1 /* Target dependent code for GDB on TI C6x systems.
3 Copyright (C) 2010-2014 Free Software Foundation, Inc.
4 Contributed by Andrew Jenner <andrew@codesourcery.com>
5 Contributed by Yao Qi <yao@codesourcery.com>
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "frame-unwind.h"
25 #include "frame-base.h"
26 #include "trad-frame.h"
27 #include "dwarf2-frame.h"
38 #include "arch-utils.h"
39 #include "floatformat.h"
40 #include "glibc-tdep.h"
43 #include "tramp-frame.h"
44 #include "linux-tdep.h"
48 #include "tic6x-tdep.h"
50 #include "target-descriptions.h"
52 #include "features/tic6x-c64xp.c"
53 #include "features/tic6x-c64x.c"
54 #include "features/tic6x-c62x.c"
56 #define TIC6X_OPCODE_SIZE 4
57 #define TIC6X_FETCH_PACKET_SIZE 32
59 #define INST_S_BIT(INST) ((INST >> 1) & 1)
60 #define INST_X_BIT(INST) ((INST >> 12) & 1)
62 const gdb_byte tic6x_bkpt_illegal_opcode_be[] = { 0x56, 0x45, 0x43, 0x14 };
63 const gdb_byte tic6x_bkpt_illegal_opcode_le[] = { 0x14, 0x43, 0x45, 0x56 };
65 struct tic6x_unwind_cache
67 /* The frame's base, optionally used by the high-level debug info. */
70 /* The previous frame's inner most stack address. Used as this
71 frame ID's stack_addr. */
74 /* The address of the first instruction in this function */
77 /* Which register holds the return address for the frame. */
80 /* The offset of register saved on stack. If register is not saved, the
81 corresponding element is -1. */
82 CORE_ADDR reg_saved[TIC6X_NUM_CORE_REGS];
86 /* Name of TI C6x core registers. */
87 static const char *const tic6x_register_names[] =
89 "A0", "A1", "A2", "A3", /* 0 1 2 3 */
90 "A4", "A5", "A6", "A7", /* 4 5 6 7 */
91 "A8", "A9", "A10", "A11", /* 8 9 10 11 */
92 "A12", "A13", "A14", "A15", /* 12 13 14 15 */
93 "B0", "B1", "B2", "B3", /* 16 17 18 19 */
94 "B4", "B5", "B6", "B7", /* 20 21 22 23 */
95 "B8", "B9", "B10", "B11", /* 24 25 26 27 */
96 "B12", "B13", "B14", "B15", /* 28 29 30 31 */
97 "CSR", "PC", /* 32 33 */
100 /* This array maps the arguments to the register number which passes argument
101 in function call according to C6000 ELF ABI. */
102 static const int arg_regs[] = { 4, 20, 6, 22, 8, 24, 10, 26, 12, 28 };
104 /* This is the implementation of gdbarch method register_name. */
107 tic6x_register_name (struct gdbarch *gdbarch, int regno)
112 if (tdesc_has_registers (gdbarch_target_desc (gdbarch)))
113 return tdesc_register_name (gdbarch, regno);
114 else if (regno >= ARRAY_SIZE (tic6x_register_names))
117 return tic6x_register_names[regno];
120 /* This is the implementation of gdbarch method register_type. */
123 tic6x_register_type (struct gdbarch *gdbarch, int regno)
126 if (regno == TIC6X_PC_REGNUM)
127 return builtin_type (gdbarch)->builtin_func_ptr;
129 return builtin_type (gdbarch)->builtin_uint32;
133 tic6x_setup_default (struct tic6x_unwind_cache *cache)
137 for (i = 0; i < TIC6X_NUM_CORE_REGS; i++)
138 cache->reg_saved[i] = -1;
141 static unsigned long tic6x_fetch_instruction (struct gdbarch *, CORE_ADDR);
142 static int tic6x_register_number (int reg, int side, int crosspath);
144 /* Do a full analysis of the prologue at START_PC and update CACHE accordingly.
145 Bail out early if CURRENT_PC is reached. Returns the address of the first
146 instruction after the prologue. */
149 tic6x_analyze_prologue (struct gdbarch *gdbarch, const CORE_ADDR start_pc,
150 const CORE_ADDR current_pc,
151 struct tic6x_unwind_cache *cache,
152 struct frame_info *this_frame)
154 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
156 unsigned int src_reg, base_reg, dst_reg;
158 CORE_ADDR pc = start_pc;
159 CORE_ADDR return_pc = start_pc;
160 int frame_base_offset_to_sp = 0;
161 /* Counter of non-stw instructions after first insn ` sub sp, xxx, sp'. */
162 int non_stw_insn_counter = 0;
164 if (start_pc >= current_pc)
165 return_pc = current_pc;
169 /* The landmarks in prologue is one or two SUB instructions to SP.
170 Instructions on setting up dsbt are in the last part of prologue, if
171 needed. In maxim, prologue can be divided to three parts by two
172 `sub sp, xx, sp' insns. */
174 /* Step 1: Look for the 1st and 2nd insn `sub sp, xx, sp', in which, the
175 2nd one is optional. */
176 while (pc < current_pc)
180 unsigned long inst = tic6x_fetch_instruction (gdbarch, pc);
182 if ((inst & 0x1ffc) == 0x1dc0 || (inst & 0x1ffc) == 0x1bc0
183 || (inst & 0x0ffc) == 0x9c0)
185 /* SUBAW/SUBAH/SUB, and src1 is ucst 5. */
186 unsigned int src2 = tic6x_register_number ((inst >> 18) & 0x1f,
187 INST_S_BIT (inst), 0);
188 unsigned int dst = tic6x_register_number ((inst >> 23) & 0x1f,
189 INST_S_BIT (inst), 0);
191 if (src2 == TIC6X_SP_REGNUM && dst == TIC6X_SP_REGNUM)
193 /* Extract const from insn SUBAW/SUBAH/SUB, and translate it to
194 offset. The constant offset is decoded in bit 13-17 in all
195 these three kinds of instructions. */
196 unsigned int ucst5 = (inst >> 13) & 0x1f;
198 if ((inst & 0x1ffc) == 0x1dc0) /* SUBAW */
199 frame_base_offset_to_sp += ucst5 << 2;
200 else if ((inst & 0x1ffc) == 0x1bc0) /* SUBAH */
201 frame_base_offset_to_sp += ucst5 << 1;
202 else if ((inst & 0x0ffc) == 0x9c0) /* SUB */
203 frame_base_offset_to_sp += ucst5;
205 gdb_assert_not_reached ("unexpected instruction");
210 else if ((inst & 0x174) == 0x74) /* stw SRC, *+b15(uconst) */
212 /* The y bit determines which file base is read from. */
213 base_reg = tic6x_register_number ((inst >> 18) & 0x1f,
216 if (base_reg == TIC6X_SP_REGNUM)
218 src_reg = tic6x_register_number ((inst >> 23) & 0x1f,
219 INST_S_BIT (inst), 0);
221 cache->reg_saved[src_reg] = ((inst >> 13) & 0x1f) << 2;
225 non_stw_insn_counter = 0;
229 non_stw_insn_counter++;
230 /* Following instruction sequence may be emitted in prologue:
232 <+0>: subah .D2 b15,28,b15
233 <+4>: or .L2X 0,a4,b0
234 <+8>: || stw .D2T2 b14,*+b15(56)
235 <+12>:[!b0] b .S1 0xe50e4c1c <sleep+220>
236 <+16>:|| stw .D2T1 a10,*+b15(48)
237 <+20>:stw .D2T2 b3,*+b15(52)
238 <+24>:stw .D2T1 a4,*+b15(40)
240 we should look forward for next instruction instead of breaking loop
241 here. So far, we allow almost two sequential non-stw instructions
243 if (non_stw_insn_counter >= 2)
250 /* Step 2: Skip insn on setting up dsbt if it is. Usually, it looks like,
251 ldw .D2T2 *+b14(0),b14 */
252 inst = tic6x_fetch_instruction (gdbarch, pc);
253 /* The s bit determines which file dst will be loaded into, same effect as
255 dst_reg = tic6x_register_number ((inst >> 23) & 0x1f, (inst >> 1) & 1, 0);
256 /* The y bit (bit 7), instead of s bit, determines which file base be
258 base_reg = tic6x_register_number ((inst >> 18) & 0x1f, (inst >> 7) & 1, 0);
260 if ((inst & 0x164) == 0x64 /* ldw */
261 && dst_reg == TIC6X_DP_REGNUM /* dst is B14 */
262 && base_reg == TIC6X_DP_REGNUM) /* baseR is B14 */
269 cache->base = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM);
271 if (cache->reg_saved[TIC6X_FP_REGNUM] != -1)
273 /* If the FP now holds an offset from the CFA then this is a frame
274 which uses the frame pointer. */
276 cache->cfa = get_frame_register_unsigned (this_frame,
281 /* FP doesn't hold an offset from the CFA. If SP still holds an
282 offset from the CFA then we might be in a function which omits
283 the frame pointer. */
285 cache->cfa = cache->base + frame_base_offset_to_sp;
289 /* Adjust all the saved registers such that they contain addresses
290 instead of offsets. */
291 for (i = 0; i < TIC6X_NUM_CORE_REGS; i++)
292 if (cache->reg_saved[i] != -1)
293 cache->reg_saved[i] = cache->base + cache->reg_saved[i];
298 /* This is the implementation of gdbarch method skip_prologue. */
301 tic6x_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
304 struct tic6x_unwind_cache cache;
306 /* See if we can determine the end of the prologue via the symbol table.
307 If so, then return either PC, or the PC after the prologue, whichever is
309 if (find_pc_partial_function (start_pc, NULL, &func_addr, NULL))
311 CORE_ADDR post_prologue_pc
312 = skip_prologue_using_sal (gdbarch, func_addr);
313 if (post_prologue_pc != 0)
314 return max (start_pc, post_prologue_pc);
317 /* Can't determine prologue from the symbol table, need to examine
319 return tic6x_analyze_prologue (gdbarch, start_pc, (CORE_ADDR) -1, &cache,
323 /* This is the implementation of gdbarch method breakpiont_from_pc. */
325 static const gdb_byte *
326 tic6x_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *bp_addr,
329 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
333 if (tdep == NULL || tdep->breakpoint == NULL)
335 if (BFD_ENDIAN_BIG == gdbarch_byte_order_for_code (gdbarch))
336 return tic6x_bkpt_illegal_opcode_be;
338 return tic6x_bkpt_illegal_opcode_le;
341 return tdep->breakpoint;
344 /* This is the implementation of gdbarch method print_insn. */
347 tic6x_print_insn (bfd_vma memaddr, disassemble_info *info)
349 return print_insn_tic6x (memaddr, info);
353 tic6x_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
354 struct dwarf2_frame_state_reg *reg,
355 struct frame_info *this_frame)
357 /* Mark the PC as the destination for the return address. */
358 if (regnum == gdbarch_pc_regnum (gdbarch))
359 reg->how = DWARF2_FRAME_REG_RA;
361 /* Mark the stack pointer as the call frame address. */
362 else if (regnum == gdbarch_sp_regnum (gdbarch))
363 reg->how = DWARF2_FRAME_REG_CFA;
365 /* The above was taken from the default init_reg in dwarf2-frame.c
366 while the below is c6x specific. */
368 /* Callee save registers. The ABI designates A10-A15 and B10-B15 as
370 else if ((regnum >= 10 && regnum <= 15) || (regnum >= 26 && regnum <= 31))
371 reg->how = DWARF2_FRAME_REG_SAME_VALUE;
373 /* All other registers are caller-save. */
374 reg->how = DWARF2_FRAME_REG_UNDEFINED;
377 /* This is the implementation of gdbarch method unwind_pc. */
380 tic6x_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
384 frame_unwind_register (next_frame, TIC6X_PC_REGNUM, buf);
385 return extract_typed_address (buf, builtin_type (gdbarch)->builtin_func_ptr);
388 /* This is the implementation of gdbarch method unwind_sp. */
391 tic6x_unwind_sp (struct gdbarch *gdbarch, struct frame_info *this_frame)
393 return frame_unwind_register_unsigned (this_frame, TIC6X_SP_REGNUM);
397 /* Frame base handling. */
399 static struct tic6x_unwind_cache*
400 tic6x_frame_unwind_cache (struct frame_info *this_frame,
401 void **this_prologue_cache)
403 struct gdbarch *gdbarch = get_frame_arch (this_frame);
404 CORE_ADDR current_pc;
405 struct tic6x_unwind_cache *cache;
407 if (*this_prologue_cache)
408 return *this_prologue_cache;
410 cache = FRAME_OBSTACK_ZALLOC (struct tic6x_unwind_cache);
411 (*this_prologue_cache) = cache;
413 cache->return_regnum = TIC6X_RA_REGNUM;
415 tic6x_setup_default (cache);
417 cache->pc = get_frame_func (this_frame);
418 current_pc = get_frame_pc (this_frame);
420 /* Prologue analysis does the rest... */
422 tic6x_analyze_prologue (gdbarch, cache->pc, current_pc, cache, this_frame);
428 tic6x_frame_this_id (struct frame_info *this_frame, void **this_cache,
429 struct frame_id *this_id)
431 struct tic6x_unwind_cache *cache =
432 tic6x_frame_unwind_cache (this_frame, this_cache);
434 /* This marks the outermost frame. */
435 if (cache->base == 0)
438 (*this_id) = frame_id_build (cache->cfa, cache->pc);
441 static struct value *
442 tic6x_frame_prev_register (struct frame_info *this_frame, void **this_cache,
445 struct tic6x_unwind_cache *cache =
446 tic6x_frame_unwind_cache (this_frame, this_cache);
448 gdb_assert (regnum >= 0);
450 /* The PC of the previous frame is stored in the RA register of
451 the current frame. Frob regnum so that we pull the value from
452 the correct place. */
453 if (regnum == TIC6X_PC_REGNUM)
454 regnum = cache->return_regnum;
456 if (regnum == TIC6X_SP_REGNUM && cache->cfa)
457 return frame_unwind_got_constant (this_frame, regnum, cache->cfa);
459 /* If we've worked out where a register is stored then load it from
461 if (regnum < TIC6X_NUM_CORE_REGS && cache->reg_saved[regnum] != -1)
462 return frame_unwind_got_memory (this_frame, regnum,
463 cache->reg_saved[regnum]);
465 return frame_unwind_got_register (this_frame, regnum, regnum);
469 tic6x_frame_base_address (struct frame_info *this_frame, void **this_cache)
471 struct tic6x_unwind_cache *info
472 = tic6x_frame_unwind_cache (this_frame, this_cache);
476 static const struct frame_unwind tic6x_frame_unwind =
479 default_frame_unwind_stop_reason,
481 tic6x_frame_prev_register,
483 default_frame_sniffer
486 static const struct frame_base tic6x_frame_base =
489 tic6x_frame_base_address,
490 tic6x_frame_base_address,
491 tic6x_frame_base_address
495 static struct tic6x_unwind_cache *
496 tic6x_make_stub_cache (struct frame_info *this_frame)
498 struct tic6x_unwind_cache *cache;
500 cache = FRAME_OBSTACK_ZALLOC (struct tic6x_unwind_cache);
502 cache->return_regnum = TIC6X_RA_REGNUM;
504 tic6x_setup_default (cache);
506 cache->cfa = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM);
512 tic6x_stub_this_id (struct frame_info *this_frame, void **this_cache,
513 struct frame_id *this_id)
515 struct tic6x_unwind_cache *cache;
517 if (*this_cache == NULL)
518 *this_cache = tic6x_make_stub_cache (this_frame);
521 *this_id = frame_id_build (cache->cfa, get_frame_pc (this_frame));
525 tic6x_stub_unwind_sniffer (const struct frame_unwind *self,
526 struct frame_info *this_frame,
527 void **this_prologue_cache)
529 CORE_ADDR addr_in_block;
531 addr_in_block = get_frame_address_in_block (this_frame);
532 if (in_plt_section (addr_in_block))
538 static const struct frame_unwind tic6x_stub_unwind =
541 default_frame_unwind_stop_reason,
543 tic6x_frame_prev_register,
545 tic6x_stub_unwind_sniffer
548 /* Return the instruction on address PC. */
551 tic6x_fetch_instruction (struct gdbarch *gdbarch, CORE_ADDR pc)
553 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
554 return read_memory_unsigned_integer (pc, TIC6X_OPCODE_SIZE, byte_order);
557 /* Compute the condition of INST if it is a conditional instruction. Always
558 return 1 if INST is not a conditional instruction. */
561 tic6x_condition_true (struct frame_info *frame, unsigned long inst)
565 static const int register_numbers[8] = { -1, 16, 17, 18, 1, 2, 0, -1 };
567 register_number = register_numbers[(inst >> 29) & 7];
568 if (register_number == -1)
571 register_value = get_frame_register_signed (frame, register_number);
572 if ((inst & 0x10000000) != 0)
573 return register_value == 0;
574 return register_value != 0;
577 /* Get the register number by decoding raw bits REG, SIDE, and CROSSPATH in
581 tic6x_register_number (int reg, int side, int crosspath)
583 int r = (reg & 15) | ((crosspath ^ side) << 4);
584 if ((reg & 16) != 0) /* A16 - A31, B16 - B31 */
590 tic6x_extract_signed_field (int value, int low_bit, int bits)
592 int mask = (1 << bits) - 1;
593 int r = (value >> low_bit) & mask;
594 if ((r & (1 << (bits - 1))) != 0)
599 /* Determine where to set a single step breakpoint. */
602 tic6x_get_next_pc (struct frame_info *frame, CORE_ADDR pc)
604 struct gdbarch *gdbarch = get_frame_arch (frame);
611 inst = tic6x_fetch_instruction (gdbarch, pc);
615 if (inst == TIC6X_INST_SWE)
617 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
619 if (tdep->syscall_next_pc != NULL)
620 return tdep->syscall_next_pc (frame);
623 if (tic6x_condition_true (frame, inst))
625 if ((inst & 0x0000007c) == 0x00000010)
627 /* B with displacement */
628 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
629 pc += tic6x_extract_signed_field (inst, 7, 21) << 2;
632 if ((inst & 0x0f83effc) == 0x00000360)
634 /* B with register */
636 register_number = tic6x_register_number ((inst >> 18) & 0x1f,
639 pc = get_frame_register_unsigned (frame, register_number);
642 if ((inst & 0x00001ffc) == 0x00001020)
645 register_number = tic6x_register_number ((inst >> 23) & 0x1f,
646 INST_S_BIT (inst), 0);
647 if (get_frame_register_signed (frame, register_number) >= 0)
649 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
650 pc += tic6x_extract_signed_field (inst, 7, 10) << 2;
654 if ((inst & 0x00001ffc) == 0x00000120)
656 /* BNOP with displacement */
657 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
658 pc += tic6x_extract_signed_field (inst, 16, 12) << 2;
661 if ((inst & 0x0f830ffe) == 0x00800362)
663 /* BNOP with register */
664 register_number = tic6x_register_number ((inst >> 18) & 0x1f,
665 1, INST_X_BIT (inst));
666 pc = get_frame_register_unsigned (frame, register_number);
669 if ((inst & 0x00001ffc) == 0x00000020)
672 register_number = tic6x_register_number ((inst >> 23) & 0x1f,
673 INST_S_BIT (inst), 0);
674 if (get_frame_register_signed (frame, register_number) >= 0)
676 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
677 pc += tic6x_extract_signed_field (inst, 13, 10) << 2;
681 if ((inst & 0xf000007c) == 0x10000010)
684 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
685 pc += tic6x_extract_signed_field (inst, 7, 21) << 2;
689 pc += TIC6X_OPCODE_SIZE;
695 /* This is the implementation of gdbarch method software_single_step. */
698 tic6x_software_single_step (struct frame_info *frame)
700 struct gdbarch *gdbarch = get_frame_arch (frame);
701 struct address_space *aspace = get_frame_address_space (frame);
702 CORE_ADDR next_pc = tic6x_get_next_pc (frame, get_frame_pc (frame));
704 insert_single_step_breakpoint (gdbarch, aspace, next_pc);
709 /* This is the implementation of gdbarch method frame_align. */
712 tic6x_frame_align (struct gdbarch *gdbarch, CORE_ADDR addr)
714 return align_down (addr, 8);
717 /* Given a return value in REGCACHE with a type VALTYPE, extract and copy its
718 value into VALBUF. */
721 tic6x_extract_return_value (struct type *valtype, struct regcache *regcache,
722 enum bfd_endian byte_order, gdb_byte *valbuf)
724 int len = TYPE_LENGTH (valtype);
726 /* pointer types are returned in register A4,
727 up to 32-bit types in A4
728 up to 64-bit types in A5:A4 */
732 - one-byte structure or union occupies the LSB of single even register.
733 - for two-byte structure or union, the first byte occupies byte 1 of
734 register and the second byte occupies byte 0.
735 so, we read the contents in VAL from the LSBs of register. */
736 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
737 regcache_cooked_read_part (regcache, TIC6X_A4_REGNUM, 4 - len, len,
740 regcache_cooked_read (regcache, TIC6X_A4_REGNUM, valbuf);
744 /* For a 5-8 byte structure or union in big-endian, the first byte
745 occupies byte 3 (the MSB) of the upper (odd) register and the
746 remaining bytes fill the decreasingly significant bytes. 5-7
747 byte structures or unions have padding in the LSBs of the
748 lower (even) register. */
749 if (byte_order == BFD_ENDIAN_BIG)
751 regcache_cooked_read (regcache, TIC6X_A4_REGNUM, valbuf + 4);
752 regcache_cooked_read (regcache, TIC6X_A5_REGNUM, valbuf);
756 regcache_cooked_read (regcache, TIC6X_A4_REGNUM, valbuf);
757 regcache_cooked_read (regcache, TIC6X_A5_REGNUM, valbuf + 4);
762 /* Write into appropriate registers a function return value
763 of type TYPE, given in virtual format. */
766 tic6x_store_return_value (struct type *valtype, struct regcache *regcache,
767 enum bfd_endian byte_order, const gdb_byte *valbuf)
769 int len = TYPE_LENGTH (valtype);
771 /* return values of up to 8 bytes are returned in A5:A4 */
775 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
776 regcache_cooked_write_part (regcache, TIC6X_A4_REGNUM, 4 - len, len,
779 regcache_cooked_write (regcache, TIC6X_A4_REGNUM, valbuf);
783 if (byte_order == BFD_ENDIAN_BIG)
785 regcache_cooked_write (regcache, TIC6X_A4_REGNUM, valbuf + 4);
786 regcache_cooked_write (regcache, TIC6X_A5_REGNUM, valbuf);
790 regcache_cooked_write (regcache, TIC6X_A4_REGNUM, valbuf);
791 regcache_cooked_write (regcache, TIC6X_A5_REGNUM, valbuf + 4);
796 /* This is the implementation of gdbarch method return_value. */
798 static enum return_value_convention
799 tic6x_return_value (struct gdbarch *gdbarch, struct value *function,
800 struct type *type, struct regcache *regcache,
801 gdb_byte *readbuf, const gdb_byte *writebuf)
803 /* In C++, when function returns an object, even its size is small
804 enough, it stii has to be passed via reference, pointed by register
806 if (current_language->la_language == language_cplus)
810 CHECK_TYPEDEF (type);
811 if (language_pass_by_reference (type))
812 return RETURN_VALUE_STRUCT_CONVENTION;
816 if (TYPE_LENGTH (type) > 8)
817 return RETURN_VALUE_STRUCT_CONVENTION;
820 tic6x_extract_return_value (type, regcache,
821 gdbarch_byte_order (gdbarch), readbuf);
823 tic6x_store_return_value (type, regcache,
824 gdbarch_byte_order (gdbarch), writebuf);
826 return RETURN_VALUE_REGISTER_CONVENTION;
829 /* This is the implementation of gdbarch method dummy_id. */
831 static struct frame_id
832 tic6x_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
834 return frame_id_build
835 (get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM),
836 get_frame_pc (this_frame));
839 /* Get the alignment requirement of TYPE. */
842 tic6x_arg_type_alignment (struct type *type)
844 int len = TYPE_LENGTH (check_typedef (type));
845 enum type_code typecode = TYPE_CODE (check_typedef (type));
847 if (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION)
849 /* The stack alignment of a structure (and union) passed by value is the
850 smallest power of two greater than or equal to its size.
851 This cannot exceed 8 bytes, which is the largest allowable size for
852 a structure passed by value. */
861 gdb_assert_not_reached ("unexpected length of data");
869 if (typecode == TYPE_CODE_COMPLEX)
876 if (typecode == TYPE_CODE_COMPLEX)
882 internal_error (__FILE__, __LINE__, _("unexpected length %d of type"),
887 /* This is the implementation of gdbarch method push_dummy_call. */
890 tic6x_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
891 struct regcache *regcache, CORE_ADDR bp_addr,
892 int nargs, struct value **args, CORE_ADDR sp,
893 int struct_return, CORE_ADDR struct_addr)
897 int stack_offset = 4;
898 int references_offset = 4;
899 CORE_ADDR func_addr = find_function_addr (function, NULL);
900 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
901 struct type *func_type = value_type (function);
902 /* The first arg passed on stack. Mostly the first 10 args are passed by
904 int first_arg_on_stack = 10;
906 /* Set the return address register to point to the entry point of
907 the program, where a breakpoint lies in wait. */
908 regcache_cooked_write_unsigned (regcache, TIC6X_RA_REGNUM, bp_addr);
910 /* The caller must pass an argument in A3 containing a destination address
911 for the returned value. The callee returns the object by copying it to
912 the address in A3. */
914 regcache_cooked_write_unsigned (regcache, 3, struct_addr);
916 /* Determine the type of this function. */
917 func_type = check_typedef (func_type);
918 if (TYPE_CODE (func_type) == TYPE_CODE_PTR)
919 func_type = check_typedef (TYPE_TARGET_TYPE (func_type));
921 gdb_assert (TYPE_CODE (func_type) == TYPE_CODE_FUNC
922 || TYPE_CODE (func_type) == TYPE_CODE_METHOD);
924 /* For a variadic C function, the last explicitly declared argument and all
925 remaining arguments are passed on the stack. */
926 if (TYPE_VARARGS (func_type))
927 first_arg_on_stack = TYPE_NFIELDS (func_type) - 1;
929 /* Now make space on the stack for the args. */
930 for (argnum = 0; argnum < nargs; argnum++)
932 int len = align_up (TYPE_LENGTH (value_type (args[argnum])), 4);
933 if (argnum >= 10 - argreg)
934 references_offset += len;
938 /* SP should be 8-byte aligned, see C6000 ABI section 4.4.1
940 sp = align_down (sp, 8);
943 /* Now load as many as possible of the first arguments into
944 registers, and push the rest onto the stack. Loop through args
945 from first to last. */
946 for (argnum = 0; argnum < nargs; argnum++)
949 struct value *arg = args[argnum];
950 struct type *arg_type = check_typedef (value_type (arg));
951 int len = TYPE_LENGTH (arg_type);
952 enum type_code typecode = TYPE_CODE (arg_type);
954 val = value_contents (arg);
956 /* Copy the argument to general registers or the stack in
957 register-sized pieces. */
958 if (argreg < first_arg_on_stack)
962 if (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION)
965 - one-byte structure or union occupies the LSB of single
967 - for two-byte structure or union, the first byte
968 occupies byte 1 of register and the second byte occupies
970 so, we write the contents in VAL to the lsp of
972 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
973 regcache_cooked_write_part (regcache, arg_regs[argreg],
976 regcache_cooked_write (regcache, arg_regs[argreg], val);
980 /* The argument is being passed by value in a single
982 CORE_ADDR regval = extract_unsigned_integer (val, len,
985 regcache_cooked_write_unsigned (regcache, arg_regs[argreg],
993 if (typecode == TYPE_CODE_STRUCT
994 || typecode == TYPE_CODE_UNION)
996 /* For a 5-8 byte structure or union in big-endian, the
997 first byte occupies byte 3 (the MSB) of the upper (odd)
998 register and the remaining bytes fill the decreasingly
999 significant bytes. 5-7 byte structures or unions have
1000 padding in the LSBs of the lower (even) register. */
1001 if (byte_order == BFD_ENDIAN_BIG)
1003 regcache_cooked_write (regcache,
1004 arg_regs[argreg] + 1, val);
1005 regcache_cooked_write_part (regcache,
1006 arg_regs[argreg], 0,
1011 regcache_cooked_write (regcache, arg_regs[argreg],
1013 regcache_cooked_write_part (regcache,
1014 arg_regs[argreg] + 1, 0,
1020 /* The argument is being passed by value in a pair of
1022 ULONGEST regval = extract_unsigned_integer (val, len,
1025 regcache_cooked_write_unsigned (regcache,
1028 regcache_cooked_write_unsigned (regcache,
1029 arg_regs[argreg] + 1,
1035 /* The argument is being passed by reference in a single
1039 /* It is not necessary to adjust REFERENCES_OFFSET to
1040 8-byte aligned in some cases, in which 4-byte alignment
1041 is sufficient. For simplicity, we adjust
1042 REFERENCES_OFFSET to 8-byte aligned. */
1043 references_offset = align_up (references_offset, 8);
1045 addr = sp + references_offset;
1046 write_memory (addr, val, len);
1047 references_offset += align_up (len, 4);
1048 regcache_cooked_write_unsigned (regcache, arg_regs[argreg],
1056 /* The argument is being passed on the stack. */
1059 /* There are six different cases of alignment, and these rules can
1060 be found in tic6x_arg_type_alignment:
1062 1) 4-byte aligned if size is less than or equal to 4 byte, such
1063 as short, int, struct, union etc.
1064 2) 8-byte aligned if size is less than or equal to 8-byte, such
1065 as double, long long,
1066 3) 4-byte aligned if it is of type _Complex float, even its size
1068 4) 8-byte aligned if it is of type _Complex double or _Complex
1069 long double, even its size is 16-byte. Because, the address of
1070 variable is passed as reference.
1071 5) struct and union larger than 8-byte are passed by reference, so
1072 it is 4-byte aligned.
1073 6) struct and union of size between 4 byte and 8 byte varies.
1074 alignment of struct variable is the alignment of its first field,
1075 while alignment of union variable is the max of all its fields'
1079 ; /* Default is 4-byte aligned. Nothing to be done. */
1081 stack_offset = align_up (stack_offset,
1082 tic6x_arg_type_alignment (arg_type));
1085 /* _Complex double or _Complex long double */
1086 if (typecode == TYPE_CODE_COMPLEX)
1088 /* The argument is being passed by reference on stack. */
1090 references_offset = align_up (references_offset, 8);
1092 addr = sp + references_offset;
1093 /* Store variable on stack. */
1094 write_memory (addr, val, len);
1096 references_offset += align_up (len, 4);
1098 /* Pass the address of variable on stack as reference. */
1099 store_unsigned_integer ((gdb_byte *) val, 4, byte_order,
1105 internal_error (__FILE__, __LINE__,
1106 _("unexpected type %d of arg %d"),
1110 internal_error (__FILE__, __LINE__,
1111 _("unexpected length %d of arg %d"), len, argnum);
1113 addr = sp + stack_offset;
1114 write_memory (addr, val, len);
1115 stack_offset += align_up (len, 4);
1119 regcache_cooked_write_signed (regcache, TIC6X_SP_REGNUM, sp);
1121 /* Return adjusted stack pointer. */
1125 /* This is the implementation of gdbarch method in_function_epilogue_p. */
1128 tic6x_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
1130 unsigned long inst = tic6x_fetch_instruction (gdbarch, pc);
1131 /* Normally, the epilogue is composed by instruction `b .S2 b3'. */
1132 if ((inst & 0x0f83effc) == 0x360)
1134 unsigned int src2 = tic6x_register_number ((inst >> 18) & 0x1f,
1137 if (src2 == TIC6X_RA_REGNUM)
1144 /* This is the implementation of gdbarch method get_longjmp_target. */
1147 tic6x_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
1149 struct gdbarch *gdbarch = get_frame_arch (frame);
1150 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
1154 /* JMP_BUF is passed by reference in A4. */
1155 jb_addr = get_frame_register_unsigned (frame, 4);
1157 /* JMP_BUF contains 13 elements of type int, and return address is stored
1158 in the last slot. */
1159 if (target_read_memory (jb_addr + 12 * 4, buf, 4))
1162 *pc = extract_unsigned_integer (buf, 4, byte_order);
1167 /* This is the implementation of gdbarch method
1168 return_in_first_hidden_param_p. */
1171 tic6x_return_in_first_hidden_param_p (struct gdbarch *gdbarch,
1177 static struct gdbarch *
1178 tic6x_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1180 struct gdbarch *gdbarch;
1181 struct gdbarch_tdep *tdep;
1182 struct tdesc_arch_data *tdesc_data = NULL;
1183 const struct target_desc *tdesc = info.target_desc;
1186 /* Check any target description for validity. */
1187 if (tdesc_has_registers (tdesc))
1189 const struct tdesc_feature *feature;
1192 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.core");
1194 if (feature == NULL)
1197 tdesc_data = tdesc_data_alloc ();
1200 for (i = 0; i < 32; i++) /* A0 - A15, B0 - B15 */
1201 valid_p &= tdesc_numbered_register (feature, tdesc_data, i,
1202 tic6x_register_names[i]);
1205 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1206 tic6x_register_names[TIC6X_CSR_REGNUM]);
1207 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1208 tic6x_register_names[TIC6X_PC_REGNUM]);
1212 tdesc_data_cleanup (tdesc_data);
1216 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.gp");
1220 static const char *const gp[] =
1222 "A16", "A17", "A18", "A19", "A20", "A21", "A22", "A23",
1223 "A24", "A25", "A26", "A27", "A28", "A29", "A30", "A31",
1224 "B16", "B17", "B18", "B19", "B20", "B21", "B22", "B23",
1225 "B24", "B25", "B26", "B27", "B28", "B29", "B30", "B31",
1230 for (j = 0; j < 32; j++) /* A16 - A31, B16 - B31 */
1231 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1236 tdesc_data_cleanup (tdesc_data);
1241 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.c6xp");
1244 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "TSR");
1245 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "ILC");
1246 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "RILC");
1250 tdesc_data_cleanup (tdesc_data);
1257 /* Find a candidate among extant architectures. */
1258 for (arches = gdbarch_list_lookup_by_info (arches, &info);
1260 arches = gdbarch_list_lookup_by_info (arches->next, &info))
1262 tdep = gdbarch_tdep (arches->gdbarch);
1264 if (has_gp != tdep->has_gp)
1267 if (tdep && tdep->breakpoint)
1268 return arches->gdbarch;
1271 tdep = xcalloc (1, sizeof (struct gdbarch_tdep));
1273 tdep->has_gp = has_gp;
1274 gdbarch = gdbarch_alloc (&info, tdep);
1276 /* Data type sizes. */
1277 set_gdbarch_ptr_bit (gdbarch, 32);
1278 set_gdbarch_addr_bit (gdbarch, 32);
1279 set_gdbarch_short_bit (gdbarch, 16);
1280 set_gdbarch_int_bit (gdbarch, 32);
1281 set_gdbarch_long_bit (gdbarch, 32);
1282 set_gdbarch_long_long_bit (gdbarch, 64);
1283 set_gdbarch_float_bit (gdbarch, 32);
1284 set_gdbarch_double_bit (gdbarch, 64);
1286 set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
1287 set_gdbarch_double_format (gdbarch, floatformats_ieee_double);
1289 /* The register set. */
1290 set_gdbarch_num_regs (gdbarch, TIC6X_NUM_REGS);
1291 set_gdbarch_sp_regnum (gdbarch, TIC6X_SP_REGNUM);
1292 set_gdbarch_pc_regnum (gdbarch, TIC6X_PC_REGNUM);
1294 set_gdbarch_register_name (gdbarch, tic6x_register_name);
1295 set_gdbarch_register_type (gdbarch, tic6x_register_type);
1297 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1299 set_gdbarch_skip_prologue (gdbarch, tic6x_skip_prologue);
1300 set_gdbarch_breakpoint_from_pc (gdbarch, tic6x_breakpoint_from_pc);
1302 set_gdbarch_unwind_pc (gdbarch, tic6x_unwind_pc);
1303 set_gdbarch_unwind_sp (gdbarch, tic6x_unwind_sp);
1306 dwarf2_append_unwinders (gdbarch);
1308 frame_unwind_append_unwinder (gdbarch, &tic6x_stub_unwind);
1309 frame_unwind_append_unwinder (gdbarch, &tic6x_frame_unwind);
1310 frame_base_set_default (gdbarch, &tic6x_frame_base);
1312 dwarf2_frame_set_init_reg (gdbarch, tic6x_dwarf2_frame_init_reg);
1314 /* Single stepping. */
1315 set_gdbarch_software_single_step (gdbarch, tic6x_software_single_step);
1317 set_gdbarch_print_insn (gdbarch, tic6x_print_insn);
1319 /* Call dummy code. */
1320 set_gdbarch_frame_align (gdbarch, tic6x_frame_align);
1322 set_gdbarch_return_value (gdbarch, tic6x_return_value);
1324 set_gdbarch_dummy_id (gdbarch, tic6x_dummy_id);
1326 /* Enable inferior call support. */
1327 set_gdbarch_push_dummy_call (gdbarch, tic6x_push_dummy_call);
1329 set_gdbarch_get_longjmp_target (gdbarch, tic6x_get_longjmp_target);
1331 set_gdbarch_in_function_epilogue_p (gdbarch, tic6x_in_function_epilogue_p);
1333 set_gdbarch_return_in_first_hidden_param_p (gdbarch,
1334 tic6x_return_in_first_hidden_param_p);
1336 /* Hook in ABI-specific overrides, if they have been registered. */
1337 gdbarch_init_osabi (info, gdbarch);
1340 tdesc_use_registers (gdbarch, tdesc, tdesc_data);
1345 /* -Wmissing-prototypes */
1346 extern initialize_file_ftype _initialize_tic6x_tdep;
1349 _initialize_tic6x_tdep (void)
1351 register_gdbarch_init (bfd_arch_tic6x, tic6x_gdbarch_init);
1353 initialize_tdesc_tic6x_c64xp ();
1354 initialize_tdesc_tic6x_c64x ();
1355 initialize_tdesc_tic6x_c62x ();