[thirdparty/gcc.git] / gcc / config / nios2 / nios2.h

/* Definitions of target machine for Altera Nios II.
   Copyright (C) 2012-2013 Free Software Foundation, Inc.
   Contributed by Jonah Graham (jgraham@altera.com), 
   Will Reece (wreece@altera.com), and Jeff DaSilva (jdasilva@altera.com).
   Contributed by Mentor Graphics, Inc.

   This file is part of GCC.

   GCC is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published
   by the Free Software Foundation; either version 3, or (at your
   option) any later version.

   GCC is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
   License for more details.

   You should have received a copy of the GNU General Public License
   along with GCC; see the file COPYING3.  If not see
   <http://www.gnu.org/licenses/>.  */

#ifndef GCC_NIOS2_H
#define GCC_NIOS2_H

/* FPU insn codes declared here.  */
#include "config/nios2/nios2-opts.h"

/* Define built-in preprocessor macros.  */
#define TARGET_CPU_CPP_BUILTINS()                   \
  do                                                \
    {                                               \
      builtin_define_std ("NIOS2");                 \
      builtin_define_std ("nios2");                 \
      if (TARGET_BIG_ENDIAN)                        \
        builtin_define_std ("nios2_big_endian");    \
      else                                          \
        builtin_define_std ("nios2_little_endian"); \
    }                                               \
  while (0)

/* We're little endian, unless otherwise specified by defining
   BIG_ENDIAN_FLAG.  */
#ifndef TARGET_ENDIAN_DEFAULT
# define TARGET_ENDIAN_DEFAULT 0
#endif

/* Default target_flags if no switches specified.  */
#ifndef TARGET_DEFAULT
# define TARGET_DEFAULT (MASK_HAS_MUL | TARGET_ENDIAN_DEFAULT)
#endif

#define CC1_SPEC "%{G*}"

#if TARGET_ENDIAN_DEFAULT == 0
# define ASM_SPEC "%{!meb:-EL} %{meb:-EB}"
# define LINK_SPEC_ENDIAN "%{!meb:-EL} %{meb:-EB}"
# define MULTILIB_DEFAULTS { "EL" }
#else
# define ASM_SPEC "%{!mel:-EB} %{mel:-EL}"
# define LINK_SPEC_ENDIAN "%{!mel:-EB} %{mel:-EL}"
# define MULTILIB_DEFAULTS { "EB" }
#endif

#define LINK_SPEC LINK_SPEC_ENDIAN \
  " %{shared:-shared} \
    %{static:-Bstatic}"


/* Storage layout.  */

#define DEFAULT_SIGNED_CHAR 1
#define BITS_BIG_ENDIAN 0
#define BYTES_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
#define WORDS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
#define BITS_PER_UNIT 8
#define BITS_PER_WORD 32
#define UNITS_PER_WORD 4
#define POINTER_SIZE 32
#define BIGGEST_ALIGNMENT 32
#define STRICT_ALIGNMENT 1
#define FUNCTION_BOUNDARY 32
#define PARM_BOUNDARY 32
#define STACK_BOUNDARY 32
#define PREFERRED_STACK_BOUNDARY 32
#define MAX_FIXED_MODE_SIZE 64

#define CONSTANT_ALIGNMENT(EXP, ALIGN)                          \
  ((TREE_CODE (EXP) == STRING_CST)                              \
   && (ALIGN) < BITS_PER_WORD ? BITS_PER_WORD : (ALIGN))

/* Layout of source language data types.  */

#define INT_TYPE_SIZE 32
#define SHORT_TYPE_SIZE 16
#define LONG_TYPE_SIZE 32
#define LONG_LONG_TYPE_SIZE 64
#define FLOAT_TYPE_SIZE 32
#define DOUBLE_TYPE_SIZE 64
#define LONG_DOUBLE_TYPE_SIZE DOUBLE_TYPE_SIZE

#undef SIZE_TYPE
#define SIZE_TYPE "unsigned int"

#undef PTRDIFF_TYPE
#define PTRDIFF_TYPE "int"


/* Basic characteristics of Nios II registers:

   Regno  Name
   0      r0       zero    always zero
   1      r1       at      Assembler Temporary
   2-3    r2-r3            Return Location
   4-7    r4-r7            Register Arguments
   8-15   r8-r15           Caller Saved Registers
   16-22  r16-r22          Callee Saved Registers
   22     r22              Global Offset Table pointer (Linux ABI only)
   23     r23              Thread pointer (Linux ABI only)
   24     r24      et      Exception Temporary
   25     r25      bt      Breakpoint Temporary
   26     r26      gp      Global Pointer
   27     r27      sp      Stack Pointer
   28     r28      fp      Frame Pointer
   29     r29      ea      Exception Return Address
   30     r30      ba      Breakpoint Return Address
   31     r31      ra      Return Address
			   
   32     ctl0     status
   33     ctl1     estatus STATUS saved by exception
   34     ctl2     bstatus STATUS saved by break
   35     ctl3     ipri    Interrupt Priority Mask
   36     ctl4     ecause  Exception Cause

   37     pc               Not an actual register

   38     fake_fp          Fake Frame Pointer (always eliminated)
   39     fake_ap          Fake Argument Pointer (always eliminated)
   40                      First Pseudo Register

   In addition, r12 is used as the static chain register and r13, r14, and r15
   are clobbered by PLT code sequences.  

   The definitions for all the hard register numbers are located in nios2.md.
*/

#define FIXED_REGISTERS                      \
  {					     \
/*        +0  1  2  3  4  5  6  7  8  9 */   \
/*   0 */  1, 1, 0, 0, 0, 0, 0, 0, 0, 0,     \
/*  10 */  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,     \
/*  20 */  0, 0, TARGET_LINUX_ABI, TARGET_LINUX_ABI, 1, 1, 1, 1, 0, 1,     \
/*  30 */  1, 0, 1, 1, 1, 1, 1, 1, 1, 1,     \
  }

/* Call used == caller saved + fixed regs + args + ret vals.  */
#define CALL_USED_REGISTERS                  \
  {					     \
/*        +0  1  2  3  4  5  6  7  8  9 */   \
/*   0 */  1, 1, 1, 1, 1, 1, 1, 1, 1, 1,     \
/*  10 */  1, 1, 1, 1, 1, 1, 0, 0, 0, 0,     \
/*  20 */  0, 0, TARGET_LINUX_ABI, TARGET_LINUX_ABI, 1, 1, 1, 1, 0, 1,     \
/*  30 */  1, 1, 1, 1, 1, 1, 1, 1, 1, 1,     \
  }

#define MODES_TIEABLE_P(MODE1, MODE2) 1
#define HARD_REGNO_MODE_OK(REGNO, MODE) 1
#define HARD_REGNO_NREGS(REGNO, MODE)            \
  ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)

/* Register Classes.  */

enum reg_class
{
  NO_REGS,
  SIB_REGS,
  GP_REGS,
  ALL_REGS,
  LIM_REG_CLASSES
};

#define N_REG_CLASSES (int) LIM_REG_CLASSES

#define REG_CLASS_NAMES   \
  {  "NO_REGS",		  \
     "SIB_REGS",	  \
     "GP_REGS",           \
     "ALL_REGS" }

#define GENERAL_REGS ALL_REGS

#define REG_CLASS_CONTENTS			\
  {						\
    /* NO_REGS  */ { 0, 0},			\
    /* SIB_REGS */ { 0xfe0c, 0},		\
    /* GP_REGS  */ {~0, 0},			\
    /* ALL_REGS */ {~0,~0}			\
  }


#define GP_REG_P(REGNO) ((unsigned)(REGNO) <= LAST_GP_REG)
#define REGNO_REG_CLASS(REGNO) (GP_REG_P (REGNO) ? GP_REGS : ALL_REGS)
#define CLASS_MAX_NREGS(CLASS, MODE)					\
  ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)

/* Tests for various kinds of constants used in the Nios II port.  */

#define SMALL_INT(X) ((unsigned HOST_WIDE_INT)(X) + 0x8000 < 0x10000)
#define SMALL_INT_UNSIGNED(X) ((X) >= 0 && (X) < 0x10000)
#define UPPER16_INT(X) (((X) & 0xffff) == 0)
#define SHIFT_INT(X) ((X) >= 0 && (X) <= 31)
#define RDWRCTL_INT(X) ((X) >= 0 && (X) <= 31)
#define CUSTOM_INSN_OPCODE(X) ((X) >= 0 && (X) <= 255)

/* Say that the epilogue uses the return address register.  Note that
   in the case of sibcalls, the values "used by the epilogue" are
   considered live at the start of the called function.  */
#define EPILOGUE_USES(REGNO) (epilogue_completed && (REGNO) == RA_REGNO)

/* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
   the stack pointer does not matter.  The value is tested only in
   functions that have frame pointers.
   No definition is equivalent to always zero.  */

#define EXIT_IGNORE_STACK 1

/* Trampolines use a 5-instruction sequence.  */
#define TRAMPOLINE_SIZE 20

/* Stack layout.  */
#define STACK_GROWS_DOWNWARD
#define STARTING_FRAME_OFFSET 0
#define FIRST_PARM_OFFSET(FUNDECL) 0

/* Before the prologue, RA lives in r31.  */
#define INCOMING_RETURN_ADDR_RTX  gen_rtx_REG (VOIDmode, RA_REGNO)
#define RETURN_ADDR_RTX(C,F) nios2_get_return_address (C)

#define DWARF_FRAME_RETURN_COLUMN RA_REGNO

/* The CFA includes the pretend args.  */
#define ARG_POINTER_CFA_OFFSET(FNDECL) \
  (gcc_assert ((FNDECL) == current_function_decl), \
   FIRST_PARM_OFFSET (FNDECL) + crtl->args.pretend_args_size)

/* Frame/arg pointer elimination settings.  */
#define ELIMINABLE_REGS                                                 \
{{ ARG_POINTER_REGNUM,   STACK_POINTER_REGNUM},                         \
 { ARG_POINTER_REGNUM,   HARD_FRAME_POINTER_REGNUM},                    \
 { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM},                         \
 { FRAME_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}}

#define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
  (OFFSET) = nios2_initial_elimination_offset ((FROM), (TO))

/* Calling convention definitions.  */
typedef struct nios2_args
{
  int regs_used;
} CUMULATIVE_ARGS;

#define NUM_ARG_REGS (LAST_ARG_REGNO - FIRST_ARG_REGNO + 1)

#define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, FNDECL, N_NAMED_ARGS) \
  do { (CUM).regs_used = 0; } while (0)

#define FUNCTION_ARG_PADDING(MODE, TYPE) \
  (nios2_function_arg_padding ((MODE), (TYPE)))

#define PAD_VARARGS_DOWN \
  (FUNCTION_ARG_PADDING (TYPE_MODE (type), type) == downward)

#define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
  (nios2_block_reg_padding ((MODE), (TYPE), (FIRST)))

#define FUNCTION_ARG_REGNO_P(REGNO) \
  ((REGNO) >= FIRST_ARG_REGNO && (REGNO) <= LAST_ARG_REGNO)

/* Passing function arguments on stack.  */
#define PUSH_ARGS 0
#define ACCUMULATE_OUTGOING_ARGS 1

/* We define TARGET_RETURN_IN_MEMORY, so set to zero.  */
#define DEFAULT_PCC_STRUCT_RETURN 0

/* Profiling.  */
#define PROFILE_BEFORE_PROLOGUE
#define NO_PROFILE_COUNTERS 1
#define FUNCTION_PROFILER(FILE, LABELNO) \
  nios2_function_profiler ((FILE), (LABELNO))

/* Addressing modes.  */

#define CONSTANT_ADDRESS_P(X) \
  (CONSTANT_P (X) && memory_address_p (SImode, X))

#define MAX_REGS_PER_ADDRESS 1
#define BASE_REG_CLASS ALL_REGS
#define INDEX_REG_CLASS NO_REGS

#define REGNO_OK_FOR_BASE_P(REGNO) nios2_regno_ok_for_base_p ((REGNO), true)
#define REGNO_OK_FOR_INDEX_P(REGNO) 0

/* Describing Relative Costs of Operations.  */
#define MOVE_MAX 4
#define SLOW_BYTE_ACCESS 1

/* It is as good to call a constant function address as to call an address
   kept in a register.  */
#define NO_FUNCTION_CSE

/* Position independent code.  */

#define PIC_OFFSET_TABLE_REGNUM 22
#define LEGITIMATE_PIC_OPERAND_P(X) nios2_legitimate_pic_operand_p (X)

/* Define output assembler language.  */

#define ASM_APP_ON "#APP\n"
#define ASM_APP_OFF "#NO_APP\n"

#define ASM_COMMENT_START "# "

#define GLOBAL_ASM_OP "\t.global\t"

#define REGISTER_NAMES \
  {		       \
    "zero", \
    "at", \
    "r2", \
    "r3", \
    "r4", \
    "r5", \
    "r6", \
    "r7", \
    "r8", \
    "r9", \
    "r10", \
    "r11", \
    "r12", \
    "r13", \
    "r14", \
    "r15", \
    "r16", \
    "r17", \
    "r18", \
    "r19", \
    "r20", \
    "r21", \
    "r22", \
    "r23", \
    "et", \
    "bt", \
    "gp", \
    "sp", \
    "fp", \
    "ta", \
    "ba", \
    "ra", \
    "status", \
    "estatus", \
    "bstatus", \
    "ipri", \
    "ecause", \
    "pc", \
    "fake_fp", \
    "fake_ap", \
}

#define ADDITIONAL_REGISTER_NAMES       \
{					\
  {"r0", 0},				\
  {"r1", 1},				\
  {"r24", 24},                          \
  {"r25", 25},                          \
  {"r26", 26},                          \
  {"r27", 27},                          \
  {"r28", 28},                          \
  {"r29", 29},                          \
  {"r30", 30},                          \
  {"r31", 31}                           \
}

#define ASM_OUTPUT_ADDR_VEC_ELT(FILE, VALUE)  \
  do									\
    {									\
      fputs (integer_asm_op (POINTER_SIZE / BITS_PER_UNIT, TRUE), FILE); \
      fprintf (FILE, ".L%u\n", (unsigned) (VALUE));			\
    }									\
  while (0)

#define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM, BODY, VALUE, REL)\
  do									\
    {									\
      fputs (integer_asm_op (POINTER_SIZE / BITS_PER_UNIT, TRUE), STREAM); \
      fprintf (STREAM, ".L%u-.L%u\n", (unsigned) (VALUE), (unsigned) (REL)); \
    }									\
  while (0)

/* Section directives.  */

/* Output before read-only data.  */
#define TEXT_SECTION_ASM_OP "\t.section\t.text"

/* Output before writable data.  */
#define DATA_SECTION_ASM_OP "\t.section\t.data"

/* Output before uninitialized data.  */
#define BSS_SECTION_ASM_OP "\t.section\t.bss"

/* Output before 'small' uninitialized data.  */
#define SBSS_SECTION_ASM_OP "\t.section\t.sbss"

#ifndef IN_LIBGCC2
/* Default the definition of "small data" to 8 bytes.  */
extern unsigned HOST_WIDE_INT nios2_section_threshold;
#endif

#define NIOS2_DEFAULT_GVALUE 8

/* This says how to output assembler code to declare an
   uninitialized external linkage data object.  Under SVR4,
   the linker seems to want the alignment of data objects
   to depend on their types.  We do exactly that here.  */
#undef COMMON_ASM_OP
#define COMMON_ASM_OP   "\t.comm\t"

#define ASM_OUTPUT_ALIGN(FILE, LOG)		     \
  do {						     \
    fprintf ((FILE), "%s%d\n", ALIGN_ASM_OP, (LOG)); \
  } while (0)

#undef  ASM_OUTPUT_ALIGNED_COMMON
#define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN)              \
do                                                                      \
  {									\
    fprintf ((FILE), "%s", COMMON_ASM_OP);				\
    assemble_name ((FILE), (NAME));					\
    fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", (SIZE),	\
	     (ALIGN) / BITS_PER_UNIT);					\
  }									\
while (0)


/* This says how to output assembler code to declare an
   uninitialized internal linkage data object.  Under SVR4,
   the linker seems to want the alignment of data objects
   to depend on their types.  We do exactly that here.  */

#undef  ASM_OUTPUT_ALIGNED_LOCAL
#define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN)               \
do {                                                                    \
  if ((SIZE) <= nios2_section_threshold)                                \
    switch_to_section (sbss_section);					\
  else                                                                  \
    switch_to_section (bss_section);					\
  ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object");                     \
  if (!flag_inhibit_size_directive)                                     \
    ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, SIZE);                       \
  ASM_OUTPUT_ALIGN ((FILE), exact_log2((ALIGN) / BITS_PER_UNIT));       \
  ASM_OUTPUT_LABEL(FILE, NAME);                                         \
  ASM_OUTPUT_SKIP((FILE), (SIZE) ? (SIZE) : 1);                         \
} while (0)

/* Put the jump tables in .text because when using position-independent code,
   Nios II elf has no relocation that can represent arbitrary differences
   between symbols in different sections.  */
#define JUMP_TABLES_IN_TEXT_SECTION 1

/* Exception handling.  */

/* Describe __builtin_eh_return.  */
#define EH_RETURN_STACKADJ_RTX gen_rtx_REG (Pmode, LAST_RETVAL_REGNO)
#define EH_RETURN_DATA_REGNO(N) ((N) <= (LAST_ARG_REGNO - FIRST_ARG_REGNO) \
				 ? (N) + FIRST_ARG_REGNO : INVALID_REGNUM)

/* Nios II has no appropriate relocations for a 32-bit PC-relative or
   section-relative pointer encoding.  This therefore always chooses an
   absolute representation for pointers.  An unfortunate consequence of
   this is that ld complains about the absolute fde encoding when linking
   with -shared or -fpie, but the warning is harmless and there seems to
   be no good way to suppress it.  */
#define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL)		\
  (flag_pic ? DW_EH_PE_aligned : DW_EH_PE_sdata4)

/* Misc. parameters.  */

#define STORE_FLAG_VALUE 1
#define Pmode SImode
#define FUNCTION_MODE QImode

#define CASE_VECTOR_MODE Pmode

#define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1

#define LOAD_EXTEND_OP(MODE) (ZERO_EXTEND)

#define WORD_REGISTER_OPERATIONS

#endif /* GCC_NIOS2_H */
Commit	Line	Data
e430824f CLT	1	/* Definitions of target machine for Altera Nios II.
	2	Copyright (C) 2012-2013 Free Software Foundation, Inc.
	3	Contributed by Jonah Graham (jgraham@altera.com),
	4	Will Reece (wreece@altera.com), and Jeff DaSilva (jdasilva@altera.com).
	5	Contributed by Mentor Graphics, Inc.
	6
	7	This file is part of GCC.
	8
	9	GCC is free software; you can redistribute it and/or modify it
	10	under the terms of the GNU General Public License as published
	11	by the Free Software Foundation; either version 3, or (at your
	12	option) any later version.
	13
	14	GCC is distributed in the hope that it will be useful, but WITHOUT
	15	ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
	16	or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
	17	License for more details.
	18
	19	You should have received a copy of the GNU General Public License
	20	along with GCC; see the file COPYING3. If not see
	21	<http://www.gnu.org/licenses/>. */
	22
	23	#ifndef GCC_NIOS2_H
	24	#define GCC_NIOS2_H
	25
	26	/* FPU insn codes declared here. */
	27	#include "config/nios2/nios2-opts.h"
	28
	29	/* Define built-in preprocessor macros. */
	30	#define TARGET_CPU_CPP_BUILTINS() \
	31	do \
	32	{ \
	33	builtin_define_std ("NIOS2"); \
	34	builtin_define_std ("nios2"); \
	35	if (TARGET_BIG_ENDIAN) \
	36	builtin_define_std ("nios2_big_endian"); \
	37	else \
	38	builtin_define_std ("nios2_little_endian"); \
	39	} \
	40	while (0)
	41
	42	/* We're little endian, unless otherwise specified by defining
	43	BIG_ENDIAN_FLAG. */
	44	#ifndef TARGET_ENDIAN_DEFAULT
	45	# define TARGET_ENDIAN_DEFAULT 0
	46	#endif
	47
	48	/* Default target_flags if no switches specified. */
	49	#ifndef TARGET_DEFAULT
	50	# define TARGET_DEFAULT (MASK_HAS_MUL \| TARGET_ENDIAN_DEFAULT)
	51	#endif
	52
	53	#define CC1_SPEC "%{G*}"
	54
	55	#if TARGET_ENDIAN_DEFAULT == 0
	56	# define ASM_SPEC "%{!meb:-EL} %{meb:-EB}"
	57	# define LINK_SPEC_ENDIAN "%{!meb:-EL} %{meb:-EB}"
	58	# define MULTILIB_DEFAULTS { "EL" }
	59	#else
	60	# define ASM_SPEC "%{!mel:-EB} %{mel:-EL}"
	61	# define LINK_SPEC_ENDIAN "%{!mel:-EB} %{mel:-EL}"
	62	# define MULTILIB_DEFAULTS { "EB" }
	63	#endif
	64
65	#define LINK_SPEC LINK_SPEC_ENDIAN \
66	" %{shared:-shared} \
67	%{static:-Bstatic}"
68
69
70	/* Storage layout. */
71
72	#define DEFAULT_SIGNED_CHAR 1
73	#define BITS_BIG_ENDIAN 0
74	#define BYTES_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
75	#define WORDS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
76	#define BITS_PER_UNIT 8
77	#define BITS_PER_WORD 32
78	#define UNITS_PER_WORD 4
79	#define POINTER_SIZE 32
80	#define BIGGEST_ALIGNMENT 32
81	#define STRICT_ALIGNMENT 1
82	#define FUNCTION_BOUNDARY 32
83	#define PARM_BOUNDARY 32
84	#define STACK_BOUNDARY 32
85	#define PREFERRED_STACK_BOUNDARY 32
86	#define MAX_FIXED_MODE_SIZE 64
87
88	#define CONSTANT_ALIGNMENT(EXP, ALIGN) \
89	((TREE_CODE (EXP) == STRING_CST) \
90	&& (ALIGN) < BITS_PER_WORD ? BITS_PER_WORD : (ALIGN))
91
92	/* Layout of source language data types. */
93
94	#define INT_TYPE_SIZE 32
95	#define SHORT_TYPE_SIZE 16
96	#define LONG_TYPE_SIZE 32
97	#define LONG_LONG_TYPE_SIZE 64
98	#define FLOAT_TYPE_SIZE 32
99	#define DOUBLE_TYPE_SIZE 64
100	#define LONG_DOUBLE_TYPE_SIZE DOUBLE_TYPE_SIZE
101
102	#undef SIZE_TYPE
103	#define SIZE_TYPE "unsigned int"
104
105	#undef PTRDIFF_TYPE
106	#define PTRDIFF_TYPE "int"
107
108
109	/* Basic characteristics of Nios II registers:
110
111	Regno Name
112	0 r0 zero always zero
113	1 r1 at Assembler Temporary
114	2-3 r2-r3 Return Location
115	4-7 r4-r7 Register Arguments
116	8-15 r8-r15 Caller Saved Registers
117	16-22 r16-r22 Callee Saved Registers
118	22 r22 Global Offset Table pointer (Linux ABI only)
119	23 r23 Thread pointer (Linux ABI only)
120	24 r24 et Exception Temporary
121	25 r25 bt Breakpoint Temporary
122	26 r26 gp Global Pointer
123	27 r27 sp Stack Pointer
124	28 r28 fp Frame Pointer
125	29 r29 ea Exception Return Address
126	30 r30 ba Breakpoint Return Address
127	31 r31 ra Return Address
128
129	32 ctl0 status
130	33 ctl1 estatus STATUS saved by exception
131	34 ctl2 bstatus STATUS saved by break
132	35 ctl3 ipri Interrupt Priority Mask
133	36 ctl4 ecause Exception Cause
134
135	37 pc Not an actual register
136
137	38 fake_fp Fake Frame Pointer (always eliminated)
138	39 fake_ap Fake Argument Pointer (always eliminated)
139	40 First Pseudo Register
140
141	In addition, r12 is used as the static chain register and r13, r14, and r15
142	are clobbered by PLT code sequences.
143
144	The definitions for all the hard register numbers are located in nios2.md.
145	*/
146
147	#define FIXED_REGISTERS \
148	{ \
149	/* +0 1 2 3 4 5 6 7 8 9 */ \
150	/* 0 */ 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, \
151	/* 10 */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
152	/* 20 */ 0, 0, TARGET_LINUX_ABI, TARGET_LINUX_ABI, 1, 1, 1, 1, 0, 1, \
153	/* 30 */ 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, \
154	}
155
156	/* Call used == caller saved + fixed regs + args + ret vals. */
157	#define CALL_USED_REGISTERS \
158	{ \
159	/* +0 1 2 3 4 5 6 7 8 9 */ \
160	/* 0 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
161	/* 10 */ 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, \
162	/* 20 */ 0, 0, TARGET_LINUX_ABI, TARGET_LINUX_ABI, 1, 1, 1, 1, 0, 1, \
163	/* 30 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
164	}
165
166	#define MODES_TIEABLE_P(MODE1, MODE2) 1
167	#define HARD_REGNO_MODE_OK(REGNO, MODE) 1
168	#define HARD_REGNO_NREGS(REGNO, MODE) \
169	((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
170
171	/* Register Classes. */
172
173	enum reg_class
174	{
175	NO_REGS,
176	SIB_REGS,
177	GP_REGS,
178	ALL_REGS,
179	LIM_REG_CLASSES
180	};
181
182	#define N_REG_CLASSES (int) LIM_REG_CLASSES
183
184	#define REG_CLASS_NAMES \
185	{ "NO_REGS", \
186	"SIB_REGS", \
187	"GP_REGS", \
188	"ALL_REGS" }
189
190	#define GENERAL_REGS ALL_REGS
191
192	#define REG_CLASS_CONTENTS \
193	{ \
194	/* NO_REGS */ { 0, 0}, \
195	/* SIB_REGS */ { 0xfe0c, 0}, \
196	/* GP_REGS */ {~0, 0}, \
197	/* ALL_REGS */ {~0,~0} \
198	}
199
200
201	#define GP_REG_P(REGNO) ((unsigned)(REGNO) <= LAST_GP_REG)
202	#define REGNO_REG_CLASS(REGNO) (GP_REG_P (REGNO) ? GP_REGS : ALL_REGS)
203	#define CLASS_MAX_NREGS(CLASS, MODE) \
204	((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
205
206	/* Tests for various kinds of constants used in the Nios II port. */
207
208	#define SMALL_INT(X) ((unsigned HOST_WIDE_INT)(X) + 0x8000 < 0x10000)
209	#define SMALL_INT_UNSIGNED(X) ((X) >= 0 && (X) < 0x10000)
210	#define UPPER16_INT(X) (((X) & 0xffff) == 0)
211	#define SHIFT_INT(X) ((X) >= 0 && (X) <= 31)
212	#define RDWRCTL_INT(X) ((X) >= 0 && (X) <= 31)
213	#define CUSTOM_INSN_OPCODE(X) ((X) >= 0 && (X) <= 255)
214
215	/* Say that the epilogue uses the return address register. Note that
216	in the case of sibcalls, the values "used by the epilogue" are
217	considered live at the start of the called function. */
218	#define EPILOGUE_USES(REGNO) (epilogue_completed && (REGNO) == RA_REGNO)
219
220	/* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
221	the stack pointer does not matter. The value is tested only in
222	functions that have frame pointers.
223	No definition is equivalent to always zero. */
224
225	#define EXIT_IGNORE_STACK 1
226
227	/* Trampolines use a 5-instruction sequence. */
228	#define TRAMPOLINE_SIZE 20
229
230	/* Stack layout. */
231	#define STACK_GROWS_DOWNWARD
232	#define STARTING_FRAME_OFFSET 0
233	#define FIRST_PARM_OFFSET(FUNDECL) 0
234
235	/* Before the prologue, RA lives in r31. */
236	#define INCOMING_RETURN_ADDR_RTX gen_rtx_REG (VOIDmode, RA_REGNO)
237	#define RETURN_ADDR_RTX(C,F) nios2_get_return_address (C)
238
239	#define DWARF_FRAME_RETURN_COLUMN RA_REGNO
240
241	/* The CFA includes the pretend args. */
242	#define ARG_POINTER_CFA_OFFSET(FNDECL) \
243	(gcc_assert ((FNDECL) == current_function_decl), \
244	FIRST_PARM_OFFSET (FNDECL) + crtl->args.pretend_args_size)
245
246	/* Frame/arg pointer elimination settings. */
247	#define ELIMINABLE_REGS \
248	{{ ARG_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
249	{ ARG_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}, \
250	{ FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
251	{ FRAME_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}}
252
253	#define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
254	(OFFSET) = nios2_initial_elimination_offset ((FROM), (TO))
255
256	/* Calling convention definitions. */
257	typedef struct nios2_args
258	{
259	int regs_used;
260	} CUMULATIVE_ARGS;
261
262	#define NUM_ARG_REGS (LAST_ARG_REGNO - FIRST_ARG_REGNO + 1)
263
264	#define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, FNDECL, N_NAMED_ARGS) \
265	do { (CUM).regs_used = 0; } while (0)
266
267	#define FUNCTION_ARG_PADDING(MODE, TYPE) \
268	(nios2_function_arg_padding ((MODE), (TYPE)))
269
270	#define PAD_VARARGS_DOWN \
271	(FUNCTION_ARG_PADDING (TYPE_MODE (type), type) == downward)
272
273	#define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
274	(nios2_block_reg_padding ((MODE), (TYPE), (FIRST)))
275
276	#define FUNCTION_ARG_REGNO_P(REGNO) \
277	((REGNO) >= FIRST_ARG_REGNO && (REGNO) <= LAST_ARG_REGNO)
278
279	/* Passing function arguments on stack. */
280	#define PUSH_ARGS 0
281	#define ACCUMULATE_OUTGOING_ARGS 1
282
283	/* We define TARGET_RETURN_IN_MEMORY, so set to zero. */
284	#define DEFAULT_PCC_STRUCT_RETURN 0
285
286	/* Profiling. */
287	#define PROFILE_BEFORE_PROLOGUE
288	#define NO_PROFILE_COUNTERS 1
289	#define FUNCTION_PROFILER(FILE, LABELNO) \
290	nios2_function_profiler ((FILE), (LABELNO))
291
292	/* Addressing modes. */
293
294	#define CONSTANT_ADDRESS_P(X) \
295	(CONSTANT_P (X) && memory_address_p (SImode, X))
296
297	#define MAX_REGS_PER_ADDRESS 1
298	#define BASE_REG_CLASS ALL_REGS
299	#define INDEX_REG_CLASS NO_REGS
300
301	#define REGNO_OK_FOR_BASE_P(REGNO) nios2_regno_ok_for_base_p ((REGNO), true)
302	#define REGNO_OK_FOR_INDEX_P(REGNO) 0
303
304	/* Describing Relative Costs of Operations. */
305	#define MOVE_MAX 4
306	#define SLOW_BYTE_ACCESS 1
307
308	/* It is as good to call a constant function address as to call an address
309	kept in a register. */
310	#define NO_FUNCTION_CSE
311
312	/* Position independent code. */
313
314	#define PIC_OFFSET_TABLE_REGNUM 22
315	#define LEGITIMATE_PIC_OPERAND_P(X) nios2_legitimate_pic_operand_p (X)
316
317	/* Define output assembler language. */
318
319	#define ASM_APP_ON "#APP\n"
320	#define ASM_APP_OFF "#NO_APP\n"
321
322	#define ASM_COMMENT_START "# "
323
324	#define GLOBAL_ASM_OP "\t.global\t"
325
326	#define REGISTER_NAMES \
327	{ \
328	"zero", \
329	"at", \
330	"r2", \
331	"r3", \
332	"r4", \
333	"r5", \
334	"r6", \
335	"r7", \
336	"r8", \
337	"r9", \
338	"r10", \
339	"r11", \
340	"r12", \
341	"r13", \
342	"r14", \
343	"r15", \
344	"r16", \
345	"r17", \
346	"r18", \
347	"r19", \
348	"r20", \
349	"r21", \
350	"r22", \
351	"r23", \
352	"et", \
353	"bt", \
354	"gp", \
355	"sp", \
356	"fp", \
357	"ta", \
358	"ba", \
359	"ra", \
360	"status", \
361	"estatus", \
362	"bstatus", \
363	"ipri", \
364	"ecause", \
365	"pc", \
366	"fake_fp", \
367	"fake_ap", \
368	}
369
370	#define ADDITIONAL_REGISTER_NAMES \
371	{ \
372	{"r0", 0}, \
373	{"r1", 1}, \
374	{"r24", 24}, \
375	{"r25", 25}, \
376	{"r26", 26}, \
377	{"r27", 27}, \
378	{"r28", 28}, \
379	{"r29", 29}, \
380	{"r30", 30}, \
381	{"r31", 31} \
382	}
383
384	#define ASM_OUTPUT_ADDR_VEC_ELT(FILE, VALUE) \
385	do \
386	{ \
387	fputs (integer_asm_op (POINTER_SIZE / BITS_PER_UNIT, TRUE), FILE); \
388	fprintf (FILE, ".L%u\n", (unsigned) (VALUE)); \
389	} \
390	while (0)
391
392	#define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM, BODY, VALUE, REL)\
393	do \
394	{ \
395	fputs (integer_asm_op (POINTER_SIZE / BITS_PER_UNIT, TRUE), STREAM); \
396	fprintf (STREAM, ".L%u-.L%u\n", (unsigned) (VALUE), (unsigned) (REL)); \
397	} \
398	while (0)
399
400	/* Section directives. */
401
402	/* Output before read-only data. */
403	#define TEXT_SECTION_ASM_OP "\t.section\t.text"
404
405	/* Output before writable data. */
406	#define DATA_SECTION_ASM_OP "\t.section\t.data"
407
408	/* Output before uninitialized data. */
409	#define BSS_SECTION_ASM_OP "\t.section\t.bss"
410
411	/* Output before 'small' uninitialized data. */
412	#define SBSS_SECTION_ASM_OP "\t.section\t.sbss"
413
414	#ifndef IN_LIBGCC2
415	/* Default the definition of "small data" to 8 bytes. */
416	extern unsigned HOST_WIDE_INT nios2_section_threshold;
417	#endif
418
419	#define NIOS2_DEFAULT_GVALUE 8
420
421	/* This says how to output assembler code to declare an
422	uninitialized external linkage data object. Under SVR4,
423	the linker seems to want the alignment of data objects
424	to depend on their types. We do exactly that here. */
425	#undef COMMON_ASM_OP
426	#define COMMON_ASM_OP "\t.comm\t"
427
428	#define ASM_OUTPUT_ALIGN(FILE, LOG) \
429	do { \
430	fprintf ((FILE), "%s%d\n", ALIGN_ASM_OP, (LOG)); \
431	} while (0)
432
433	#undef ASM_OUTPUT_ALIGNED_COMMON
434	#define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN) \
435	do \
436	{ \
437	fprintf ((FILE), "%s", COMMON_ASM_OP); \
438	assemble_name ((FILE), (NAME)); \
439	fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", (SIZE), \
440	(ALIGN) / BITS_PER_UNIT); \
441	} \
442	while (0)
443
444
445	/* This says how to output assembler code to declare an
446	uninitialized internal linkage data object. Under SVR4,
447	the linker seems to want the alignment of data objects
448	to depend on their types. We do exactly that here. */
449
450	#undef ASM_OUTPUT_ALIGNED_LOCAL
451	#define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN) \
452	do { \
453	if ((SIZE) <= nios2_section_threshold) \
454	switch_to_section (sbss_section); \
455	else \
456	switch_to_section (bss_section); \
457	ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object"); \
458	if (!flag_inhibit_size_directive) \
459	ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, SIZE); \
460	ASM_OUTPUT_ALIGN ((FILE), exact_log2((ALIGN) / BITS_PER_UNIT)); \
461	ASM_OUTPUT_LABEL(FILE, NAME); \
462	ASM_OUTPUT_SKIP((FILE), (SIZE) ? (SIZE) : 1); \
463	} while (0)
464
465	/* Put the jump tables in .text because when using position-independent code,
466	Nios II elf has no relocation that can represent arbitrary differences
467	between symbols in different sections. */
468	#define JUMP_TABLES_IN_TEXT_SECTION 1
469
470	/* Exception handling. */
471
472	/* Describe __builtin_eh_return. */
473	#define EH_RETURN_STACKADJ_RTX gen_rtx_REG (Pmode, LAST_RETVAL_REGNO)
474	#define EH_RETURN_DATA_REGNO(N) ((N) <= (LAST_ARG_REGNO - FIRST_ARG_REGNO) \
475	? (N) + FIRST_ARG_REGNO : INVALID_REGNUM)
476
477	/* Nios II has no appropriate relocations for a 32-bit PC-relative or
478	section-relative pointer encoding. This therefore always chooses an
479	absolute representation for pointers. An unfortunate consequence of
480	this is that ld complains about the absolute fde encoding when linking
481	with -shared or -fpie, but the warning is harmless and there seems to
482	be no good way to suppress it. */
483	#define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
484	(flag_pic ? DW_EH_PE_aligned : DW_EH_PE_sdata4)
485
486	/* Misc. parameters. */
487
488	#define STORE_FLAG_VALUE 1
489	#define Pmode SImode
490	#define FUNCTION_MODE QImode
491
492	#define CASE_VECTOR_MODE Pmode
493
494	#define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
495
496	#define LOAD_EXTEND_OP(MODE) (ZERO_EXTEND)
497
498	#define WORD_REGISTER_OPERATIONS
499
500	#endif /* GCC_NIOS2_H */