1 /* Target dependent code for GDB on TI C6x systems.
3 Copyright (C) 2010-2016 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)
155 unsigned int src_reg, base_reg, dst_reg;
157 CORE_ADDR pc = start_pc;
158 CORE_ADDR return_pc = start_pc;
159 int frame_base_offset_to_sp = 0;
160 /* Counter of non-stw instructions after first insn ` sub sp, xxx, sp'. */
161 int non_stw_insn_counter = 0;
163 if (start_pc >= current_pc)
164 return_pc = current_pc;
168 /* The landmarks in prologue is one or two SUB instructions to SP.
169 Instructions on setting up dsbt are in the last part of prologue, if
170 needed. In maxim, prologue can be divided to three parts by two
171 `sub sp, xx, sp' insns. */
173 /* Step 1: Look for the 1st and 2nd insn `sub sp, xx, sp', in which, the
174 2nd one is optional. */
175 while (pc < current_pc)
177 unsigned long inst = tic6x_fetch_instruction (gdbarch, pc);
179 if ((inst & 0x1ffc) == 0x1dc0 || (inst & 0x1ffc) == 0x1bc0
180 || (inst & 0x0ffc) == 0x9c0)
182 /* SUBAW/SUBAH/SUB, and src1 is ucst 5. */
183 unsigned int src2 = tic6x_register_number ((inst >> 18) & 0x1f,
184 INST_S_BIT (inst), 0);
185 unsigned int dst = tic6x_register_number ((inst >> 23) & 0x1f,
186 INST_S_BIT (inst), 0);
188 if (src2 == TIC6X_SP_REGNUM && dst == TIC6X_SP_REGNUM)
190 /* Extract const from insn SUBAW/SUBAH/SUB, and translate it to
191 offset. The constant offset is decoded in bit 13-17 in all
192 these three kinds of instructions. */
193 unsigned int ucst5 = (inst >> 13) & 0x1f;
195 if ((inst & 0x1ffc) == 0x1dc0) /* SUBAW */
196 frame_base_offset_to_sp += ucst5 << 2;
197 else if ((inst & 0x1ffc) == 0x1bc0) /* SUBAH */
198 frame_base_offset_to_sp += ucst5 << 1;
199 else if ((inst & 0x0ffc) == 0x9c0) /* SUB */
200 frame_base_offset_to_sp += ucst5;
202 gdb_assert_not_reached ("unexpected instruction");
207 else if ((inst & 0x174) == 0x74) /* stw SRC, *+b15(uconst) */
209 /* The y bit determines which file base is read from. */
210 base_reg = tic6x_register_number ((inst >> 18) & 0x1f,
213 if (base_reg == TIC6X_SP_REGNUM)
215 src_reg = tic6x_register_number ((inst >> 23) & 0x1f,
216 INST_S_BIT (inst), 0);
218 cache->reg_saved[src_reg] = ((inst >> 13) & 0x1f) << 2;
222 non_stw_insn_counter = 0;
226 non_stw_insn_counter++;
227 /* Following instruction sequence may be emitted in prologue:
229 <+0>: subah .D2 b15,28,b15
230 <+4>: or .L2X 0,a4,b0
231 <+8>: || stw .D2T2 b14,*+b15(56)
232 <+12>:[!b0] b .S1 0xe50e4c1c <sleep+220>
233 <+16>:|| stw .D2T1 a10,*+b15(48)
234 <+20>:stw .D2T2 b3,*+b15(52)
235 <+24>:stw .D2T1 a4,*+b15(40)
237 we should look forward for next instruction instead of breaking loop
238 here. So far, we allow almost two sequential non-stw instructions
240 if (non_stw_insn_counter >= 2)
247 /* Step 2: Skip insn on setting up dsbt if it is. Usually, it looks like,
248 ldw .D2T2 *+b14(0),b14 */
249 inst = tic6x_fetch_instruction (gdbarch, pc);
250 /* The s bit determines which file dst will be loaded into, same effect as
252 dst_reg = tic6x_register_number ((inst >> 23) & 0x1f, (inst >> 1) & 1, 0);
253 /* The y bit (bit 7), instead of s bit, determines which file base be
255 base_reg = tic6x_register_number ((inst >> 18) & 0x1f, (inst >> 7) & 1, 0);
257 if ((inst & 0x164) == 0x64 /* ldw */
258 && dst_reg == TIC6X_DP_REGNUM /* dst is B14 */
259 && base_reg == TIC6X_DP_REGNUM) /* baseR is B14 */
266 cache->base = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM);
268 if (cache->reg_saved[TIC6X_FP_REGNUM] != -1)
270 /* If the FP now holds an offset from the CFA then this is a frame
271 which uses the frame pointer. */
273 cache->cfa = get_frame_register_unsigned (this_frame,
278 /* FP doesn't hold an offset from the CFA. If SP still holds an
279 offset from the CFA then we might be in a function which omits
280 the frame pointer. */
282 cache->cfa = cache->base + frame_base_offset_to_sp;
286 /* Adjust all the saved registers such that they contain addresses
287 instead of offsets. */
288 for (i = 0; i < TIC6X_NUM_CORE_REGS; i++)
289 if (cache->reg_saved[i] != -1)
290 cache->reg_saved[i] = cache->base + cache->reg_saved[i];
295 /* This is the implementation of gdbarch method skip_prologue. */
298 tic6x_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
301 struct tic6x_unwind_cache cache;
303 /* See if we can determine the end of the prologue via the symbol table.
304 If so, then return either PC, or the PC after the prologue, whichever is
306 if (find_pc_partial_function (start_pc, NULL, &func_addr, NULL))
308 CORE_ADDR post_prologue_pc
309 = skip_prologue_using_sal (gdbarch, func_addr);
310 if (post_prologue_pc != 0)
311 return max (start_pc, post_prologue_pc);
314 /* Can't determine prologue from the symbol table, need to examine
316 return tic6x_analyze_prologue (gdbarch, start_pc, (CORE_ADDR) -1, &cache,
320 /* This is the implementation of gdbarch method breakpiont_from_pc. */
322 static const gdb_byte *
323 tic6x_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *bp_addr,
326 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
330 if (tdep == NULL || tdep->breakpoint == NULL)
332 if (BFD_ENDIAN_BIG == gdbarch_byte_order_for_code (gdbarch))
333 return tic6x_bkpt_illegal_opcode_be;
335 return tic6x_bkpt_illegal_opcode_le;
338 return tdep->breakpoint;
341 /* This is the implementation of gdbarch method print_insn. */
344 tic6x_print_insn (bfd_vma memaddr, disassemble_info *info)
346 return print_insn_tic6x (memaddr, info);
350 tic6x_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
351 struct dwarf2_frame_state_reg *reg,
352 struct frame_info *this_frame)
354 /* Mark the PC as the destination for the return address. */
355 if (regnum == gdbarch_pc_regnum (gdbarch))
356 reg->how = DWARF2_FRAME_REG_RA;
358 /* Mark the stack pointer as the call frame address. */
359 else if (regnum == gdbarch_sp_regnum (gdbarch))
360 reg->how = DWARF2_FRAME_REG_CFA;
362 /* The above was taken from the default init_reg in dwarf2-frame.c
363 while the below is c6x specific. */
365 /* Callee save registers. The ABI designates A10-A15 and B10-B15 as
367 else if ((regnum >= 10 && regnum <= 15) || (regnum >= 26 && regnum <= 31))
368 reg->how = DWARF2_FRAME_REG_SAME_VALUE;
370 /* All other registers are caller-save. */
371 reg->how = DWARF2_FRAME_REG_UNDEFINED;
374 /* This is the implementation of gdbarch method unwind_pc. */
377 tic6x_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
381 frame_unwind_register (next_frame, TIC6X_PC_REGNUM, buf);
382 return extract_typed_address (buf, builtin_type (gdbarch)->builtin_func_ptr);
385 /* This is the implementation of gdbarch method unwind_sp. */
388 tic6x_unwind_sp (struct gdbarch *gdbarch, struct frame_info *this_frame)
390 return frame_unwind_register_unsigned (this_frame, TIC6X_SP_REGNUM);
394 /* Frame base handling. */
396 static struct tic6x_unwind_cache*
397 tic6x_frame_unwind_cache (struct frame_info *this_frame,
398 void **this_prologue_cache)
400 struct gdbarch *gdbarch = get_frame_arch (this_frame);
401 CORE_ADDR current_pc;
402 struct tic6x_unwind_cache *cache;
404 if (*this_prologue_cache)
405 return (struct tic6x_unwind_cache *) *this_prologue_cache;
407 cache = FRAME_OBSTACK_ZALLOC (struct tic6x_unwind_cache);
408 (*this_prologue_cache) = cache;
410 cache->return_regnum = TIC6X_RA_REGNUM;
412 tic6x_setup_default (cache);
414 cache->pc = get_frame_func (this_frame);
415 current_pc = get_frame_pc (this_frame);
417 /* Prologue analysis does the rest... */
419 tic6x_analyze_prologue (gdbarch, cache->pc, current_pc, cache, this_frame);
425 tic6x_frame_this_id (struct frame_info *this_frame, void **this_cache,
426 struct frame_id *this_id)
428 struct tic6x_unwind_cache *cache =
429 tic6x_frame_unwind_cache (this_frame, this_cache);
431 /* This marks the outermost frame. */
432 if (cache->base == 0)
435 (*this_id) = frame_id_build (cache->cfa, cache->pc);
438 static struct value *
439 tic6x_frame_prev_register (struct frame_info *this_frame, void **this_cache,
442 struct tic6x_unwind_cache *cache =
443 tic6x_frame_unwind_cache (this_frame, this_cache);
445 gdb_assert (regnum >= 0);
447 /* The PC of the previous frame is stored in the RA register of
448 the current frame. Frob regnum so that we pull the value from
449 the correct place. */
450 if (regnum == TIC6X_PC_REGNUM)
451 regnum = cache->return_regnum;
453 if (regnum == TIC6X_SP_REGNUM && cache->cfa)
454 return frame_unwind_got_constant (this_frame, regnum, cache->cfa);
456 /* If we've worked out where a register is stored then load it from
458 if (regnum < TIC6X_NUM_CORE_REGS && cache->reg_saved[regnum] != -1)
459 return frame_unwind_got_memory (this_frame, regnum,
460 cache->reg_saved[regnum]);
462 return frame_unwind_got_register (this_frame, regnum, regnum);
466 tic6x_frame_base_address (struct frame_info *this_frame, void **this_cache)
468 struct tic6x_unwind_cache *info
469 = tic6x_frame_unwind_cache (this_frame, this_cache);
473 static const struct frame_unwind tic6x_frame_unwind =
476 default_frame_unwind_stop_reason,
478 tic6x_frame_prev_register,
480 default_frame_sniffer
483 static const struct frame_base tic6x_frame_base =
486 tic6x_frame_base_address,
487 tic6x_frame_base_address,
488 tic6x_frame_base_address
492 static struct tic6x_unwind_cache *
493 tic6x_make_stub_cache (struct frame_info *this_frame)
495 struct tic6x_unwind_cache *cache;
497 cache = FRAME_OBSTACK_ZALLOC (struct tic6x_unwind_cache);
499 cache->return_regnum = TIC6X_RA_REGNUM;
501 tic6x_setup_default (cache);
503 cache->cfa = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM);
509 tic6x_stub_this_id (struct frame_info *this_frame, void **this_cache,
510 struct frame_id *this_id)
512 struct tic6x_unwind_cache *cache;
514 if (*this_cache == NULL)
515 *this_cache = tic6x_make_stub_cache (this_frame);
516 cache = (struct tic6x_unwind_cache *) *this_cache;
518 *this_id = frame_id_build (cache->cfa, get_frame_pc (this_frame));
522 tic6x_stub_unwind_sniffer (const struct frame_unwind *self,
523 struct frame_info *this_frame,
524 void **this_prologue_cache)
526 CORE_ADDR addr_in_block;
528 addr_in_block = get_frame_address_in_block (this_frame);
529 if (in_plt_section (addr_in_block))
535 static const struct frame_unwind tic6x_stub_unwind =
538 default_frame_unwind_stop_reason,
540 tic6x_frame_prev_register,
542 tic6x_stub_unwind_sniffer
545 /* Return the instruction on address PC. */
548 tic6x_fetch_instruction (struct gdbarch *gdbarch, CORE_ADDR pc)
550 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
551 return read_memory_unsigned_integer (pc, TIC6X_OPCODE_SIZE, byte_order);
554 /* Compute the condition of INST if it is a conditional instruction. Always
555 return 1 if INST is not a conditional instruction. */
558 tic6x_condition_true (struct frame_info *frame, unsigned long inst)
562 static const int register_numbers[8] = { -1, 16, 17, 18, 1, 2, 0, -1 };
564 register_number = register_numbers[(inst >> 29) & 7];
565 if (register_number == -1)
568 register_value = get_frame_register_signed (frame, register_number);
569 if ((inst & 0x10000000) != 0)
570 return register_value == 0;
571 return register_value != 0;
574 /* Get the register number by decoding raw bits REG, SIDE, and CROSSPATH in
578 tic6x_register_number (int reg, int side, int crosspath)
580 int r = (reg & 15) | ((crosspath ^ side) << 4);
581 if ((reg & 16) != 0) /* A16 - A31, B16 - B31 */
587 tic6x_extract_signed_field (int value, int low_bit, int bits)
589 int mask = (1 << bits) - 1;
590 int r = (value >> low_bit) & mask;
591 if ((r & (1 << (bits - 1))) != 0)
596 /* Determine where to set a single step breakpoint. */
599 tic6x_get_next_pc (struct frame_info *frame, CORE_ADDR pc)
601 struct gdbarch *gdbarch = get_frame_arch (frame);
608 inst = tic6x_fetch_instruction (gdbarch, pc);
612 if (inst == TIC6X_INST_SWE)
614 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
616 if (tdep->syscall_next_pc != NULL)
617 return tdep->syscall_next_pc (frame);
620 if (tic6x_condition_true (frame, inst))
622 if ((inst & 0x0000007c) == 0x00000010)
624 /* B with displacement */
625 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
626 pc += tic6x_extract_signed_field (inst, 7, 21) << 2;
629 if ((inst & 0x0f83effc) == 0x00000360)
631 /* B with register */
633 register_number = tic6x_register_number ((inst >> 18) & 0x1f,
636 pc = get_frame_register_unsigned (frame, register_number);
639 if ((inst & 0x00001ffc) == 0x00001020)
642 register_number = tic6x_register_number ((inst >> 23) & 0x1f,
643 INST_S_BIT (inst), 0);
644 if (get_frame_register_signed (frame, register_number) >= 0)
646 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
647 pc += tic6x_extract_signed_field (inst, 7, 10) << 2;
651 if ((inst & 0x00001ffc) == 0x00000120)
653 /* BNOP with displacement */
654 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
655 pc += tic6x_extract_signed_field (inst, 16, 12) << 2;
658 if ((inst & 0x0f830ffe) == 0x00800362)
660 /* BNOP with register */
661 register_number = tic6x_register_number ((inst >> 18) & 0x1f,
662 1, INST_X_BIT (inst));
663 pc = get_frame_register_unsigned (frame, register_number);
666 if ((inst & 0x00001ffc) == 0x00000020)
669 register_number = tic6x_register_number ((inst >> 23) & 0x1f,
670 INST_S_BIT (inst), 0);
671 if (get_frame_register_signed (frame, register_number) >= 0)
673 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
674 pc += tic6x_extract_signed_field (inst, 13, 10) << 2;
678 if ((inst & 0xf000007c) == 0x10000010)
681 pc &= ~(TIC6X_FETCH_PACKET_SIZE - 1);
682 pc += tic6x_extract_signed_field (inst, 7, 21) << 2;
686 pc += TIC6X_OPCODE_SIZE;
692 /* This is the implementation of gdbarch method software_single_step. */
695 tic6x_software_single_step (struct frame_info *frame)
697 struct gdbarch *gdbarch = get_frame_arch (frame);
698 struct address_space *aspace = get_frame_address_space (frame);
699 CORE_ADDR next_pc = tic6x_get_next_pc (frame, get_frame_pc (frame));
701 insert_single_step_breakpoint (gdbarch, aspace, next_pc);
706 /* This is the implementation of gdbarch method frame_align. */
709 tic6x_frame_align (struct gdbarch *gdbarch, CORE_ADDR addr)
711 return align_down (addr, 8);
714 /* Given a return value in REGCACHE with a type VALTYPE, extract and copy its
715 value into VALBUF. */
718 tic6x_extract_return_value (struct type *valtype, struct regcache *regcache,
719 enum bfd_endian byte_order, gdb_byte *valbuf)
721 int len = TYPE_LENGTH (valtype);
723 /* pointer types are returned in register A4,
724 up to 32-bit types in A4
725 up to 64-bit types in A5:A4 */
729 - one-byte structure or union occupies the LSB of single even register.
730 - for two-byte structure or union, the first byte occupies byte 1 of
731 register and the second byte occupies byte 0.
732 so, we read the contents in VAL from the LSBs of register. */
733 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
734 regcache_cooked_read_part (regcache, TIC6X_A4_REGNUM, 4 - len, len,
737 regcache_cooked_read (regcache, TIC6X_A4_REGNUM, valbuf);
741 /* For a 5-8 byte structure or union in big-endian, the first byte
742 occupies byte 3 (the MSB) of the upper (odd) register and the
743 remaining bytes fill the decreasingly significant bytes. 5-7
744 byte structures or unions have padding in the LSBs of the
745 lower (even) register. */
746 if (byte_order == BFD_ENDIAN_BIG)
748 regcache_cooked_read (regcache, TIC6X_A4_REGNUM, valbuf + 4);
749 regcache_cooked_read (regcache, TIC6X_A5_REGNUM, valbuf);
753 regcache_cooked_read (regcache, TIC6X_A4_REGNUM, valbuf);
754 regcache_cooked_read (regcache, TIC6X_A5_REGNUM, valbuf + 4);
759 /* Write into appropriate registers a function return value
760 of type TYPE, given in virtual format. */
763 tic6x_store_return_value (struct type *valtype, struct regcache *regcache,
764 enum bfd_endian byte_order, const gdb_byte *valbuf)
766 int len = TYPE_LENGTH (valtype);
768 /* return values of up to 8 bytes are returned in A5:A4 */
772 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
773 regcache_cooked_write_part (regcache, TIC6X_A4_REGNUM, 4 - len, len,
776 regcache_cooked_write (regcache, TIC6X_A4_REGNUM, valbuf);
780 if (byte_order == BFD_ENDIAN_BIG)
782 regcache_cooked_write (regcache, TIC6X_A4_REGNUM, valbuf + 4);
783 regcache_cooked_write (regcache, TIC6X_A5_REGNUM, valbuf);
787 regcache_cooked_write (regcache, TIC6X_A4_REGNUM, valbuf);
788 regcache_cooked_write (regcache, TIC6X_A5_REGNUM, valbuf + 4);
793 /* This is the implementation of gdbarch method return_value. */
795 static enum return_value_convention
796 tic6x_return_value (struct gdbarch *gdbarch, struct value *function,
797 struct type *type, struct regcache *regcache,
798 gdb_byte *readbuf, const gdb_byte *writebuf)
800 /* In C++, when function returns an object, even its size is small
801 enough, it stii has to be passed via reference, pointed by register
803 if (current_language->la_language == language_cplus)
807 type = check_typedef (type);
808 if (language_pass_by_reference (type))
809 return RETURN_VALUE_STRUCT_CONVENTION;
813 if (TYPE_LENGTH (type) > 8)
814 return RETURN_VALUE_STRUCT_CONVENTION;
817 tic6x_extract_return_value (type, regcache,
818 gdbarch_byte_order (gdbarch), readbuf);
820 tic6x_store_return_value (type, regcache,
821 gdbarch_byte_order (gdbarch), writebuf);
823 return RETURN_VALUE_REGISTER_CONVENTION;
826 /* This is the implementation of gdbarch method dummy_id. */
828 static struct frame_id
829 tic6x_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
831 return frame_id_build
832 (get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM),
833 get_frame_pc (this_frame));
836 /* Get the alignment requirement of TYPE. */
839 tic6x_arg_type_alignment (struct type *type)
841 int len = TYPE_LENGTH (check_typedef (type));
842 enum type_code typecode = TYPE_CODE (check_typedef (type));
844 if (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION)
846 /* The stack alignment of a structure (and union) passed by value is the
847 smallest power of two greater than or equal to its size.
848 This cannot exceed 8 bytes, which is the largest allowable size for
849 a structure passed by value. */
858 gdb_assert_not_reached ("unexpected length of data");
866 if (typecode == TYPE_CODE_COMPLEX)
873 if (typecode == TYPE_CODE_COMPLEX)
879 internal_error (__FILE__, __LINE__, _("unexpected length %d of type"),
884 /* This is the implementation of gdbarch method push_dummy_call. */
887 tic6x_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
888 struct regcache *regcache, CORE_ADDR bp_addr,
889 int nargs, struct value **args, CORE_ADDR sp,
890 int struct_return, CORE_ADDR struct_addr)
894 int stack_offset = 4;
895 int references_offset = 4;
896 CORE_ADDR func_addr = find_function_addr (function, NULL);
897 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
898 struct type *func_type = value_type (function);
899 /* The first arg passed on stack. Mostly the first 10 args are passed by
901 int first_arg_on_stack = 10;
903 /* Set the return address register to point to the entry point of
904 the program, where a breakpoint lies in wait. */
905 regcache_cooked_write_unsigned (regcache, TIC6X_RA_REGNUM, bp_addr);
907 /* The caller must pass an argument in A3 containing a destination address
908 for the returned value. The callee returns the object by copying it to
909 the address in A3. */
911 regcache_cooked_write_unsigned (regcache, 3, struct_addr);
913 /* Determine the type of this function. */
914 func_type = check_typedef (func_type);
915 if (TYPE_CODE (func_type) == TYPE_CODE_PTR)
916 func_type = check_typedef (TYPE_TARGET_TYPE (func_type));
918 gdb_assert (TYPE_CODE (func_type) == TYPE_CODE_FUNC
919 || TYPE_CODE (func_type) == TYPE_CODE_METHOD);
921 /* For a variadic C function, the last explicitly declared argument and all
922 remaining arguments are passed on the stack. */
923 if (TYPE_VARARGS (func_type))
924 first_arg_on_stack = TYPE_NFIELDS (func_type) - 1;
926 /* Now make space on the stack for the args. */
927 for (argnum = 0; argnum < nargs; argnum++)
929 int len = align_up (TYPE_LENGTH (value_type (args[argnum])), 4);
930 if (argnum >= 10 - argreg)
931 references_offset += len;
935 /* SP should be 8-byte aligned, see C6000 ABI section 4.4.1
937 sp = align_down (sp, 8);
940 /* Now load as many as possible of the first arguments into
941 registers, and push the rest onto the stack. Loop through args
942 from first to last. */
943 for (argnum = 0; argnum < nargs; argnum++)
946 struct value *arg = args[argnum];
947 struct type *arg_type = check_typedef (value_type (arg));
948 int len = TYPE_LENGTH (arg_type);
949 enum type_code typecode = TYPE_CODE (arg_type);
951 val = value_contents (arg);
953 /* Copy the argument to general registers or the stack in
954 register-sized pieces. */
955 if (argreg < first_arg_on_stack)
959 if (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION)
962 - one-byte structure or union occupies the LSB of single
964 - for two-byte structure or union, the first byte
965 occupies byte 1 of register and the second byte occupies
967 so, we write the contents in VAL to the lsp of
969 if (len < 3 && byte_order == BFD_ENDIAN_BIG)
970 regcache_cooked_write_part (regcache, arg_regs[argreg],
973 regcache_cooked_write (regcache, arg_regs[argreg], val);
977 /* The argument is being passed by value in a single
979 CORE_ADDR regval = extract_unsigned_integer (val, len,
982 regcache_cooked_write_unsigned (regcache, arg_regs[argreg],
990 if (typecode == TYPE_CODE_STRUCT
991 || typecode == TYPE_CODE_UNION)
993 /* For a 5-8 byte structure or union in big-endian, the
994 first byte occupies byte 3 (the MSB) of the upper (odd)
995 register and the remaining bytes fill the decreasingly
996 significant bytes. 5-7 byte structures or unions have
997 padding in the LSBs of the lower (even) register. */
998 if (byte_order == BFD_ENDIAN_BIG)
1000 regcache_cooked_write (regcache,
1001 arg_regs[argreg] + 1, val);
1002 regcache_cooked_write_part (regcache,
1003 arg_regs[argreg], 0,
1008 regcache_cooked_write (regcache, arg_regs[argreg],
1010 regcache_cooked_write_part (regcache,
1011 arg_regs[argreg] + 1, 0,
1017 /* The argument is being passed by value in a pair of
1019 ULONGEST regval = extract_unsigned_integer (val, len,
1022 regcache_cooked_write_unsigned (regcache,
1025 regcache_cooked_write_unsigned (regcache,
1026 arg_regs[argreg] + 1,
1032 /* The argument is being passed by reference in a single
1036 /* It is not necessary to adjust REFERENCES_OFFSET to
1037 8-byte aligned in some cases, in which 4-byte alignment
1038 is sufficient. For simplicity, we adjust
1039 REFERENCES_OFFSET to 8-byte aligned. */
1040 references_offset = align_up (references_offset, 8);
1042 addr = sp + references_offset;
1043 write_memory (addr, val, len);
1044 references_offset += align_up (len, 4);
1045 regcache_cooked_write_unsigned (regcache, arg_regs[argreg],
1053 /* The argument is being passed on the stack. */
1056 /* There are six different cases of alignment, and these rules can
1057 be found in tic6x_arg_type_alignment:
1059 1) 4-byte aligned if size is less than or equal to 4 byte, such
1060 as short, int, struct, union etc.
1061 2) 8-byte aligned if size is less than or equal to 8-byte, such
1062 as double, long long,
1063 3) 4-byte aligned if it is of type _Complex float, even its size
1065 4) 8-byte aligned if it is of type _Complex double or _Complex
1066 long double, even its size is 16-byte. Because, the address of
1067 variable is passed as reference.
1068 5) struct and union larger than 8-byte are passed by reference, so
1069 it is 4-byte aligned.
1070 6) struct and union of size between 4 byte and 8 byte varies.
1071 alignment of struct variable is the alignment of its first field,
1072 while alignment of union variable is the max of all its fields'
1076 ; /* Default is 4-byte aligned. Nothing to be done. */
1078 stack_offset = align_up (stack_offset,
1079 tic6x_arg_type_alignment (arg_type));
1082 /* _Complex double or _Complex long double */
1083 if (typecode == TYPE_CODE_COMPLEX)
1085 /* The argument is being passed by reference on stack. */
1087 references_offset = align_up (references_offset, 8);
1089 addr = sp + references_offset;
1090 /* Store variable on stack. */
1091 write_memory (addr, val, len);
1093 references_offset += align_up (len, 4);
1095 /* Pass the address of variable on stack as reference. */
1096 store_unsigned_integer ((gdb_byte *) val, 4, byte_order,
1102 internal_error (__FILE__, __LINE__,
1103 _("unexpected type %d of arg %d"),
1107 internal_error (__FILE__, __LINE__,
1108 _("unexpected length %d of arg %d"), len, argnum);
1110 addr = sp + stack_offset;
1111 write_memory (addr, val, len);
1112 stack_offset += align_up (len, 4);
1116 regcache_cooked_write_signed (regcache, TIC6X_SP_REGNUM, sp);
1118 /* Return adjusted stack pointer. */
1122 /* This is the implementation of gdbarch method stack_frame_destroyed_p. */
1125 tic6x_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR pc)
1127 unsigned long inst = tic6x_fetch_instruction (gdbarch, pc);
1128 /* Normally, the epilogue is composed by instruction `b .S2 b3'. */
1129 if ((inst & 0x0f83effc) == 0x360)
1131 unsigned int src2 = tic6x_register_number ((inst >> 18) & 0x1f,
1134 if (src2 == TIC6X_RA_REGNUM)
1141 /* This is the implementation of gdbarch method get_longjmp_target. */
1144 tic6x_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
1146 struct gdbarch *gdbarch = get_frame_arch (frame);
1147 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
1151 /* JMP_BUF is passed by reference in A4. */
1152 jb_addr = get_frame_register_unsigned (frame, 4);
1154 /* JMP_BUF contains 13 elements of type int, and return address is stored
1155 in the last slot. */
1156 if (target_read_memory (jb_addr + 12 * 4, buf, 4))
1159 *pc = extract_unsigned_integer (buf, 4, byte_order);
1164 /* This is the implementation of gdbarch method
1165 return_in_first_hidden_param_p. */
1168 tic6x_return_in_first_hidden_param_p (struct gdbarch *gdbarch,
1174 static struct gdbarch *
1175 tic6x_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1177 struct gdbarch *gdbarch;
1178 struct gdbarch_tdep *tdep;
1179 struct tdesc_arch_data *tdesc_data = NULL;
1180 const struct target_desc *tdesc = info.target_desc;
1183 /* Check any target description for validity. */
1184 if (tdesc_has_registers (tdesc))
1186 const struct tdesc_feature *feature;
1189 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.core");
1191 if (feature == NULL)
1194 tdesc_data = tdesc_data_alloc ();
1197 for (i = 0; i < 32; i++) /* A0 - A15, B0 - B15 */
1198 valid_p &= tdesc_numbered_register (feature, tdesc_data, i,
1199 tic6x_register_names[i]);
1202 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1203 tic6x_register_names[TIC6X_CSR_REGNUM]);
1204 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1205 tic6x_register_names[TIC6X_PC_REGNUM]);
1209 tdesc_data_cleanup (tdesc_data);
1213 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.gp");
1217 static const char *const gp[] =
1219 "A16", "A17", "A18", "A19", "A20", "A21", "A22", "A23",
1220 "A24", "A25", "A26", "A27", "A28", "A29", "A30", "A31",
1221 "B16", "B17", "B18", "B19", "B20", "B21", "B22", "B23",
1222 "B24", "B25", "B26", "B27", "B28", "B29", "B30", "B31",
1227 for (j = 0; j < 32; j++) /* A16 - A31, B16 - B31 */
1228 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++,
1233 tdesc_data_cleanup (tdesc_data);
1238 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.tic6x.c6xp");
1241 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "TSR");
1242 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "ILC");
1243 valid_p &= tdesc_numbered_register (feature, tdesc_data, i++, "RILC");
1247 tdesc_data_cleanup (tdesc_data);
1254 /* Find a candidate among extant architectures. */
1255 for (arches = gdbarch_list_lookup_by_info (arches, &info);
1257 arches = gdbarch_list_lookup_by_info (arches->next, &info))
1259 tdep = gdbarch_tdep (arches->gdbarch);
1261 if (has_gp != tdep->has_gp)
1264 if (tdep && tdep->breakpoint)
1265 return arches->gdbarch;
1268 tdep = XCNEW (struct gdbarch_tdep);
1270 tdep->has_gp = has_gp;
1271 gdbarch = gdbarch_alloc (&info, tdep);
1273 /* Data type sizes. */
1274 set_gdbarch_ptr_bit (gdbarch, 32);
1275 set_gdbarch_addr_bit (gdbarch, 32);
1276 set_gdbarch_short_bit (gdbarch, 16);
1277 set_gdbarch_int_bit (gdbarch, 32);
1278 set_gdbarch_long_bit (gdbarch, 32);
1279 set_gdbarch_long_long_bit (gdbarch, 64);
1280 set_gdbarch_float_bit (gdbarch, 32);
1281 set_gdbarch_double_bit (gdbarch, 64);
1283 set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
1284 set_gdbarch_double_format (gdbarch, floatformats_ieee_double);
1286 /* The register set. */
1287 set_gdbarch_num_regs (gdbarch, TIC6X_NUM_REGS);
1288 set_gdbarch_sp_regnum (gdbarch, TIC6X_SP_REGNUM);
1289 set_gdbarch_pc_regnum (gdbarch, TIC6X_PC_REGNUM);
1291 set_gdbarch_register_name (gdbarch, tic6x_register_name);
1292 set_gdbarch_register_type (gdbarch, tic6x_register_type);
1294 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1296 set_gdbarch_skip_prologue (gdbarch, tic6x_skip_prologue);
1297 set_gdbarch_breakpoint_from_pc (gdbarch, tic6x_breakpoint_from_pc);
1299 set_gdbarch_unwind_pc (gdbarch, tic6x_unwind_pc);
1300 set_gdbarch_unwind_sp (gdbarch, tic6x_unwind_sp);
1303 dwarf2_append_unwinders (gdbarch);
1305 frame_unwind_append_unwinder (gdbarch, &tic6x_stub_unwind);
1306 frame_unwind_append_unwinder (gdbarch, &tic6x_frame_unwind);
1307 frame_base_set_default (gdbarch, &tic6x_frame_base);
1309 dwarf2_frame_set_init_reg (gdbarch, tic6x_dwarf2_frame_init_reg);
1311 /* Single stepping. */
1312 set_gdbarch_software_single_step (gdbarch, tic6x_software_single_step);
1314 set_gdbarch_print_insn (gdbarch, tic6x_print_insn);
1316 /* Call dummy code. */
1317 set_gdbarch_frame_align (gdbarch, tic6x_frame_align);
1319 set_gdbarch_return_value (gdbarch, tic6x_return_value);
1321 set_gdbarch_dummy_id (gdbarch, tic6x_dummy_id);
1323 /* Enable inferior call support. */
1324 set_gdbarch_push_dummy_call (gdbarch, tic6x_push_dummy_call);
1326 set_gdbarch_get_longjmp_target (gdbarch, tic6x_get_longjmp_target);
1328 set_gdbarch_stack_frame_destroyed_p (gdbarch, tic6x_stack_frame_destroyed_p);
1330 set_gdbarch_return_in_first_hidden_param_p (gdbarch,
1331 tic6x_return_in_first_hidden_param_p);
1333 /* Hook in ABI-specific overrides, if they have been registered. */
1334 gdbarch_init_osabi (info, gdbarch);
1337 tdesc_use_registers (gdbarch, tdesc, tdesc_data);
1342 /* -Wmissing-prototypes */
1343 extern initialize_file_ftype _initialize_tic6x_tdep;
1346 _initialize_tic6x_tdep (void)
1348 register_gdbarch_init (bfd_arch_tic6x, tic6x_gdbarch_init);
1350 initialize_tdesc_tic6x_c64xp ();
1351 initialize_tdesc_tic6x_c64x ();
1352 initialize_tdesc_tic6x_c62x ();