sparc.h

gcc库的原代码,对编程有很大帮助.

/* Definitions of target machine for GNU compiler, for Sun SPARC.
   Copyright (C) 1987, 88, 89, 92, 94, 1995 Free Software Foundation, Inc.
   Contributed by Michael Tiemann ([e-mail]).
   64 bit SPARC V9 support by Michael Tiemann, Jim Wilson, and Doug Evans,
   at Cygnus Support.

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.  */

/* Note that some other tm.h files include this one and then override
   many of the definitions that relate to assembler syntax.  */

/* Sparc64 support has been added by trying to allow for a day when one
   compiler can handle both v8 and v9.  There are a few cases where this
   isn't doable, but keep them to a minimum!  Two macros are used to help out:
   TARGET_V9 is used to select (at runtime) !v9-ness or v9-ness.
   SPARCV9 is defined when compiling for sparc64 only.
   In places where it is possible to choose between the two at runtime, use
   TARGET_V9.  In places where it is currently not possible to select
   between the two at runtime use SPARCV9.  Again, keep uses of SPARCV9 to a
   minimum.  No attempt is made to support both v8 and v9 in the v9 compiler.

   If a combination v8/v9 compiler is too slow, it should always be possible
   to #define TARGET_V9 as 0 (and potentially other v9-only options), and
   #undef SPARCV9.  */

/* What architecture we're compiling for.  This must coincide with the
   `arch_type' attribute in the .md file.  The names were chosen to avoid
   potential misunderstandings with the various 32 bit flavors (v7, v8, etc.):
   if we used ARCH_V9 then we'd want to use something like ARCH_V8 but that
   could be misleading and ARCH_NOTV9 sounds klunky.  */
enum arch_type { ARCH_32BIT, ARCH_64BIT };
extern enum arch_type sparc_arch_type;

/* Names to predefine in the preprocessor for this target machine.  */

/* ??? The GCC_NEW_VARARGS macro is now obsolete, because gcc always uses
   the right varags.h file when bootstrapping.  */

#ifdef SPARCV9
#define CPP_PREDEFINES \
  "-Dsparc -Dsun -Dunix -D__sparc_v9__ \
   -Asystem(unix) -Asystem(bsd) -Acpu(sparc64) -Amachine(sparc64)"
#else
#define CPP_PREDEFINES \
  "-Dsparc -Dsun -Dunix -D__GCC_NEW_VARARGS__ \
   -Asystem(unix) -Asystem(bsd) -Acpu(sparc) -Amachine(sparc)"
#endif

#define LIB_SPEC "%{!shared:%{!p:%{!pg:-lc}}%{p:-lc_p}%{pg:-lc_p} %{g:-lg}}"

/* Provide required defaults for linker -e and -d switches.  */

#define LINK_SPEC \
 "%{!shared:%{!nostdlib:%{!r*:%{!e*:-e start}}} -dc -dp} %{static:-Bstatic} \
  %{assert*} %{shared:-assert pure-text}"

/* Special flags to the Sun-4 assembler when using pipe for input.  */

#define ASM_SPEC \
  " %| %{R} %{!pg:%{!p:%{fpic:-k} %{fPIC:-k}}} %{keep-local-as-symbols:-L}"

/* Define macros to distinguish architectures.  */

#ifdef SPARCV9
#define CPP_SPEC "\
%{mint64:-D__INT_MAX__=9223372036854775807LL -D__LONG_MAX__=9223372036854775807LL} \
%{mlong64:-D__LONG_MAX__=9223372036854775807LL} \
"
#else
#define CPP_SPEC "\
%{msparclite:-D__sparclite__} \
%{mf930:-D__sparclite__} %{mf934:-D__sparclite__} \
%{mv8:-D__sparc_v8__} \
%{msupersparc:-D__supersparc__ -D__sparc_v8__}	\
"
#endif

/* Prevent error on `-sun4' and `-target sun4' options.  */
/* This used to translate -dalign to -malign, but that is no good
   because it can't turn off the usual meaning of making debugging dumps.  */

#define CC1_SPEC "%{sun4:} %{target:}"

#ifdef SPARCV9
#define PTRDIFF_TYPE "long long int"
#define SIZE_TYPE "long long unsigned int"
#else
#define PTRDIFF_TYPE "int"
/* In 2.4 it should work to delete this.
   #define SIZE_TYPE "int"  */
#endif

/* ??? This should be 32 bits for v9 but what can we do?  */
#define WCHAR_TYPE "short unsigned int"
#define WCHAR_TYPE_SIZE 16
#define MAX_WCHAR_TYPE_SIZE 16

/* Show we can debug even without a frame pointer.  */
#define CAN_DEBUG_WITHOUT_FP

/* To make profiling work with -f{pic,PIC}, we need to emit the profiling
   code into the rtl.  Also, if we are profiling, we cannot eliminate
   the frame pointer (because the return address will get smashed).  */

void sparc_override_options ();

#define OVERRIDE_OPTIONS \
  do {									\
    if (profile_flag || profile_block_flag)				\
      {									\
	if (flag_pic)							\
	  {								\
	    char *pic_string = (flag_pic == 1) ? "-fpic" : "-fPIC";	\
	    warning ("%s and profiling conflict: disabling %s",		\
		     pic_string, pic_string);				\
	    flag_pic = 0;						\
	  }								\
	flag_omit_frame_pointer = 0;					\
      }									\
    SUBTARGET_OVERRIDE_OPTIONS;						\
    sparc_override_options ();						\
  } while (0)

/* This is meant to be redefined in the host dependent files.  */
#define SUBTARGET_OVERRIDE_OPTIONS

/* These compiler options take an argument.  We ignore -target for now.  */

#define WORD_SWITCH_TAKES_ARG(STR)				\
 (DEFAULT_WORD_SWITCH_TAKES_ARG (STR)				\
  || !strcmp (STR, "target") || !strcmp (STR, "assert"))

/* Print subsidiary information on the compiler version in use.  */

#define TARGET_VERSION fprintf (stderr, " (sparc)");

/* Generate DBX debugging information.  */

#define DBX_DEBUGGING_INFO

/* Run-time compilation parameters selecting different hardware subsets.  */

extern int target_flags;

/* Nonzero if we should generate code to use the fpu.  */
#define MASK_FPU 1
#define TARGET_FPU (target_flags & MASK_FPU)

/* Nonzero if we should use FUNCTION_EPILOGUE.  Otherwise, we
   use fast return insns, but lose some generality.  */
#define MASK_EPILOGUE 2
#define TARGET_EPILOGUE (target_flags & MASK_EPILOGUE)

/* Nonzero if we should assume that double pointers might be unaligned.
   This can happen when linking gcc compiled code with other compilers,
   because the ABI only guarantees 4 byte alignment.  */
#define MASK_UNALIGNED_DOUBLES 4
#define TARGET_UNALIGNED_DOUBLES (target_flags & MASK_UNALIGNED_DOUBLES)

/* ??? Bits 0x18 are currently unused.  */

/* Nonzero means we should schedule code for the TMS390Z55 SuperSparc chip.  */
#define MASK_SUPERSPARC 0x20
#define TARGET_SUPERSPARC (target_flags & MASK_SUPERSPARC)

/* Nonzero means that we should generate code for a v8 sparc.  */
#define MASK_V8 0x40
#define TARGET_V8 (target_flags & MASK_V8)

/* Nonzero means that we should generate code for a sparclite.
   This enables the sparclite specific instructions, but does not affect
   whether FPU instructions are emitted.  */
#define MASK_SPARCLITE 0x80
#define TARGET_SPARCLITE (target_flags & MASK_SPARCLITE)

/* Nonzero means that we should generate code using a flat register window
   model, i.e. no save/restore instructions are generated, in the most
   efficient manner.  This code is not compatible with normal sparc code.  */
/* This is not a user selectable option yet, because it requires changes
   that are not yet switchable via command line arguments.  */
/* ??? This flag is deprecated and may disappear at some point.  */
#define MASK_FRW 0x100
#define TARGET_FRW (target_flags & MASK_FRW)

/* Nonzero means that we should generate code using a flat register window
   model, i.e. no save/restore instructions are generated, but which is
   compatible with normal sparc code.   This is the same as above, except
   that the frame pointer is %i7 instead of %fp.  */
/* ??? This use to be named TARGET_FRW_COMPAT.  At some point TARGET_FRW will
   go away, but until that time only use this one when necessary.
   -mflat sets both.  */
#define MASK_FLAT 0x200
#define TARGET_FLAT (target_flags & MASK_FLAT)

/* Nonzero means use the registers that the Sparc ABI reserves for
   application software.  This is the default for v8, but not v9.  */
#define MASK_APP_REGS 0x400
#define TARGET_APP_REGS (target_flags & MASK_APP_REGS)

/*  Option to select how quad word floating point is implemented.
    When TARGET_HARD_QUAD is true, we use the hardware quad instructions.
    Otherwise, we use the SPARC ABI quad library functions.  */
#define MASK_HARD_QUAD 0x800
#define TARGET_HARD_QUAD (target_flags & MASK_HARD_QUAD)

/* Nonzero if we're compiling for 64 bit sparc.  */
#define MASK_V9 0x1000
#define TARGET_V9 (target_flags & MASK_V9)

/* Nonzero if ints are 64 bits.
   This automatically implies longs are 64 bits too.
   This option is for v9 only.  */
#define MASK_INT64 0x2000
#define TARGET_INT64 (target_flags & MASK_INT64)

/* Nonzero if longs are 64 bits.
   This option is for v9 only.  */
#define MASK_LONG64 0x4000
#define TARGET_LONG64 (target_flags & MASK_LONG64)

/* Nonzero if pointers are 64 bits.
   This is not a user selectable option, though it may be one day -
   so it is used to determine pointer size instead of an architecture flag.  */
#define MASK_PTR64 0x8000
#define TARGET_PTR64 (target_flags & MASK_PTR64)

/* Nonzero if we are generating code to be tested in a 32 bit environment.
   Hence, we assume the upper 32 bits of symbolic addresses are zero, and
   avoid generating %uhi and %ulo terms.
   Pointers are still 64 bits though!  This option is for v9 only.  */
/* ??? This option is deprecated.  Try to use -mmedlow.  */
#define MASK_ENV32 0x10000
#define TARGET_ENV32 (target_flags & MASK_ENV32)

/* Memory models.
   Two memory models are supported:
   TARGET_MEDLOW: 32 bit address space, top 32 bits = 0
                  (pointers still 64 bits)
   TARGET_MEDANY: 32 bit address space, data segment loaded anywhere
                  (use %g4 as offset).
   TARGET_FULLANY: not supported yet.
   These options are for v9 only.  All mask values are nonzero so the v8
   compiler can assume this stuff won't interfere.  */
#define MASK_MEDLOW 0x20000
#define MASK_MEDANY 0x40000
#define MASK_FULLANY 0x60000
#define MASK_CODE_MODEL (MASK_MEDLOW + MASK_MEDANY)
#define TARGET_MEDLOW ((target_flags & MASK_CODE_MODEL) == MASK_MEDLOW)
#define TARGET_MEDANY ((target_flags & MASK_CODE_MODEL) == MASK_MEDANY)
#define TARGET_FULLANY ((target_flags & MASK_CODE_MODEL) == MASK_FULLANY)

/* ??? There are hardcoded references to this reg in the .md file.  */
#define MEDANY_BASE_REG "%g4"

/* Non-zero means use a stack bias of 2047.  Stack offsets are obtained by
   adding 2047 to %sp.  This option is for v9 only and is the default.  */
#define MASK_STACK_BIAS 0x80000
#define TARGET_STACK_BIAS (target_flags & MASK_STACK_BIAS)

/* Macro to define tables used to set the flags.
   This is a list in braces of pairs in braces,
   each pair being { "NAME", VALUE }
   where VALUE is the bits to set or minus the bits to clear.
   An empty string NAME is used to identify the default VALUE.  */

/* The Fujitsu MB86930 is the original sparclite chip, with no fpu.
   The Fujitsu MB86934 is the recent sparclite chip, with an fpu.
   We use -mf930 and -mf934 options to choose which.
   ??? These should perhaps be -mcpu= options.  */

#define TARGET_SWITCHES  \
  { {"fpu", MASK_FPU},			\
    {"no-fpu", -MASK_FPU},		\
    {"hard-float", MASK_FPU},		\
    {"soft-float", -MASK_FPU},		\
    {"epilogue", MASK_EPILOGUE},	\
    {"no-epilogue", -MASK_EPILOGUE},	\
    {"unaligned-doubles", MASK_UNALIGNED_DOUBLES}, \
    {"no-unaligned-doubles", -MASK_UNALIGNED_DOUBLES}, \
    {"supersparc", MASK_SUPERSPARC+MASK_V8},	\
    {"cypress", -MASK_SUPERSPARC-MASK_V8},	\
    {"v8", MASK_V8},			\
    {"no-v8", -MASK_V8},		\
    {"sparclite", MASK_SPARCLITE},	\
    {"no-sparclite", -MASK_SPARCLITE},	\
    {"f930", MASK_SPARCLITE},		\
    {"f930", -MASK_FPU},		\
    {"f934", MASK_SPARCLITE},		\
    {"flat", MASK_FRW+MASK_FLAT},	\
    {"no-flat", -(MASK_FRW+MASK_FLAT)},	\
    {"app-regs", MASK_APP_REGS},	\
    {"no-app-regs", -MASK_APP_REGS},	\
    {"hard-quad-float", MASK_HARD_QUAD}, \
    {"soft-quad-float", -MASK_HARD_QUAD}, \
    SUBTARGET_SWITCHES			\
    V9_SWITCHES				\
    { "", TARGET_DEFAULT}}

#define TARGET_DEFAULT (MASK_APP_REGS + MASK_EPILOGUE + MASK_FPU)

/* This is meant to be redefined in the host dependent files */
#define SUBTARGET_SWITCHES

/* ??? Until we support a combination v8/v9 compiler, the v9 specific options
   are only defined for the v9 compiler.  */
#ifdef SPARCV9
#define V9_SWITCHES \
/*  {"v9", MASK_V9}, */			\
    {"int64", MASK_INT64+MASK_LONG64},	\
    {"int32", -MASK_INT64},		\
    {"int32", MASK_LONG64},		\
    {"long64", -MASK_INT64},		\
    {"long64", MASK_LONG64},		\
    {"long32", -(MASK_INT64+MASK_LONG64)}, \
/*  {"ptr64", MASK_PTR64}, */		\
/*  {"ptr32", -MASK_PTR64}, */		\
    {"stack-bias", MASK_STACK_BIAS},	\
    {"no-stack-bias", -MASK_STACK_BIAS}, \
    {"medlow", -MASK_CODE_MODEL},	\
    {"medlow", MASK_MEDLOW},		\
    {"medany", -MASK_CODE_MODEL},	\
    {"medany", MASK_MEDANY},
#else
#define V9_SWITCHES
#endif