Temporarily disable -frename-registers on d30v, add help strings

[Michael Meissner <meissner at redhat dot com>]

Right now, -frename-registers doesn't work on the d30v, so the
following patch temporarily disables it until Stan or I have a chance
to debug it.  It also adds --help support.

2000-11-22  Michael Meissner  <meissner@redhat.com>

	* d30v.h (TARGET_SWITCHES): Add documentation strings.
	(TARGET_OPTIONS): Ditto.
	(OPTIMIZATION_OPTIONS): Temporarily turn off -frename-registers if
	-O3.
	
*** gcc/config/d30v/d30v.h.~1~	Tue Nov  7 20:51:00 2000
--- gcc/config/d30v/d30v.h	Wed Nov 22 13:04:16 2000
*************** extern int target_flags;
*** 419,455 ****
     `target_flags'.  Its definition is an initializer with a subgrouping for
     each command option.
  
!    Each subgrouping contains a string constant, that defines the option name,
!    and a number, which contains the bits to set in `target_flags'.  A negative
!    number says to clear bits instead; the negative of the number is which bits
!    to clear.  The actual option name is made by appending `-m' to the specified
!    name.
  
     One of the subgroupings should have a null string.  The number in this
!    grouping is the default value for `target_flags'.  Any target options act
     starting with that value.
  
!    Here is an example which defines `-m68000' and `-m68020' with opposite
!    meanings, and picks the latter as the default:
  
!         #define TARGET_SWITCHES \
!           { { "68020", 1},      \
!             { "68000", -1},     \
!             { "", 1}}  */
  
  #define TARGET_SWITCHES							\
  {									\
!   { "cond-move",	-MASK_NO_COND_MOVE },				\
!   { "no-cond-move",	 MASK_NO_COND_MOVE },				\
!   { "debug-arg",	 MASK_DEBUG_ARG },				\
!   { "debug-stack",	 MASK_DEBUG_STACK }, 				\
!   { "debug-addr",	 MASK_DEBUG_ADDR },				\
!   { "asm-optimize",	 0 },						\
!   { "no-asm-optimize",	 0 },						\
!   { "extmem",		 0 },						\
!   { "extmemory",	 0 },						\
!   { "onchip",		 0 },						\
!   { "",			 TARGET_DEFAULT },				\
  }
  
  /* This macro is similar to `TARGET_SWITCHES' but defines names of command
--- 419,478 ----
     `target_flags'.  Its definition is an initializer with a subgrouping for
     each command option.
  
!    Each subgrouping contains a string constant, that defines the option name, a
!    number, which contains the bits to set in `target_flags', and a second
!    string which is the description displayed by `--help'.  If the number is
!    negative then the bits specified by the number are cleared instead of being
!    set.  If the description string is present but empty, then no help
!    information will be displayed for that option, but it will not count as an
!    undocumented option.  The actual option name is made by appending `-m' to
!    the specified name.
  
     One of the subgroupings should have a null string.  The number in this
!    grouping is the default value for target_flags.  Any target options act
     starting with that value.
  
!    Here is an example which defines -m68000 and -m68020 with opposite meanings,
!    and picks the latter as the default:
  
!   #define TARGET_SWITCHES \
!     { { "68020", TARGET_MASK_68020, "" },      \
!       { "68000", -TARGET_MASK_68020, "Compile for the 68000" }, \
!       { "", TARGET_MASK_68020, "" }}  */
  
  #define TARGET_SWITCHES							\
  {									\
!   { "cond-move",	-MASK_NO_COND_MOVE,				\
!       N_("Enable use of conditional move instructions") },		\
! 									\
!   { "no-cond-move",	MASK_NO_COND_MOVE,				\
!       N_("Disable use of conditional move instructions") },		\
! 									\
!   { "debug-arg",	 MASK_DEBUG_ARG,				\
!       N_("Debug argument support in compiler") },			\
! 									\
!   { "debug-stack",	 MASK_DEBUG_STACK,				\
!       N_("Debug stack support in compiler") },				\
! 									\
!   { "debug-addr",	 MASK_DEBUG_ADDR,				\
!       N_("Debug memory address support in compiler") },			\
! 									\
!   { "asm-optimize",	 0,						\
!       N_("Make adjacent short instructions parallel if possible.") },	\
! 									\
!   { "no-asm-optimize",	 0,						\
!       N_("Do not make adjacent short instructions parallel.") },	\
! 									\
!   { "extmem",		 0,						\
!       N_("Link programs/data to be in external memory by default") },	\
! 									\
!   { "extmemory",	 0,						\
!       N_("Link programs/data to be in external memory by default") },	\
! 									\
!   { "onchip",		 0,						\
!       N_("Link programs/data to be in onchip memory by default") },	\
! 									\
!   { "",			 TARGET_DEFAULT, "" },				\
  }
  
  /* This macro is similar to `TARGET_SWITCHES' but defines names of command
*************** extern int target_flags;
*** 457,479 ****
     subgrouping for each command option.
  
     Each subgrouping contains a string constant, that defines the fixed part of
!    the option name, and the address of a variable.  The variable, type `char
!    *', is set to the variable part of the given option if the fixed part
!    matches.  The actual option name is made by appending `-m' to the specified
!    name.
! 
!    Here is an example which defines `-mshort-data-NUMBER'.  If the given option
!    is `-mshort-data-512', the variable `m88k_short_data' will be set to the
!    string `"512"'.
! 
!         extern char *m88k_short_data;
!         #define TARGET_OPTIONS \
!          { { "short-data-", &m88k_short_data } }  */
  
  #define TARGET_OPTIONS							\
  {									\
!    {"branch-cost=",  &d30v_branch_cost_string},				\
!    {"cond-exec=",    &d30v_cond_exec_string},				\
  }
  
  /* This macro is a C statement to print on `stderr' a string describing the
--- 480,506 ----
     subgrouping for each command option.
  
     Each subgrouping contains a string constant, that defines the fixed part of
!    the option name, the address of a variable, and a description string.  The
!    variable, type `char *', is set to the variable part of the given option if
!    the fixed part matches.  The actual option name is made by appending `-m' to
!    the specified name.
! 
!    Here is an example which defines `-mshort-data-<number>'.  If the given
!    option is `-mshort-data-512', the variable `m88k_short_data' will be set to
!    the string "512".
! 
!    extern char *m88k_short_data;
!    #define TARGET_OPTIONS \
!      { { "short-data-", &m88k_short_data, \
! 	 "Specify the size of the short data section" } } */
  
  #define TARGET_OPTIONS							\
  {									\
!   {"branch-cost=",  &d30v_branch_cost_string,				\
!      N_("Change the branch costs within the compiler") },		\
! 									\
!   {"cond-exec=",    &d30v_cond_exec_string,				\
!      N_("Change the threshold for conversion to conditional execution") }, \
  }
  
  /* This macro is a C statement to print on `stderr' a string describing the
*************** extern int target_flags;
*** 517,523 ****
  
     *Do not examine `write_symbols' in this macro!* The debugging options are
     *not supposed to alter the generated code.  */
! /* #define OPTIMIZATION_OPTIONS(LEVEL,SIZE) */
  
  /* Define this macro if debugging can be performed even without a frame
     pointer.  If this macro is defined, GNU CC will turn on the
--- 544,556 ----
  
     *Do not examine `write_symbols' in this macro!* The debugging options are
     *not supposed to alter the generated code.  */
! 
! /* -frename-registers seems to abort on d30v, turn off until fixed.  */
! #define OPTIMIZATION_OPTIONS(LEVEL,SIZE) 				\
! do {									\
!   if (LEVEL >= 3)							\
!     flag_rename_registers = 0;						\
! } while (0)
  
  /* Define this macro if debugging can be performed even without a frame
     pointer.  If this macro is defined, GNU CC will turn on the