path: root/gcc-4.7/gcc/config/arm/arm.c

/* Output routines for GCC for ARM.
   Copyright (C) 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
   2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
   Free Software Foundation, Inc.
   Contributed by Pieter `Tiggr' Schoenmakers (rcpieter@win.tue.nl)
   and Martin Simmons (@harleqn.co.uk).
   More major hacks by Richard Earnshaw (rearnsha@arm.com).

   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/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
#include "tree.h"
#include "obstack.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "insn-config.h"
#include "conditions.h"
#include "output.h"
#include "insn-attr.h"
#include "flags.h"
#include "reload.h"
#include "function.h"
#include "expr.h"
#include "optabs.h"
#include "diagnostic-core.h"
#include "recog.h"
#include "cgraph.h"
#include "ggc.h"
#include "except.h"
#include "c-family/c-pragma.h"	/* ??? */
#include "integrate.h"
#include "tm_p.h"
#include "target.h"
#include "target-def.h"
#include "debug.h"
#include "langhooks.h"
#include "df.h"
#include "intl.h"
#include "libfuncs.h"
#include "params.h"
#include "opts.h"

/* Forward definitions of types.  */
typedef struct minipool_node    Mnode;
typedef struct minipool_fixup   Mfix;

void (*arm_lang_output_object_attributes_hook)(void);

struct four_ints
{
  int i[4];
};

/* Forward function declarations.  */
static bool arm_needs_doubleword_align (enum machine_mode, const_tree);
static int arm_compute_static_chain_stack_bytes (void);
static arm_stack_offsets *arm_get_frame_offsets (void);
static void arm_add_gc_roots (void);
static int arm_gen_constant (enum rtx_code, enum machine_mode, rtx,
			     HOST_WIDE_INT, rtx, rtx, int, int);
static unsigned bit_count (unsigned long);
static int arm_address_register_rtx_p (rtx, int);
static int arm_legitimate_index_p (enum machine_mode, rtx, RTX_CODE, int);
static int thumb2_legitimate_index_p (enum machine_mode, rtx, int);
static int thumb1_base_register_rtx_p (rtx, enum machine_mode, int);
static rtx arm_legitimize_address (rtx, rtx, enum machine_mode);
static rtx thumb_legitimize_address (rtx, rtx, enum machine_mode);
inline static int thumb1_index_register_rtx_p (rtx, int);
static bool arm_legitimate_address_p (enum machine_mode, rtx, bool);
static int thumb_far_jump_used_p (void);
static bool thumb_force_lr_save (void);
static rtx emit_sfm (int, int);
static unsigned arm_size_return_regs (void);
static bool arm_assemble_integer (rtx, unsigned int, int);
static void arm_print_operand (FILE *, rtx, int);
static void arm_print_operand_address (FILE *, rtx);
static bool arm_print_operand_punct_valid_p (unsigned char code);
static const char *fp_const_from_val (REAL_VALUE_TYPE *);
static arm_cc get_arm_condition_code (rtx);
static HOST_WIDE_INT int_log2 (HOST_WIDE_INT);
static rtx is_jump_table (rtx);
static const char *output_multi_immediate (rtx *, const char *, const char *,
					   int, HOST_WIDE_INT);
static const char *shift_op (rtx, HOST_WIDE_INT *);
static struct machine_function *arm_init_machine_status (void);
static void thumb_exit (FILE *, int);
static rtx is_jump_table (rtx);
static HOST_WIDE_INT get_jump_table_size (rtx);
static Mnode *move_minipool_fix_forward_ref (Mnode *, Mnode *, HOST_WIDE_INT);
static Mnode *add_minipool_forward_ref (Mfix *);
static Mnode *move_minipool_fix_backward_ref (Mnode *, Mnode *, HOST_WIDE_INT);
static Mnode *add_minipool_backward_ref (Mfix *);
static void assign_minipool_offsets (Mfix *);
static void arm_print_value (FILE *, rtx);
static void dump_minipool (rtx);
static int arm_barrier_cost (rtx);
static Mfix *create_fix_barrier (Mfix *, HOST_WIDE_INT);
static void push_minipool_barrier (rtx, HOST_WIDE_INT);
static void push_minipool_fix (rtx, HOST_WIDE_INT, rtx *, enum machine_mode,
			       rtx);
static void arm_reorg (void);
static bool note_invalid_constants (rtx, HOST_WIDE_INT, int);
static unsigned long arm_compute_save_reg0_reg12_mask (void);
static unsigned long arm_compute_save_reg_mask (void);
static unsigned long arm_isr_value (tree);
static unsigned long arm_compute_func_type (void);
static tree arm_handle_fndecl_attribute (tree *, tree, tree, int, bool *);
static tree arm_handle_pcs_attribute (tree *, tree, tree, int, bool *);
static tree arm_handle_isr_attribute (tree *, tree, tree, int, bool *);
#if TARGET_DLLIMPORT_DECL_ATTRIBUTES
static tree arm_handle_notshared_attribute (tree *, tree, tree, int, bool *);
#endif
static void arm_output_function_epilogue (FILE *, HOST_WIDE_INT);
static void arm_output_function_prologue (FILE *, HOST_WIDE_INT);
static int arm_comp_type_attributes (const_tree, const_tree);
static void arm_set_default_type_attributes (tree);
static int arm_adjust_cost (rtx, rtx, rtx, int);
static int optimal_immediate_sequence (enum rtx_code code,
				       unsigned HOST_WIDE_INT val,
				       struct four_ints *return_sequence);
static int optimal_immediate_sequence_1 (enum rtx_code code,
					 unsigned HOST_WIDE_INT val,
					 struct four_ints *return_sequence,
					 int i);
static int arm_get_strip_length (int);
static bool arm_function_ok_for_sibcall (tree, tree);
static enum machine_mode arm_promote_function_mode (const_tree,
						    enum machine_mode, int *,
						    const_tree, int);
static bool arm_return_in_memory (const_tree, const_tree);
static rtx arm_function_value (const_tree, const_tree, bool);
static rtx arm_libcall_value_1 (enum machine_mode);
static rtx arm_libcall_value (enum machine_mode, const_rtx);
static bool arm_function_value_regno_p (const unsigned int);
static void arm_internal_label (FILE *, const char *, unsigned long);
static void arm_output_mi_thunk (FILE *, tree, HOST_WIDE_INT, HOST_WIDE_INT,
				 tree);
static bool arm_have_conditional_execution (void);
static bool arm_cannot_force_const_mem (enum machine_mode, rtx);
static bool arm_legitimate_constant_p (enum machine_mode, rtx);
static bool arm_rtx_costs_1 (rtx, enum rtx_code, int*, bool);
static bool arm_size_rtx_costs (rtx, enum rtx_code, enum rtx_code, int *);
static bool arm_slowmul_rtx_costs (rtx, enum rtx_code, enum rtx_code, int *, bool);
static bool arm_fastmul_rtx_costs (rtx, enum rtx_code, enum rtx_code, int *, bool);
static bool arm_xscale_rtx_costs (rtx, enum rtx_code, enum rtx_code, int *, bool);
static bool arm_9e_rtx_costs (rtx, enum rtx_code, enum rtx_code, int *, bool);
static bool arm_rtx_costs (rtx, int, int, int, int *, bool);
static int arm_address_cost (rtx, bool);
static int arm_register_move_cost (enum machine_mode, reg_class_t, reg_class_t);
static int arm_memory_move_cost (enum machine_mode, reg_class_t, bool);
static bool arm_memory_load_p (rtx);
static bool arm_cirrus_insn_p (rtx);
static void cirrus_reorg (rtx);
static void arm_init_builtins (void);
static void arm_init_iwmmxt_builtins (void);
static rtx safe_vector_operand (rtx, enum machine_mode);
static rtx arm_expand_binop_builtin (enum insn_code, tree, rtx);
static rtx arm_expand_unop_builtin (enum insn_code, tree, rtx, int);
static rtx arm_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
static tree arm_builtin_decl (unsigned, bool);
static void emit_constant_insn (rtx cond, rtx pattern);
static rtx emit_set_insn (rtx, rtx);
static int arm_arg_partial_bytes (cumulative_args_t, enum machine_mode,
				  tree, bool);
static rtx arm_function_arg (cumulative_args_t, enum machine_mode,
			     const_tree, bool);
static void arm_function_arg_advance (cumulative_args_t, enum machine_mode,
				      const_tree, bool);
static unsigned int arm_function_arg_boundary (enum machine_mode, const_tree);
static rtx aapcs_allocate_return_reg (enum machine_mode, const_tree,
				      const_tree);
static rtx aapcs_libcall_value (enum machine_mode);
static int aapcs_select_return_coproc (const_tree, const_tree);

#ifdef OBJECT_FORMAT_ELF
static void arm_elf_asm_constructor (rtx, int) ATTRIBUTE_UNUSED;
static void arm_elf_asm_destructor (rtx, int) ATTRIBUTE_UNUSED;
#endif
#ifndef ARM_PE
static void arm_encode_section_info (tree, rtx, int);
#endif

static void arm_file_end (void);
static void arm_file_start (void);

static void arm_setup_incoming_varargs (cumulative_args_t, enum machine_mode,
					tree, int *, int);
static bool arm_pass_by_reference (cumulative_args_t,
				   enum machine_mode, const_tree, bool);
static bool arm_promote_prototypes (const_tree);
static bool arm_default_short_enums (void);
static bool arm_align_anon_bitfield (void);
static bool arm_return_in_msb (const_tree);
static bool arm_must_pass_in_stack (enum machine_mode, const_tree);
static bool arm_return_in_memory (const_tree, const_tree);
#if ARM_UNWIND_INFO
static void arm_unwind_emit (FILE *, rtx);
static bool arm_output_ttype (rtx);
static void arm_asm_emit_except_personality (rtx);
static void arm_asm_init_sections (void);
#endif
static rtx arm_dwarf_register_span (rtx);

static tree arm_cxx_guard_type (void);
static bool arm_cxx_guard_mask_bit (void);
static tree arm_get_cookie_size (tree);
static bool arm_cookie_has_size (void);
static bool arm_cxx_cdtor_returns_this (void);
static bool arm_cxx_key_method_may_be_inline (void);
static void arm_cxx_determine_class_data_visibility (tree);
static bool arm_cxx_class_data_always_comdat (void);
static bool arm_cxx_use_aeabi_atexit (void);
static void arm_init_libfuncs (void);
static tree arm_build_builtin_va_list (void);
static void arm_expand_builtin_va_start (tree, rtx);
static tree arm_gimplify_va_arg_expr (tree, tree, gimple_seq *, gimple_seq *);
static void arm_option_override (void);
static unsigned HOST_WIDE_INT arm_shift_truncation_mask (enum machine_mode);
static bool arm_cannot_copy_insn_p (rtx);
static bool arm_tls_symbol_p (rtx x);
static int arm_issue_rate (void);
static void arm_output_dwarf_dtprel (FILE *, int, rtx) ATTRIBUTE_UNUSED;
static bool arm_output_addr_const_extra (FILE *, rtx);
static bool arm_allocate_stack_slots_for_args (void);
static const char *arm_invalid_parameter_type (const_tree t);
static const char *arm_invalid_return_type (const_tree t);
static tree arm_promoted_type (const_tree t);
static tree arm_convert_to_type (tree type, tree expr);
static bool arm_scalar_mode_supported_p (enum machine_mode);
static bool arm_frame_pointer_required (void);
static bool arm_can_eliminate (const int, const int);
static void arm_asm_trampoline_template (FILE *);
static void arm_trampoline_init (rtx, tree, rtx);
static rtx arm_trampoline_adjust_address (rtx);
static rtx arm_pic_static_addr (rtx orig, rtx reg);
static bool cortex_a9_sched_adjust_cost (rtx, rtx, rtx, int *);
static bool xscale_sched_adjust_cost (rtx, rtx, rtx, int *);
static bool fa726te_sched_adjust_cost (rtx, rtx, rtx, int *);
static bool arm_array_mode_supported_p (enum machine_mode,
					unsigned HOST_WIDE_INT);
static enum machine_mode arm_preferred_simd_mode (enum machine_mode);
static bool arm_class_likely_spilled_p (reg_class_t);
static HOST_WIDE_INT arm_vector_alignment (const_tree type);
static bool arm_vector_alignment_reachable (const_tree type, bool is_packed);
static bool arm_builtin_support_vector_misalignment (enum machine_mode mode,
						     const_tree type,
						     int misalignment,
						     bool is_packed);
static void arm_conditional_register_usage (void);
static reg_class_t arm_preferred_rename_class (reg_class_t rclass);
static unsigned int arm_autovectorize_vector_sizes (void);
static int arm_default_branch_cost (bool, bool);
static int arm_cortex_a5_branch_cost (bool, bool);

static bool arm_vectorize_vec_perm_const_ok (enum machine_mode vmode,
					     const unsigned char *sel);


/* Table of machine attributes.  */
static const struct attribute_spec arm_attribute_table[] =
{
  /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler,
       affects_type_identity } */
  /* Function calls made to this symbol must be done indirectly, because
     it may lie outside of the 26 bit addressing range of a normal function
     call.  */
  { "long_call",    0, 0, false, true,  true,  NULL, false },
  /* Whereas these functions are always known to reside within the 26 bit
     addressing range.  */
  { "short_call",   0, 0, false, true,  true,  NULL, false },
  /* Specify the procedure call conventions for a function.  */
  { "pcs",          1, 1, false, true,  true,  arm_handle_pcs_attribute,
    false },
  /* Interrupt Service Routines have special prologue and epilogue requirements.  */
  { "isr",          0, 1, false, false, false, arm_handle_isr_attribute,
    false },
  { "interrupt",    0, 1, false, false, false, arm_handle_isr_attribute,
    false },
  { "naked",        0, 0, true,  false, false, arm_handle_fndecl_attribute,
    false },
#ifdef ARM_PE
  /* ARM/PE has three new attributes:
     interfacearm - ?
     dllexport - for exporting a function/variable that will live in a dll
     dllimport - for importing a function/variable from a dll

     Microsoft allows multiple declspecs in one __declspec, separating
     them with spaces.  We do NOT support this.  Instead, use __declspec
     multiple times.
  */
  { "dllimport",    0, 0, true,  false, false, NULL, false },
  { "dllexport",    0, 0, true,  false, false, NULL, false },
  { "interfacearm", 0, 0, true,  false, false, arm_handle_fndecl_attribute,
    false },
#elif TARGET_DLLIMPORT_DECL_ATTRIBUTES
  { "dllimport",    0, 0, false, false, false, handle_dll_attribute, false },
  { "dllexport",    0, 0, false, false, false, handle_dll_attribute, false },
  { "notshared",    0, 0, false, true, false, arm_handle_notshared_attribute