1 /* GCC backend definitions for the TI MSP430 Processor
2    Copyright (C) 2012-2018 Free Software Foundation, Inc.
3    Contributed by Red Hat.
4 
5    This file is part of GCC.
6 
7    GCC is free software; you can redistribute it and/or modify it
8    under the terms of the GNU General Public License as published
9    by the Free Software Foundation; either version 3, or (at your
10    option) any later version.
11 
12    GCC is distributed in the hope that it will be useful, but WITHOUT
13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
15    License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with GCC; see the file COPYING3.  If not see
19    <http://www.gnu.org/licenses/>.  */
20 
21 
22 /* Run-time Target Specification */
23 
24 /* True if the MSP430x extensions are enabled.  */
25 #ifndef IN_LIBGCC2
26 extern bool msp430x;
27 #endif
28 
29 #define TARGET_CPU_CPP_BUILTINS()               \
30   do                                            \
31     {                                           \
32       builtin_define ("NO_TRAMPOLINES");        \
33       builtin_define ("__MSP430__"); 		\
34       builtin_define (msp430_mcu_name ());	\
35       if (msp430x)				\
36 	{					\
37 	  builtin_define ("__MSP430X__");	\
38 	  builtin_assert ("cpu=MSP430X");	\
39 	  if (TARGET_LARGE)			\
40 	    builtin_define ("__MSP430X_LARGE__");	\
41 	}					\
42       else					\
43 	builtin_assert ("cpu=MSP430"); 		\
44     }                                           \
45   while (0)
46 
47 #undef  STARTFILE_SPEC
48 #define STARTFILE_SPEC "%{pg:gcrt0.o%s}%{!pg:%{minrt:crt0-minrt.o%s}%{!minrt:crt0.o%s}} %{!minrt:crtbegin.o%s}"
49 
50 /* -lgcc is included because crtend.o needs __mspabi_func_epilog_1.  */
51 #undef  ENDFILE_SPEC
52 #define ENDFILE_SPEC "%{!minrt:crtend.o%s} %{minrt:crtn-minrt.o%s}%{!minrt:crtn.o%s} -lgcc"
53 
54 #define ASM_SPEC "-mP " /* Enable polymorphic instructions.  */ \
55   "%{mcpu=*:-mcpu=%*}%{!mcpu=*:%{mmcu=*:-mmcu=%*}} " /* Pass the CPU type on to the assembler.  */ \
56   "%{mrelax=-mQ} " /* Pass the relax option on to the assembler.  */ \
57   "%{mlarge:-ml} " /* Tell the assembler if we are building for the LARGE pointer model.  */ \
58   "%{!msim:-md} %{msim:%{mlarge:-md}} " /* Copy data from ROM to RAM if necessary.  */ \
59   "%{msilicon-errata=*:-msilicon-errata=%*} " /* Pass on -msilicon-errata.  */ \
60   "%{msilicon-errata-warn=*:-msilicon-errata-warn=%*} " /* Pass on -msilicon-errata-warn.  */ \
61   "%{ffunction-sections:-gdwarf-sections} " /* If function sections are being created then create DWARF line number sections as well.  */ \
62   "%{mdata-region=*:-mdata-region=%*} " /* Pass on -mdata-region.  */
63 
64 /* Enable linker section garbage collection by default, unless we
65    are creating a relocatable binary (gc does not work) or debugging
66    is enabled  (the GDB testsuite relies upon unused entities not being deleted).  */
67 #define LINK_SPEC "%{mrelax:--relax} %{mlarge:%{!r:%{!g:--gc-sections}}} " \
68   "%{mcode-region=*:--code-region=%*} %{mdata-region=*:--data-region=%*}"
69 
70 extern const char * msp430_select_hwmult_lib (int, const char **);
71 # define EXTRA_SPEC_FUNCTIONS				\
72   { "msp430_hwmult_lib", msp430_select_hwmult_lib },
73 
74 /* Specify the libraries to include on the linker command line.
75 
76    Selecting the hardware multiply library to use is quite complex.
77    If the user has specified -mhwmult=FOO then the mapping is quite
78    easy (and could be handled here in the SPEC string), unless FOO
79    is set to AUTO.  In this case the -mmcu= option must be consulted
80    instead.  If the -mhwmult= option is not specified then the -mmcu=
81    option must then be examined.  If neither -mhwmult= nor -mmcu= are
82    specified then a default hardware multiply library is used.
83 
84    Examining the -mmcu=FOO option is difficult, and it is so this
85    reason that a spec function is used.  There are so many possible
86    values of FOO that a table is used to look up the name and map
87    it to a hardware multiply library.  This table (in device-msp430.c)
88    must be kept in sync with the same table in msp430.c.  */
89 #undef  LIB_SPEC
90 #define LIB_SPEC "					\
91 --start-group						\
92 %{mhwmult=auto:%{mmcu=*:%:msp430_hwmult_lib(mcu %{mmcu=*:%*});:%:msp430_hwmult_lib(default)}; \
93   mhwmult=*:%:msp430_hwmult_lib(hwmult %{mhwmult=*:%*}); \
94   mmcu=*:%:msp430_hwmult_lib(mcu %{mmcu=*:%*});		\
95   :%:msp430_hwmult_lib(default)}			\
96 -lc							\
97 -lgcc							\
98 -lcrt							\
99 %{msim:-lsim}						\
100 %{!msim:-lnosys}					\
101 --end-group					   	\
102 %{!T*:%{!msim:%{mmcu=*:--script=%*.ld}}}		\
103 %{!T*:%{msim:%{mlarge:%Tmsp430xl-sim.ld}%{!mlarge:%Tmsp430-sim.ld}}} \
104 "
105 
106 /* Storage Layout */
107 
108 #define BITS_BIG_ENDIAN 		0
109 #define BYTES_BIG_ENDIAN 		0
110 #define WORDS_BIG_ENDIAN 		0
111 
112 
113 #ifdef IN_LIBGCC2
114 /* This is to get correct SI and DI modes in libgcc2.c (32 and 64 bits).  */
115 #define	UNITS_PER_WORD			4
116 /* We have a problem with libgcc2.  It only defines two versions of
117    each function, one for "int" and one for "long long".  Ie it assumes
118    that "sizeof (int) == sizeof (long)".  For the MSP430 this is not true
119    and we need a third set of functions.  We explicitly define
120    LIBGCC2_UNITS_PER_WORD here so that it is clear that we are expecting
121    to get the SI and DI versions from the libgcc2.c sources, and we
122    provide our own set of HI functions, which is why this
123    definition is surrounded by #ifndef..#endif.  */
124 #ifndef LIBGCC2_UNITS_PER_WORD
125 #define LIBGCC2_UNITS_PER_WORD 		4
126 #endif
127 #else
128 /* Actual width of a word, in units (bytes).  */
129 #define	UNITS_PER_WORD 			2
130 #endif
131 
132 #define SHORT_TYPE_SIZE			16
133 #define INT_TYPE_SIZE			16
134 #define LONG_TYPE_SIZE			32
135 #define LONG_LONG_TYPE_SIZE		64
136 
137 #define FLOAT_TYPE_SIZE 		32
138 #define DOUBLE_TYPE_SIZE 		64
139 #define LONG_DOUBLE_TYPE_SIZE		64 /*DOUBLE_TYPE_SIZE*/
140 
141 #define DEFAULT_SIGNED_CHAR		0
142 
143 #define STRICT_ALIGNMENT 		1
144 #define FUNCTION_BOUNDARY 		16
145 #define BIGGEST_ALIGNMENT 		16
146 #define STACK_BOUNDARY 			16
147 #define PARM_BOUNDARY 			8
148 #define PCC_BITFIELD_TYPE_MATTERS	1
149 
150 #define STACK_GROWS_DOWNWARD		1
151 #define FRAME_GROWS_DOWNWARD		1
152 #define FIRST_PARM_OFFSET(FNDECL) 	0
153 
154 #define MAX_REGS_PER_ADDRESS 		1
155 
156 #define Pmode 				(TARGET_LARGE ? PSImode : HImode)
157 #define POINTER_SIZE			(TARGET_LARGE ? 20 : 16)
158 /* This is just for .eh_frame, to match bfd.  */
159 #define PTR_SIZE			(TARGET_LARGE ? 4 : 2)
160 #define	POINTERS_EXTEND_UNSIGNED	1
161 
162 #define ADDR_SPACE_NEAR	1
163 #define ADDR_SPACE_FAR	2
164 
165 #define REGISTER_TARGET_PRAGMAS() msp430_register_pragmas()
166 
167 #if 1 /* XXX */
168 /* Define this macro if it is advisable to hold scalars in registers
169    in a wider mode than that declared by the program.  In such cases,
170    the value is constrained to be within the bounds of the declared
171    type, but kept valid in the wider mode.  The signedness of the
172    extension may differ from that of the type.  */
173 
174 #define PROMOTE_MODE(MODE, UNSIGNEDP, TYPE)	\
175   if (GET_MODE_CLASS (MODE) == MODE_INT		\
176       && GET_MODE_SIZE (MODE) < 2)      	\
177     (MODE) = HImode;
178 #endif
179 
180 /* Layout of Source Language Data Types */
181 
182 #undef  SIZE_TYPE
183 #define SIZE_TYPE			(TARGET_LARGE ? "__int20 unsigned" : "unsigned int")
184 #undef  PTRDIFF_TYPE
185 #define PTRDIFF_TYPE			(TARGET_LARGE ? "__int20" : "int")
186 #undef  WCHAR_TYPE
187 #define WCHAR_TYPE			"long int"
188 #undef  WCHAR_TYPE_SIZE
189 #define WCHAR_TYPE_SIZE			BITS_PER_WORD
190 #define FUNCTION_MODE 			HImode
191 #define CASE_VECTOR_MODE		Pmode
192 #define HAS_LONG_COND_BRANCH		0
193 #define HAS_LONG_UNCOND_BRANCH		0
194 
195 #define LOAD_EXTEND_OP(M)		ZERO_EXTEND
196 #define WORD_REGISTER_OPERATIONS	1
197 
198 #define MOVE_MAX 			8
199 
200 #define INCOMING_RETURN_ADDR_RTX \
201   msp430_incoming_return_addr_rtx ()
202 
203 #define RETURN_ADDR_RTX(COUNT, FA)		\
204   msp430_return_addr_rtx (COUNT)
205 
206 #define SLOW_BYTE_ACCESS		0
207 
208 
209 /* Register Usage */
210 
211 /* gas doesn't recognize PC (R0), SP (R1), and SR (R2) as register
212    names.  */
213 #define REGISTER_NAMES						\
214 {								\
215   "R0", "R1", "R2", "R3", "R4", "R5", "R6", "R7",		\
216     "R8", "R9", "R10", "R11", "R12", "R13", "R14", "R15",	\
217   "argptr"							\
218 }
219 
220 enum reg_class
221 {
222   NO_REGS,
223   R12_REGS,
224   R13_REGS,
225   GEN_REGS,
226   ALL_REGS,
227   LIM_REG_CLASSES
228 };
229 
230 #define REG_CLASS_NAMES \
231 {			\
232   "NO_REGS",		\
233   "R12_REGS",		\
234   "R13_REGS",		\
235   "GEN_REGS",		\
236   "ALL_REGS"		\
237 }
238 
239 #define REG_CLASS_CONTENTS \
240 {			   \
241   0x00000000,		   \
242   0x00001000,		   \
243   0x00002000,		   \
244   0x0000fff2,		   \
245   0x0001ffff		   \
246 }
247 
248 #define GENERAL_REGS			GEN_REGS
249 #define BASE_REG_CLASS  		GEN_REGS
250 #define INDEX_REG_CLASS			GEN_REGS
251 #define N_REG_CLASSES			(int) LIM_REG_CLASSES
252 
253 #define PC_REGNUM 		        0
254 #define STACK_POINTER_REGNUM 	        1
255 #define CC_REGNUM                       2
256 #define FRAME_POINTER_REGNUM 		4 /* not usually used, call preserved */
257 #define ARG_POINTER_REGNUM 		16
258 #define STATIC_CHAIN_REGNUM 		5 /* FIXME */
259 
260 #define FIRST_PSEUDO_REGISTER 		17
261 
262 #define REGNO_REG_CLASS(REGNO)          ((REGNO) < 17 \
263 					 ? GEN_REGS : NO_REGS)
264 
265 #define TRAMPOLINE_SIZE			4 /* FIXME */
266 #define TRAMPOLINE_ALIGNMENT		16 /* FIXME */
267 
268 #define ELIMINABLE_REGS					\
269 {{ ARG_POINTER_REGNUM,   STACK_POINTER_REGNUM },	\
270  { ARG_POINTER_REGNUM,   FRAME_POINTER_REGNUM },	\
271  { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM }}
272 
273 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET)	\
274   (OFFSET) = msp430_initial_elimination_offset ((FROM), (TO))
275 
276 
277 #define FUNCTION_ARG_REGNO_P(N)	  	((N) >= 8 && (N) < ARG_POINTER_REGNUM)
278 #define DEFAULT_PCC_STRUCT_RETURN	0
279 
280 /* 1 == register can't be used by gcc, in general
281    0 == register can be used by gcc, in general */
282 #define FIXED_REGISTERS					\
283 {							\
284   1,0,1,1, 0,0,0,0,					\
285   0,0,0,0, 0,0,0,0,					\
286   1,							\
287 }
288 
289 /* 1 == value changes across function calls
290    0 == value is the same after a call      */
291 /* R4 through R10 are callee-saved */
292 #define CALL_USED_REGISTERS				\
293 {							\
294   1,0,1,1, 0,0,0,0,					\
295   0,0,0,1, 1,1,1,1,					\
296   1,						\
297 }
298 
299 #define REG_ALLOC_ORDER					\
300   { 12, 13, 14, 15, 10, 9, 8, 7, 6, 5, 4, 11, 0, 1, 2, 3, 16 }
301 /*  { 11, 15, 14, 13, 12, 10, 9, 8, 7, 6, 5, 4, 0, 1, 2, 3, 16 }*/
302 
303 #define REGNO_OK_FOR_BASE_P(regno)	1
304 #define REGNO_OK_FOR_INDEX_P(regno)	1
305 
306 
307 
308 typedef struct
309 {
310   /* These two are the current argument status.  */
311   char reg_used[4];
312 #define CA_FIRST_REG 12
313   char can_split;
314   /* These two are temporaries used internally.  */
315   char start_reg;
316   char reg_count;
317   char mem_count;
318   char special_p;
319 } CUMULATIVE_ARGS;
320 
321 #define INIT_CUMULATIVE_ARGS(CA, FNTYPE, LIBNAME, INDIRECT, N_NAMED_ARGS) \
322   msp430_init_cumulative_args (&CA, FNTYPE, LIBNAME, INDIRECT, N_NAMED_ARGS)
323 
324 
325 /* FIXME */
326 #define NO_PROFILE_COUNTERS     1
327 #define PROFILE_BEFORE_PROLOGUE 1
328 
329 #define FUNCTION_PROFILER(FILE, LABELNO)	\
330     fprintf (FILE, "\tcall\t__mcount\n");
331 
332 /* Exception Handling */
333 
334 /* R12,R13,R14 - EH data
335    R15 - stack adjustment */
336 
337 #define EH_RETURN_DATA_REGNO(N) \
338   (((N) < 3) ? ((N) + 12) : INVALID_REGNUM)
339 
340 #define EH_RETURN_HANDLER_RTX \
341   gen_rtx_MEM(Pmode, gen_rtx_PLUS (Pmode, gen_rtx_REG(Pmode, SP_REGNO), gen_rtx_REG (Pmode, 15)))
342 
343 #define EH_RETURN_STACKADJ_RTX gen_rtx_REG (Pmode, 15)
344 
345 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE,GLOBAL) DW_EH_PE_udata4
346 
347 
348 /* Stack Layout and Calling Conventions */
349 
350 
351 /* Addressing Modes */
352 
353 
354 
355 #define TEXT_SECTION_ASM_OP ".text"
356 #define DATA_SECTION_ASM_OP ".data"
357 #define BSS_SECTION_ASM_OP   "\t.section .bss"
358 
359 #define ASM_COMMENT_START	" ;"
360 #define ASM_APP_ON		""
361 #define ASM_APP_OFF 		""
362 #define LOCAL_LABEL_PREFIX	".L"
363 #undef  USER_LABEL_PREFIX
364 #define USER_LABEL_PREFIX	""
365 
366 #define GLOBAL_ASM_OP 		"\t.global\t"
367 
368 #define ASM_OUTPUT_LABELREF(FILE, SYM) msp430_output_labelref ((FILE), (SYM))
369 
370 #define ASM_OUTPUT_ADDR_VEC_ELT(FILE, VALUE) \
371   fprintf (FILE, "\t.long .L%d\n", VALUE)
372 
373 /* This is how to output an element of a case-vector that is relative.
374    Note: The local label referenced by the "3b" below is emitted by
375    the tablejump insn.  */
376 
377 #define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, BODY, VALUE, REL) \
378   fprintf (FILE, "\t.long .L%d - 1b\n", VALUE)
379 
380 
381 #define ASM_OUTPUT_ALIGN(STREAM, LOG)		\
382   do						\
383     {						\
384       if ((LOG) == 0)				\
385         break;					\
386       fprintf (STREAM, "\t.balign %d\n", 1 << (LOG));	\
387     }						\
388   while (0)
389 
390 #define JUMP_TABLES_IN_TEXT_SECTION	1
391 
392 #undef	DWARF2_ADDR_SIZE
393 #define	DWARF2_ADDR_SIZE			4
394 
395 #define INCOMING_FRAME_SP_OFFSET		(TARGET_LARGE ? 4 : 2)
396 
397 #undef  PREFERRED_DEBUGGING_TYPE
398 #define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
399 
400 #define DWARF2_ASM_LINE_DEBUG_INFO		1
401 
402 /* Prevent reload (and others) from choosing HImode stack slots
403    when spilling hard registers when they may contain PSImode values.  */
404 #define HARD_REGNO_CALLER_SAVE_MODE(REGNO,NREGS,MODE) \
405   ((TARGET_LARGE && ((NREGS) <= 2)) ? PSImode : choose_hard_reg_mode ((REGNO), (NREGS), false))
406 
407 #define ACCUMULATE_OUTGOING_ARGS 1
408 
409 #undef  ASM_DECLARE_FUNCTION_NAME
410 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
411   msp430_start_function ((FILE), (NAME), (DECL))
412 
413 #define TARGET_HAS_NO_HW_DIVIDE (! TARGET_HWMULT)
414 
415 #undef  USE_SELECT_SECTION_FOR_FUNCTIONS
416 #define USE_SELECT_SECTION_FOR_FUNCTIONS 1
417 
418 #define ASM_OUTPUT_ALIGNED_DECL_COMMON(FILE, DECL, NAME, SIZE, ALIGN)	\
419   msp430_output_aligned_decl_common ((FILE), (DECL), (NAME), (SIZE), (ALIGN))
420