--- gcc/gcc.info-18 2018/04/24 17:56:54 1.1 +++ gcc/gcc.info-18 2018/04/24 18:18:54 1.1.1.5 @@ -1,9 +1,13 @@ -This is Info file gcc.info, produced by Makeinfo-1.47 from the input +This is Info file gcc.info, produced by Makeinfo-1.55 from the input file gcc.texi. This file documents the use and the internals of the GNU compiler. - Copyright (C) 1988, 1989, 1992 Free Software Foundation, Inc. + Published by the Free Software Foundation 675 Massachusetts Avenue +Cambridge, MA 02139 USA + + Copyright (C) 1988, 1989, 1992, 1993, 1994 Free Software Foundation, +Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are @@ -11,1648 +15,1223 @@ preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also -that the sections entitled "GNU General Public License" and "Boycott" -are included exactly as in the original, and provided that the entire +that the sections entitled "GNU General Public License," "Funding for +Free Software," and "Protect Your Freedom--Fight `Look And Feel'" are +included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that the sections entitled "GNU General Public -License" and "Boycott", and this permission notice, may be included in +License," "Funding for Free Software," and "Protect Your Freedom--Fight +`Look And Feel'", and this permission notice, may be included in translations approved by the Free Software Foundation instead of in the original English.  -File: gcc.info, Node: Index, Prev: Config, Up: Top +File: gcc.info, Node: Driver, Next: Run-time Target, Up: Target Macros + +Controlling the Compilation Driver, `gcc' +========================================= + + You can control the compilation driver. + +`SWITCH_TAKES_ARG (CHAR)' + A C expression which determines whether the option `-CHAR' takes + arguments. The value should be the number of arguments that + option takes-zero, for many options. + + By default, this macro is defined to handle the standard options + properly. You need not define it unless you wish to add additional + options which take arguments. + +`WORD_SWITCH_TAKES_ARG (NAME)' + A C expression which determines whether the option `-NAME' takes + arguments. The value should be the number of arguments that + option takes-zero, for many options. This macro rather than + `SWITCH_TAKES_ARG' is used for multi-character option names. + + By default, this macro is defined as + `DEFAULT_WORD_SWITCH_TAKES_ARG', which handles the standard options + properly. You need not define `WORD_SWITCH_TAKES_ARG' unless you + wish to add additional options which take arguments. Any + redefinition should call `DEFAULT_WORD_SWITCH_TAKES_ARG' and then + check for additional options. + +`SWITCHES_NEED_SPACES' + A string-valued C expression which is nonempty if the linker needs + a space between the `-L' or `-o' option and its argument. + + If this macro is not defined, the default value is 0. + +`CPP_SPEC' + A C string constant that tells the GNU CC driver program options to + pass to CPP. It can also specify how to translate options you + give to GNU CC into options for GNU CC to pass to the CPP. + + Do not define this macro if it does not need to do anything. + +`NO_BUILTIN_SIZE_TYPE' + If this macro is defined, the preprocessor will not define the + builtin macro `__SIZE_TYPE__'. The macro `__SIZE_TYPE__' must + then be defined by `CPP_SPEC' instead. + + This should be defined if `SIZE_TYPE' depends on target dependent + flags which are not accessible to the preprocessor. Otherwise, it + should not be defined. + +`NO_BUILTIN_PTRDIFF_TYPE' + If this macro is defined, the preprocessor will not define the + builtin macro `__PTRDIFF_TYPE__'. The macro `__PTRDIFF_TYPE__' + must then be defined by `CPP_SPEC' instead. + + This should be defined if `PTRDIFF_TYPE' depends on target + dependent flags which are not accessible to the preprocessor. + Otherwise, it should not be defined. + +`SIGNED_CHAR_SPEC' + A C string constant that tells the GNU CC driver program options to + pass to CPP. By default, this macro is defined to pass the option + `-D__CHAR_UNSIGNED__' to CPP if `char' will be treated as + `unsigned char' by `cc1'. + + Do not define this macro unless you need to override the default + definition. + +`CC1_SPEC' + A C string constant that tells the GNU CC driver program options to + pass to `cc1'. It can also specify how to translate options you + give to GNU CC into options for GNU CC to pass to the `cc1'. + + Do not define this macro if it does not need to do anything. + +`CC1PLUS_SPEC' + A C string constant that tells the GNU CC driver program options to + pass to `cc1plus'. It can also specify how to translate options + you give to GNU CC into options for GNU CC to pass to the + `cc1plus'. + + Do not define this macro if it does not need to do anything. + +`ASM_SPEC' + A C string constant that tells the GNU CC driver program options to + pass to the assembler. It can also specify how to translate + options you give to GNU CC into options for GNU CC to pass to the + assembler. See the file `sun3.h' for an example of this. + + Do not define this macro if it does not need to do anything. + +`ASM_FINAL_SPEC' + A C string constant that tells the GNU CC driver program how to + run any programs which cleanup after the normal assembler. + Normally, this is not needed. See the file `mips.h' for an + example of this. + + Do not define this macro if it does not need to do anything. + +`LINK_SPEC' + A C string constant that tells the GNU CC driver program options to + pass to the linker. It can also specify how to translate options + you give to GNU CC into options for GNU CC to pass to the linker. + + Do not define this macro if it does not need to do anything. + +`LIB_SPEC' + Another C string constant used much like `LINK_SPEC'. The + difference between the two is that `LIB_SPEC' is used at the end + of the command given to the linker. + + If this macro is not defined, a default is provided that loads the + standard C library from the usual place. See `gcc.c'. + +`STARTFILE_SPEC' + Another C string constant used much like `LINK_SPEC'. The + difference between the two is that `STARTFILE_SPEC' is used at the + very beginning of the command given to the linker. + + If this macro is not defined, a default is provided that loads the + standard C startup file from the usual place. See `gcc.c'. + +`ENDFILE_SPEC' + Another C string constant used much like `LINK_SPEC'. The + difference between the two is that `ENDFILE_SPEC' is used at the + very end of the command given to the linker. + + Do not define this macro if it does not need to do anything. + +`LINK_LIBGCC_SPECIAL' + Define this macro meaning that `gcc' should find the library + `libgcc.a' by hand, rather than passing the argument `-lgcc' to + tell the linker to do the search; also, `gcc' should not generate + `-L' options to pass to the linker (as it normally does). + +`LINK_LIBGCC_SPECIAL_1' + Define this macro meaning that `gcc' should find the library + `libgcc.a' by hand, rather than passing the argument `-lgcc' to + tell the linker to do the search. + +`RELATIVE_PREFIX_NOT_LINKDIR' + Define this macro to tell `gcc' that it should only translate a + `-B' prefix into a `-L' linker option if the prefix indicates an + absolute file name. + +`STANDARD_EXEC_PREFIX' + Define this macro as a C string constant if you wish to override + the standard choice of `/usr/local/lib/gcc-lib/' as the default + prefix to try when searching for the executable files of the + compiler. + +`MD_EXEC_PREFIX' + If defined, this macro is an additional prefix to try after + `STANDARD_EXEC_PREFIX'. `MD_EXEC_PREFIX' is not searched when the + `-b' option is used, or the compiler is built as a cross compiler. + +`STANDARD_STARTFILE_PREFIX' + Define this macro as a C string constant if you wish to override + the standard choice of `/usr/local/lib/' as the default prefix to + try when searching for startup files such as `crt0.o'. + +`MD_STARTFILE_PREFIX' + If defined, this macro supplies an additional prefix to try after + the standard prefixes. `MD_EXEC_PREFIX' is not searched when the + `-b' option is used, or when the compiler is built as a cross + compiler. + +`MD_STARTFILE_PREFIX_1' + If defined, this macro supplies yet another prefix to try after the + standard prefixes. It is not searched when the `-b' option is + used, or when the compiler is built as a cross compiler. + +`LOCAL_INCLUDE_DIR' + Define this macro as a C string constant if you wish to override + the standard choice of `/usr/local/include' as the default prefix + to try when searching for local header files. `LOCAL_INCLUDE_DIR' + comes before `SYSTEM_INCLUDE_DIR' in the search order. + + Cross compilers do not use this macro and do not search either + `/usr/local/include' or its replacement. + +`SYSTEM_INCLUDE_DIR' + Define this macro as a C string constant if you wish to specify a + system-specific directory to search for header files before the + standard directory. `SYSTEM_INCLUDE_DIR' comes before + `STANDARD_INCLUDE_DIR' in the search order. + + Cross compilers do not use this macro and do not search the + directory specified. + +`STANDARD_INCLUDE_DIR' + Define this macro as a C string constant if you wish to override + the standard choice of `/usr/include' as the default prefix to try + when searching for header files. + + Cross compilers do not use this macro and do not search either + `/usr/include' or its replacement. + +`INCLUDE_DEFAULTS' + Define this macro if you wish to override the entire default + search path for include files. The default search path includes + `GCC_INCLUDE_DIR', `LOCAL_INCLUDE_DIR', `SYSTEM_INCLUDE_DIR', + `GPLUSPLUS_INCLUDE_DIR', and `STANDARD_INCLUDE_DIR'. In addition, + `GPLUSPLUS_INCLUDE_DIR' and `GCC_INCLUDE_DIR' are defined + automatically by `Makefile', and specify private search areas for + GCC. The directory `GPLUSPLUS_INCLUDE_DIR' is used only for C++ + programs. + + The definition should be an initializer for an array of structures. + Each array element should have two elements: the directory name (a + string constant) and a flag for C++-only directories. Mark the + end of the array with a null element. For example, here is the + definition used for VMS: + + #define INCLUDE_DEFAULTS \ + { \ + { "GNU_GXX_INCLUDE:", 1}, \ + { "GNU_CC_INCLUDE:", 0}, \ + { "SYS$SYSROOT:[SYSLIB.]", 0}, \ + { ".", 0}, \ + { 0, 0} \ + } + + Here is the order of prefixes tried for exec files: + + 1. Any prefixes specified by the user with `-B'. + + 2. The environment variable `GCC_EXEC_PREFIX', if any. + + 3. The directories specified by the environment variable + `COMPILER_PATH'. + + 4. The macro `STANDARD_EXEC_PREFIX'. + + 5. `/usr/lib/gcc/'. + + 6. The macro `MD_EXEC_PREFIX', if any. + + Here is the order of prefixes tried for startfiles: + + 1. Any prefixes specified by the user with `-B'. + + 2. The environment variable `GCC_EXEC_PREFIX', if any. + + 3. The directories specified by the environment variable + `LIBRARY_PATH'. + + 4. The macro `STANDARD_EXEC_PREFIX'. + + 5. `/usr/lib/gcc/'. + + 6. The macro `MD_EXEC_PREFIX', if any. + + 7. The macro `MD_STARTFILE_PREFIX', if any. + + 8. The macro `STANDARD_STARTFILE_PREFIX'. + + 9. `/lib/'. + + 10. `/usr/lib/'. + + +File: gcc.info, Node: Run-time Target, Next: Storage Layout, Prev: Driver, Up: Target Macros + +Run-time Target Specification +============================= + + Here are run-time target specifications. + +`CPP_PREDEFINES' + Define this to be a string constant containing `-D' options to + define the predefined macros that identify this machine and system. + These macros will be predefined unless the `-ansi' option is + specified. + + In addition, a parallel set of macros are predefined, whose names + are made by appending `__' at the beginning and at the end. These + `__' macros are permitted by the ANSI standard, so they are + predefined regardless of whether `-ansi' is specified. + + For example, on the Sun, one can use the following value: + + "-Dmc68000 -Dsun -Dunix" + + The result is to define the macros `__mc68000__', `__sun__' and + `__unix__' unconditionally, and the macros `mc68000', `sun' and + `unix' provided `-ansi' is not specified. + +`STDC_VALUE' + Define the value to be assigned to the built-in macro `__STDC__'. + The default is the value `1'. + +`extern int target_flags;' + This declaration should be present. + +`TARGET_...' + This series of macros is to allow compiler command arguments to + enable or disable the use of optional features of the target + machine. For example, one machine description serves both the + 68000 and the 68020; a command argument tells the compiler whether + it should use 68020-only instructions or not. This command + argument works by means of a macro `TARGET_68020' that tests a bit + in `target_flags'. + + Define a macro `TARGET_FEATURENAME' for each such option. Its + definition should test a bit in `target_flags'; for example: + + #define TARGET_68020 (target_flags & 1) + + One place where these macros are used is in the + condition-expressions of instruction patterns. Note how + `TARGET_68020' appears frequently in the 68000 machine description + file, `m68k.md'. Another place they are used is in the + definitions of the other macros in the `MACHINE.h' file. + +`TARGET_SWITCHES' + This macro defines names of command options to set and clear bits + in `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}} + +`TARGET_OPTIONS' + This macro is similar to `TARGET_SWITCHES' but defines names of + command options that have values. Its definition is an + initializer with a 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 } } + +`TARGET_VERSION' + This macro is a C statement to print on `stderr' a string + describing the particular machine description choice. Every + machine description should define `TARGET_VERSION'. For example: + + #ifdef MOTOROLA + #define TARGET_VERSION \ + fprintf (stderr, " (68k, Motorola syntax)"); + #else + #define TARGET_VERSION \ + fprintf (stderr, " (68k, MIT syntax)"); + #endif + +`OVERRIDE_OPTIONS' + Sometimes certain combinations of command options do not make + sense on a particular target machine. You can define a macro + `OVERRIDE_OPTIONS' to take account of this. This macro, if + defined, is executed once just after all the command options have + been parsed. + + Don't use this macro to turn on various extra optimizations for + `-O'. That is what `OPTIMIZATION_OPTIONS' is for. + +`OPTIMIZATION_OPTIONS (LEVEL)' + Some machines may desire to change what optimizations are + performed for various optimization levels. This macro, if + defined, is executed once just after the optimization level is + determined and before the remainder of the command options have + been parsed. Values set in this macro are used as the default + values for the other command line options. + + LEVEL is the optimization level specified; 2 if `-O2' is + specified, 1 if `-O' is specified, and 0 if neither is specified. + + You should not use this macro to change options that are not + machine-specific. These should uniformly selected by the same + optimization level on all supported machines. Use this macro to + enable machbine-specific optimizations. + + *Do not examine `write_symbols' in this macro!* The debugging + options are not supposed to alter the generated code. + +`CAN_DEBUG_WITHOUT_FP' + Define this macro if debugging can be performed even without a + frame pointer. If this macro is defined, GNU CC will turn on the + `-fomit-frame-pointer' option whenever `-O' is specified. + + +File: gcc.info, Node: Storage Layout, Next: Type Layout, Prev: Run-time Target, Up: Target Macros + +Storage Layout +============== + + Note that the definitions of the macros in this table which are +sizes or alignments measured in bits do not need to be constant. They +can be C expressions that refer to static variables, such as the +`target_flags'. *Note Run-time Target::. + +`BITS_BIG_ENDIAN' + Define this macro to be the value 1 if the most significant bit in + a byte has the lowest number; otherwise define it to be the value + zero. This means that bit-field instructions count from the most + significant bit. If the machine has no bit-field instructions, + then this must still be defined, but it doesn't matter which value + it is defined to. + + This macro does not affect the way structure fields are packed into + bytes or words; that is controlled by `BYTES_BIG_ENDIAN'. + +`BYTES_BIG_ENDIAN' + Define this macro to be 1 if the most significant byte in a word + has the lowest number. + +`WORDS_BIG_ENDIAN' + Define this macro to be 1 if, in a multiword object, the most + significant word has the lowest number. This applies to both + memory locations and registers; GNU CC fundamentally assumes that + the order of words in memory is the same as the order in registers. + +`FLOAT_WORDS_BIG_ENDIAN' + Define this macro to be 1 if `DFmode', `XFmode' or `TFmode' + floating point numbers are stored in memory with the word + containing the sign bit at the lowest address; otherwise define it + to be 0. + + You need not define this macro if the ordering is the same as for + multi-word integers. + +`BITS_PER_UNIT' + Define this macro to be the number of bits in an addressable + storage unit (byte); normally 8. + +`BITS_PER_WORD' + Number of bits in a word; normally 32. + +`MAX_BITS_PER_WORD' + Maximum number of bits in a word. If this is undefined, the + default is `BITS_PER_WORD'. Otherwise, it is the constant value + that is the largest value that `BITS_PER_WORD' can have at + run-time. + +`UNITS_PER_WORD' + Number of storage units in a word; normally 4. + +`MAX_UNITS_PER_WORD' + Maximum number of units in a word. If this is undefined, the + default is `UNITS_PER_WORD'. Otherwise, it is the constant value + that is the largest value that `UNITS_PER_WORD' can have at + run-time. + +`POINTER_SIZE' + Width of a pointer, in bits. + +`PROMOTE_MODE (M, UNSIGNEDP, TYPE)' + A macro to update M and UNSIGNEDP when an object whose type is + TYPE and which has the specified mode and signedness is to be + stored in a register. This macro is only called when TYPE is a + scalar type. + + On most RISC machines, which only have operations that operate on + a full register, define this macro to set M to `word_mode' if M is + an integer mode narrower than `BITS_PER_WORD'. In most cases, + only integer modes should be widened because wider-precision + floating-point operations are usually more expensive than their + narrower counterparts. + + For most machines, the macro definition does not change UNSIGNEDP. + However, some machines, have instructions that preferentially + handle either signed or unsigned quantities of certain modes. For + example, on the DEC Alpha, 32-bit loads from memory and 32-bit add + instructions sign-extend the result to 64 bits. On such machines, + set UNSIGNEDP according to which kind of extension is more + efficient. + + Do not define this macro if it would never modify M. + +`PROMOTE_FUNCTION_ARGS' + Define this macro if the promotion described by `PROMOTE_MODE' + should also be done for outgoing function arguments. + +`PROMOTE_FUNCTION_RETURN' + Define this macro if the promotion described by `PROMOTE_MODE' + should also be done for the return value of functions. + + If this macro is defined, `FUNCTION_VALUE' must perform the same + promotions done by `PROMOTE_MODE'. + +`PROMOTE_FOR_CALL_ONLY' + Define this macro if the promotion described by `PROMOTE_MODE' + should *only* be performed for outgoing function arguments or + function return values, as specified by `PROMOTE_FUNCTION_ARGS' + and `PROMOTE_FUNCTION_RETURN', respectively. + +`PARM_BOUNDARY' + Normal alignment required for function parameters on the stack, in + bits. All stack parameters receive at least this much alignment + regardless of data type. On most machines, this is the same as the + size of an integer. + +`STACK_BOUNDARY' + Define this macro if you wish to preserve a certain alignment for + the stack pointer. The definition is a C expression for the + desired alignment (measured in bits). + + If `PUSH_ROUNDING' is not defined, the stack will always be aligned + to the specified boundary. If `PUSH_ROUNDING' is defined and + specifies a less strict alignment than `STACK_BOUNDARY', the stack + may be momentarily unaligned while pushing arguments. + +`FUNCTION_BOUNDARY' + Alignment required for a function entry point, in bits. + +`BIGGEST_ALIGNMENT' + Biggest alignment that any data type can require on this machine, + in bits. + +`BIGGEST_FIELD_ALIGNMENT' + Biggest alignment that any structure field can require on this + machine, in bits. If defined, this overrides `BIGGEST_ALIGNMENT' + for structure fields only. + +`MAX_OFILE_ALIGNMENT' + Biggest alignment supported by the object file format of this + machine. Use this macro to limit the alignment which can be + specified using the `__attribute__ ((aligned (N)))' construct. If + not defined, the default value is `BIGGEST_ALIGNMENT'. + +`DATA_ALIGNMENT (TYPE, BASIC-ALIGN)' + If defined, a C expression to compute the alignment for a static + variable. TYPE is the data type, and BASIC-ALIGN is the alignment + that the object would ordinarily have. The value of this macro is + used instead of that alignment to align the object. + + If this macro is not defined, then BASIC-ALIGN is used. + + One use of this macro is to increase alignment of medium-size data + to make it all fit in fewer cache lines. Another is to cause + character arrays to be word-aligned so that `strcpy' calls that + copy constants to character arrays can be done inline. + +`CONSTANT_ALIGNMENT (CONSTANT, BASIC-ALIGN)' + If defined, a C expression to compute the alignment given to a + constant that is being placed in memory. CONSTANT is the constant + and BASIC-ALIGN is the alignment that the object would ordinarily + have. The value of this macro is used instead of that alignment to + align the object. + + If this macro is not defined, then BASIC-ALIGN is used. + + The typical use of this macro is to increase alignment for string + constants to be word aligned so that `strcpy' calls that copy + constants can be done inline. + +`EMPTY_FIELD_BOUNDARY' + Alignment in bits to be given to a structure bit field that + follows an empty field such as `int : 0;'. + + Note that `PCC_BITFIELD_TYPE_MATTERS' also affects the alignment + that results from an empty field. + +`STRUCTURE_SIZE_BOUNDARY' + Number of bits which any structure or union's size must be a + multiple of. Each structure or union's size is rounded up to a + multiple of this. + + If you do not define this macro, the default is the same as + `BITS_PER_UNIT'. + +`STRICT_ALIGNMENT' + Define this macro to be the value 1 if instructions will fail to + work if given data not on the nominal alignment. If instructions + will merely go slower in that case, define this macro as 0. + +`PCC_BITFIELD_TYPE_MATTERS' + Define this if you wish to imitate the way many other C compilers + handle alignment of bitfields and the structures that contain them. + + The behavior is that the type written for a bitfield (`int', + `short', or other integer type) imposes an alignment for the + entire structure, as if the structure really did contain an + ordinary field of that type. In addition, the bitfield is placed + within the structure so that it would fit within such a field, not + crossing a boundary for it. + + Thus, on most machines, a bitfield whose type is written as `int' + would not cross a four-byte boundary, and would force four-byte + alignment for the whole structure. (The alignment used may not be + four bytes; it is controlled by the other alignment parameters.) + + If the macro is defined, its definition should be a C expression; + a nonzero value for the expression enables this behavior. + + Note that if this macro is not defined, or its value is zero, some + bitfields may cross more than one alignment boundary. The + compiler can support such references if there are `insv', `extv', + and `extzv' insns that can directly reference memory. + + The other known way of making bitfields work is to define + `STRUCTURE_SIZE_BOUNDARY' as large as `BIGGEST_ALIGNMENT'. Then + every structure can be accessed with fullwords. + + Unless the machine has bitfield instructions or you define + `STRUCTURE_SIZE_BOUNDARY' that way, you must define + `PCC_BITFIELD_TYPE_MATTERS' to have a nonzero value. + + If your aim is to make GNU CC use the same conventions for laying + out bitfields as are used by another compiler, here is how to + investigate what the other compiler does. Compile and run this + program: + + struct foo1 + { + char x; + char :0; + char y; + }; + + struct foo2 + { + char x; + int :0; + char y; + }; + + main () + { + printf ("Size of foo1 is %d\n", + sizeof (struct foo1)); + printf ("Size of foo2 is %d\n", + sizeof (struct foo2)); + exit (0); + } + + If this prints 2 and 5, then the compiler's behavior is what you + would get from `PCC_BITFIELD_TYPE_MATTERS'. + +`BITFIELD_NBYTES_LIMITED' + Like PCC_BITFIELD_TYPE_MATTERS except that its effect is limited to + aligning a bitfield within the structure. + +`ROUND_TYPE_SIZE (STRUCT, SIZE, ALIGN)' + Define this macro as an expression for the overall size of a + structure (given by STRUCT as a tree node) when the size computed + from the fields is SIZE and the alignment is ALIGN. + + The default is to round SIZE up to a multiple of ALIGN. + +`ROUND_TYPE_ALIGN (STRUCT, COMPUTED, SPECIFIED)' + Define this macro as an expression for the alignment of a structure + (given by STRUCT as a tree node) if the alignment computed in the + usual way is COMPUTED and the alignment explicitly specified was + SPECIFIED. + + The default is to use SPECIFIED if it is larger; otherwise, use + the smaller of COMPUTED and `BIGGEST_ALIGNMENT' + +`MAX_FIXED_MODE_SIZE' + An integer expression for the size in bits of the largest integer + machine mode that should actually be used. All integer machine + modes of this size or smaller can be used for structures and + unions with the appropriate sizes. If this macro is undefined, + `GET_MODE_BITSIZE (DImode)' is assumed. + +`CHECK_FLOAT_VALUE (MODE, VALUE, OVERFLOW)' + A C statement to validate the value VALUE (of type `double') for + mode MODE. This means that you check whether VALUE fits within + the possible range of values for mode MODE on this target machine. + The mode MODE is always a mode of class `MODE_FLOAT'. OVERFLOW + is nonzero if the value is already known to be out of range. + + If VALUE is not valid or if OVERFLOW is nonzero, you should set + OVERFLOW to 1 and then assign some valid value to VALUE. Allowing + an invalid value to go through the compiler can produce incorrect + assembler code which may even cause Unix assemblers to crash. + + This macro need not be defined if there is no work for it to do. + +`TARGET_FLOAT_FORMAT' + A code distinguishing the floating point format of the target + machine. There are three defined values: + + `IEEE_FLOAT_FORMAT' + This code indicates IEEE floating point. It is the default; + there is no need to define this macro when the format is IEEE. + + `VAX_FLOAT_FORMAT' + This code indicates the peculiar format used on the Vax. + + `UNKNOWN_FLOAT_FORMAT' + This code indicates any other format. + + The value of this macro is compared with `HOST_FLOAT_FORMAT' + (*note Config::.) to determine whether the target machine has the + same format as the host machine. If any other formats are + actually in use on supported machines, new codes should be defined + for them. + + The ordering of the component words of floating point values + stored in memory is controlled by `FLOAT_WORDS_BIG_ENDIAN' for the + target machine and `HOST_FLOAT_WORDS_BIG_ENDIAN' for the host. + + +File: gcc.info, Node: Type Layout, Next: Registers, Prev: Storage Layout, Up: Target Macros + +Layout of Source Language Data Types +==================================== + + These macros define the sizes and other characteristics of the +standard basic data types used in programs being compiled. Unlike the +macros in the previous section, these apply to specific features of C +and related languages, rather than to fundamental aspects of storage +layout. + +`INT_TYPE_SIZE' + A C expression for the size in bits of the type `int' on the + target machine. If you don't define this, the default is one word. + +`MAX_INT_TYPE_SIZE' + Maximum number for the size in bits of the type `int' on the target + machine. If this is undefined, the default is `INT_TYPE_SIZE'. + Otherwise, it is the constant value that is the largest value that + `INT_TYPE_SIZE' can have at run-time. This is used in `cpp'. + +`SHORT_TYPE_SIZE' + A C expression for the size in bits of the type `short' on the + target machine. If you don't define this, the default is half a + word. (If this would be less than one storage unit, it is rounded + up to one unit.) + +`LONG_TYPE_SIZE' + A C expression for the size in bits of the type `long' on the + target machine. If you don't define this, the default is one word. + +`MAX_LONG_TYPE_SIZE' + Maximum number for the size in bits of the type `long' on the + target machine. If this is undefined, the default is + `LONG_TYPE_SIZE'. Otherwise, it is the constant value that is the + largest value that `LONG_TYPE_SIZE' can have at run-time. This is + used in `cpp'. + +`LONG_LONG_TYPE_SIZE' + A C expression for the size in bits of the type `long long' on the + target machine. If you don't define this, the default is two + words. + +`CHAR_TYPE_SIZE' + A C expression for the size in bits of the type `char' on the + target machine. If you don't define this, the default is one + quarter of a word. (If this would be less than one storage unit, + it is rounded up to one unit.) + +`MAX_CHAR_TYPE_SIZE' + Maximum number for the size in bits of the type `char' on the + target machine. If this is undefined, the default is + `CHAR_TYPE_SIZE'. Otherwise, it is the constant value that is the + largest value that `CHAR_TYPE_SIZE' can have at run-time. This is + used in `cpp'. + +`FLOAT_TYPE_SIZE' + A C expression for the size in bits of the type `float' on the + target machine. If you don't define this, the default is one word. + +`DOUBLE_TYPE_SIZE' + A C expression for the size in bits of the type `double' on the + target machine. If you don't define this, the default is two + words. + +`LONG_DOUBLE_TYPE_SIZE' + A C expression for the size in bits of the type `long double' on + the target machine. If you don't define this, the default is two + words. + +`DEFAULT_SIGNED_CHAR' + An expression whose value is 1 or 0, according to whether the type + `char' should be signed or unsigned by default. The user can + always override this default with the options `-fsigned-char' and + `-funsigned-char'. + +`DEFAULT_SHORT_ENUMS' + A C expression to determine whether to give an `enum' type only as + many bytes as it takes to represent the range of possible values + of that type. A nonzero value means to do that; a zero value + means all `enum' types should be allocated like `int'. + + If you don't define the macro, the default is 0. + +`SIZE_TYPE' + A C expression for a string describing the name of the data type + to use for size values. The typedef name `size_t' is defined + using the contents of the string. + + The string can contain more than one keyword. If so, separate + them with spaces, and write first any length keyword, then + `unsigned' if appropriate, and finally `int'. The string must + exactly match one of the data type names defined in the function + `init_decl_processing' in the file `c-decl.c'. You may not omit + `int' or change the order--that would cause the compiler to crash + on startup. + + If you don't define this macro, the default is `"long unsigned + int"'. + +`PTRDIFF_TYPE' + A C expression for a string describing the name of the data type + to use for the result of subtracting two pointers. The typedef + name `ptrdiff_t' is defined using the contents of the string. See + `SIZE_TYPE' above for more information. + + If you don't define this macro, the default is `"long int"'. + +`WCHAR_TYPE' + A C expression for a string describing the name of the data type + to use for wide characters. The typedef name `wchar_t' is defined + using the contents of the string. See `SIZE_TYPE' above for more + information. + + If you don't define this macro, the default is `"int"'. + +`WCHAR_TYPE_SIZE' + A C expression for the size in bits of the data type for wide + characters. This is used in `cpp', which cannot make use of + `WCHAR_TYPE'. + +`MAX_WCHAR_TYPE_SIZE' + Maximum number for the size in bits of the data type for wide + characters. If this is undefined, the default is + `WCHAR_TYPE_SIZE'. Otherwise, it is the constant value that is the + largest value that `WCHAR_TYPE_SIZE' can have at run-time. This is + used in `cpp'. + +`OBJC_INT_SELECTORS' + Define this macro if the type of Objective C selectors should be + `int'. + + If this macro is not defined, then selectors should have the type + `struct objc_selector *'. + +`OBJC_SELECTORS_WITHOUT_LABELS' + Define this macro if the compiler can group all the selectors + together into a vector and use just one label at the beginning of + the vector. Otherwise, the compiler must give each selector its + own assembler label. + + On certain machines, it is important to have a separate label for + each selector because this enables the linker to eliminate + duplicate selectors. + +`TARGET_BELL' + A C constant expression for the integer value for escape sequence + `\a'. + +`TARGET_BS' +`TARGET_TAB' +`TARGET_NEWLINE' + C constant expressions for the integer values for escape sequences + `\b', `\t' and `\n'. + +`TARGET_VT' +`TARGET_FF' +`TARGET_CR' + C constant expressions for the integer values for escape sequences + `\v', `\f' and `\r'. + + +File: gcc.info, Node: Registers, Next: Register Classes, Prev: Type Layout, Up: Target Macros + +Register Usage +============== + + This section explains how to describe what registers the target +machine has, and how (in general) they can be used. -Index -***** + The description of which registers a specific instruction can use is +done with register classes; see *Note Register Classes::. For +information on using registers to access a stack frame, see *Note Frame +Registers::. For passing values in registers, see *Note Register +Arguments::. For returning values in registers, see *Note Scalar +Return::. * Menu: -* #pragma: Misc. -* $: Dollar Signs. -* ': Incompatibilities. -* (nil): RTL Objects. -* 3b1 installation: 3b1 Install. -* ?: side effect: Conditionals. -* #pragma, reason for not using: Function Attributes. -* * in template: Output Statement. -* ?: extensions: Conditionals. -* ?: extensions: Lvalues. -* ACCUMULATE_OUTGOING_ARGS and stack frames: Function Entry. -* ARG_POINTER_REGNUM and virtual registers: Regs and Memory. -* BITS_BIG_ENDIAN, effect on sign_extract: Bit Fields. -* BLKmode, and function return values: Calls. -* ENCODE_SECTION_INFO and address validation: Addressing Modes. -* ENCODE_SECTION_INFO usage: Instruction Output. -* FIRST_PARM_OFFSET and virtual registers: Regs and Memory. -* FRAME_GROWS_DOWNWARD and virtual registers: Regs and Memory. -* FRAME_POINTER_REGNUM and virtual registers: Regs and Memory. -* FUNCTION_EPILOGUE and trampolines: Trampolines. -* FUNCTION_PROLOGUE and trampolines: Trampolines. -* HImode, in insn: Insns. -* MUST_PASS_IN_STACK, and FUNCTION_ARG: Register Arguments. -* PUSH_ROUNDING, interaction with STACK_BOUNDARY: Storage Layout. -* QImode, in insn: Insns. -* REG_PARM_STACK_SPACE, and FUNCTION_ARG: Register Arguments. -* STACK_DYNAMIC_OFFSET and virtual registers: Regs and Memory. -* STACK_POINTER_OFFSET and virtual registers: Regs and Memory. -* STACK_POINTER_REGNUM and virtual registers: Regs and Memory. -* STARTING_FRAME_OFFSET and virtual registers: Regs and Memory. -* SYMBOL_REF_FLAG, in ENCODE_SECTION_INFO: Sections. -* WORDS_BIG_ENDIAN, effect on subreg: Regs and Memory. -* absM2 instruction pattern: Standard Names. -* abs and attributes: Expressions. -* addM3 instruction pattern: Standard Names. -* addr_diff_vec, length of: Insn Lengths. -* addr_vec, length of: Insn Lengths. -* allocate_stack instruction pattern: Standard Names. -* alloca and SunOs: Installation. -* alloca vs variable-length arrays: Variable Length. -* alloca, for SunOs: Sun Install. -* alloca, for Unos: Unos Install. -* andM3 instruction pattern: Standard Names. -* and and attributes: Expressions. -* and, canonicalization of: Insn Canonicalizations. -* ashiftrt and attributes: Expressions. -* ashift and attributes: Expressions. -* ashlM3 instruction pattern: Standard Names. -* ashrM3 instruction pattern: Standard Names. -* asm_operands, RTL sharing: Sharing. -* asm_operands, usage: Assembler. -* asm expressions: Extended Asm. -* bCOND instruction pattern: Standard Names. -* bcopy, implicit usage: Library Calls. -* bzero, implicit usage: Library Calls. -* call_insn and /u: Flags. -* call_pop instruction pattern: Standard Names. -* call_value_pop instruction pattern: Standard Names. -* call_value instruction pattern: Standard Names. -* call instruction pattern: Standard Names. -* call usage: Calls. -* casesi instruction pattern: Standard Names. -* cc0, RTL sharing: Sharing. -* cmpM instruction pattern: Standard Names. -* cmpstrM instruction pattern: Standard Names. -* code_label and /i: Flags. -* compare, canonicalization of: Insn Canonicalizations. -* cond and attributes: Expressions. -* const_double, RTL sharing: Sharing. -* const_int and attribute tests: Expressions. -* const_int and attributes: Expressions. -* const_int, RTL sharing: Sharing. -* const_string and attributes: Expressions. -* const applied to function: Function Attributes. -* define_insn example: Example. -* divM3 instruction pattern: Standard Names. -* divmodM4 instruction pattern: Standard Names. -* div and attributes: Expressions. -* eq and attributes: Expressions. -* extendMN instruction pattern: Standard Names. -* extv instruction pattern: Standard Names. -* extzv instruction pattern: Standard Names. -* ffsM2 instruction pattern: Standard Names. -* fixMN2 instruction pattern: Standard Names. -* fix_truncMN2 instruction pattern: Standard Names. -* fixunsMN2 instruction pattern: Standard Names. -* fixuns_truncMN2 instruction pattern: Standard Names. -* floatMN2 instruction pattern: Standard Names. -* floatunsMN2 instruction pattern: Standard Names. -* float as function value type: Incompatibilities. -* fscanf, and constant strings: Incompatibilities. -* ftruncM2 instruction pattern: Standard Names. -* genflags, crash on Sun 4: Installation Problems. -* geu and attributes: Expressions. -* ge and attributes: Expressions. -* gprof: Debugging Options. -* gtu and attributes: Expressions. -* gt and attributes: Expressions. -* if_then_else and attributes: Expressions. -* if_then_else usage: Side Effects. -* in_struct, in code_label: Flags. -* in_struct, in insn: Flags. -* in_struct, in insn: Flags. -* in_struct, in label_ref: Flags. -* in_struct, in mem: Flags. -* in_struct, in reg: Flags. -* indirect_jump instruction pattern: Standard Names. -* insn and /i: Flags. -* insn and /s: Flags. -* insn and /u: Flags. -* insv instruction pattern: Standard Names. -* integrated, in insn: Flags. -* integrated, in reg: Flags. -* iorM3 instruction pattern: Standard Names. -* ior and attributes: Expressions. -* ior, canonicalization of: Insn Canonicalizations. -* label_ref and /s: Flags. -* label_ref, RTL sharing: Sharing. -* leu and attributes: Expressions. -* le and attributes: Expressions. -* load_multiple instruction pattern: Standard Names. -* long long data types: Long Long. -* longjmp and automatic variables: Interface. -* longjmp and automatic variables: Dialect Options. -* longjmp incompatibilities: Incompatibilities. -* longjmp warnings: Warning Options. -* lshiftrt and attributes: Expressions. -* lshift and attributes: Expressions. -* lshlM3 instruction pattern: Standard Names. -* lshrM3 instruction pattern: Standard Names. -* lt and attributes: Expressions. -* main and the exit status: VMS Misc. -* match_dup and attributes: Insn Lengths. -* match_operand and attributes: Expressions. -* maxM3 instruction pattern: Standard Names. -* memcpy, implicit usage: Library Calls. -* memset, implicit usage: Library Calls. -* mem and /s: Flags. -* mem and /u: Flags. -* mem and /v: Flags. -* mem, RTL sharing: Sharing. -* minM3 instruction pattern: Standard Names. -* minus and attributes: Expressions. -* minus, canonicalization of: Insn Canonicalizations. -* mktemp, and constant strings: Incompatibilities. -* modM3 instruction pattern: Standard Names. -* mod and attributes: Expressions. -* movM instruction pattern: Standard Names. -* movstrM instruction pattern: Standard Names. -* movstrictM instruction pattern: Standard Names. -* mulM3 instruction pattern: Standard Names. -* mulhisi3 instruction pattern: Standard Names. -* mulqihi3 instruction pattern: Standard Names. -* mulsidi3 instruction pattern: Standard Names. -* mult and attributes: Expressions. -* mult, canonicalization of: Insn Canonicalizations. -* negM2 instruction pattern: Standard Names. -* neg and attributes: Expressions. -* neg, canonicalization of: Insn Canonicalizations. -* ne and attributes: Expressions. -* nop instruction pattern: Standard Names. -* not and attributes: Expressions. -* not, canonicalization of: Insn Canonicalizations. -* one_cmplM2 instruction pattern: Standard Names. -* pc and attributes: Insn Lengths. -* pc, RTL sharing: Sharing. -* plus and attributes: Expressions. -* plus, canonicalization of: Insn Canonicalizations. -* prof: Debugging Options. -* qsort, and global register variables: Global Reg Vars. -* reg and /i: Flags. -* reg and /s: Flags. -* reg and /u: Flags. -* reg and /v: Flags. -* reg, RTL sharing: Sharing. -* reload_in instruction pattern: Standard Names. -* reload_out instruction pattern: Standard Names. -* restore_stack_block instruction pattern: Standard Names. -* restore_stack_function instruction pattern: Standard Names. -* restore_stack_nonlocal instruction pattern: Standard Names. -* return instruction pattern: Standard Names. -* rotlM3 instruction pattern: Standard Names. -* rotrM3 instruction pattern: Standard Names. -* sCOND instruction pattern: Standard Names. -* save_stack_block instruction pattern: Standard Names. -* save_stack_function instruction pattern: Standard Names. -* save_stack_nonlocal instruction pattern: Standard Names. -* scanf, and constant strings: Incompatibilities. -* scratch, RTL sharing: Sharing. -* setjmp incompatibilities: Incompatibilities. -* sign_extract, canonicalization of: Insn Canonicalizations. -* sqrtM2 instruction pattern: Standard Names. -* sscanf, and constant strings: Incompatibilities. -* subM3 instruction pattern: Standard Names. -* subreg, in strict_low_part: RTL Declarations. -* subreg, special reload handling: Regs and Memory. -* symbol_ref and /u: Flags. -* symbol_ref and /v: Flags. -* symbol_ref, RTL sharing: Sharing. -* tablejump instruction pattern: Standard Names. -* tcov: Debugging Options. -* truncMN instruction pattern: Standard Names. -* tstM instruction pattern: Standard Names. -* udivM3 instruction pattern: Standard Names. -* udivmodM4 instruction pattern: Standard Names. -* umaxM3 instruction pattern: Standard Names. -* uminM3 instruction pattern: Standard Names. -* umodM3 instruction pattern: Standard Names. -* umulhisi3 instruction pattern: Standard Names. -* umulqihi3 instruction pattern: Standard Names. -* umulsidi3 instruction pattern: Standard Names. -* unchanging, in call_insn: Flags. -* unchanging, in insn: Flags. -* unchanging, in reg and mem: Flags. -* unchanging, in symbol_ref: Flags. -* used, in symbol_ref: Flags. -* volatile applied to function: Function Attributes. -* volatil, in insn: Flags. -* volatil, in mem: Flags. -* volatil, in reg: Flags. -* volatil, in symbol_ref: Flags. -* xorM3 instruction pattern: Standard Names. -* xor, canonicalization of: Insn Canonicalizations. -* zero_extendMN instruction pattern: Standard Names. -* zero_extract, canonicalization of: Insn Canonicalizations. -* VAXCRTL: VMS Misc. -* libgcc.a: Library Calls. -* stdarg.h and RT PC: RT Options. -* stdarg.h and register arguments: Register Arguments. -* tm.h macros: Target Macros. -* varargs.h and RT PC: RT Options. -* xm-MACHINE.h: Config. -* ! in constraint: Multi-Alternative. -* # in constraint: Modifiers. -* % in constraint: Modifiers. -* % in template: Output Template. -* & in constraint: Modifiers. -* * in constraint: Modifiers. -* + in constraint: Modifiers. -* /i in RTL dump: Flags. -* /s in RTL dump: Flags. -* /s in RTL dump: Flags. -* /u in RTL dump: Flags. -* /v in RTL dump: Flags. -* 0 in constraint: Simple Constraints. -* < in constraint: Simple Constraints. -* = in constraint: Modifiers. -* > in constraint: Simple Constraints. -* ? in constraint: Multi-Alternative. -* E in constraint: Simple Constraints. -* F in constraint: Simple Constraints. -* G in constraint: Simple Constraints. -* H in constraint: Simple Constraints. -* I in constraint: Simple Constraints. -* Q, in constraint: Simple Constraints. -* V in constraint: Simple Constraints. -* X in constraint: Simple Constraints. -* _ in variables in macros: Naming Types. -* d in constraint: Simple Constraints. -* g in constraint: Simple Constraints. -* i in constraint: Simple Constraints. -* m in constraint: Simple Constraints. -* n in constraint: Simple Constraints. -* o in constraint: Simple Constraints. -* p in constraint: Simple Constraints. -* r in constraint: Simple Constraints. -* store_multiple instruction pattern: Standard Names. -* s in constraint: Simple Constraints. -* ACCUMULATE_OUTGOING_ARGS: Stack Arguments. -* ADDITIONAL_REGISTER_NAMES: Instruction Output. -* ADDRESS_COST: Costs. -* ADJUST_INSN_LENGTH: Insn Lengths. -* ALLOCATE_TRAMPOLINE: Trampolines. -* ALL_REGS: Register Classes. -* AMD29K options: AMD29K Options. -* ANSI support: Dialect Options. -* ARGS_GROW_DOWNWARD: Frame Layout. -* ARG_POINTER_REGNUM: Frame Registers. -* ASM_APP_OFF: File Framework. -* ASM_APP_ON: File Framework. -* ASM_BYTE_OP: Data Output. -* ASM_CLOSE_PAREN: Data Output. -* ASM_COMMENT_START: File Framework. -* ASM_DECLARE_FUNCTION_NAME: Label Output. -* ASM_DECLARE_FUNCTION_SIZE: Label Output. -* ASM_DECLARE_OBJECT_NAME: Label Output. -* ASM_FILE_END: File Framework. -* ASM_FILE_START: File Framework. -* ASM_FINAL_SPEC: Driver. -* ASM_FORMAT_PRIVATE_NAME: Label Output. -* ASM_GENERATE_INTERNAL_LABEL: Label Output. -* ASM_GLOBALIZE_LABEL: Label Output. -* ASM_IDENTIFY_GCC: File Framework. -* ASM_NO_SKIP_IN_TEXT: Alignment Output. -* ASM_OPEN_PAREN: Data Output. -* ASM_OUTPUT_ADDR_DIFF_ELT: Dispatch Tables. -* ASM_OUTPUT_ADDR_VEC_ELT: Dispatch Tables. -* ASM_OUTPUT_ALIGN: Alignment Output. -* ASM_OUTPUT_ALIGNED_COMMON: Uninitialized Data. -* ASM_OUTPUT_ALIGNED_LOCAL: Uninitialized Data. -* ASM_OUTPUT_ALIGN_CODE: Alignment Output. -* ASM_OUTPUT_ASCII: Data Output. -* ASM_OUTPUT_BYTE: Data Output. -* ASM_OUTPUT_CASE_END: Dispatch Tables. -* ASM_OUTPUT_CASE_LABEL: Dispatch Tables. -* ASM_OUTPUT_CHAR: Data Output. -* ASM_OUTPUT_COMMON: Uninitialized Data. -* ASM_OUTPUT_CONSTRUCTOR: Constructor Output. -* ASM_OUTPUT_DESTRUCTOR: Constructor Output. -* ASM_OUTPUT_DOUBLE: Data Output. -* ASM_OUTPUT_DOUBLE_INT: Data Output. -* ASM_OUTPUT_EXTERNAL: Label Output. -* ASM_OUTPUT_EXTERNAL_LIBCALL: Label Output. -* ASM_OUTPUT_FLOAT: Data Output. -* ASM_OUTPUT_IDENT: File Framework. -* ASM_OUTPUT_INT: Data Output. -* ASM_OUTPUT_INTERNAL_LABEL: Label Output. -* ASM_OUTPUT_LABEL: Label Output. -* ASM_OUTPUT_LABELREF: Label Output. -* ASM_OUTPUT_LABELREF_AS_INT: Label Output. -* ASM_OUTPUT_LOCAL: Uninitialized Data. -* ASM_OUTPUT_LONG_DOUBLE: Data Output. -* ASM_OUTPUT_LOOP_ALIGN: Alignment Output. -* ASM_OUTPUT_OPCODE: Instruction Output. -* ASM_OUTPUT_POOL_PROLOGUE: Data Output. -* ASM_OUTPUT_QUADRUPLE_INT: Data Output. -* ASM_OUTPUT_REG_POP: Instruction Output. -* ASM_OUTPUT_REG_PUSH: Instruction Output. -* ASM_OUTPUT_SHARED_COMMON: Uninitialized Data. -* ASM_OUTPUT_SHARED_LOCAL: Uninitialized Data. -* ASM_OUTPUT_SHORT: Data Output. -* ASM_OUTPUT_SKIP: Alignment Output. -* ASM_OUTPUT_SOURCE_FILENAME: File Framework. -* ASM_OUTPUT_SOURCE_LINE: File Framework. -* ASM_OUTPUT_SPECIAL_POOL_ENTRY: Data Output. -* ASM_SPEC: Driver. -* ASM_STABD_OP: DBX Options. -* ASM_STABN_OP: DBX Options. -* ASM_STABS_OP: DBX Options. -* Alliant: Interoperation. -* BASE_REG_CLASS: Register Classes. -* BIGGEST_ALIGNMENT: Storage Layout. -* BIGGEST_FIELD_ALIGNMENT: Storage Layout. -* BITFIELD_NBYTES_LIMITED: Storage Layout. -* BITS_BIG_ENDIAN: Storage Layout. -* BITS_PER_UNIT: Storage Layout. -* BITS_PER_WORD: Storage Layout. -* BLKmode: Machine Modes. -* BLOCK_PROFILER: Profiling. -* BRANCH_COST: Costs. -* BYTES_BIG_ENDIAN: Storage Layout. -* BYTE_LOADS_ZERO_EXTEND: Misc. -* Bison parser generator: Installation. -* C language extensions: Extensions. -* C language, traditional: Dialect Options. -* C statements for assembler output: Output Statement. -* CALLER_SAVE_PROFITABLE: Caller Saves. -* CALL_USED_REGISTERS: Register Basics. -* CAN_ELIMINATE: Elimination. -* CASE_DROPS_THROUGH: Misc. -* CASE_VECTOR_MODE: Misc. -* CASE_VECTOR_PC_RELATIVE: Misc. -* CC1PLUS_SPEC: Driver. -* CC1_SPEC: Driver. -* CC_STATUS_MDEP: Condition Code. -* CC_STATUS_MDEP_INIT: Condition Code. -* CCmode: Machine Modes. -* CHAR_TYPE_SIZE: Type Layout. -* CHECK_FLOAT_VALUE: Storage Layout. -* CLASS_MAX_NREGS: Register Classes. -* CODE_LABEL_NUMBER: Insns. -* COMPILER_PATH: Environment Variables. -* CONDITIONAL_REGISTER_USAGE: Register Basics. -* CONST0_RTX: Constants. -* CONST1_RTX: Constants. -* CONST2_RTX: Constants. -* CONSTANT_ADDRESS_P: Addressing Modes. -* CONSTANT_ALIGNMENT: Storage Layout. -* CONSTANT_P: Addressing Modes. -* CONSTANT_POOL_ADDRESS_P: Flags. -* CONST_CALL_P: Flags. -* CONST_COSTS: Costs. -* CONST_DOUBLE_CHAIN: Constants. -* CONST_DOUBLE_LOW: Constants. -* CONST_DOUBLE_MEM: Constants. -* CONST_DOUBLE_OK_FOR_LETTER_P: Register Classes. -* CONST_OK_FOR_LETTER_P: Register Classes. -* COSTS_N_INSNS: Costs. -* CPLUS_INCLUDE_PATH: Environment Variables. -* CPP_PREDEFINES: Run-time Target. -* CPP_SPEC: Driver. -* CUMULATIVE_ARGS: Register Arguments. -* C_INCLUDE_PATH: Environment Variables. -* Convex options: Convex Options. -* DATA_ALIGNMENT: Storage Layout. -* DATA_SECTION_ASM_OP: Sections. -* DBR_OUTPUT_SEQEND: Instruction Output. -* DBX: Interoperation. -* DBX_CONTIN_CHAR: DBX Options. -* DBX_CONTIN_LENGTH: DBX Options. -* DBX_DEBUGGING_INFO: DBX Options. -* DBX_FUNCTION_FIRST: DBX Options. -* DBX_LBRAC_FIRST: DBX Options. -* DBX_MEMPARM_STABS_LETTER: DBX Options. -* DBX_NO_XREFS: DBX Options. -* DBX_OUTPUT_ENUM: DBX Hooks. -* DBX_OUTPUT_FUNCTION_END: DBX Hooks. -* DBX_OUTPUT_LBRAC: DBX Hooks. -* DBX_OUTPUT_MAIN_SOURCE_DIRECTORY: File Names and DBX. -* DBX_OUTPUT_MAIN_SOURCE_FILENAME: File Names and DBX. -* DBX_OUTPUT_MAIN_SOURCE_FILE_END: File Names and DBX. -* DBX_OUTPUT_RBRAC: DBX Hooks. -* DBX_OUTPUT_SOURCE_FILENAME: File Names and DBX. -* DBX_OUTPUT_STANDARD_TYPES: DBX Hooks. -* DBX_REGISTER_NUMBER: All Debuggers. -* DBX_REGPARM_STABS_CODE: DBX Options. -* DBX_REGPARM_STABS_LETTER: DBX Options. -* DBX_STATIC_CONST_VAR_CODE: DBX Options. -* DBX_STATIC_STAB_DATA_SECTION: DBX Options. -* DBX_TYPE_DECL_STABS_CODE: DBX Options. -* DBX_WORKING_DIRECTORY: File Names and DBX. -* DCmode: Machine Modes. -* DEBUGGER_ARG_OFFSET: All Debuggers. -* DEBUGGER_AUTO_OFFSET: All Debuggers. -* DEBUG_SYMS_TEXT: DBX Options. -* DEFAULT_CALLER_SAVES: Caller Saves. -* DEFAULT_GDB_EXTENSIONS: DBX Options. -* DEFAULT_MAIN_RETURN: Misc. -* DEFAULT_SHORT_ENUMS: Type Layout. -* DEFAULT_SIGNED_CHAR: Type Layout. -* DELAY_SLOTS_FOR_EPILOGUE: Function Entry. -* DEPENDENCIES_OUTPUT: Environment Variables. -* DFmode: Machine Modes. -* DIVDI3_LIBCALL: Library Calls. -* DIVSI3_LIBCALL: Library Calls. -* DImode: Machine Modes. -* DOLLARS_IN_IDENTIFIERS: Misc. -* DONE: Expander Definitions. -* DONT_REDUCE_ADDR: Costs. -* DOUBLE_TYPE_SIZE: Type Layout. -* DWARF_DEBUGGING_INFO: SDB and DWARF. -* DYNAMIC_CHAIN_ADDRESS: Frame Layout. -* De Morgan's law: Insn Canonicalizations. -* Dependent Patterns: Dependent Patterns. -* EASY_DIV_EXPR: Misc. -* ELIGIBLE_FOR_EPILOGUE_DELAY: Function Entry. -* ELIMINABLE_REGS: Elimination. -* EMPTY_FIELD_BOUNDARY: Storage Layout. -* ENCODE_SECTION_INFO: Sections. -* ENDFILE_SPEC: Driver. -* EXECUTABLE_SUFFIX: Config. -* EXIT_BODY: Misc. -* EXIT_IGNORE_STACK: Function Entry. -* EXPAND_BUILTIN_SAVEREGS: Varargs. -* EXTRA_CC_MODES: Condition Code. -* EXTRA_CC_NAMES: Condition Code. -* EXTRA_CONSTRAINT: Register Classes. -* EXTRA_SECTIONS: Sections. -* EXTRA_SECTION_FUNCTIONS: Sections. -* FAIL: Expander Definitions. -* FAILURE_EXIT_CODE: Config. -* FINALIZE_PIC: PIC. -* FINAL_PRESCAN_INSN: Instruction Output. -* FINAL_REG_PARM_STACK_SPACE: Stack Arguments. -* FIRST_INSN_ADDRESS: Insn Lengths. -* FIRST_PARM_OFFSET: Frame Layout. -* FIRST_PSEUDO_REGISTER: Register Basics. -* FIRST_STACK_REG: Stack Registers. -* FIRST_VIRTUAL_REGISTER: Regs and Memory. -* FIXED_REGISTERS: Register Basics. -* FIXUNS_TRUNC_LIKE_FIX_TRUNC: Misc. -* FLOATIFY: Library Calls. -* FLOAT_ARG_TYPE: Library Calls. -* FLOAT_TYPE_SIZE: Type Layout. -* FLOAT_VALUE_TYPE: Library Calls. -* FRAME_GROWS_DOWNWARD: Frame Layout. -* FRAME_POINTER_REGNUM: Frame Registers. -* FRAME_POINTER_REQUIRED: Elimination. -* FUNCTION_ARG: Register Arguments. -* FUNCTION_ARG_ADVANCE: Register Arguments. -* FUNCTION_ARG_BOUNDARY: Register Arguments. -* FUNCTION_ARG_PADDING: Register Arguments. -* FUNCTION_ARG_PARTIAL_NREGS: Register Arguments. -* FUNCTION_ARG_PASS_BY_REFERENCE: Register Arguments. -* FUNCTION_ARG_REGNO_P: Register Arguments. -* FUNCTION_BLOCK_PROFILER: Profiling. -* FUNCTION_BOUNDARY: Storage Layout. -* FUNCTION_CONVERSION_BUG: Config. -* FUNCTION_EPILOGUE: Function Entry. -* FUNCTION_INCOMING_ARG: Register Arguments. -* FUNCTION_MODE: Misc. -* FUNCTION_OUTGOING_VALUE: Scalar Return. -* FUNCTION_PROFILER: Profiling. -* FUNCTION_PROLOGUE: Function Entry. -* FUNCTION_VALUE: Scalar Return. -* FUNCTION_VALUE_REGNO_P: Scalar Return. -* GCC_EXEC_PREFIX: Environment Variables. -* GENERAL_REGS: Register Classes. -* GET_CLASS_NARROWEST_MODE: Machine Modes. -* GET_CODE: RTL Objects. -* GET_MODE: Machine Modes. -* GET_MODE_ALIGNMENT: Machine Modes. -* GET_MODE_BITSIZE: Machine Modes. -* GET_MODE_CLASS: Machine Modes. -* GET_MODE_MASK: Machine Modes. -* GET_MODE_NAME: Machine Modes. -* GET_MODE_NUNITS: Machine Modes. -* GET_MODE_SIZE: Machine Modes. -* GET_MODE_UNIT_SIZE: Machine Modes. -* GET_MODE_WIDER_MODE: Machine Modes. -* GET_RTX_CLASS: Accessors. -* GET_RTX_FORMAT: Accessors. -* GET_RTX_LENGTH: Accessors. -* GLOBALDEF: Global Declarations. -* GLOBALREF: Global Declarations. -* GLOBALVALUEDEF: Global Declarations. -* GLOBALVALUEREF: Global Declarations. -* GNU CC and portability: Portability. -* GNU CC command options: Invoking GCC. -* GNU extensions to the C language: Extensions. -* GO_IF_LEGITIMATE_ADDRESS: Addressing Modes. -* GO_IF_MODE_DEPENDENT_ADDRESS: Addressing Modes. -* HANDLE_PRAGMA: Misc. -* HARD_REGNO_MODE_OK: Values in Registers. -* HARD_REGNO_NREGS: Values in Registers. -* HAVE_ATEXIT: Misc. -* HAVE_POST_DECREMENT: Addressing Modes. -* HAVE_POST_INCREMENT: Addressing Modes. -* HAVE_PRE_DECREMENT: Addressing Modes. -* HAVE_PRE_INCREMENT: Addressing Modes. -* HAVE_PUTENV: Config. -* HAVE_VPRINTF: Config. -* HImode: Machine Modes. -* HOST_BITS_PER_CHAR: Config. -* HOST_BITS_PER_INT: Config. -* HOST_BITS_PER_LONG: Config. -* HOST_BITS_PER_SHORT: Config. -* HOST_FLOAT_FORMAT: Config. -* HOST_WORDS_BIG_ENDIAN: Config. -* IBM RS/6000 Options: RS/6000 Options. -* IBM RT PC: Interoperation. -* IBM RT options: RT Options. -* IEEE_FLOAT_FORMAT: Storage Layout. -* IMMEDIATE_PREFIX: Instruction Output. -* IMPLICIT_FIX_EXPR: Misc. -* INCLUDE_DEFAULTS: Driver. -* INDEX_REG_CLASS: Register Classes. -* INITIALIZE_TRAMPOLINE: Trampolines. -* INITIAL_ELIMINATION_OFFSET: Elimination. -* INITIAL_FRAME_POINTER_OFFSET: Elimination. -* INIT_CUMULATIVE_ARGS: Register Arguments. -* INIT_CUMULATIVE_INCOMING_ARGS: Register Arguments. -* INIT_SECTION_ASM_OP: Sections. -* INSN_ANNULLED_BRANCH_P: Flags. -* INSN_CACHE_DEPTH: Trampolines. -* INSN_CACHE_LINE_WIDTH: Trampolines. -* INSN_CACHE_SIZE: Trampolines. -* INSN_CLOBBERS_REGNO_P: Obsolete Register Macros. -* INSN_CODE: Insns. -* INSN_DELETED_P: Flags. -* INSN_FROM_TARGET_P: Flags. -* INSN_UID: Insns. -* INTEGRATE_THRESHOLD: Misc. -* INTIFY: Library Calls. -* INT_TYPE_SIZE: Type Layout. -* Intel 386 Options: i386 Options. -* Interdependence of Patterns: Dependent Patterns. -* JUMP_LABEL: Insns. -* JUMP_TABLES_IN_TEXT_SECTION: Sections. -* LABEL_NUSES: Insns. -* LABEL_OUTSIDE_LOOP_P: Flags. -* LABEL_PRESERVE_P: Flags. -* LAST_STACK_REG: Stack Registers. -* LAST_VIRTUAL_REGISTER: Regs and Memory. -* LEAF_REGISTERS: Leaf Functions. -* LEAF_REG_REMAP: Leaf Functions. -* LEGITIMATE_CONSTANT_P: Addressing Modes. -* LEGITIMATE_PIC_OPERAND_P: Addressing Modes. -* LEGITIMIZE_ADDRESS: Addressing Modes. -* LIBCALL_VALUE: Scalar Return. -* LIBGCC_NEEDS_DOUBLE: Library Calls. -* LIBRARY_PATH: Environment Variables. -* LIB_SPEC: Driver. -* LIMIT_RELOAD_CLASS: Register Classes. -* LINK_LIBGCC_SPECIAL: Driver. -* LINK_SPEC: Driver. -* LOCAL_INCLUDE_DIR: Driver. -* LOCAL_LABEL_PREFIX: Instruction Output. -* LOG_LINKS: Insns. -* LONGJMP_RESTORE_FROM_STACK: Elimination. -* LONG_DOUBLE_TYPE_SIZE: Type Layout. -* LONG_LONG_TYPE_SIZE: Type Layout. -* LONG_TYPE_SIZE: Type Layout. -* Libraries: Link Options. -* M680x0 options: M680x0 Options. -* M88k options: M88K Options. -* MAX_BITS_PER_WORD: Storage Layout. -* MAX_FIXED_MODE_SIZE: Storage Layout. -* MAX_OFILE_ALIGNMENT: Storage Layout. -* MAX_REGS_PER_ADDRESS: Addressing Modes. -* MAYBE_REG_PARM_STACK_SPACE: Stack Arguments. -* MD_EXEC_PREFIX: Driver. -* MD_STARTFILE_PREFIX: Driver. -* MD_STARTFILE_PREFIX_1: Driver. -* MEMORY_MOVE_COST: Costs. -* MEM_IN_STRUCT_P: Flags. -* MEM_VOLATILE_P: Flags. -* MIPS options: MIPS Options. -* MODDI3_LIBCALL: Library Calls. -* MODES_TIEABLE_P: Values in Registers. -* MODE_CC: Machine Modes. -* MODE_COMPLEX_FLOAT: Machine Modes. -* MODE_COMPLEX_INT: Machine Modes. -* MODE_FLOAT: Machine Modes. -* MODE_FUNCTION: Machine Modes. -* MODE_INT: Machine Modes. -* MODE_PARTIAL_INT: Machine Modes. -* MODE_RANDOM: Machine Modes. -* MODSI3_LIBCALL: Library Calls. -* MOVE_MAX: Misc. -* MOVE_RATIO: Costs. -* MULDI3_LIBCALL: Library Calls. -* MULSI3_LIBCALL: Library Calls. -* MULTIBYTE_CHARS: Config. -* NEXT_INSN: Insns. -* NEXT_OBJC_RUNTIME: Library Calls. -* NON_SAVING_SETJMP: Register Basics. -* NOTE_INSN_BLOCK_BEG: Insns. -* NOTE_INSN_BLOCK_END: Insns. -* NOTE_INSN_DELETED: Insns. -* NOTE_INSN_FUNCTION_END: Insns. -* NOTE_INSN_LOOP_BEG: Insns. -* NOTE_INSN_LOOP_CONT: Insns. -* NOTE_INSN_LOOP_END: Insns. -* NOTE_INSN_LOOP_VTOP: Insns. -* NOTE_INSN_SETJMP: Insns. -* NOTE_LINE_NUMBER: Insns. -* NOTE_SOURCE_FILE: Insns. -* NOTICE_UPDATE_CC: Condition Code. -* NO_DOLLAR_IN_LABEL: Misc. -* NO_FUNCTION_CSE: Costs. -* NO_RECURSIVE_FUNCTION_CSE: Costs. -* NO_REGS: Register Classes. -* NO_STAB_H: Config. -* NO_SYS_SIGLIST: Config. -* NUM_MACHINE_MODES: Machine Modes. -* N_REG_CLASSES: Register Classes. -* OBJC_GEN_METHOD_LABEL: Label Output. -* OBJC_INCLUDE_PATH: Environment Variables. -* OBJC_INT_SELECTORS: Type Layout. -* OBJC_PROLOGUE: File Framework. -* OBJC_SELECTORS_WITHOUT_LABELS: Type Layout. -* OBJECT_FORMAT_COFF: Constructor Output. -* OBJECT_FORMAT_ROSE: Constructor Output. -* OBSTACK_CHUNK_ALLOC: Config. -* OBSTACK_CHUNK_FREE: Config. -* OBSTACK_CHUNK_SIZE: Config. -* OCS (88k): M88K Options. -* ONLY_INT_FIELDS: Config. -* OPTIMIZATION_OPTIONS: Run-time Target. -* ORDER_REGS_FOR_LOCAL_ALLOC: Allocation Order. -* OUTGOING_REG_PARM_STACK_SPACE: Stack Arguments. -* OVERLAPPING_REGNO_P: Obsolete Register Macros. -* OVERRIDE_OPTIONS: Run-time Target. -* Ordering of Patterns: Pattern Ordering. -* PARM_BOUNDARY: Storage Layout. -* PATTERN: Insns. -* PCC_BITFIELD_TYPE_MATTERS: Storage Layout. -* PCC_STATIC_STRUCT_RETURN: Aggregate Return. -* PDImode: Machine Modes. -* PIC: PIC. -* PIC_OFFSET_TABLE_REGNUM: PIC. -* POINTER_SIZE: Storage Layout. -* PREDICATE_CODES: Misc. -* PREFERRED_RELOAD_CLASS: Register Classes. -* PRESERVE_DEATH_INFO_REGNO_P: Obsolete Register Macros. -* PREV_INSN: Insns. -* PRINT_OPERAND: Instruction Output. -* PRINT_OPERAND_ADDRESS: Instruction Output. -* PRINT_OPERAND_PUNCT_VALID_P: Instruction Output. -* PROFILE_BEFORE_PROLOGUE: Profiling. -* PROMOTE_PROTOTYPES: Stack Arguments. -* PSImode: Machine Modes. -* PTRDIFF_TYPE: Type Layout. -* PUSH_ROUNDING: Stack Arguments. -* PUT_CODE: RTL Objects. -* PUT_MODE: Machine Modes. -* PUT_REG_NOTE_KIND: Insns. -* PUT_SDB_...: SDB and DWARF. -* Pattern Ordering: Pattern Ordering. -* Pmode: Misc. -* QImode: Machine Modes. -* READONLY_DATA_SECTION: Sections. -* REAL_ARITHMETIC: Cross-compilation. -* REAL_INFINITY: Cross-compilation. -* REAL_NM_FILE_NAME: Constructor Output. -* REAL_VALUES_EQUAL: Cross-compilation. -* REAL_VALUES_LESS: Cross-compilation. -* REAL_VALUE_ATOF: Cross-compilation. -* REAL_VALUE_FIX: Cross-compilation. -* REAL_VALUE_FIX_TRUNCATE: Cross-compilation. -* REAL_VALUE_FROM_INT: Cross-compilation. -* REAL_VALUE_ISINF: Cross-compilation. -* REAL_VALUE_ISNAN: Cross-compilation. -* REAL_VALUE_LDEXP: Cross-compilation. -* REAL_VALUE_NEGATE: Cross-compilation. -* REAL_VALUE_TO_INT: Cross-compilation. -* REAL_VALUE_TRUNCATE: Cross-compilation. -* REAL_VALUE_TYPE: Cross-compilation. -* REAL_VALUE_UNSIGNED_FIX: Cross-compilation. -* REAL_VALUE_UNSIGNED_FIX_TRUNCATE: Cross-compilation. -* REGISTER_MOVE_COST: Costs. -* REGISTER_NAMES: Instruction Output. -* REGISTER_PREFIX: Instruction Output. -* REGNO_OK_FOR_BASE_P: Register Classes. -* REGNO_OK_FOR_INDEX_P: Register Classes. -* REGNO_REG_CLASS: Register Classes. -* REG_ALLOC_ORDER: Allocation Order. -* REG_CC_SETTER: Insns. -* REG_CC_USER: Insns. -* REG_CLASS_CONTENTS: Register Classes. -* REG_CLASS_FROM_LETTER: Register Classes. -* REG_CLASS_NAMES: Register Classes. -* REG_DEAD: Insns. -* REG_DEP_ANTI: Insns. -* REG_DEP_OUTPUT: Insns. -* REG_EQUAL: Insns. -* REG_EQUIV: Insns. -* REG_FUNCTION_VALUE_P: Flags. -* REG_INC: Insns. -* REG_LABEL: Insns. -* REG_LEAF_ALLOC_ORDER: Leaf Functions. -* REG_LIBCALL: Insns. -* REG_LOOP_TEST_P: Flags. -* REG_NONNEG: Insns. -* REG_NOTES: Insns. -* REG_NOTE_KIND: Insns. -* REG_NO_CONFLICT: Insns. -* REG_OK_FOR_BASE_P: Addressing Modes. -* REG_OK_FOR_INDEX_P: Addressing Modes. -* REG_OK_STRICT: Addressing Modes. -* REG_PARM_STACK_SPACE: Stack Arguments. -* REG_RETVAL: Insns. -* REG_UNUSED: Insns. -* REG_USERVAR_P: Flags. -* REG_WAS_0: Insns. -* RELATIVE_PREFIX_NOT_LINKDIR: Driver. -* RETURN_IN_MEMORY: Aggregate Return. -* RETURN_POPS_ARGS: Stack Arguments. -* ROUND_TYPE_ALIGN: Storage Layout. -* ROUND_TYPE_SIZE: Storage Layout. -* RS/6000 Options: RS/6000 Options. -* RT PC: Interoperation. -* RT options: RT Options. -* RTL addition: Arithmetic. -* RTL comparison: Arithmetic. -* RTL comparison operations: Comparisons. -* RTL constant expression types: Constants. -* RTL constants: Constants. -* RTL declarations: RTL Declarations. -* RTL difference: Arithmetic. -* RTL expression: RTL Objects. -* RTL expressions for arithmetic: Arithmetic. -* RTL format: Accessors. -* RTL format characters: Accessors. -* RTL function-call insns: Calls. -* RTL generation: Passes. -* RTL insn template: RTL Template. -* RTL integers: RTL Objects. -* RTL memory expressions: Regs and Memory. -* RTL object types: RTL Objects. -* RTL postdecrement: Incdec. -* RTL postincrement: Incdec. -* RTL predecrement: Incdec. -* RTL preincrement: Incdec. -* RTL register expressions: Regs and Memory. -* RTL representation: RTL. -* RTL side effect expressions: Side Effects. -* RTL strings: RTL Objects. -* RTL structure sharing assumptions: Sharing. -* RTL subtraction: Arithmetic. -* RTL sum: Arithmetic. -* RTL vectors: RTL Objects. -* RTX (See RTL): RTL Objects. -* RTX_COSTS: Costs. -* RTX_INTEGRATED_P: Flags. -* RTX_UNCHANGING_P: Flags. -* Register Transfer Language (RTL): RTL. -* SCCS_DIRECTIVE: Misc. -* SCHED_GROUP_P: Flags. -* SCmode: Machine Modes. -* SDB_ALLOW_FORWARD_REFERENCES: SDB and DWARF. -* SDB_ALLOW_UNKNOWN_REFERENCES: SDB and DWARF. -* SDB_DEBUGGING_INFO: SDB and DWARF. -* SDB_DELIM: SDB and DWARF. -* SDB_GENERATE_FAKE: SDB and DWARF. -* SECONDARY_INPUT_RELOAD_CLASS: Register Classes. -* SECONDARY_OUTPUT_RELOAD_CLASS: Register Classes. -* SECONDARY_RELOAD_CLASS: Register Classes. -* SELECT_CC_MODE: Condition Code. -* SELECT_RTX_SECTION: Sections. -* SELECT_SECTION: Sections. -* SETUP_INCOMING_VARARGS: Varargs. -* SET_DEST: Side Effects. -* SET_SRC: Side Effects. -* SFmode: Machine Modes. -* SHARED_SECTION_ASM_OP: Sections. -* SHIFT_COUNT_TRUNCATED: Misc. -* SHORT_TYPE_SIZE: Type Layout. -* SIGNED_CHAR_SPEC: Driver. -* SIZE_TYPE: Type Layout. -* SImode: Machine Modes. -* SLOW_BYTE_ACCESS: Costs. -* SLOW_UNALIGNED_ACCESS: Costs. -* SLOW_ZERO_EXTEND: Costs. -* SMALL_REGISTER_CLASSES: Register Classes. -* SPARC options: Sparc Options. -* STACK_BOUNDARY: Storage Layout. -* STACK_DYNAMIC_OFFSET: Frame Layout. -* STACK_GROWS_DOWNWARD: Frame Layout. -* STACK_PARMS_IN_REG_PARM_AREA: Stack Arguments. -* STACK_POINTER_OFFSET: Frame Layout. -* STACK_POINTER_REGNUM: Frame Registers. -* STACK_REGS: Stack Registers. -* STANDARD_EXEC_PREFIX: Driver. -* STANDARD_INCLUDE_DIR: Driver. -* STANDARD_STARTFILE_PREFIX: Driver. -* STARTFILE_SPEC: Driver. -* STARTING_FRAME_OFFSET: Frame Layout. -* STATIC_CHAIN: Frame Registers. -* STATIC_CHAIN_INCOMING: Frame Registers. -* STATIC_CHAIN_INCOMING_REGNUM: Frame Registers. -* STATIC_CHAIN_REGNUM: Frame Registers. -* STDC_VALUE: Run-time Target. -* STORE_FLAG_VALUE: Misc. -* STRICT_ALIGNMENT: Storage Layout. -* STRUCTURE_SIZE_BOUNDARY: Storage Layout. -* STRUCT_VALUE: Aggregate Return. -* STRUCT_VALUE_INCOMING: Aggregate Return. -* STRUCT_VALUE_INCOMING_REGNUM: Aggregate Return. -* STRUCT_VALUE_REGNUM: Aggregate Return. -* SUBREG_REG: Regs and Memory. -* SUBREG_WORD: Regs and Memory. -* SUCCESS_EXIT_CODE: Config. -* SVr4: M88K Options. -* SWITCHES_NEED_SPACES: Driver. -* SWITCH_TAKES_ARG: Driver. -* SYMBOL_REF_FLAG: Flags. -* SYMBOL_REF_USED: Flags. -* SYSTEM_INCLUDE_DIR: Driver. -* Sun installation: Sun Install. -* TARGET_BELL: Type Layout. -* TARGET_BS: Type Layout. -* TARGET_CR: Type Layout. -* TARGET_FF: Type Layout. -* TARGET_FLOAT_FORMAT: Storage Layout. -* TARGET_MEM_FUNCTIONS: Library Calls. -* TARGET_NEWLINE: Type Layout. -* TARGET_OPTIONS: Run-time Target. -* TARGET_SWITCHES: Run-time Target. -* TARGET_TAB: Type Layout. -* TARGET_VERSION: Run-time Target. -* TARGET_VT: Type Layout. -* TCmode: Machine Modes. -* TEXT_SECTION_ASM_OP: Sections. -* TFmode: Machine Modes. -* TImode: Machine Modes. -* TMPDIR: Environment Variables. -* TRADITIONAL_RETURN_FLOAT: Scalar Return. -* TRAMPOLINE_ALIGNMENT: Trampolines. -* TRAMPOLINE_SIZE: Trampolines. -* TRAMPOLINE_TEMPLATE: Trampolines. -* TRANSFER_FROM_TRAMPOLINE: Trampolines. -* TRULY_NOOP_TRUNCATION: Misc. -* UDIVDI3_LIBCALL: Library Calls. -* UDIVSI3_LIBCALL: Library Calls. -* UMODDI3_LIBCALL: Library Calls. -* UMODSI3_LIBCALL: Library Calls. -* UNITS_PER_WORD: Storage Layout. -* UNKNOWN_FLOAT_FORMAT: Storage Layout. -* USER_LABEL_PREFIX: Instruction Output. -* USE_C_ALLOCA: Config. -* USG: Config. -* Ultrix calling convention: Interoperation. -* Unos installation: Unos Install. -* VAX options: VAX Options. -* VAX_FLOAT_FORMAT: Storage Layout. -* VIRTUAL_INCOMING_ARGS_REGNUM: Regs and Memory. -* VIRTUAL_OUTGOING_ARGS_REGNUM: Regs and Memory. -* VIRTUAL_STACK_DYNAMIC_REGNUM: Regs and Memory. -* VIRTUAL_STACK_VARS_REGNUM: Regs and Memory. -* VMS: Config. -* VMS and case sensitivity: VMS Misc. -* VMS and include files: Include Files and VMS. -* VMS installation: VMS Install. -* VOIDmode: Machine Modes. -* Vax calling convention: Interoperation. -* WCHAR_TYPE: Type Layout. -* WCHAR_TYPE_SIZE: Type Layout. -* WORDS_BIG_ENDIAN: Storage Layout. -* WORD_SWITCH_TAKES_ARG: Driver. -* XCOFF_DEBUGGING_INFO: DBX Options. -* XCmode: Machine Modes. -* XEXP: Accessors. -* XFmode: Machine Modes. -* XINT: Accessors. -* XSTR: Accessors. -* XVEC: Accessors. -* XVECEXP: Accessors. -* XVECLEN: Accessors. -* \: Output Template. -* __bb_init_func: Profiling. -* __builtin_args_info: Varargs. -* __builtin_classify_type: Varargs. -* __builtin_next_arg: Varargs. -* __builtin_saveregs: Varargs. -* abort: Portability. -* abs: Arithmetic. -* absolute value: Arithmetic. -* access to operands: Accessors. -* accessors: Accessors. -* addr_diff_vec: Side Effects. -* addr_vec: Side Effects. -* address: RTL Template. -* address constraints: Simple Constraints. -* address of a label: Labels as Values. -* address_operand: Simple Constraints. -* addressing modes: Addressing Modes. -* aggregates as return values: Aggregate Return. -* alignment: Alignment. -* alternate keywords: Alternate Keywords. -* analysis, data flow: Passes. -* and: Arithmetic. -* apostrophes: Incompatibilities. -* arg_pointer_rtx: Frame Registers. -* argument passing: Interface. -* arguments in frame (88k): M88K Options. -* arguments in registers: Register Arguments. -* arguments on stack: Stack Arguments. -* arithmetic libraries: Interface. -* arithmetic shift: Arithmetic. -* arithmetic simplifications: Passes. -* arithmetic, in RTL: Arithmetic. -* arrays of length zero: Zero Length. -* arrays of variable length: Variable Length. -* arrays, non-lvalue: Subscripting. -* ashift: Arithmetic. -* ashiftrt: Arithmetic. -* asm_fprintf: Instruction Output. -* asm_input: Side Effects. -* asm_noperands: Insns. -* assemble_name: Label Output. -* assembler format: File Framework. -* assembler instructions: Extended Asm. -* assembler instructions in RTL: Assembler. -* assembler names for identifiers: Asm Labels. -* assembler syntax, 88k: M88K Options. -* assembly code, invalid: Bug Criteria. -* assigning attribute values to insns: Tagging Insns. -* asterisk in template: Output Statement. -* atof: Cross-compilation. -* attr: Tagging Insns. -* attribute expressions: Expressions. -* attribute of variables: Variable Attributes. -* attribute specifications: Attr Example. -* attribute specifications example: Attr Example. -* attributes, defining: Defining Attributes. -* autoincrement addressing, availability: Portability. -* autoincrement/decrement addressing: Simple Constraints. -* autoincrement/decrement analysis: Passes. -* backslash: Output Template. -* backtrace for bug reports: Bug Reporting. -* barrier: Insns. -* basic blocks: Passes. -* bcmp: Config. -* bit fields: Bit Fields. -* bit shift overflow (88k): M88K Options. -* bitwise complement: Arithmetic. -* bitwise exclusive-or: Arithmetic. -* bitwise inclusive-or: Arithmetic. -* bitwise logical-and: Arithmetic. -* break_out_memory_refs: Addressing Modes. -* bug criteria: Bug Criteria. -* bug report mailing lists: Bug Lists. -* bugs: Bugs. -* bugs, known: Trouble. -* byte_mode: Machine Modes. -* bzero: Config. -* call: Side Effects. -* call-clobbered register: Register Basics. -* call-saved register: Register Basics. -* call-used register: Register Basics. -* call_insn: Insns. -* call_used_regs: Register Basics. -* calling conventions: Stack and Calling. -* calling functions in RTL: Calls. -* canonicalization of instructions: Insn Canonicalizations. -* case labels in initializers: Labeled Elements. -* case ranges: Case Ranges. -* case sensitivity and VMS: VMS Misc. -* cast to a union: Cast to Union. -* casts as lvalues: Lvalues. -* cc0: Regs and Memory. -* cc0_rtx: Regs and Memory. -* cc_status: Condition Code. -* change_address: Standard Names. -* class definitions, register: Register Classes. -* class preference constraints: Class Preferences. -* classes of RTX codes: Accessors. -* clobber: Side Effects. -* code generation RTL sequences: Expander Definitions. -* code generation conventions: Code Gen Options. -* code motion: Passes. -* code_label: Insns. -* codes, RTL expression: RTL Objects. -* combiner pass: Regs and Memory. -* command options: Invoking GCC. -* common subexpression elimination: Passes. -* compare: Arithmetic. -* compilation in a separate directory: Other Dir. -* compiler bugs, reporting: Bug Reporting. -* compiler passes and files: Passes. -* compiler version, specifying: Target Options. -* complement, bitwise: Arithmetic. -* compound expressions as lvalues: Lvalues. -* computed gotos: Labels as Values. -* computing the length of an insn: Insn Lengths. -* cond: Comparisons. -* condition code register: Regs and Memory. -* condition code status: Condition Code. -* condition codes: Comparisons. -* conditional expressions as lvalues: Lvalues. -* conditional expressions, extensions: Conditionals. -* conditions, in patterns: Patterns. -* configuration file: Config. -* conflicting types: Disappointments. -* const0_rtx: Constants. -* const1_rtx: Constants. -* const2_rtx: Constants. -* const_double: Constants. -* const_int: Constants. -* const_string: Constants. -* const_true_rtx: Constants. -* constant attributes: Constant Attributes. -* constant folding: Passes. -* constant folding and floating point: Cross-compilation. -* constant propagation: Passes. -* constants in constraints: Simple Constraints. -* constm1_rtx: Constants. -* constraint modifier characters: Modifiers. -* constraint, matching: Simple Constraints. -* constraints: Constraints. -* constructor expressions: Constructors. -* constructors, output of: Constructor Output. -* contributors: Contributors. -* controlling register usage: Register Basics. -* controlling the compilation driver: Driver. -* conventions, run-time: Interface. -* conversions: Conversions. -* copy_rtx_if_shared: Sharing. -* core dump: Bug Criteria. -* costs of instructions: Costs. -* cross compilation and floating point: Cross-compilation. -* cross compiling: Target Options. -* cross-compiler, installation: Cross-Compiler. -* cross-jumping: Passes. -* current_function_epilogue_delay_list: Function Entry. -* current_function_outgoing_args_size: Stack Arguments. -* current_function_pops_args: Function Entry. -* current_function_pretend_args_size: Function Entry. -* data flow analysis: Passes. -* data_section: Sections. -* dbr_sequence_length: Instruction Output. -* dead code: Passes. -* dead_or_set_p: Peephole Definitions. -* deallocating variable length arrays: Variable Length. -* death notes: Obsolete Register Macros. -* debug_rtx: Bug Reporting. -* debugging information generation: Passes. -* debugging information options: Debugging Options. -* debugging, 88k OCS: M88K Options. -* declaration scope: Incompatibilities. -* declarations inside expressions: Statement Exprs. -* declarations, RTL: RTL Declarations. -* declaring attributes of functions: Function Attributes. -* define_asm_attributes: Tagging Insns. -* define_attr: Defining Attributes. -* define_delay: Delay Slots. -* define_expand: Expander Definitions. -* define_function_unit: Function Units. -* define_insn: Patterns. -* define_peephole: Expander Definitions. -* define_split: Insn Splitting. -* defining RTL sequences for code generation: Expander Definitions. -* defining attributes and their values: Defining Attributes. -* defining jump instruction patterns: Jump Patterns. -* defining peephole optimizers: Peephole Definitions. -* delay slots, defining: Delay Slots. -* delayed branch scheduling: Passes. -* dependencies for make as output: Environment Variables. -* dependencies, make: Preprocessor Options. -* destructors, output of: Constructor Output. -* dialect options: Dialect Options. -* digits in constraint: Simple Constraints. -* directory options: Directory Options. -* disabling certain registers: Register Basics. -* dispatch table: Dispatch Tables. -* div: Arithmetic. -* divide instruction, 88k: M88K Options. -* division: Arithmetic. -* division: Arithmetic. -* division: Arithmetic. -* dollar signs in identifier names: Dollar Signs. -* double-word arithmetic: Long Long. -* downward funargs: Nested Functions. -* driver: Driver. -* empty constraints: No Constraints. -* endianness: Portability. -* enum machine_mode: Machine Modes. -* enum reg_class: Register Classes. -* environment variables: Environment Variables. -* epilogue: Function Entry. -* eq: Comparisons. -* eq_attr: Expressions. -* equal: Comparisons. -* error: Storage Layout. -* exclamation point: Multi-Alternative. -* exclusive-or, bitwise: Arithmetic. -* exit status and VMS: VMS Misc. -* expander definitions: Expander Definitions. -* explicit register variables: Explicit Reg Vars. -* expr_list: Insns. -* expression codes: RTL Objects. -* expressions containing statements: Statement Exprs. -* expressions, compound, as lvalues: Lvalues. -* expressions, conditional, as lvalues: Lvalues. -* expressions, constructor: Constructors. -* extended asm: Extended Asm. -* extensible constraints: Simple Constraints. -* extensions, ?:: Lvalues. -* extensions, ?:: Conditionals. -* extensions, C language: Extensions. -* extern int target_flags: Run-time Target. -* external declaration scope: Incompatibilities. -* fatal signal: Bug Criteria. -* features, optional, in system conventions: Run-time Target. -* ffs: Arithmetic. -* file name suffix: Overall Options. -* file names: Link Options. -* files and passes of the compiler: Passes. -* final pass: Passes. -* final_scan_insn: Function Entry. -* final_sequence: Instruction Output. -* fix: Conversions. -* fix: Conversions. -* fixed register: Register Basics. -* fixed_regs: Register Basics. -* flags in RTL expression: Flags. -* float: Conversions. -* float_extend: Conversions. -* float_truncate: Conversions. -* floating point format and cross compilation: Cross-compilation. -* force_reg: Standard Names. -* frame layout: Frame Layout. -* frame_pointer_needed: Function Entry. -* frame_pointer_rtx: Frame Registers. -* function attributes: Function Attributes. -* function call conventions: Interface. -* function entry and exit: Function Entry. -* function pointers, arithmetic: Pointer Arith. -* function prototype declarations: Function Prototypes. -* function units, for scheduling: Function Units. -* function, size of pointer to: Pointer Arith. -* function-call insns: Calls. -* functions that have no side effects: Function Attributes. -* functions that never return: Function Attributes. -* functions, leaf: Leaf Functions. -* ge: Comparisons. -* gencodes: Passes. -* genconfig: Passes. -* general_operand: RTL Template. -* generalized lvalues: Lvalues. -* generating assembler output: Output Statement. -* generating insns: RTL Template. -* genflags: Passes. -* get_attr: Expressions. -* get_attr_length: Insn Lengths. -* get_frame_size: Elimination. -* get_insns: Insns. -* get_last_insn: Insns. -* geu: Comparisons. -* global offset table: Code Gen Options. -* global register after longjmp: Global Reg Vars. -* global register allocation: Passes. -* global register variables: Global Reg Vars. -* goto with computed label: Labels as Values. -* gp-relative references (MIPS): MIPS Options. -* greater than: Comparisons. -* greater than: Comparisons. -* greater than: Comparisons. -* grouping options: Invoking GCC. -* gt: Comparisons. -* gtu: Comparisons. -* hard registers: Regs and Memory. -* hardware models and configurations, specifying: Submodel Options. -* header files and VMS: Include Files and VMS. -* high: Constants. -* i386 Options: i386 Options. -* identifier names, dollar signs in: Dollar Signs. -* identifiers, names in assembler code: Asm Labels. -* identifying source, compiler (88k): M88K Options. -* if_then_else: Comparisons. -* immediate_operand: RTL Template. -* in_data: Sections. -* in_struct: Flags. -* in_text: Sections. -* include files and VMS: Include Files and VMS. -* inclusive-or, bitwise: Arithmetic. -* incompatibilities of GNU CC: Incompatibilities. -* increment operators: Bug Criteria. -* initialization routines: Constructor Output. -* initializations in expressions: Constructors. -* initializers with labeled elements: Labeled Elements. -* initializers, non-constant: Initializers. -* inline functions: Inline. -* inline functions, omission of: Inline. -* inline, automatic: Passes. -* insn: Insns. -* insn attributes: Insn Attributes. -* insn canonicalization: Insn Canonicalizations. -* insn lengths, computing: Insn Lengths. -* insn splitting: Insn Splitting. -* insn-attr.h: Defining Attributes. -* insn_list: Insns. -* insns: Insns. -* insns, generating: RTL Template. -* insns, recognizing: RTL Template. -* installation trouble: Trouble. -* installing GNU CC: Installation. -* installing GNU CC on Unos: Unos Install. -* installing GNU CC on VMS: VMS Install. -* installing GNU CC on the 3b1: 3b1 Install. -* installing GNU CC on the Sun: Sun Install. -* instruction attributes: Insn Attributes. -* instruction combination: Passes. -* instruction patterns: Patterns. -* instruction recognizer: Passes. -* instruction scheduling: Passes. -* instruction scheduling: Passes. -* instruction splitting: Insn Splitting. -* integrated: Flags. -* integrating function code: Inline. -* interfacing to GNU CC output: Interface. -* introduction: Top. -* invalid assembly code: Bug Criteria. -* invalid input: Bug Criteria. -* ior: Arithmetic. -* isinf: Cross-compilation. -* isnan: Cross-compilation. -* jump instruction patterns: Jump Patterns. -* jump instructions and set: Side Effects. -* jump optimization: Passes. -* jump threading: Passes. -* jump_insn: Insns. -* keywords, alternate: Alternate Keywords. -* known causes of trouble: Trouble. -* label_ref: Constants. -* labeled elements in initializers: Labeled Elements. -* labels as values: Labels as Values. -* language dialect options: Dialect Options. -* large bit shifts (88k): M88K Options. -* large return values: Aggregate Return. -* ldexp: Cross-compilation. -* le: Comparisons. -* leaf functions: Leaf Functions. -* leaf_function: Leaf Functions. -* leaf_function_p: Standard Names. -* left rotate: Arithmetic. -* left shift: Arithmetic. -* left shift: Arithmetic. -* length-zero arrays: Zero Length. -* less than: Comparisons. -* less than or equal: Comparisons. -* leu: Comparisons. -* library subroutine names: Library Calls. -* link options: Link Options. -* lo_sum: Arithmetic. -* load address instruction: Simple Constraints. -* local labels: Local Labels. -* local register allocation: Passes. -* local variables in macros: Naming Types. -* local variables, specifying registers: Local Reg Vars. -* logical shift: Arithmetic. -* logical-and, bitwise: Arithmetic. -* longjmp: Global Reg Vars. -* loop optimization: Passes. -* lshift: Arithmetic. -* lshiftrt: Arithmetic. -* lt: Comparisons. -* ltu: Comparisons. -* lvalues, generalized: Lvalues. -* machine dependent options: Submodel Options. -* machine description macros: Target Macros. -* machine descriptions: Machine Desc. -* machine mode conversions: Conversions. -* machine modes: Machine Modes. -* macro with variable arguments: Macro Varargs. -* macros containing asm: Extended Asm. -* macros, inline alternative: Inline. -* macros, local labels: Local Labels. -* macros, local variables in: Naming Types. -* macros, statements in expressions: Statement Exprs. -* macros, target description: Target Macros. -* macros, types of arguments: Typeof. -* make: Preprocessor Options. -* make_safe_from: Expander Definitions. -* match_dup: RTL Template. -* match_operand: RTL Template. -* match_operator: RTL Template. -* match_parallel: RTL Template. -* match_scratch: RTL Template. -* matching constraint: Simple Constraints. -* matching operands: Output Template. -* math libraries: Interface. -* math, in RTL: Arithmetic. -* mcount: Profiling. -* mem: Regs and Memory. -* memory reference, nonoffsettable: Simple Constraints. -* memory references in constraints: Simple Constraints. -* messages, warning: Warning Options. -* middle-operands, omitted: Conditionals. -* minus: Arithmetic. -* mod: Arithmetic. -* mode classes: Machine Modes. -* modifiers in constraints: Modifiers. -* mult: Arithmetic. -* multiple alternative constraints: Multi-Alternative. -* multiplication: Arithmetic. -* multiprecision arithmetic: Long Long. -* name augmentation: VMS Misc. -* named patterns and conditions: Patterns. -* names used in assembler code: Asm Labels. -* names, pattern: Standard Names. -* naming types: Naming Types. -* ne: Comparisons. -* neg: Arithmetic. -* nested functions: Nested Functions. -* nested functions, trampolines for: Trampolines. -* next_cc0_user: Jump Patterns. -* nil: RTL Objects. -* no constraints: No Constraints. -* no-op move instructions: Passes. -* non-constant initializers: Initializers. -* non-static inline function: Inline. -* nongcc_SI_type: Library Calls. -* nonoffsettable memory reference: Simple Constraints. -* not: Arithmetic. -* not equal: Comparisons. -* not using constraints: No Constraints. -* note: Insns. -* obstack_free: 3b1 Install. -* offsettable address: Simple Constraints. -* old-style function definitions: Function Prototypes. -* omitted middle-operands: Conditionals. -* open coding: Inline. -* operand access: Accessors. -* operand constraints: Constraints. -* operand substitution: Output Template. -* operands: Patterns. -* optimize options: Optimize Options. -* optional hardware or system features: Run-time Target. -* options to control warnings: Warning Options. -* options, GNU CC command: Invoking GCC. -* options, code generation: Code Gen Options. -* options, debugging: Debugging Options. -* options, dialect: Dialect Options. -* options, directory search: Directory Options. -* options, grouping: Invoking GCC. -* options, linking: Link Options. -* options, optimization: Optimize Options. -* options, order: Invoking GCC. -* options, preprocessor: Preprocessor Options. -* order of options: Invoking GCC. -* order of register allocation: Allocation Order. -* other directory, compilation in: Other Dir. -* output file option: Overall Options. -* output of assembler code: File Framework. -* output statements: Output Statement. -* output templates: Output Template. -* output_addr_const: Data Output. -* output_asm_insn: Output Statement. -* overflow while constant folding: Cross-compilation. -* parallel: Side Effects. -* parameter forward declaration: Variable Length. -* parameters, miscellaneous: Misc. -* parser generator, Bison: Installation. -* parsing pass: Passes. -* passes and files of the compiler: Passes. -* passing arguments: Interface. -* pattern conditions: Patterns. -* pattern names: Standard Names. -* patterns: Patterns. -* pc: Regs and Memory. -* pc_rtx: Regs and Memory. -* peephole optimization: Passes. -* peephole optimization, RTL representation: Side Effects. -* peephole optimizer definitions: Peephole Definitions. -* percent sign: Output Template. -* perform_...: Library Calls. -* plus: Arithmetic. -* pointer arguments: Function Attributes. -* portability: Portability. -* position independent code: PIC. -* post_dec: Incdec. -* post_inc: Incdec. -* pragma: Misc. -* pragma, reason for not using: Function Attributes. -* pre_dec: Incdec. -* pre_inc: Incdec. -* predefined macros: Run-time Target. -* preprocessor options: Preprocessor Options. -* prev_cc0_setter: Jump Patterns. -* prev_nonnote_insn: Peephole Definitions. -* product: Arithmetic. -* profiling, code generation: Profiling. -* program counter: Regs and Memory. -* prologue: Function Entry. -* promotion of formal parameters: Function Prototypes. -* pseudo registers: Regs and Memory. -* push address instruction: Simple Constraints. -* putenv: Config. -* question mark: Multi-Alternative. -* quotient: Arithmetic. -* r0-relative references (88k): M88K Options. -* ranges in case statements: Case Ranges. -* read-only strings: Incompatibilities. -* recog_operand: Instruction Output. -* recognizing insns: RTL Template. -* reg: Regs and Memory. -* reg_names: Instruction Output. -* register allocation: Passes. -* register allocation order: Allocation Order. -* register allocation, stupid: Passes. -* register class definitions: Register Classes. -* register class preference constraints: Class Preferences. -* register class preference pass: Passes. -* register pairs: Values in Registers. -* register positions in frame (88k): M88K Options. -* register positions in frame (88k): M88K Options. -* register usage: Registers. -* register use analysis: Passes. -* register variable after longjmp: Global Reg Vars. -* register-to-stack conversion: Passes. -* register_operand: RTL Template. -* registers: Extended Asm. -* registers arguments: Register Arguments. -* registers for local variables: Local Reg Vars. -* registers in constraints: Simple Constraints. -* registers, global allocation: Explicit Reg Vars. -* registers, global variables in: Global Reg Vars. -* regs_ever_live: Function Entry. -* relative costs: Costs. -* reload pass: Regs and Memory. -* reload_completed: Standard Names. -* reload_in_progress: Standard Names. -* reloading: Passes. -* remainder: Arithmetic. -* reporting bugs: Bugs. -* representation of RTL: RTL. -* rest argument (in macro): Macro Varargs. -* rest_of_compilation: Passes. -* rest_of_decl_compilation: Passes. -* return: Side Effects. -* return value of main: VMS Misc. -* return values in registers: Scalar Return. -* returning aggregate values: Aggregate Return. -* returning structures and unions: Interface. -* right rotate: Arithmetic. -* right shift: Arithmetic. -* rotate: Arithmetic. -* rotate: Arithmetic. -* rotatert: Arithmetic. -* run-time conventions: Interface. -* run-time options: Code Gen Options. -* run-time target specification: Run-time Target. -* saveable_obstack: Addressing Modes. -* scalars, returned as values: Scalar Return. -* scheduling, delayed branch: Passes. -* scheduling, instruction: Passes. -* scheduling, instruction: Passes. -* scope of a variable length array: Variable Length. -* scope of declaration: Disappointments. -* scope of external declarations: Incompatibilities. -* scratch: Regs and Memory. -* scratch operands: Regs and Memory. -* search path: Directory Options. -* separate directory, compilation in: Other Dir. -* sequence: Side Effects. -* set: Side Effects. -* set_attr: Tagging Insns. -* set_attr_alternative: Tagging Insns. -* setjmp: Global Reg Vars. -* shared VMS run time system: VMS Misc. -* shared strings: Incompatibilities. -* sharing of RTL components: Sharing. -* shift: Arithmetic. -* side effect in ?:: Conditionals. -* side effects, macro argument: Statement Exprs. -* sign_extend: Conversions. -* sign_extract: Bit Fields. -* signed division: Arithmetic. -* signed maximum: Arithmetic. -* signed minimum: Arithmetic. -* simple constraints: Simple Constraints. -* simplifications, arithmetic: Passes. -* sizeof: Typeof. -* smaller data references (88k): M88K Options. -* smaller data references (MIPS): MIPS Options. -* smax: Arithmetic. -* smin: Arithmetic. -* specified registers: Explicit Reg Vars. -* specifying compiler version and target machine: Target Options. -* specifying hardware config: Submodel Options. -* specifying machine version: Target Options. -* specifying registers for local variables: Local Reg Vars. -* speed of instructions: Costs. -* splitting instructions: Insn Splitting. -* sqrt: Arithmetic. -* square root: Arithmetic. -* stack arguments: Stack Arguments. -* stack frame layout: Frame Layout. -* stack_pointer_rtx: Frame Registers. -* stage1: Installation. -* standard pattern names: Standard Names. -* statements inside expressions: Statement Exprs. -* storage layout: Storage Layout. -* strcpy: Storage Layout. -* strength-reduction: Passes. -* strict_low_part: RTL Declarations. -* string constants: Incompatibilities. -* structure passing (88k): M88K Options. -* structure value address: Aggregate Return. -* structures: Incompatibilities. -* structures, constructor expression: Constructors. -* structures, returning: Interface. -* stupid register allocation: Passes. -* submodel options: Submodel Options. -* subreg: Regs and Memory. -* subscripting: Subscripting. -* subscripting and function values: Subscripting. -* suppressing warnings: Warning Options. -* symbol_ref: Constants. -* symbolic label: Sharing. -* syntax checking: Warning Options. -* sys_siglist: Config. -* tagging insns: Tagging Insns. -* tail recursion optimization: Passes. -* target description macros: Target Macros. -* target machine, specifying: Target Options. -* target options: Target Options. -* target specifications: Run-time Target. -* target-parameter-dependent code: Passes. -* termination routines: Constructor Output. -* text_section: Sections. -* thunks: Nested Functions. -* top level of compiler: Passes. -* traditional C language: Dialect Options. -* trampolines for nested functions: Trampolines. -* truncate: Conversions. -* type alignment: Alignment. -* typedef names as function parameters: Incompatibilities. -* typeof: Typeof. -* udiv: Arithmetic. -* umax: Arithmetic. -* umin: Arithmetic. -* umod: Arithmetic. -* unchanging: Flags. -* undefined behavior: Bug Criteria. -* undefined function value: Bug Criteria. -* underscores in variables in macros: Naming Types. -* underscores, avoiding (88k): M88K Options. -* union, casting to a: Cast to Union. -* unions: Incompatibilities. -* unions, returning: Interface. -* unreachable code: Passes. -* unshare_all_rtl: Sharing. -* unsigned division: Arithmetic. -* unsigned greater than: Comparisons. -* unsigned greater than: Comparisons. -* unsigned less than: Comparisons. -* unsigned less than: Comparisons. -* unsigned minimum and maximum: Arithmetic. -* unsigned_fix: Conversions. -* unsigned_float: Conversions. -* unspec: Side Effects. -* unspec_volatile: Side Effects. -* use: Side Effects. -* used: Flags. -* value after longjmp: Global Reg Vars. -* values, returned by functions: Scalar Return. -* varargs implementation: Varargs. -* variable alignment: Alignment. -* variable attributes: Variable Attributes. -* variable number of arguments: Macro Varargs. -* variable-length array scope: Variable Length. -* variable-length arrays: Variable Length. -* variables in specified registers: Explicit Reg Vars. -* variables, local, in macros: Naming Types. -* void pointers, arithmetic: Pointer Arith. -* void, size of pointer to: Pointer Arith. -* volatil: Flags. -* volatile memory references: Flags. -* voting between constraint alternatives: Class Preferences. -* vprintf: Config. -* warning messages: Warning Options. -* which_alternative: Output Statement. -* whitespace: Incompatibilities. -* word_mode: Machine Modes. -* xor: Arithmetic. -* zero division on 88k: M88K Options. -* zero-length arrays: Zero Length. -* zero_extend: Conversions. -* zero_extract: Bit Fields. +* Register Basics:: Number and kinds of registers. +* Allocation Order:: Order in which registers are allocated. +* Values in Registers:: What kinds of values each reg can hold. +* Leaf Functions:: Renumbering registers for leaf functions. +* Stack Registers:: Handling a register stack such as 80387. +* Obsolete Register Macros:: Macros formerly used for the 80387. + + +File: gcc.info, Node: Register Basics, Next: Allocation Order, Up: Registers + +Basic Characteristics of Registers +---------------------------------- + + Registers have various characteristics. + +`FIRST_PSEUDO_REGISTER' + Number of hardware registers known to the compiler. They receive + numbers 0 through `FIRST_PSEUDO_REGISTER-1'; thus, the first + pseudo register's number really is assigned the number + `FIRST_PSEUDO_REGISTER'. + +`FIXED_REGISTERS' + An initializer that says which registers are used for fixed + purposes all throughout the compiled code and are therefore not + available for general allocation. These would include the stack + pointer, the frame pointer (except on machines where that can be + used as a general register when no frame pointer is needed), the + program counter on machines where that is considered one of the + addressable registers, and any other numbered register with a + standard use. + + This information is expressed as a sequence of numbers, separated + by commas and surrounded by braces. The Nth number is 1 if + register N is fixed, 0 otherwise. + + The table initialized from this macro, and the table initialized by + the following one, may be overridden at run time either + automatically, by the actions of the macro + `CONDITIONAL_REGISTER_USAGE', or by the user with the command + options `-ffixed-REG', `-fcall-used-REG' and `-fcall-saved-REG'. + +`CALL_USED_REGISTERS' + Like `FIXED_REGISTERS' but has 1 for each register that is + clobbered (in general) by function calls as well as for fixed + registers. This macro therefore identifies the registers that are + not available for general allocation of values that must live + across function calls. + + If a register has 0 in `CALL_USED_REGISTERS', the compiler + automatically saves it on function entry and restores it on + function exit, if the register is used within the function. + +`CONDITIONAL_REGISTER_USAGE' + Zero or more C statements that may conditionally modify two + variables `fixed_regs' and `call_used_regs' (both of type `char + []') after they have been initialized from the two preceding + macros. + + This is necessary in case the fixed or call-clobbered registers + depend on target flags. + + You need not define this macro if it has no work to do. + + If the usage of an entire class of registers depends on the target + flags, you may indicate this to GCC by using this macro to modify + `fixed_regs' and `call_used_regs' to 1 for each of the registers + in the classes which should not be used by GCC. Also define the + macro `REG_CLASS_FROM_LETTER' to return `NO_REGS' if it is called + with a letter for a class that shouldn't be used. + + (However, if this class is not included in `GENERAL_REGS' and all + of the insn patterns whose constraints permit this class are + controlled by target switches, then GCC will automatically avoid + using these registers when the target switches are opposed to + them.) + +`NON_SAVING_SETJMP' + If this macro is defined and has a nonzero value, it means that + `setjmp' and related functions fail to save the registers, or that + `longjmp' fails to restore them. To compensate, the compiler + avoids putting variables in registers in functions that use + `setjmp'. + +`INCOMING_REGNO (OUT)' + Define this macro if the target machine has register windows. + This C expression returns the register number as seen by the + called function corresponding to the register number OUT as seen + by the calling function. Return OUT if register number OUT is not + an outbound register. + +`OUTGOING_REGNO (IN)' + Define this macro if the target machine has register windows. + This C expression returns the register number as seen by the + calling function corresponding to the register number IN as seen + by the called function. Return IN if register number IN is not an + inbound register. + + +File: gcc.info, Node: Allocation Order, Next: Values in Registers, Prev: Register Basics, Up: Registers + +Order of Allocation of Registers +-------------------------------- + + Registers are allocated in order. + +`REG_ALLOC_ORDER' + If defined, an initializer for a vector of integers, containing the + numbers of hard registers in the order in which GNU CC should + prefer to use them (from most preferred to least). + + If this macro is not defined, registers are used lowest numbered + first (all else being equal). + + One use of this macro is on machines where the highest numbered + registers must always be saved and the save-multiple-registers + instruction supports only sequences of consecutive registers. On + such machines, define `REG_ALLOC_ORDER' to be an initializer that + lists the highest numbered allocatable register first. + +`ORDER_REGS_FOR_LOCAL_ALLOC' + A C statement (sans semicolon) to choose the order in which to + allocate hard registers for pseudo-registers local to a basic + block. + + Store the desired register order in the array `reg_alloc_order'. + Element 0 should be the register to allocate first; element 1, the + next register; and so on. + + The macro body should not assume anything about the contents of + `reg_alloc_order' before execution of the macro. + + On most machines, it is not necessary to define this macro. + + +File: gcc.info, Node: Values in Registers, Next: Leaf Functions, Prev: Allocation Order, Up: Registers + +How Values Fit in Registers +--------------------------- + + This section discusses the macros that describe which kinds of values +(specifically, which machine modes) each register can hold, and how many +consecutive registers are needed for a given mode. + +`HARD_REGNO_NREGS (REGNO, MODE)' + A C expression for the number of consecutive hard registers, + starting at register number REGNO, required to hold a value of mode + MODE. + + On a machine where all registers are exactly one word, a suitable + definition of this macro is + + #define HARD_REGNO_NREGS(REGNO, MODE) \ + ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) \ + / UNITS_PER_WORD)) + +`HARD_REGNO_MODE_OK (REGNO, MODE)' + A C expression that is nonzero if it is permissible to store a + value of mode MODE in hard register number REGNO (or in several + registers starting with that one). For a machine where all + registers are equivalent, a suitable definition is + + #define HARD_REGNO_MODE_OK(REGNO, MODE) 1 + + It is not necessary for this macro to check for the numbers of + fixed registers, because the allocation mechanism considers them + to be always occupied. + + On some machines, double-precision values must be kept in even/odd + register pairs. The way to implement that is to define this macro + to reject odd register numbers for such modes. + + The minimum requirement for a mode to be OK in a register is that + the `movMODE' instruction pattern support moves between the + register and any other hard register for which the mode is OK; and + that moving a value into the register and back out not alter it. + + Since the same instruction used to move `SImode' will work for all + narrower integer modes, it is not necessary on any machine for + `HARD_REGNO_MODE_OK' to distinguish between these modes, provided + you define patterns `movhi', etc., to take advantage of this. This + is useful because of the interaction between `HARD_REGNO_MODE_OK' + and `MODES_TIEABLE_P'; it is very desirable for all integer modes + to be tieable. + + Many machines have special registers for floating point arithmetic. + Often people assume that floating point machine modes are allowed + only in floating point registers. This is not true. Any + registers that can hold integers can safely *hold* a floating + point machine mode, whether or not floating arithmetic can be done + on it in those registers. Integer move instructions can be used + to move the values. + + On some machines, though, the converse is true: fixed-point machine + modes may not go in floating registers. This is true if the + floating registers normalize any value stored in them, because + storing a non-floating value there would garble it. In this case, + `HARD_REGNO_MODE_OK' should reject fixed-point machine modes in + floating registers. But if the floating registers do not + automatically normalize, if you can store any bit pattern in one + and retrieve it unchanged without a trap, then any machine mode + may go in a floating register, so you can define this macro to say + so. + + The primary significance of special floating registers is rather + that they are the registers acceptable in floating point arithmetic + instructions. However, this is of no concern to + `HARD_REGNO_MODE_OK'. You handle it by writing the proper + constraints for those instructions. + + On some machines, the floating registers are especially slow to + access, so that it is better to store a value in a stack frame + than in such a register if floating point arithmetic is not being + done. As long as the floating registers are not in class + `GENERAL_REGS', they will not be used unless some pattern's + constraint asks for one. + +`MODES_TIEABLE_P (MODE1, MODE2)' + A C expression that is nonzero if it is desirable to choose + register allocation so as to avoid move instructions between a + value of mode MODE1 and a value of mode MODE2. + + If `HARD_REGNO_MODE_OK (R, MODE1)' and `HARD_REGNO_MODE_OK (R, + MODE2)' are ever different for any R, then `MODES_TIEABLE_P (MODE1, + MODE2)' must be zero. + + +File: gcc.info, Node: Leaf Functions, Next: Stack Registers, Prev: Values in Registers, Up: Registers + +Handling Leaf Functions +----------------------- + + On some machines, a leaf function (i.e., one which makes no calls) +can run more efficiently if it does not make its own register window. +Often this means it is required to receive its arguments in the +registers where they are passed by the caller, instead of the registers +where they would normally arrive. + + The special treatment for leaf functions generally applies only when +other conditions are met; for example, often they may use only those +registers for its own variables and temporaries. We use the term "leaf +function" to mean a function that is suitable for this special +handling, so that functions with no calls are not necessarily "leaf +functions". + + GNU CC assigns register numbers before it knows whether the function +is suitable for leaf function treatment. So it needs to renumber the +registers in order to output a leaf function. The following macros +accomplish this. + +`LEAF_REGISTERS' + A C initializer for a vector, indexed by hard register number, + which contains 1 for a register that is allowable in a candidate + for leaf function treatment. + + If leaf function treatment involves renumbering the registers, + then the registers marked here should be the ones before + renumbering--those that GNU CC would ordinarily allocate. The + registers which will actually be used in the assembler code, after + renumbering, should not be marked with 1 in this vector. + + Define this macro only if the target machine offers a way to + optimize the treatment of leaf functions. + +`LEAF_REG_REMAP (REGNO)' + A C expression whose value is the register number to which REGNO + should be renumbered, when a function is treated as a leaf + function. + + If REGNO is a register number which should not appear in a leaf + function before renumbering, then the expression should yield -1, + which will cause the compiler to abort. + + Define this macro only if the target machine offers a way to + optimize the treatment of leaf functions, and registers need to be + renumbered to do this. + + Normally, `FUNCTION_PROLOGUE' and `FUNCTION_EPILOGUE' must treat +leaf functions specially. It can test the C variable `leaf_function' +which is nonzero for leaf functions. (The variable `leaf_function' is +defined only if `LEAF_REGISTERS' is defined.) + + +File: gcc.info, Node: Stack Registers, Next: Obsolete Register Macros, Prev: Leaf Functions, Up: Registers + +Registers That Form a Stack +--------------------------- + + There are special features to handle computers where some of the +"registers" form a stack, as in the 80387 coprocessor for the 80386. +Stack registers are normally written by pushing onto the stack, and are +numbered relative to the top of the stack. + + Currently, GNU CC can only handle one group of stack-like registers, +and they must be consecutively numbered. + +`STACK_REGS' + Define this if the machine has any stack-like registers. + +`FIRST_STACK_REG' + The number of the first stack-like register. This one is the top + of the stack. +`LAST_STACK_REG' + The number of the last stack-like register. This one is the + bottom of the stack.