rs6000.c

linux下的gcc编译器

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

This file is part of GNU CC.

GNU CC 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.

GNU CC 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "config.h"
#include "system.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"

#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))

/* 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 },
};

/* Size of long double */
const char *rs6000_long_double_size_string;
int rs6000_long_double_type_size;

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

/* Whether VRSAVE instructions should be generated.  */
int rs6000_altivec_vrsave;

/* String from -mvrsave= option.  */
const char *rs6000_altivec_vrsave_string;

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

/* Whether isel instructions should be generated.  */
int rs6000_isel;

/* Nonzero if we have FPRs.  */
int rs6000_fprs = 1;

/* String from -misel=.  */
const char *rs6000_isel_string;

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

/* Private copy of original value of flag_pic for ABI_AIX.  */
static int rs6000_flag_pic;

/* 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 = 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

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

/* ABI string from -mabi= option.  */
const char *rs6000_abi_string;

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

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 int rs6000_sr_alias_set;

/* Call distance, overridden by -mlongcall and #pragma longcall(1).
   The only place that looks at this is rs6000_set_default_type_attributes;
   everywhere else should rely on the presence or absence of a longcall
   attribute on the function declaration.  Exception: init_cumulative_args
   looks at it too, for libcalls.  */
int rs6000_default_long_calls;
const char *rs6000_longcall_switch;

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;
};

static void rs6000_add_gc_roots PARAMS ((void));
static int num_insns_constant_wide PARAMS ((HOST_WIDE_INT));
static void validate_condition_mode 
  PARAMS ((enum rtx_code, enum machine_mode));
static rtx rs6000_generate_compare PARAMS ((enum rtx_code));
static void rs6000_maybe_dead PARAMS ((rtx));
static void rs6000_emit_stack_tie PARAMS ((void));
static void rs6000_frame_related PARAMS ((rtx, rtx, HOST_WIDE_INT, rtx, rtx));
static void emit_frame_save PARAMS ((rtx, rtx, enum machine_mode,
				     unsigned int, int, int));
static rtx gen_frame_mem_offset PARAMS ((enum machine_mode, rtx, int));
static void rs6000_emit_allocate_stack PARAMS ((HOST_WIDE_INT, int));
static unsigned rs6000_hash_constant PARAMS ((rtx));
static unsigned toc_hash_function PARAMS ((const void *));
static int toc_hash_eq PARAMS ((const void *, const void *));
static int toc_hash_mark_entry PARAMS ((void **, void *));
static void toc_hash_mark_table PARAMS ((void *));
static int constant_pool_expr_1 PARAMS ((rtx, int *, int *));
static struct machine_function * rs6000_init_machine_status PARAMS ((void));
static bool rs6000_assemble_integer PARAMS ((rtx, unsigned int, int));
#ifdef HAVE_GAS_HIDDEN
static void rs6000_assemble_visibility PARAMS ((tree, int));
#endif
static int rs6000_ra_ever_killed PARAMS ((void));
static tree rs6000_handle_longcall_attribute PARAMS ((tree *, tree, tree, int, bool *));
const struct attribute_spec rs6000_attribute_table[];
static void rs6000_set_default_type_attributes PARAMS ((tree));
static void rs6000_output_function_prologue PARAMS ((FILE *, HOST_WIDE_INT));
static void rs6000_output_function_epilogue PARAMS ((FILE *, HOST_WIDE_INT));
static void rs6000_output_mi_thunk PARAMS ((FILE *, tree, HOST_WIDE_INT,
					    HOST_WIDE_INT, tree));
static rtx rs6000_emit_set_long_const PARAMS ((rtx,
  HOST_WIDE_INT, HOST_WIDE_INT));
#if TARGET_ELF
static unsigned int rs6000_elf_section_type_flags PARAMS ((tree, const char *,
							   int));
static void rs6000_elf_asm_out_constructor PARAMS ((rtx, int));
static void rs6000_elf_asm_out_destructor PARAMS ((rtx, int));
static void rs6000_elf_select_section PARAMS ((tree, int,
						 unsigned HOST_WIDE_INT));
static void rs6000_elf_unique_section PARAMS ((tree, int));
static void rs6000_elf_select_rtx_section PARAMS ((enum machine_mode, rtx,
						   unsigned HOST_WIDE_INT));
static void rs6000_elf_encode_section_info PARAMS ((tree, int))
     ATTRIBUTE_UNUSED;
static const char *rs6000_elf_strip_name_encoding PARAMS ((const char *));
static bool rs6000_elf_in_small_data_p PARAMS ((tree));
#endif
#if TARGET_XCOFF
static void rs6000_xcoff_asm_globalize_label PARAMS ((FILE *, const char *));
static void rs6000_xcoff_asm_named_section PARAMS ((const char *, unsigned int));
static void rs6000_xcoff_select_section PARAMS ((tree, int,
						 unsigned HOST_WIDE_INT));
static void rs6000_xcoff_unique_section PARAMS ((tree, int));
static void rs6000_xcoff_select_rtx_section PARAMS ((enum machine_mode, rtx,
						     unsigned HOST_WIDE_INT));
static const char * rs6000_xcoff_strip_name_encoding PARAMS ((const char *));
static unsigned int rs6000_xcoff_section_type_flags PARAMS ((tree, const char *, int));
#endif
static void rs6000_xcoff_encode_section_info PARAMS ((tree, int))
     ATTRIBUTE_UNUSED;
static bool rs6000_binds_local_p PARAMS ((tree));
static int rs6000_adjust_cost PARAMS ((rtx, rtx, rtx, int));
static int rs6000_adjust_priority PARAMS ((rtx, int));
static int rs6000_issue_rate PARAMS ((void));

static void rs6000_init_builtins PARAMS ((void));
static rtx rs6000_expand_unop_builtin PARAMS ((enum insn_code, tree, rtx));
static rtx rs6000_expand_binop_builtin PARAMS ((enum insn_code, tree, rtx));
static rtx rs6000_expand_ternop_builtin PARAMS ((enum insn_code, tree, rtx));
static rtx rs6000_expand_builtin PARAMS ((tree, rtx, rtx, enum machine_mode, int));
static void altivec_init_builtins PARAMS ((void));
static void rs6000_common_init_builtins PARAMS ((void));

static void enable_mask_for_builtins PARAMS ((struct builtin_description *,
					      int, enum rs6000_builtins,
					      enum rs6000_builtins));
static void spe_init_builtins PARAMS ((void));
static rtx spe_expand_builtin PARAMS ((tree, rtx, bool *));
static rtx spe_expand_predicate_builtin PARAMS ((enum insn_code, tree, rtx));
static rtx spe_expand_evsel_builtin PARAMS ((enum insn_code, tree, rtx));
static int rs6000_emit_int_cmove PARAMS ((rtx, rtx, rtx, rtx));

static rtx altivec_expand_builtin PARAMS ((tree, rtx, bool *));
static rtx altivec_expand_ld_builtin PARAMS ((tree, rtx, bool *));
static rtx altivec_expand_st_builtin PARAMS ((tree, rtx, bool *));
static rtx altivec_expand_dst_builtin PARAMS ((tree, rtx, bool *));
static rtx altivec_expand_abs_builtin PARAMS ((enum insn_code, tree, rtx));
static rtx altivec_expand_predicate_builtin PARAMS ((enum insn_code, const char *, tree, rtx));
static rtx altivec_expand_stv_builtin PARAMS ((enum insn_code, tree));
static void rs6000_parse_abi_options PARAMS ((void));
static void rs6000_parse_vrsave_option PARAMS ((void));
static void rs6000_parse_isel_option PARAMS ((void));
static int first_altivec_reg_to_save PARAMS ((void));
static unsigned int compute_vrsave_mask PARAMS ((void));
static void is_altivec_return_reg PARAMS ((rtx, void *));
static rtx generate_set_vrsave PARAMS ((rtx, rs6000_stack_t *, int));
static void altivec_frame_fixup PARAMS ((rtx, rtx, HOST_WIDE_INT));
static int easy_vector_constant PARAMS ((rtx));

/* Default register names.  */
char rs6000_reg_names[][8] =
{
      "0",  "1",  "2",  "3",  "4",  "5",  "6",  "7",
      "8",  "9", "10", "11", "12", "13", "14", "15",
     "16", "17", "18", "19", "20", "21", "22", "23",
     "24", "25", "26", "27", "28", "29", "30", "31",
      "0",  "1",  "2",  "3",  "4",  "5",  "6",  "7",
      "8",  "9", "10", "11", "12", "13", "14", "15",
     "16", "17", "18", "19", "20", "21", "22", "23",
     "24", "25", "26", "27", "28", "29", "30", "31",
     "mq", "lr", "ctr","ap",
      "0",  "1",  "2",  "3",  "4",  "5",  "6",  "7",
      "xer",
      /* AltiVec registers.  */
      "0",  "1",  "2",  "3",  "4",  "5",  "6", "7",
      "8",  "9",  "10", "11", "12", "13", "14", "15",
      "16", "17", "18", "19", "20", "21", "22", "23",
      "24", "25", "26", "27", "28", "29", "30", "31",
      "vrsave", "vscr",
      /* SPE registers.  */
      "spe_acc", "spefscr"
};

#ifdef TARGET_REGNAMES
static const char alt_reg_names[][8] =
{
   "%r0",   "%r1",  "%r2",  "%r3",  "%r4",  "%r5",  "%r6",  "%r7",
   "%r8",   "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15",
  "%r16",  "%r17", "%r18", "%r19", "%r20", "%r21", "%r22", "%r23",
  "%r24",  "%r25", "%r26", "%r27", "%r28", "%r29", "%r30", "%r31",
   "%f0",   "%f1",  "%f2",  "%f3",  "%f4",  "%f5",  "%f6",  "%f7",
   "%f8",   "%f9", "%f10", "%f11", "%f12", "%f13", "%f14", "%f15",
  "%f16",  "%f17", "%f18", "%f19", "%f20", "%f21", "%f22", "%f23",
  "%f24",  "%f25", "%f26", "%f27", "%f28", "%f29", "%f30", "%f31",
    "mq",    "lr",  "ctr",   "ap",
  "%cr0",  "%cr1", "%cr2", "%cr3", "%cr4", "%cr5", "%cr6", "%cr7",
   "xer",
  /* AltiVec registers.  */
   "%v0",  "%v1",  "%v2",  "%v3",  "%v4",  "%v5",  "%v6", "%v7",
   "%v8",  "%v9", "%v10", "%v11", "%v12", "%v13", "%v14", "%v15",
  "%v16", "%v17", "%v18", "%v19", "%v20", "%v21", "%v22", "%v23",
  "%v24", "%v25", "%v26", "%v27", "%v28", "%v29", "%v30", "%v31",
  "vrsave", "vscr",
  /* SPE registers.  */
  "spe_acc", "spefscr"
};
#endif

#ifndef MASK_STRICT_ALIGN
#define MASK_STRICT_ALIGN 0
#endif

/* The VRSAVE bitmask puts bit %v0 as the most significant bit.  */
#define ALTIVEC_REG_BIT(REGNO) (0x80000000 >> ((REGNO) - FIRST_ALTIVEC_REGNO))

/* Initialize the GCC target structure.  */
#undef TARGET_ATTRIBUTE_TABLE
#define TARGET_ATTRIBUTE_TABLE rs6000_attribute_table
#undef TARGET_SET_DEFAULT_TYPE_ATTRIBUTES
#define TARGET_SET_DEFAULT_TYPE_ATTRIBUTES rs6000_set_default_type_attributes

#undef TARGET_ASM_ALIGNED_DI_OP
#define TARGET_ASM_ALIGNED_DI_OP DOUBLE_INT_ASM_OP

/* Default unaligned ops are only provided for ELF.  Find the ops needed
   for non-ELF systems.  */
#ifndef OBJECT_FORMAT_ELF
#if TARGET_XCOFF
/* For XCOFF.  rs6000_assemble_integer will handle unaligned DIs on
   64-bit targets.  */
#undef TARGET_ASM_UNALIGNED_HI_OP
#define TARGET_ASM_UNALIGNED_HI_OP "\t.vbyte\t2,"
#undef TARGET_ASM_UNALIGNED_SI_OP
#define TARGET_ASM_UNALIGNED_SI_OP "\t.vbyte\t4,"
#undef TARGET_ASM_UNALIGNED_DI_OP
#define TARGET_ASM_UNALIGNED_DI_OP "\t.vbyte\t8,"
#else
/* For Darwin.  */
#undef TARGET_ASM_UNALIGNED_HI_OP
#define TARGET_ASM_UNALIGNED_HI_OP "\t.short\t"
#undef TARGET_ASM_UNALIGNED_SI_OP
#define TARGET_ASM_UNALIGNED_SI_OP "\t.long\t"
#endif
#endif

/* This hook deals with fixups for relocatable code and DI-mode objects
   in 64-bit code.  */
#undef TARGET_ASM_INTEGER
#define TARGET_ASM_INTEGER rs6000_assemble_integer

#ifdef HAVE_GAS_HIDDEN
#undef TARGET_ASM_ASSEMBLE_VISIBILITY
#define TARGET_ASM_ASSEMBLE_VISIBILITY rs6000_assemble_visibility
#endif

#undef TARGET_ASM_FUNCTION_PROLOGUE
#define TARGET_ASM_FUNCTION_PROLOGUE rs6000_output_function_prologue
#undef TARGET_ASM_FUNCTION_EPILOGUE
#define TARGET_ASM_FUNCTION_EPILOGUE rs6000_output_function_epilogue

#undef TARGET_SCHED_ISSUE_RATE
#define TARGET_SCHED_ISSUE_RATE rs6000_issue_rate
#undef TARGET_SCHED_ADJUST_COST
#define TARGET_SCHED_ADJUST_COST rs6000_adjust_cost
#undef TARGET_SCHED_ADJUST_PRIORITY
#define TARGET_SCHED_ADJUST_PRIORITY rs6000_adjust_priority

#undef TARGET_INIT_BUILTINS
#define TARGET_INIT_BUILTINS rs6000_init_builtins

#undef TARGET_EXPAND_BUILTIN
#define TARGET_EXPAND_BUILTIN rs6000_expand_builtin

#undef TARGET_BINDS_LOCAL_P
#define TARGET_BINDS_LOCAL_P rs6000_binds_local_p

#undef TARGET_ASM_OUTPUT_MI_THUNK
#define TARGET_ASM_OUTPUT_MI_THUNK rs6000_output_mi_thunk

/* ??? Should work everywhere, but ask [e-mail] before
   enabling for AIX.  */
#if TARGET_OBJECT_FORMAT != OBJECT_XCOFF
#undef TARGET_ASM_CAN_OUTPUT_MI_THUNK
#define TARGET_ASM_CAN_OUTPUT_MI_THUNK default_can_output_mi_thunk_no_vcall
#endif

struct gcc_target targetm = TARGET_INITIALIZER;

/* Override command line options.  Mostly we process the processor
   type and sometimes adjust other TARGET_ options.  */

void
rs6000_override_options (default_cpu)
     const char *default_cpu;
{
  size_t i, j;
  struct rs6000_cpu_select *ptr;

  /* Simplify the entries below by making a mask for any POWER
     variant and any PowerPC variant.  */

#define POWER_MASKS (MASK_POWER | MASK_POWER2 | MASK_MULTIPLE | MASK_STRING)
#define POWERPC_MASKS (MASK_POWERPC | MASK_PPC_GPOPT \
		       | MASK_PPC_GFXOPT | MASK_POWERPC64)
#define POWERPC_OPT_MASKS (MASK_PPC_GPOPT | MASK_PPC_GFXOPT)

  static struct ptt
    {
      const char *const name;		/* Canonical processor name.  */
      const enum processor_type processor; /* Processor type enum value.  */
      const int target_enable;	/* Target flags to enable.  */
      const int target_disable;	/* Target flags to disable.  */
    } const processor_target_table[]
      = {{"common", PROCESSOR_COMMON, MASK_NEW_MNEMONICS,
	    POWER_MASKS | POWERPC_MASKS},
	 {"power", PROCESSOR_POWER,
	    MASK_POWER | MASK_MULTIPLE | MASK_STRING,
	    MASK_POWER2 | POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"power2", PROCESSOR_POWER,
	    MASK_POWER | MASK_POWER2 | MASK_MULTIPLE | MASK_STRING,
	    POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"power3", PROCESSOR_PPC630,
	    MASK_POWERPC | MASK_PPC_GFXOPT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | MASK_PPC_GPOPT},
	 {"power4", PROCESSOR_POWER4,
	    MASK_POWERPC | MASK_PPC_GFXOPT | MASK_NEW_MNEMONICS,
	    POWER_MASKS | MASK_PPC_GPOPT},
	 {"powerpc", PROCESSOR_POWERPC,
	    MASK_POWERPC | MASK_NEW_MNEMONICS,
	    POWER_MASKS | POWERPC_OPT_MASKS | MASK_POWERPC64},
	 {"powerpc64", PROCESSOR_POWERPC64,
	    MASK_POWERPC | MASK_POWERPC64 | MASK_NEW_MNEMONICS,
	    POWER_MASKS | POWERPC_OPT_MASKS},
	 {"rios", PROCESSOR_RIOS1,
	    MASK_POWER | MASK_MULTIPLE | MASK_STRING,
	    MASK_POWER2 | POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"rios1", PROCESSOR_RIOS1,
	    MASK_POWER | MASK_MULTIPLE | MASK_STRING,
	    MASK_POWER2 | POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"rsc", PROCESSOR_PPC601,
	    MASK_POWER | MASK_MULTIPLE | MASK_STRING,
	    MASK_POWER2 | POWERPC_MASKS | MASK_NEW_MNEMONICS},
	 {"rsc1", PROCESSOR_PPC601,