register state, the array `registers'.
282
283 32 4-byte gpr's
284 32 8-byte fpr's
285 7 4-byte special purpose registers,
286
287 total 416 bytes. Keep some extra space for now, in case to add more. */
288
289 #define REGISTER_BYTES 420
290
291
292 /* Index within `registers' of the first byte of the space for
293 register N. */
294
295 #define REGISTER_BYTE(N) \
296 ( \
297 ((N) > FPLAST_REGNUM) ? ((((N) - FPLAST_REGNUM -1) * 4) + 384)\
298 :((N) >= FP0_REGNUM) ? ((((N) - FP0_REGNUM) * 8) + 128) \
299 :((N) * 4) )
300
301 /* Number of bytes of storage in the actual machine representation
302 for register N. */
303 /* Note that the unsigned cast here forces the result of the
304 subtractiion to very high positive values if N < FP0_REGNUM */
305
306 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
307
308 /* Number of bytes of storage in the program's representation
309 for register N. On the RS6000, all regs are 4 bytes
310 except the floating point regs which are 8-byte doubles. */
311
312 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
313
314 /* Largest value REGISTER_RAW_SIZE can have. */
315
316 #define MAX_REGISTER_RAW_SIZE 8
317
318 /* Largest value REGISTER_VIRTUAL_SIZE can have. */
319
320 #define MAX_REGISTER_VIRTUAL_SIZE 8
321
322 /* convert a dbx stab register number (from `r' declaration) to a gdb REGNUM */
323
324 #define STAB_REG_TO_REGNUM(value) (value)
325
326 /* Nonzero if register N requires conversion
327 from raw format to virtual format. */
328
329 #define REGISTER_CONVERTIBLE(N) ((N) >= FP0_REGNUM && (N) <= FPLAST_REGNUM)
330
331 /* Convert data from raw format for register REGNUM
332 to virtual format for register REGNUM. */
333
334 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \
335 bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM))
336
337 /* Convert data from virtual format for register REGNUM
338 to raw format for register REGNUM. */
339
340 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
341 bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM))
342
343 /* Return the GDB type object for the "standard" data type
344 of data in register N. */
345
346 #define REGISTER_VIRTUAL_TYPE(N) \
347 (((unsigned)(N) - FP0_REGNUM) < 32 ? builtin_type_double : builtin_type_int)
348
349 /* Store the address of the place in which to copy the structure the
350 subroutine will return. This is called from call_function. */
351 /* in RS6000, struct return addresses are passed as an extra parameter in r3.
352 In function return, callee is not responsible of returning this address back.
353 Since gdb needs to find it, we will store in a designated variable
354 `rs6000_struct_return_address'. */
355
356 extern unsigned int rs6000_struct_return_address;
357
358 #define STORE_STRUCT_RETURN(ADDR, SP) \
359 { write_register (3, (ADDR)); \
360 rs6000_struct_return_address = (unsigned int)(ADDR); }
361
362 /* Extract from an array REGBUF containing the (raw) register state
363 a function return value of type TYPE, and copy that, in virtual format,
364 into VALBUF. */
365
366 /* #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
367 bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE)) */
368
369 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
370 extract_return_value(TYPE,REGBUF,VALBUF)
371
372 /* Write into appropriate registers a function return value
373 of type TYPE, given in virtual format. */
374
375 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
376 { \
377 if (TYPE_CODE (TYPE) == TYPE_CODE_FLT) \
378 \
379 /* Floating point values are returned starting from FPR1 and up. \
380 Say a double_double_double type could be returned in \
381 FPR1/FPR2/FPR3 triple. */ \
382 \
383 write_register_bytes (REGISTER_BYTE (FP0_REGNUM+1), (VALBUF), \
384 TYPE_LENGTH (TYPE)); \
385 else \
386 /* Everything else is returned in GPR3 and up. */ \
387 write_register_bytes (REGISTER_BYTE (GP0_REGNUM+3), (VALBUF), \
388 TYPE_LENGTH (TYPE)); \
389 }
390
391
392 /* Extract from an array REGBUF containing the (raw) register state
393 the address in which a function should return its structure value,
394 as a CORE_ADDR (or an expression that can be used as one). */
395
396 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) rs6000_struct_return_address
397 \f
398 /* Describe the pointer in each stack frame to the previous stack frame
399 (its caller). */
400
401 /* FRAME_CHAIN takes a frame's nominal address
402 and produces the frame's chain-pointer. */
403
404 /* In the case of the RS6000, the frame's nominal address
405 is the address of a 4-byte word containing the calling frame's address. */
406
407 #define FRAME_CHAIN(thisframe) \
408 (!inside_entry_file ((thisframe)->pc) ? \
409 read_memory_integer ((thisframe)->frame, 4) :\
410 0)
411
412 /* Define other aspects of the stack frame. */
413
414 /* A macro that tells us whether the function invocation represented
415 by FI does not have a frame on the stack associated with it. If it
416 does not, FRAMELESS is set to 1, else 0. */
417
418 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
419 FRAMELESS = frameless_function_invocation (FI, 0)
420
421 /* Functions calling alloca() change the value of the stack pointer. We
422 need to use initial stack pointer (which is saved in r31 by gcc) in
423 such cases. If a compiler emits traceback table, then we should use the
424 alloca register specified in traceback table. FIXME. */
425 /* Also, it is a good idea to cache information about frame's saved registers
426 in the frame structure to speed things up. See tm-m88k.h. FIXME. */
427
428 #define EXTRA_FRAME_INFO \
429 CORE_ADDR initial_sp; /* initial stack pointer. */ \
430 struct frame_saved_regs *cache_fsr; /* saved registers */
431
432 /* Frameless function invocation in IBM RS/6000 is sometimes
433 half-done. It perfectly sets up a new frame, e.g. a new frame (in
434 fact stack) pointer, etc, but it doesn't save the %pc. We call
435 frameless_function_invocation to tell us how to get the %pc. */
436
437 #define INIT_EXTRA_FRAME_INFO(fromleaf, fi) \
438 fi->initial_sp = 0; \
439 fi->cache_fsr = 0;
440
441 #define FRAME_SAVED_PC(FRAME) \
442 (frameless_function_invocation (FRAME, 1) \
443 ? SAVED_PC_AFTER_CALL (FRAME) \
444 : read_memory_integer (read_memory_integer ((FRAME)->frame, 4)+8, 4))
445
446 #define FRAME_ARGS_ADDRESS(FI) \
447 (((struct frame_info*)(FI))->initial_sp ? \
448 ((struct frame_info*)(FI))->initial_sp : \
449 frame_initial_stack_address (FI))
450
451 #define FRAME_LOCALS_ADDRESS(FI) FRAME_ARGS_ADDRESS(FI)
452
453
454 /* Set VAL to the number of args passed to frame described by FI.
455 Can set VAL to -1, meaning no way to tell. */
456
457 /* We can't tell how many args there are
458 now that the C compiler delays popping them. */
459
460 #define FRAME_NUM_ARGS(val,fi) (val = -1)
461
462 /* Return number of bytes at start of arglist that are not really args. */
463
464 #define FRAME_ARGS_SKIP 8 /* Not sure on this. FIXMEmgo */
465
466 /* Put here the code to store, into a struct frame_saved_regs,
467 the addresses of the saved registers of frame described by FRAME_INFO.
468 This includes special registers such as pc and fp saved in special
469 ways in the stack frame. sp is even more special:
470 the address we return for it IS the sp for the next frame. */
471 /* In the following implementation for RS6000, we did *not* save sp. I am
472 not sure if it will be needed. The following macro takes care of gpr's
473 and fpr's only. */
474
475 #define FRAME_FIND_SAVED_REGS(FRAME_INFO, FRAME_SAVED_REGS) \
476 { \
477 int ii; \
478 CORE_ADDR frame_addr, func_start; \
479 struct aix_framedata fdata; \
480 \
481 /* find the start of the function and collect info about its frame. */\
482 \
483 func_start = get_pc_function_start ((FRAME_INFO)->pc) + FUNCTION_START_OFFSET; \
484 function_frame_info (func_start, &fdata); \
485 bzero (&(FRAME_SAVED_REGS), sizeof (FRAME_SAVED_REGS)); \
486 \
487 /* if there were any saved registers, figure out parent's stack pointer. */ \
488 frame_addr = 0; \
489 /* the following is true only if the frame doesn't have a call to alloca(), \
490 FIXME. */ \
491 if (fdata.saved_fpr >= 0 || fdata.saved_gpr >= 0) { \
492 if ((FRAME_INFO)->prev && (FRAME_INFO)->prev->frame) \
493 frame_addr = (FRAME_INFO)->prev->frame; \
494 else \
495 frame_addr = read_memory_integer ((FRAME_INFO)->frame, 4); \
496 } \
497 \
498 /* if != -1, fdata.saved_fpr is the smallest number of saved_fpr. All fpr's \
499 from saved_fpr to fp31 are saved right underneath caller stack pointer, \
500 starting from fp31 first. */ \
501 \
502 if (fdata.saved_fpr >= 0) { \
503 for (ii=31; ii >= fdata.saved_fpr; --ii) \
504 (FRAME_SAVED_REGS).regs [FP0_REGNUM + ii] = frame_addr - ((32 - ii) * 8); \
505 frame_addr -= (32 - fdata.saved_fpr) * 8; \
506 } \
507 \
508 /* if != -1, fdata.saved_gpr is the smallest number of saved_gpr. All gpr's \
509 from saved_gpr to gpr31 are saved right under saved fprs, starting \
510 from r31 first. */ \
511 \
512 if (fdata.saved_gpr >= 0) \
513 for (ii=31; ii >= fdata.saved_gpr; --ii) \
514 (FRAME_SAVED_REGS).regs [ii] = frame_addr - ((32 - ii) * 4); \
515 }
516
517 \f
518 /* Things needed for making the inferior call functions. */
519
520 /* Push an empty stack frame, to record the current PC, etc. */
521 /* Change these names into rs6k_{push, pop}_frame(). FIXMEmgo. */
522
523 #define PUSH_DUMMY_FRAME push_dummy_frame ()
524
525 /* Discard from the stack the innermost frame,
526 restoring all saved registers. */
527
528 #define POP_FRAME pop_frame ()
529
530 /* This sequence of words is the instructions:
531
532 mflr r0 // 0x7c0802a6
533 // save fpr's
534 stfd r?, num(r1) // 0xd8010000 there should be 32 of this??
535 // save gpr's
536 stm r0, num(r1) // 0xbc010000
537 stu r1, num(r1) // 0x94210000
538
539 // the function we want to branch might be in a different load
540 // segment. reset the toc register. Note that the actual toc address
541 // will be fix by fix_call_dummy () along with function address.
542
543 st r2, 0x14(r1) // 0x90410014 save toc register
544 liu r2, 0x1234 // 0x3c401234 reset a new toc value 0x12345678
545 oril r2, r2,0x5678 // 0x60425678
546
547 // load absolute address 0x12345678 to r0
548 liu r0, 0x1234 // 0x3c001234
549 oril r0, r0,0x5678 // 0x60005678
550 mtctr r0 // 0x7c0903a6 ctr <- r0
551 bctrl // 0x4e800421 jump subroutine 0x12345678 (%ctr)
552 cror 0xf, 0xf, 0xf // 0x4def7b82
553 brpt // 0x7d821008, breakpoint
554 cror 0xf, 0xf, 0xf // 0x4def7b82 (for 8 byte alignment)
555
556
557 We actually start executing by saving the toc register first, since the pushing
558 of the registers is done by PUSH_DUMMY_FRAME. If this were real code,
559 the arguments for the function called by the `bctrl' would be pushed
560 between the `stu' and the `bctrl', and we could allow it to execute through.
561 But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
562 and we cannot allow to push the registers again.
563 */
564
565 #define CALL_DUMMY {0x7c0802a6, 0xd8010000, 0xbc010000, 0x94210000, \
566 0x90410014, 0x3c401234, 0x60425678, \
567 0x3c001234, 0x60005678, 0x7c0903a6, 0x4e800421, \
568 0x4def7b82, 0x7d821008, 0x4def7b82 }
569
570
571 /* keep this as multiple of 8 (%sp requires 8 byte alignment) */
572 #define CALL_DUMMY_LENGTH 56
573
574 #define CALL_DUMMY_START_OFFSET 16
575
576 /* Insert the specified number of args and function address
577 into a call sequence of the above form stored at DUMMYNAME. */
578
579 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, using_gcc) \
580 fix_call_dummy(dummyname, pc, fun, nargs, type)
581
582 /* Flag for machine-specific stuff in shared files. FIXME */
583 #define IBM6000_TARGET
584
585 /* RS6000/AIX does not support PT_STEP. Has to be simulated. */
586
587 #define NO_SINGLE_STEP