rs6000.c

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/* Subroutines used for code generation on IBM RS/6000.
   Copyright (C) 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   2000, 2001, 2002, 2003, 2004, 2005, 2006
   Free Software Foundation, Inc.
   Contributed by Richard Kenner ([e-mail])

   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 2, 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 COPYING.  If not, write to the
   Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301, USA.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "real.h"
#include "insn-config.h"
#include "conditions.h"
#include "insn-attr.h"
#include "flags.h"
#include "recog.h"
#include "obstack.h"
#include "tree.h"
#include "expr.h"
#include "optabs.h"
#include "except.h"
#include "function.h"
#include "output.h"
#include "basic-block.h"
#include "integrate.h"
#include "toplev.h"
#include "ggc.h"
#include "hashtab.h"
#include "tm_p.h"
#include "target.h"
#include "target-def.h"
#include "langhooks.h"
#include "reload.h"
#include "cfglayout.h"
#include "sched-int.h"
#include "tree-gimple.h"
#include "intl.h"
#include "params.h"
#if TARGET_XCOFF
#include "xcoffout.h"  /* get declarations of xcoff_*_section_name */
#endif
#if TARGET_MACHO
#include "gstab.h"  /* for N_SLINE */
#endif

#ifndef TARGET_NO_PROTOTYPE
#define TARGET_NO_PROTOTYPE 0
#endif

#define min(A,B)	((A) < (B) ? (A) : (B))
#define max(A,B)	((A) > (B) ? (A) : (B))

/* Structure used to define the rs6000 stack */
typedef struct rs6000_stack {
  int first_gp_reg_save;	/* first callee saved GP register used */
  int first_fp_reg_save;	/* first callee saved FP register used */
  int first_altivec_reg_save;	/* first callee saved AltiVec register used */
  int lr_save_p;		/* true if the link reg needs to be saved */
  int cr_save_p;		/* true if the CR reg needs to be saved */
  unsigned int vrsave_mask;	/* mask of vec registers to save */
  int toc_save_p;		/* true if the TOC needs to be saved */
  int push_p;			/* true if we need to allocate stack space */
  int calls_p;			/* true if the function makes any calls */
  int world_save_p;		/* true if we're saving *everything*:
				   r13-r31, cr, f14-f31, vrsave, v20-v31  */
  enum rs6000_abi abi;		/* which ABI to use */
  int gp_save_offset;		/* offset to save GP regs from initial SP */
  int fp_save_offset;		/* offset to save FP regs from initial SP */
  int altivec_save_offset;	/* offset to save AltiVec regs from initial SP */
  int lr_save_offset;		/* offset to save LR from initial SP */
  int cr_save_offset;		/* offset to save CR from initial SP */
  int vrsave_save_offset;	/* offset to save VRSAVE from initial SP */
  int spe_gp_save_offset;	/* offset to save spe 64-bit gprs  */
  int toc_save_offset;		/* offset to save the TOC pointer */
  int varargs_save_offset;	/* offset to save the varargs registers */
  int ehrd_offset;		/* offset to EH return data */
  int reg_size;			/* register size (4 or 8) */
  HOST_WIDE_INT vars_size;	/* variable save area size */
  int parm_size;		/* outgoing parameter size */
  int save_size;		/* save area size */
  int fixed_size;		/* fixed size of stack frame */
  int gp_size;			/* size of saved GP registers */
  int fp_size;			/* size of saved FP registers */
  int altivec_size;		/* size of saved AltiVec registers */
  int cr_size;			/* size to hold CR if not in save_size */
  int lr_size;			/* size to hold LR if not in save_size */
  int vrsave_size;		/* size to hold VRSAVE if not in save_size */
  int altivec_padding_size;	/* size of altivec alignment padding if
				   not in save_size */
  int spe_gp_size;		/* size of 64-bit GPR save size for SPE */
  int spe_padding_size;
  int toc_size;			/* size to hold TOC if not in save_size */
  HOST_WIDE_INT total_size;	/* total bytes allocated for stack */
  int spe_64bit_regs_used;
} rs6000_stack_t;

/* A C structure for machine-specific, per-function data.
   This is added to the cfun structure.  */
typedef struct machine_function GTY(())
{
  /* Flags if __builtin_return_address (n) with n >= 1 was used.  */
  int ra_needs_full_frame;
  /* Some local-dynamic symbol.  */
  const char *some_ld_name;
  /* Whether the instruction chain has been scanned already.  */
  int insn_chain_scanned_p;
  /* Flags if __builtin_return_address (0) was used.  */
  int ra_need_lr;
  /* Offset from virtual_stack_vars_rtx to the start of the ABI_V4
     varargs save area.  */
  HOST_WIDE_INT varargs_save_offset;
} machine_function;

/* Target cpu type */

enum processor_type rs6000_cpu;
struct rs6000_cpu_select rs6000_select[3] =
{
  /* switch		name,			tune	arch */
  { (const char *)0,	"--with-cpu=",		1,	1 },
  { (const char *)0,	"-mcpu=",		1,	1 },
  { (const char *)0,	"-mtune=",		1,	0 },
};

/* Always emit branch hint bits.  */
static GTY(()) bool rs6000_always_hint;

/* Schedule instructions for group formation.  */
static GTY(()) bool rs6000_sched_groups;

/* Support for -msched-costly-dep option.  */
const char *rs6000_sched_costly_dep_str;
enum rs6000_dependence_cost rs6000_sched_costly_dep;

/* Support for -minsert-sched-nops option.  */
const char *rs6000_sched_insert_nops_str;
enum rs6000_nop_insertion rs6000_sched_insert_nops;

/* Support targetm.vectorize.builtin_mask_for_load.  */
static GTY(()) tree altivec_builtin_mask_for_load;

/* Size of long double.  */
int rs6000_long_double_type_size;

/* IEEE quad extended precision long double. */
int rs6000_ieeequad;

/* Whether -mabi=altivec has appeared.  */
int rs6000_altivec_abi;

/* Nonzero if we want SPE ABI extensions.  */
int rs6000_spe_abi;

/* Nonzero if floating point operations are done in the GPRs.  */
int rs6000_float_gprs = 0;

/* Nonzero if we want Darwin's struct-by-value-in-regs ABI.  */
int rs6000_darwin64_abi;

/* Set to nonzero once AIX common-mode calls have been defined.  */
static GTY(()) int common_mode_defined;

/* Save information from a "cmpxx" operation until the branch or scc is
   emitted.  */
rtx rs6000_compare_op0, rs6000_compare_op1;
int rs6000_compare_fp_p;

/* Label number of label created for -mrelocatable, to call to so we can
   get the address of the GOT section */
int rs6000_pic_labelno;

#ifdef USING_ELFOS_H
/* Which abi to adhere to */
const char *rs6000_abi_name;

/* Semantics of the small data area */
enum rs6000_sdata_type rs6000_sdata = SDATA_DATA;

/* Which small data model to use */
const char *rs6000_sdata_name = (char *)0;

/* Counter for labels which are to be placed in .fixup.  */
int fixuplabelno = 0;
#endif

/* Bit size of immediate TLS offsets and string from which it is decoded.  */
int rs6000_tls_size = 32;
const char *rs6000_tls_size_string;

/* ABI enumeration available for subtarget to use.  */
enum rs6000_abi rs6000_current_abi;

/* Whether to use variant of AIX ABI for PowerPC64 Linux.  */
int dot_symbols;

/* Debug flags */
const char *rs6000_debug_name;
int rs6000_debug_stack;		/* debug stack applications */
int rs6000_debug_arg;		/* debug argument handling */

/* Value is TRUE if register/mode pair is acceptable.  */
bool rs6000_hard_regno_mode_ok_p[NUM_MACHINE_MODES][FIRST_PSEUDO_REGISTER];

/* Built in types.  */

tree rs6000_builtin_types[RS6000_BTI_MAX];
tree rs6000_builtin_decls[RS6000_BUILTIN_COUNT];

const char *rs6000_traceback_name;
static enum {
  traceback_default = 0,
  traceback_none,
  traceback_part,
  traceback_full
} rs6000_traceback;

/* Flag to say the TOC is initialized */
int toc_initialized;
char toc_label_name[10];

/* Alias set for saves and restores from the rs6000 stack.  */
static GTY(()) int rs6000_sr_alias_set;

/* Control alignment for fields within structures.  */
/* String from -malign-XXXXX.  */
int rs6000_alignment_flags;

/* True for any options that were explicitly set.  */
struct {
  bool aix_struct_ret;		/* True if -maix-struct-ret was used.  */
  bool alignment;		/* True if -malign- was used.  */
  bool abi;			/* True if -mabi= was used.  */
  bool spe;			/* True if -mspe= was used.  */
  bool float_gprs;		/* True if -mfloat-gprs= was used.  */
  bool isel;			/* True if -misel was used. */
  bool long_double;	        /* True if -mlong-double- was used.  */
} rs6000_explicit_options;

struct builtin_description
{
  /* mask is not const because we're going to alter it below.  This
     nonsense will go away when we rewrite the -march infrastructure
     to give us more target flag bits.  */
  unsigned int mask;
  const enum insn_code icode;
  const char *const name;
  const enum rs6000_builtins code;
};

/* Target cpu costs.  */

struct processor_costs {
  const int mulsi;	  /* cost of SImode multiplication.  */
  const int mulsi_const;  /* cost of SImode multiplication by constant.  */
  const int mulsi_const9; /* cost of SImode mult by short constant.  */
  const int muldi;	  /* cost of DImode multiplication.  */
  const int divsi;	  /* cost of SImode division.  */
  const int divdi;	  /* cost of DImode division.  */
  const int fp;		  /* cost of simple SFmode and DFmode insns.  */
  const int dmul;	  /* cost of DFmode multiplication (and fmadd).  */
  const int sdiv;	  /* cost of SFmode division (fdivs).  */
  const int ddiv;	  /* cost of DFmode division (fdiv).  */
};

const struct processor_costs *rs6000_cost;

/* Processor costs (relative to an add) */

/* Instruction size costs on 32bit processors.  */
static const
struct processor_costs size32_cost = {
  COSTS_N_INSNS (1),    /* mulsi */
  COSTS_N_INSNS (1),    /* mulsi_const */
  COSTS_N_INSNS (1),    /* mulsi_const9 */
  COSTS_N_INSNS (1),    /* muldi */
  COSTS_N_INSNS (1),    /* divsi */
  COSTS_N_INSNS (1),    /* divdi */
  COSTS_N_INSNS (1),    /* fp */
  COSTS_N_INSNS (1),    /* dmul */
  COSTS_N_INSNS (1),    /* sdiv */
  COSTS_N_INSNS (1),    /* ddiv */
};

/* Instruction size costs on 64bit processors.  */
static const
struct processor_costs size64_cost = {
  COSTS_N_INSNS (1),    /* mulsi */
  COSTS_N_INSNS (1),    /* mulsi_const */
  COSTS_N_INSNS (1),    /* mulsi_const9 */
  COSTS_N_INSNS (1),    /* muldi */
  COSTS_N_INSNS (1),    /* divsi */
  COSTS_N_INSNS (1),    /* divdi */
  COSTS_N_INSNS (1),    /* fp */
  COSTS_N_INSNS (1),    /* dmul */
  COSTS_N_INSNS (1),    /* sdiv */
  COSTS_N_INSNS (1),    /* ddiv */
};

/* Instruction costs on RIOS1 processors.  */
static const
struct processor_costs rios1_cost = {
  COSTS_N_INSNS (5),    /* mulsi */
  COSTS_N_INSNS (4),    /* mulsi_const */
  COSTS_N_INSNS (3),    /* mulsi_const9 */
  COSTS_N_INSNS (5),    /* muldi */
  COSTS_N_INSNS (19),   /* divsi */
  COSTS_N_INSNS (19),   /* divdi */
  COSTS_N_INSNS (2),    /* fp */
  COSTS_N_INSNS (2),    /* dmul */
  COSTS_N_INSNS (19),   /* sdiv */
  COSTS_N_INSNS (19),   /* ddiv */
};

/* Instruction costs on RIOS2 processors.  */
static const
struct processor_costs rios2_cost = {
  COSTS_N_INSNS (2),    /* mulsi */
  COSTS_N_INSNS (2),    /* mulsi_const */
  COSTS_N_INSNS (2),    /* mulsi_const9 */
  COSTS_N_INSNS (2),    /* muldi */
  COSTS_N_INSNS (13),   /* divsi */
  COSTS_N_INSNS (13),   /* divdi */
  COSTS_N_INSNS (2),    /* fp */
  COSTS_N_INSNS (2),    /* dmul */
  COSTS_N_INSNS (17),   /* sdiv */
  COSTS_N_INSNS (17),   /* ddiv */
};

/* Instruction costs on RS64A processors.  */
static const
struct processor_costs rs64a_cost = {
  COSTS_N_INSNS (20),   /* mulsi */
  COSTS_N_INSNS (12),   /* mulsi_const */
  COSTS_N_INSNS (8),    /* mulsi_const9 */
  COSTS_N_INSNS (34),   /* muldi */
  COSTS_N_INSNS (65),   /* divsi */
  COSTS_N_INSNS (67),   /* divdi */
  COSTS_N_INSNS (4),    /* fp */
  COSTS_N_INSNS (4),    /* dmul */
  COSTS_N_INSNS (31),   /* sdiv */
  COSTS_N_INSNS (31),   /* ddiv */
};

/* Instruction costs on MPCCORE processors.  */
static const
struct processor_costs mpccore_cost = {
  COSTS_N_INSNS (2),    /* mulsi */
  COSTS_N_INSNS (2),    /* mulsi_const */
  COSTS_N_INSNS (2),    /* mulsi_const9 */
  COSTS_N_INSNS (2),    /* muldi */
  COSTS_N_INSNS (6),    /* divsi */
  COSTS_N_INSNS (6),    /* divdi */
  COSTS_N_INSNS (4),    /* fp */
  COSTS_N_INSNS (5),    /* dmul */
  COSTS_N_INSNS (10),   /* sdiv */
  COSTS_N_INSNS (17),   /* ddiv */
};

/* Instruction costs on PPC403 processors.  */
static const
struct processor_costs ppc403_cost = {
  COSTS_N_INSNS (4),    /* mulsi */
  COSTS_N_INSNS (4),    /* mulsi_const */
  COSTS_N_INSNS (4),    /* mulsi_const9 */
  COSTS_N_INSNS (4),    /* muldi */
  COSTS_N_INSNS (33),   /* divsi */
  COSTS_N_INSNS (33),   /* divdi */
  COSTS_N_INSNS (11),   /* fp */
  COSTS_N_INSNS (11),   /* dmul */
  COSTS_N_INSNS (11),   /* sdiv */
  COSTS_N_INSNS (11),   /* ddiv */
};

/* Instruction costs on PPC405 processors.  */
static const
struct processor_costs ppc405_cost = {
  COSTS_N_INSNS (5),    /* mulsi */
  COSTS_N_INSNS (4),    /* mulsi_const */
  COSTS_N_INSNS (3),    /* mulsi_const9 */