--- gcc/gcc.info-19 2018/04/24 18:00:27 1.1 +++ gcc/gcc.info-19 2018/04/24 18:17:32 1.1.1.4 @@ -1,9 +1,13 @@ -This is Info file gcc.info, produced by Makeinfo-1.49 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 @@ -11,1686 +15,1057 @@ 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 "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. +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 "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. +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: Obsolete Register Macros, Prev: Stack Registers, Up: Registers + +Obsolete Macros for Controlling Register Usage +---------------------------------------------- + + These features do not work very well. They exist because they used +to be required to generate correct code for the 80387 coprocessor of the +80386. They are no longer used by that machine description and may be +removed in a later version of the compiler. Don't use them! + +`OVERLAPPING_REGNO_P (REGNO)' + If defined, this is a C expression whose value is nonzero if hard + register number REGNO is an overlapping register. This means a + hard register which overlaps a hard register with a different + number. (Such overlap is undesirable, but occasionally it allows + a machine to be supported which otherwise could not be.) This + macro must return nonzero for *all* the registers which overlap + each other. GNU CC can use an overlapping register only in + certain limited ways. It can be used for allocation within a + basic block, and may be spilled for reloading; that is all. + + If this macro is not defined, it means that none of the hard + registers overlap each other. This is the usual situation. + +`INSN_CLOBBERS_REGNO_P (INSN, REGNO)' + If defined, this is a C expression whose value should be nonzero if + the insn INSN has the effect of mysteriously clobbering the + contents of hard register number REGNO. By "mysterious" we mean + that the insn's RTL expression doesn't describe such an effect. + + If this macro is not defined, it means that no insn clobbers + registers mysteriously. This is the usual situation; all else + being equal, it is best for the RTL expression to show all the + activity. + +`PRESERVE_DEATH_INFO_REGNO_P (REGNO)' + If defined, this is a C expression whose value is nonzero if + accurate `REG_DEAD' notes are needed for hard register number REGNO + at the time of outputting the assembler code. When this is so, a + few optimizations that take place after register allocation and + could invalidate the death notes are not done when this register is + involved. + + You would arrange to preserve death info for a register when some + of the code in the machine description which is executed to write + the assembler code looks at the death notes. This is necessary + only when the actual hardware feature which GNU CC thinks of as a + register is not actually a register of the usual sort. (It might, + for example, be a hardware stack.) + + If this macro is not defined, it means that no death notes need to + be preserved. This is the usual situation. + + +File: gcc.info, Node: Register Classes, Next: Stack and Calling, Prev: Registers, Up: Target Macros + +Register Classes +================ + + On many machines, the numbered registers are not all equivalent. +For example, certain registers may not be allowed for indexed +addressing; certain registers may not be allowed in some instructions. +These machine restrictions are described to the compiler using +"register classes". + + You define a number of register classes, giving each one a name and +saying which of the registers belong to it. Then you can specify +register classes that are allowed as operands to particular instruction +patterns. + + In general, each register will belong to several classes. In fact, +one class must be named `ALL_REGS' and contain all the registers. +Another class must be named `NO_REGS' and contain no registers. Often +the union of two classes will be another class; however, this is not +required. + + One of the classes must be named `GENERAL_REGS'. There is nothing +terribly special about the name, but the operand constraint letters `r' +and `g' specify this class. If `GENERAL_REGS' is the same as +`ALL_REGS', just define it as a macro which expands to `ALL_REGS'. + + Order the classes so that if class X is contained in class Y then X +has a lower class number than Y. + + The way classes other than `GENERAL_REGS' are specified in operand +constraints is through machine-dependent operand constraint letters. +You can define such letters to correspond to various classes, then use +them in operand constraints. + + You should define a class for the union of two classes whenever some +instruction allows both classes. For example, if an instruction allows +either a floating point (coprocessor) register or a general register +for a certain operand, you should define a class `FLOAT_OR_GENERAL_REGS' +which includes both of them. Otherwise you will get suboptimal code. + + You must also specify certain redundant information about the +register classes: for each class, which classes contain it and which +ones are contained in it; for each pair of classes, the largest class +contained in their union. + + When a value occupying several consecutive registers is expected in a +certain class, all the registers used must belong to that class. +Therefore, register classes cannot be used to enforce a requirement for +a register pair to start with an even-numbered register. The way to +specify this requirement is with `HARD_REGNO_MODE_OK'. + + Register classes used for input-operands of bitwise-and or shift +instructions have a special requirement: each such class must have, for +each fixed-point machine mode, a subclass whose registers can transfer +that mode to or from memory. For example, on some machines, the +operations for single-byte values (`QImode') are limited to certain +registers. When this is so, each register class that is used in a +bitwise-and or shift instruction must have a subclass consisting of +registers from which single-byte values can be loaded or stored. This +is so that `PREFERRED_RELOAD_CLASS' can always have a possible value to +return. + +`enum reg_class' + An enumeral type that must be defined with all the register class + names as enumeral values. `NO_REGS' must be first. `ALL_REGS' + must be the last register class, followed by one more enumeral + value, `LIM_REG_CLASSES', which is not a register class but rather + tells how many classes there are. + + Each register class has a number, which is the value of casting + the class name to type `int'. The number serves as an index in + many of the tables described below. + +`N_REG_CLASSES' + The number of distinct register classes, defined as follows: + + #define N_REG_CLASSES (int) LIM_REG_CLASSES + +`REG_CLASS_NAMES' + An initializer containing the names of the register classes as C + string constants. These names are used in writing some of the + debugging dumps. + +`REG_CLASS_CONTENTS' + An initializer containing the contents of the register classes, as + integers which are bit masks. The Nth integer specifies the + contents of class N. The way the integer MASK is interpreted is + that register R is in the class if `MASK & (1 << R)' is 1. + + When the machine has more than 32 registers, an integer does not + suffice. Then the integers are replaced by sub-initializers, + braced groupings containing several integers. Each + sub-initializer must be suitable as an initializer for the type + `HARD_REG_SET' which is defined in `hard-reg-set.h'. + +`REGNO_REG_CLASS (REGNO)' + A C expression whose value is a register class containing hard + register REGNO. In general there is more than one such class; + choose a class which is "minimal", meaning that no smaller class + also contains the register. + +`BASE_REG_CLASS' + A macro whose definition is the name of the class to which a valid + base register must belong. A base register is one used in an + address which is the register value plus a displacement. + +`INDEX_REG_CLASS' + A macro whose definition is the name of the class to which a valid + index register must belong. An index register is one used in an + address where its value is either multiplied by a scale factor or + added to another register (as well as added to a displacement). + +`REG_CLASS_FROM_LETTER (CHAR)' + A C expression which defines the machine-dependent operand + constraint letters for register classes. If CHAR is such a + letter, the value should be the register class corresponding to + it. Otherwise, the value should be `NO_REGS'. The register + letter `r', corresponding to class `GENERAL_REGS', will not be + passed to this macro; you do not need to handle it. + +`REGNO_OK_FOR_BASE_P (NUM)' + A C expression which is nonzero if register number NUM is suitable + for use as a base register in operand addresses. It may be either + a suitable hard register or a pseudo register that has been + allocated such a hard register. + +`REGNO_OK_FOR_INDEX_P (NUM)' + A C expression which is nonzero if register number NUM is suitable + for use as an index register in operand addresses. It may be + either a suitable hard register or a pseudo register that has been + allocated such a hard register. + + The difference between an index register and a base register is + that the index register may be scaled. If an address involves the + sum of two registers, neither one of them scaled, then either one + may be labeled the "base" and the other the "index"; but whichever + labeling is used must fit the machine's constraints of which + registers may serve in each capacity. The compiler will try both + labelings, looking for one that is valid, and will reload one or + both registers only if neither labeling works. + +`PREFERRED_RELOAD_CLASS (X, CLASS)' + A C expression that places additional restrictions on the register + class to use when it is necessary to copy value X into a register + in class CLASS. The value is a register class; perhaps CLASS, or + perhaps another, smaller class. On many machines, the following + definition is safe: + + #define PREFERRED_RELOAD_CLASS(X,CLASS) CLASS + + Sometimes returning a more restrictive class makes better code. + For example, on the 68000, when X is an integer constant that is + in range for a `moveq' instruction, the value of this macro is + always `DATA_REGS' as long as CLASS includes the data registers. + Requiring a data register guarantees that a `moveq' will be used. + + If X is a `const_double', by returning `NO_REGS' you can force X + into a memory constant. This is useful on certain machines where + immediate floating values cannot be loaded into certain kinds of + registers. + +`PREFERRED_OUTPUT_RELOAD_CLASS (X, CLASS)' + Like `PREFERRED_RELOAD_CLASS', but for output reloads instead of + input reloads. If you don't define this macro, the default is to + use CLASS, unchanged. + +`LIMIT_RELOAD_CLASS (MODE, CLASS)' + A C expression that places additional restrictions on the register + class to use when it is necessary to be able to hold a value of + mode MODE in a reload register for which class CLASS would + ordinarily be used. + + Unlike `PREFERRED_RELOAD_CLASS', this macro should be used when + there are certain modes that simply can't go in certain reload + classes. + + The value is a register class; perhaps CLASS, or perhaps another, + smaller class. + + Don't define this macro unless the target machine has limitations + which require the macro to do something nontrivial. + +`SECONDARY_RELOAD_CLASS (CLASS, MODE, X)' +`SECONDARY_INPUT_RELOAD_CLASS (CLASS, MODE, X)' +`SECONDARY_OUTPUT_RELOAD_CLASS (CLASS, MODE, X)' + Many machines have some registers that cannot be copied directly + to or from memory or even from other types of registers. An + example is the `MQ' register, which on most machines, can only be + copied to or from general registers, but not memory. Some + machines allow copying all registers to and from memory, but + require a scratch register for stores to some memory locations + (e.g., those with symbolic address on the RT, and those with + certain symbolic address on the Sparc when compiling PIC). In + some cases, both an intermediate and a scratch register are + required. + + You should define these macros to indicate to the reload phase + that it may need to allocate at least one register for a reload in + addition to the register to contain the data. Specifically, if + copying X to a register CLASS in MODE requires an intermediate + register, you should define `SECONDARY_INPUT_RELOAD_CLASS' to + return the largest register class all of whose registers can be + used as intermediate registers or scratch registers. + + If copying a register CLASS in MODE to X requires an intermediate + or scratch register, `SECONDARY_OUTPUT_RELOAD_CLASS' should be + defined to return the largest register class required. If the + requirements for input and output reloads are the same, the macro + `SECONDARY_RELOAD_CLASS' should be used instead of defining both + macros identically. + + The values returned by these macros are often `GENERAL_REGS'. + Return `NO_REGS' if no spare register is needed; i.e., if X can be + directly copied to or from a register of CLASS in MODE without + requiring a scratch register. Do not define this macro if it + would always return `NO_REGS'. -Index -***** + If a scratch register is required (either with or without an + intermediate register), you should define patterns for + `reload_inM' or `reload_outM', as required (*note Standard + Names::.. These patterns, which will normally be implemented with + a `define_expand', should be similar to the `movM' patterns, + except that operand 2 is the scratch register. + + Define constraints for the reload register and scratch register + that contain a single register class. If the original reload + register (whose class is CLASS) can meet the constraint given in + the pattern, the value returned by these macros is used for the + class of the scratch register. Otherwise, two additional reload + registers are required. Their classes are obtained from the + constraints in the insn pattern. + + X might be a pseudo-register or a `subreg' of a pseudo-register, + which could either be in a hard register or in memory. Use + `true_regnum' to find out; it will return -1 if the pseudo is in + memory and the hard register number if it is in a register. + + These macros should not be used in the case where a particular + class of registers can only be copied to memory and not to another + class of registers. In that case, secondary reload registers are + not needed and would not be helpful. Instead, a stack location + must be used to perform the copy and the `movM' pattern should use + memory as a intermediate storage. This case often occurs between + floating-point and general registers. + +`SECONDARY_MEMORY_NEEDED (CLASS1, CLASS2, M)' + Certain machines have the property that some registers cannot be + copied to some other registers without using memory. Define this + macro on those machines to be a C expression that is non-zero if + objects of mode M in registers of CLASS1 can only be copied to + registers of class CLASS2 by storing a register of CLASS1 into + memory and loading that memory location into a register of CLASS2. + + Do not define this macro if its value would always be zero. + +`SECONDARY_MEMORY_NEEDED_RTX (MODE)' + Normally when `SECONDARY_MEMORY_NEEDED' is defined, the compiler + allocates a stack slot for a memory location needed for register + copies. If this macro is defined, the compiler instead uses the + memory location defined by this macro. + + Do not define this macro if you do not define + `SECONDARY_MEMORY_NEEDED'. + +`SECONDARY_MEMORY_NEEDED_MODE (MODE)' + When the compiler needs a secondary memory location to copy + between two registers of mode MODE, it normally allocates + sufficient memory to hold a quantity of `BITS_PER_WORD' bits and + performs the store and load operations in a mode that many bits + wide and whose class is the same as that of MODE. + + This is right thing to do on most machines because it ensures that + all bits of the register are copied and prevents accesses to the + registers in a narrower mode, which some machines prohibit for + floating-point registers. + + However, this default behavior is not correct on some machines, + such as the DEC Alpha, that store short integers in floating-point + registers differently than in integer registers. On those + machines, the default widening will not work correctly and you + must define this macro to suppress that widening in some cases. + See the file `alpha.h' for details. + + Do not define this macro if you do not define + `SECONDARY_MEMORY_NEEDED' or if widening MODE to a mode that is + `BITS_PER_WORD' bits wide is correct for your machine. + +`SMALL_REGISTER_CLASSES' + Normally the compiler avoids choosing registers that have been + explicitly mentioned in the rtl as spill registers (these + registers are normally those used to pass parameters and return + values). However, some machines have so few registers of certain + classes that there would not be enough registers to use as spill + registers if this were done. + + Define `SMALL_REGISTER_CLASSES' on these machines. When it is + defined, the compiler allows registers explicitly used in the rtl + to be used as spill registers but avoids extending the lifetime of + these registers. + + It is always safe to define this macro, but if you unnecessarily + define it, you will reduce the amount of optimizations that can be + performed in some cases. If you do not define this macro when it + is required, the compiler will run out of spill registers and + print a fatal error message. For most machines, you should not + define this macro. + +`CLASS_LIKELY_SPILLED_P (CLASS)' + A C expression whose value is nonzero if pseudos that have been + assigned to registers of class CLASS would likely be spilled + because registers of CLASS are needed for spill registers. + + The default value of this macro returns 1 if CLASS has exactly one + register and zero otherwise. On most machines, this default + should be used. Only define this macro to some other expression + if pseudo allocated by `local-alloc.c' end up in memory because + their hard registers were needed for spill regisers. If this + macro returns nonzero for those classes, those pseudos will only + be allocated by `global.c', which knows how to reallocate the + pseudo to another register. If there would not be another + register available for reallocation, you should not change the + definition of this macro since the only effect of such a + definition would be to slow down register allocation. + +`CLASS_MAX_NREGS (CLASS, MODE)' + A C expression for the maximum number of consecutive registers of + class CLASS needed to hold a value of mode MODE. + + This is closely related to the macro `HARD_REGNO_NREGS'. In fact, + the value of the macro `CLASS_MAX_NREGS (CLASS, MODE)' should be + the maximum value of `HARD_REGNO_NREGS (REGNO, MODE)' for all + REGNO values in the class CLASS. + + This macro helps control the handling of multiple-word values in + the reload pass. + +`CLASS_CANNOT_CHANGE_SIZE' + If defined, a C expression for a class that contains registers + which the compiler must always access in a mode that is the same + size as the mode in which it loaded the register, unless neither + mode is integral. + + For the example, loading 32-bit integer or floating-point objects + into floating-point registers on the Alpha extends them to 64-bits. + Therefore loading a 64-bit object and then storing it as a 32-bit + object does not store the low-order 32-bits, as would be the case + for a normal register. Therefore, `alpha.h' defines this macro as + `FLOAT_REGS'. + + Three other special macros describe which operands fit which +constraint letters. + +`CONST_OK_FOR_LETTER_P (VALUE, C)' + A C expression that defines the machine-dependent operand + constraint letters that specify particular ranges of integer + values. If C is one of those letters, the expression should check + that VALUE, an integer, is in the appropriate range and return 1 + if so, 0 otherwise. If C is not one of those letters, the value + should be 0 regardless of VALUE. + +`CONST_DOUBLE_OK_FOR_LETTER_P (VALUE, C)' + A C expression that defines the machine-dependent operand + constraint letters that specify particular ranges of + `const_double' values. + + If C is one of those letters, the expression should check that + VALUE, an RTX of code `const_double', is in the appropriate range + and return 1 if so, 0 otherwise. If C is not one of those + letters, the value should be 0 regardless of VALUE. + + `const_double' is used for all floating-point constants and for + `DImode' fixed-point constants. A given letter can accept either + or both kinds of values. It can use `GET_MODE' to distinguish + between these kinds. + +`EXTRA_CONSTRAINT (VALUE, C)' + A C expression that defines the optional machine-dependent + constraint letters that can be used to segregate specific types of + operands, usually memory references, for the target machine. + Normally this macro will not be defined. If it is required for a + particular target machine, it should return 1 if VALUE corresponds + to the operand type represented by the constraint letter C. If C + is not defined as an extra constraint, the value returned should + be 0 regardless of VALUE. + + For example, on the ROMP, load instructions cannot have their + output in r0 if the memory reference contains a symbolic address. + Constraint letter `Q' is defined as representing a memory address + that does *not* contain a symbolic address. An alternative is + specified with a `Q' constraint on the input and `r' on the + output. The next alternative specifies `m' on the input and a + register class that does not include r0 on the output. + + +File: gcc.info, Node: Stack and Calling, Next: Varargs, Prev: Register Classes, Up: Target Macros + +Stack Layout and Calling Conventions +==================================== + + This describes the stack layout and calling conventions. * 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. -* absM2 instruction pattern: Standard Names. -* abs and attributes: Expressions. -* ACCUMULATE_OUTGOING_ARGS and stack frames: Function Entry. -* addM3 instruction pattern: Standard Names. -* addr_diff_vec, length of: Insn Lengths. -* addr_vec, length of: Insn Lengths. -* aligned attribute: Variable Attributes. -* 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. -* ARG_POINTER_REGNUM and virtual registers: Regs and Memory. -* 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. -* BITS_BIG_ENDIAN, effect on sign_extract: Bit Fields. -* BLKmode, and function return values: 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. -* EDOM, implicit usage: Library Calls. -* ENCODE_SECTION_INFO and address validation: Addressing Modes. -* ENCODE_SECTION_INFO usage: Instruction Output. -* eq and attributes: Expressions. -* errno, implicit usage: Library Calls. -* extendMN instruction pattern: Standard Names. -* extv instruction pattern: Standard Names. -* extzv instruction pattern: Standard Names. -* ffsM2 instruction pattern: Standard Names. -* FIRST_PARM_OFFSET and virtual registers: Regs and Memory. -* fixMN2 instruction pattern: Standard Names. -* fixunsMN2 instruction pattern: Standard Names. -* fixuns_truncMN2 instruction pattern: Standard Names. -* fix_truncMN2 instruction pattern: Standard Names. -* floatMN2 instruction pattern: Standard Names. -* floatunsMN2 instruction pattern: Standard Names. -* float as function value type: Incompatibilities. -* format attribute: Function Attributes. -* FRAME_GROWS_DOWNWARD and virtual registers: Regs and Memory. -* FRAME_POINTER_REGNUM and virtual registers: Regs and Memory. -* fscanf, and constant strings: Incompatibilities. -* ftruncM2 instruction pattern: Standard Names. -* FUNCTION_EPILOGUE and trampolines: Trampolines. -* FUNCTION_PROLOGUE and trampolines: Trampolines. -* 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. -* HImode, in insn: Insns. -* if_then_else and attributes: Expressions. -* if_then_else usage: Side Effects. -* 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. -* 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. -* in_struct, in subreg: 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: Dialect Options. -* longjmp and automatic variables: Interface. -* 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. -* mode attribute: Variable Attributes. -* 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. -* MUST_PASS_IN_STACK, and FUNCTION_ARG: Register Arguments. -* 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. -* packed attribute: Variable Attributes. -* pc and attributes: Insn Lengths. -* pc, RTL sharing: Sharing. -* plus and attributes: Expressions. -* plus, canonicalization of: Insn Canonicalizations. -* prof: Debugging Options. -* PUSH_ROUNDING, interaction with STACK_BOUNDARY: Storage Layout. -* QImode, in insn: Insns. -* qsort, and global register variables: Global Reg Vars. -* REG_PARM_STACK_SPACE, and FUNCTION_ARG: Register Arguments. -* 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. -* 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. -* subM3 instruction pattern: Standard Names. -* subreg and /s: Flags. -* subreg and /u: Flags. -* subreg, in strict_low_part: RTL Declarations. -* subreg, special reload handling: Regs and Memory. -* SYMBOL_REF_FLAG, in ENCODE_SECTION_INFO: Sections. -* 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 subreg: 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. -* WORDS_BIG_ENDIAN, effect on subreg: Regs and Memory. -* xorM3 instruction pattern: Standard Names. -* xor, canonicalization of: Insn Canonicalizations. -* zero_extendMN instruction pattern: Standard Names. -* zero_extract, canonicalization of: Insn Canonicalizations. -* libgcc.a: Library Calls. -* stdarg.h and register arguments: Register Arguments. -* stdarg.h and RT PC: RT Options. -* tm.h macros: Target Macros. -* varargs.h and RT PC: RT Options. -* VAXCRTL: VMS Misc. -* 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. -* d in constraint: Simple Constraints. -* E in constraint: Simple Constraints. -* F in constraint: Simple Constraints. -* g in constraint: Simple Constraints. -* G in constraint: Simple Constraints. -* H in constraint: Simple Constraints. -* i 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. -* Q, in constraint: Simple Constraints. -* r in constraint: Simple Constraints. -* store_multiple instruction pattern: Standard Names. -* s in constraint: Simple Constraints. -* V in constraint: Simple Constraints. -* X in constraint: Simple Constraints. -* _ in variables in macros: Naming Types. -* abort: Portability. -* abs: Arithmetic. -* absolute value: Arithmetic. -* access to operands: Accessors. -* accessors: Accessors. -* ACCUMULATE_OUTGOING_ARGS: Stack Arguments. -* ADDITIONAL_REGISTER_NAMES: Instruction Output. -* address: RTL Template. -* address constraints: Simple Constraints. -* address of a label: Labels as Values. -* addressing modes: Addressing Modes. -* ADDRESS_COST: Costs. -* address_operand: Simple Constraints. -* addr_diff_vec: Side Effects. -* addr_vec: Side Effects. -* ADJUST_COST: Costs. -* ADJUST_INSN_LENGTH: Insn Lengths. -* aggregates as return values: Aggregate Return. -* alignment: Alignment. -* Alliant: Interoperation. -* ALLOCATE_TRAMPOLINE: Trampolines. -* ALL_REGS: Register Classes. -* alternate keywords: Alternate Keywords. -* AMD29K options: AMD29K Options. -* analysis, data flow: Passes. -* and: Arithmetic. -* ANSI support: Dialect Options. -* apostrophes: Incompatibilities. -* ARGS_GROW_DOWNWARD: Frame Layout. -* argument passing: Interface. -* arguments in frame (88k): M88K Options. -* arguments in registers: Register Arguments. -* arguments on stack: Stack Arguments. -* ARG_POINTER_REGNUM: Frame Registers. -* arg_pointer_rtx: Frame Registers. -* 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_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_fprintf: Instruction Output. -* ASM_GENERATE_INTERNAL_LABEL: Label Output. -* ASM_GLOBALIZE_LABEL: Label Output. -* ASM_IDENTIFY_GCC: File Framework. -* asm_input: Side Effects. -* asm_noperands: Insns. -* 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: Macros for Initialization. -* ASM_OUTPUT_DESTRUCTOR: Macros for Initialization. -* 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. -* assembler format: File Framework. -* assembler instructions: Extended Asm. -* assembler instructions in RTL: Assembler. -* assembler names for identifiers: Asm Labels. -* assembler syntax, 88k: M88K Options. -* assemble_name: Label Output. -* 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. -* BASE_REG_CLASS: Register Classes. -* basic blocks: Passes. -* bcmp: Config. -* BIGGEST_ALIGNMENT: Storage Layout. -* BIGGEST_FIELD_ALIGNMENT: Storage Layout. -* Bison parser generator: Installation. -* bit fields: Bit Fields. -* bit shift overflow (88k): M88K Options. -* BITFIELD_NBYTES_LIMITED: Storage Layout. -* BITS_BIG_ENDIAN: Storage Layout. -* BITS_PER_UNIT: Storage Layout. -* BITS_PER_WORD: Storage Layout. -* bitwise complement: Arithmetic. -* bitwise exclusive-or: Arithmetic. -* bitwise inclusive-or: Arithmetic. -* bitwise logical-and: Arithmetic. -* BLKmode: Machine Modes. -* BLOCK_PROFILER: Profiling. -* BRANCH_COST: Costs. -* break_out_memory_refs: Addressing Modes. -* bug criteria: Bug Criteria. -* bug report mailing lists: Bug Lists. -* bugs: Bugs. -* bugs, known: Trouble. -* BYTES_BIG_ENDIAN: Storage Layout. -* BYTE_LOADS_SIGN_EXTEND: Misc. -* BYTE_LOADS_ZERO_EXTEND: Misc. -* byte_mode: Machine Modes. -* bzero: Config. -* C language extensions: Extensions. -* C language, traditional: Dialect Options. -* C statements for assembler output: Output Statement. -* call: Side Effects. -* call-clobbered register: Register Basics. -* call-saved register: Register Basics. -* call-used register: Register Basics. -* CALLER_SAVE_PROFITABLE: Caller Saves. -* calling conventions: Stack and Calling. -* calling functions in RTL: Calls. -* call_insn: Insns. -* CALL_USED_REGISTERS: Register Basics. -* call_used_regs: Register Basics. -* canonicalization of instructions: Insn Canonicalizations. -* CAN_ELIMINATE: Elimination. -* case labels in initializers: Labeled Elements. -* case ranges: Case Ranges. -* case sensitivity and VMS: VMS Misc. -* CASE_DROPS_THROUGH: Misc. -* CASE_VALUES_THRESHOLD: Misc. -* CASE_VECTOR_MODE: Misc. -* CASE_VECTOR_PC_RELATIVE: Misc. -* cast to a union: Cast to Union. -* casts as lvalues: Lvalues. -* cc0: Regs and Memory. -* cc0_rtx: Regs and Memory. -* CC1PLUS_SPEC: Driver. -* CC1_SPEC: Driver. -* CCmode: Machine Modes. -* cc_status: Condition Code. -* CC_STATUS_MDEP: Condition Code. -* CC_STATUS_MDEP_INIT: Condition Code. -* change_address: Standard Names. -* CHAR_TYPE_SIZE: Type Layout. -* CHECK_FLOAT_VALUE: Storage Layout. -* class definitions, register: Register Classes. -* class preference constraints: Class Preferences. -* classes of RTX codes: Accessors. -* CLASS_MAX_NREGS: Register Classes. -* clobber: Side Effects. -* code generation conventions: Code Gen Options. -* code generation RTL sequences: Expander Definitions. -* code motion: Passes. -* codes, RTL expression: RTL Objects. -* code_label: Insns. -* CODE_LABEL_NUMBER: Insns. -* 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. -* COMPILER_PATH: Environment Variables. -* 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. -* CONDITIONAL_REGISTER_USAGE: Register Basics. -* conditions, in patterns: Patterns. -* configuration file: Config. -* conflicting types: Disappointments. -* CONST0_RTX: Constants. -* const0_rtx: Constants. -* CONST1_RTX: Constants. -* const1_rtx: Constants. -* CONST2_RTX: Constants. -* const2_rtx: Constants. -* constant attributes: Constant Attributes. -* constant folding: Passes. -* constant folding and floating point: Cross-compilation. -* constant propagation: Passes. -* constants in constraints: Simple Constraints. -* CONSTANT_ADDRESS_P: Addressing Modes. -* CONSTANT_ALIGNMENT: Storage Layout. -* CONSTANT_P: Addressing Modes. -* CONSTANT_POOL_ADDRESS_P: Flags. -* constm1_rtx: Constants. -* constraint modifier characters: Modifiers. -* constraint, matching: Simple Constraints. -* constraints: Constraints. -* constructor expressions: Constructors. -* constructors, output of: Initialization. -* CONST_CALL_P: Flags. -* CONST_COSTS: Costs. -* const_double: Constants. -* CONST_DOUBLE_CHAIN: Constants. -* CONST_DOUBLE_LOW: Constants. -* CONST_DOUBLE_MEM: Constants. -* CONST_DOUBLE_OK_FOR_LETTER_P: Register Classes. -* const_int: Constants. -* CONST_OK_FOR_LETTER_P: Register Classes. -* const_string: Constants. -* const_true_rtx: Constants. -* contributors: Contributors. -* controlling register usage: Register Basics. -* controlling the compilation driver: Driver. -* conventions, run-time: Interface. -* conversions: Conversions. -* Convex options: Convex Options. -* copy_rtx_if_shared: Sharing. -* core dump: Bug Criteria. -* costs of instructions: Costs. -* COSTS_N_INSNS: Costs. -* CPLUS_INCLUDE_PATH: Environment Variables. -* CPP_PREDEFINES: Run-time Target. -* CPP_SPEC: Driver. -* cross compilation and floating point: Cross-compilation. -* cross compiling: Target Options. -* cross-compiler, installation: Cross-Compiler. -* cross-jumping: Passes. -* CUMULATIVE_ARGS: Register Arguments. -* 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. -* C_INCLUDE_PATH: Environment Variables. -* data flow analysis: Passes. -* DATA_ALIGNMENT: Storage Layout. -* data_section: Sections. -* DATA_SECTION_ASM_OP: Sections. -* DBR_OUTPUT_SEQEND: Instruction Output. -* dbr_sequence_length: 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. -* De Morgan's law: Insn Canonicalizations. -* dead code: Passes. -* dead_or_set_p: Peephole Definitions. -* deallocating variable length arrays: Variable Length. -* death notes: Obsolete Register Macros. -* DEBUGGER_ARG_OFFSET: All Debuggers. -* DEBUGGER_AUTO_OFFSET: All Debuggers. -* debugging information generation: Passes. -* debugging information options: Debugging Options. -* debugging, 88k OCS: M88K Options. -* debug_rtx: Bug Reporting. -* DEBUG_SYMS_TEXT: DBX Options. -* declaration scope: Incompatibilities. -* declarations inside expressions: Statement Exprs. -* declarations, RTL: RTL Declarations. -* declaring attributes of functions: Function Attributes. -* DEFAULT_CALLER_SAVES: Caller Saves. -* DEFAULT_GDB_EXTENSIONS: DBX Options. -* DEFAULT_MAIN_RETURN: Misc. -* DEFAULT_SHORT_ENUMS: Type Layout. -* DEFAULT_SIGNED_CHAR: Type Layout. -* 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 attributes and their values: Defining Attributes. -* defining jump instruction patterns: Jump Patterns. -* defining peephole optimizers: Peephole Definitions. -* defining RTL sequences for code generation: Expander Definitions. -* delay slots, defining: Delay Slots. -* delayed branch scheduling: Passes. -* DELAY_SLOTS_FOR_EPILOGUE: Function Entry. -* dependencies for make as output: Environment Variables. -* dependencies, make: Preprocessor Options. -* DEPENDENCIES_OUTPUT: Environment Variables. -* Dependent Patterns: Dependent Patterns. -* destructors, output of: Initialization. -* DFmode: Machine Modes. -* dialect options: Dialect Options. -* digits in constraint: Simple Constraints. -* DImode: Machine Modes. -* directory options: Directory Options. -* disabling certain registers: Register Basics. -* dispatch table: Dispatch Tables. -* div: Arithmetic. -* DIVDI3_LIBCALL: Library Calls. -* divide instruction, 88k: M88K Options. -* division: Arithmetic. -* division: Arithmetic. -* division: Arithmetic. -* DIVSI3_LIBCALL: Library Calls. -* dollar signs in identifier names: Dollar Signs. -* DOLLARS_IN_IDENTIFIERS: Misc. -* DONE: Expander Definitions. -* DONT_REDUCE_ADDR: Costs. -* double-word arithmetic: Long Long. -* DOUBLE_TYPE_SIZE: Type Layout. -* downward funargs: Nested Functions. -* driver: Driver. -* DWARF_DEBUGGING_INFO: SDB and DWARF. -* DYNAMIC_CHAIN_ADDRESS: Frame Layout. -* EASY_DIV_EXPR: Misc. -* ELIGIBLE_FOR_EPILOGUE_DELAY: Function Entry. -* ELIMINABLE_REGS: Elimination. -* empty constraints: No Constraints. -* EMPTY_FIELD_BOUNDARY: Storage Layout. -* ENCODE_SECTION_INFO: Sections. -* ENDFILE_SPEC: Driver. -* endianness: Portability. -* enum machine_mode: Machine Modes. -* enum reg_class: Register Classes. -* environment variables: Environment Variables. -* epilogue: Function Entry. -* eq: Comparisons. -* equal: Comparisons. -* eq_attr: Expressions. -* error: Storage Layout. -* exclamation point: Multi-Alternative. -* exclusive-or, bitwise: Arithmetic. -* EXECUTABLE_SUFFIX: Config. -* exit status and VMS: VMS Misc. -* EXIT_BODY: Misc. -* EXIT_IGNORE_STACK: Function Entry. -* expander definitions: Expander Definitions. -* EXPAND_BUILTIN_SAVEREGS: Varargs. -* explicit register variables: Explicit Reg Vars. -* expression codes: RTL Objects. -* expressions containing statements: Statement Exprs. -* expressions, compound, as lvalues: Lvalues. -* expressions, conditional, as lvalues: Lvalues. -* expressions, constructor: Constructors. -* expr_list: Insns. -* extended asm: Extended Asm. -* extensible constraints: Simple Constraints. -* extensions, ?:: Conditionals. -* extensions, ?:: Lvalues. -* extensions, C language: Extensions. -* extern int target_flags: Run-time Target. -* external declaration scope: Incompatibilities. -* 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. -* 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. -* FINALIZE_PIC: PIC. -* FINAL_PRESCAN_INSN: Instruction Output. -* FINAL_REG_PARM_STACK_SPACE: Stack Arguments. -* final_scan_insn: Function Entry. -* final_sequence: Instruction Output. -* 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. -* fix: Conversions. -* fix: Conversions. -* fixed register: Register Basics. -* FIXED_REGISTERS: Register Basics. -* fixed_regs: Register Basics. -* FIXUNS_TRUNC_LIKE_FIX_TRUNC: Misc. -* flags in RTL expression: Flags. -* float: Conversions. -* FLOATIFY: Library Calls. -* floating point format and cross compilation: Cross-compilation. -* FLOAT_ARG_TYPE: Library Calls. -* float_extend: Conversions. -* FLOAT_STORE_FLAG_VALUE: Misc. -* float_truncate: Conversions. -* FLOAT_TYPE_SIZE: Type Layout. -* FLOAT_VALUE_TYPE: Library Calls. -* force_reg: Standard Names. -* frame layout: Frame Layout. -* FRAME_GROWS_DOWNWARD: Frame Layout. -* frame_pointer_needed: Function Entry. -* FRAME_POINTER_REGNUM: Frame Registers. -* FRAME_POINTER_REQUIRED: Elimination. -* 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. -* 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. -* ge: Comparisons. -* gencodes: Passes. -* genconfig: Passes. -* generalized lvalues: Lvalues. -* general_operand: RTL Template. -* GENERAL_REGS: Register Classes. -* generating assembler output: Output Statement. -* generating insns: RTL Template. -* genflags: Passes. -* GEN_ERRNO_RTX: Library Calls. -* get_attr: Expressions. -* get_attr_length: Insn Lengths. -* GET_CLASS_NARROWEST_MODE: Machine Modes. -* GET_CODE: RTL Objects. -* get_frame_size: Elimination. -* get_insns: Insns. -* get_last_insn: Insns. -* 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. -* 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. -* 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. -* goto with computed label: Labels as Values. -* GO_IF_LEGITIMATE_ADDRESS: Addressing Modes. -* GO_IF_MODE_DEPENDENT_ADDRESS: Addressing Modes. -* gp-relative references (MIPS): MIPS Options. -* greater than: Comparisons. -* greater than: Comparisons. -* greater than: Comparisons. -* grouping options: Invoking GCC. -* gt: Comparisons. -* gtu: Comparisons. -* HANDLE_PRAGMA: Misc. -* hard registers: Regs and Memory. -* hardware models and configurations, specifying: Submodel Options. -* 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. -* header files and VMS: Include Files and VMS. -* high: Constants. -* 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. -* HPPA Options: HPPA Options. -* i386 Options: i386 Options. -* IBM RS/6000 Options: RS/6000 Options. -* IBM RT options: RT Options. -* IBM RT PC: Interoperation. -* identifier names, dollar signs in: Dollar Signs. -* identifiers, names in assembler code: Asm Labels. -* identifying source, compiler (88k): M88K Options. -* IEEE_FLOAT_FORMAT: Storage Layout. -* if_then_else: Comparisons. -* immediate_operand: RTL Template. -* IMMEDIATE_PREFIX: Instruction Output. -* IMPLICIT_FIX_EXPR: Misc. -* include files and VMS: Include Files and VMS. -* INCLUDE_DEFAULTS: Driver. -* inclusive-or, bitwise: Arithmetic. -* incompatibilities of GNU CC: Incompatibilities. -* increment operators: Bug Criteria. -* INDEX_REG_CLASS: Register Classes. -* initialization routines: Initialization. -* initializations in expressions: Constructors. -* initializers with labeled elements: Labeled Elements. -* initializers, non-constant: Initializers. -* 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. -* INIT_SECTION_ASM_OP: Macros for Initialization. -* 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. -* insns: Insns. -* insns, generating: RTL Template. -* insns, recognizing: RTL Template. -* 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_list: Insns. -* INSN_UID: Insns. -* installation trouble: Trouble. -* installing GNU CC: Installation. -* installing GNU CC on the 3b1: 3b1 Install. -* installing GNU CC on the Sun: Sun Install. -* installing GNU CC on Unos: Unos Install. -* installing GNU CC on VMS: VMS 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. -* INTEGRATE_THRESHOLD: Misc. -* integrating function code: Inline. -* Intel 386 Options: i386 Options. -* Interdependence of Patterns: Dependent Patterns. -* interfacing to GNU CC output: Interface. -* INTIFY: Library Calls. -* introduction: Top. -* INT_TYPE_SIZE: Type Layout. -* invalid assembly code: Bug Criteria. -* invalid input: Bug Criteria. -* in_data: Sections. -* in_struct: Flags. -* in_text: Sections. -* 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. -* JUMP_LABEL: Insns. -* JUMP_TABLES_IN_TEXT_SECTION: Sections. -* keywords, alternate: Alternate Keywords. -* known causes of trouble: Trouble. -* labeled elements in initializers: Labeled Elements. -* labels as values: Labels as Values. -* LABEL_NUSES: Insns. -* LABEL_OUTSIDE_LOOP_P: Flags. -* LABEL_PRESERVE_P: Flags. -* label_ref: Constants. -* language dialect options: Dialect Options. -* large bit shifts (88k): M88K Options. -* large return values: Aggregate Return. -* LAST_STACK_REG: Stack Registers. -* LAST_VIRTUAL_REGISTER: Regs and Memory. -* ldexp: Cross-compilation. -* le: Comparisons. -* leaf functions: Leaf Functions. -* leaf_function: Leaf Functions. -* leaf_function_p: Standard Names. -* LEAF_REGISTERS: Leaf Functions. -* LEAF_REG_REMAP: Leaf Functions. -* left rotate: Arithmetic. -* left shift: Arithmetic. -* left shift: Arithmetic. -* LEGITIMATE_CONSTANT_P: Addressing Modes. -* LEGITIMATE_PIC_OPERAND_P: PIC. -* LEGITIMIZE_ADDRESS: Addressing Modes. -* length-zero arrays: Zero Length. -* less than: Comparisons. -* less than or equal: Comparisons. -* leu: Comparisons. -* LIBCALL_VALUE: Scalar Return. -* LIBGCC_NEEDS_DOUBLE: Library Calls. -* Libraries: Link Options. -* library subroutine names: Library Calls. -* LIBRARY_PATH: Environment Variables. -* LIB_SPEC: Driver. -* LIMIT_RELOAD_CLASS: Register Classes. -* link options: Link Options. -* LINK_LIBGCC_SPECIAL: Driver. -* LINK_SPEC: Driver. -* 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. -* LOCAL_INCLUDE_DIR: Driver. -* LOCAL_LABEL_PREFIX: Instruction Output. -* logical shift: Arithmetic. -* logical-and, bitwise: Arithmetic. -* LOG_LINKS: Insns. -* longjmp: Global Reg Vars. -* LONGJMP_RESTORE_FROM_STACK: Elimination. -* LONG_DOUBLE_TYPE_SIZE: Type Layout. -* LONG_LONG_TYPE_SIZE: Type Layout. -* LONG_TYPE_SIZE: Type Layout. -* loop optimization: Passes. -* lo_sum: Arithmetic. -* lshift: Arithmetic. -* lshiftrt: Arithmetic. -* lt: Comparisons. -* ltu: Comparisons. -* lvalues, generalized: Lvalues. -* M680x0 options: M680x0 Options. -* M88k options: M88K Options. -* 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. -* matching constraint: Simple Constraints. -* matching operands: Output Template. -* match_dup: RTL Template. -* match_operand: RTL Template. -* match_operator: RTL Template. -* match_op_dup: RTL Template. -* match_parallel: RTL Template. -* match_par_dup: RTL Template. -* match_scratch: RTL Template. -* math libraries: Interface. -* math, in RTL: Arithmetic. -* 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. -* mcount: Profiling. -* MD_CALL_PROTOTYPES: Config. -* MD_EXEC_PREFIX: Driver. -* MD_STARTFILE_PREFIX: Driver. -* MD_STARTFILE_PREFIX_1: Driver. -* mem: Regs and Memory. -* memory reference, nonoffsettable: Simple Constraints. -* memory references in constraints: Simple Constraints. -* MEMORY_MOVE_COST: Costs. -* MEM_IN_STRUCT_P: Flags. -* MEM_VOLATILE_P: Flags. -* messages, warning: Warning Options. -* middle-operands, omitted: Conditionals. -* minus: Arithmetic. -* MIPS options: MIPS Options. -* mod: Arithmetic. -* MODDI3_LIBCALL: Library Calls. -* mode classes: Machine Modes. -* 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. -* modifiers in constraints: Modifiers. -* MODSI3_LIBCALL: Library Calls. -* MOVE_MAX: Misc. -* MOVE_RATIO: Costs. -* MULDI3_LIBCALL: Library Calls. -* MULSI3_LIBCALL: Library Calls. -* mult: Arithmetic. -* MULTIBYTE_CHARS: Config. -* 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. -* NEXT_INSN: Insns. -* NEXT_OBJC_RUNTIME: Library Calls. -* 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. -* NON_SAVING_SETJMP: Register Basics. -* not: Arithmetic. -* not equal: Comparisons. -* not using constraints: No Constraints. -* note: Insns. -* 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_MD_PROTOTYPES: Config. -* 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: Macros for Initialization. -* OBJECT_FORMAT_ROSE: Macros for Initialization. -* OBSTACK_CHUNK_ALLOC: Config. -* OBSTACK_CHUNK_FREE: Config. -* OBSTACK_CHUNK_SIZE: Config. -* obstack_free: 3b1 Install. -* OCS (88k): M88K Options. -* offsettable address: Simple Constraints. -* old-style function definitions: Function Prototypes. -* omitted middle-operands: Conditionals. -* ONLY_INT_FIELDS: Config. -* open coding: Inline. -* operand access: Accessors. -* operand constraints: Constraints. -* operand substitution: Output Template. -* operands: Patterns. -* OPTIMIZATION_OPTIONS: Run-time Target. -* optimize options: Optimize Options. -* optional hardware or system features: Run-time Target. -* options to control warnings: Warning Options. -* options, code generation: Code Gen Options. -* options, debugging: Debugging Options. -* options, dialect: Dialect Options. -* options, directory search: Directory Options. -* options, GNU CC command: Invoking GCC. -* 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. -* Ordering of Patterns: Pattern Ordering. -* ORDER_REGS_FOR_LOCAL_ALLOC: Allocation Order. -* other directory, compilation in: Other Dir. -* OUTGOING_REG_PARM_STACK_SPACE: Stack Arguments. -* 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. -* OVERLAPPING_REGNO_P: Obsolete Register Macros. -* OVERRIDE_OPTIONS: Run-time Target. -* parallel: Side Effects. -* parameter forward declaration: Variable Length. -* parameters, miscellaneous: Misc. -* PARM_BOUNDARY: Storage Layout. -* parser generator, Bison: Installation. -* parsing pass: Passes. -* passes and files of the compiler: Passes. -* passing arguments: Interface. -* PATTERN: Insns. -* pattern conditions: Patterns. -* pattern names: Standard Names. -* Pattern Ordering: Pattern Ordering. -* patterns: Patterns. -* pc: Regs and Memory. -* PCC_BITFIELD_TYPE_MATTERS: Storage Layout. -* PCC_STATIC_STRUCT_RETURN: Aggregate Return. -* pc_rtx: Regs and Memory. -* PDImode: Machine Modes. -* peephole optimization: Passes. -* peephole optimization, RTL representation: Side Effects. -* peephole optimizer definitions: Peephole Definitions. -* percent sign: Output Template. -* perform_...: Library Calls. -* PIC: Code Gen Options. -* PIC: PIC. -* PIC_OFFSET_TABLE_REGNUM: PIC. -* plus: Arithmetic. -* Pmode: Misc. -* pointer arguments: Function Attributes. -* POINTER_SIZE: Storage Layout. -* portability: Portability. -* position independent code: PIC. -* post_dec: Incdec. -* post_inc: Incdec. -* pragma: Misc. -* pragma, reason for not using: Function Attributes. -* predefined macros: Run-time Target. -* PREDICATE_CODES: Misc. -* PREFERRED_OUTPUT_RELOAD_CLASS: Register Classes. -* PREFERRED_RELOAD_CLASS: Register Classes. -* preprocessor options: Preprocessor Options. -* PRESERVE_DEATH_INFO_REGNO_P: Obsolete Register Macros. -* prev_cc0_setter: Jump Patterns. -* PREV_INSN: Insns. -* prev_nonnote_insn: Peephole Definitions. -* pre_dec: Incdec. -* pre_inc: Incdec. -* PRINT_OPERAND: Instruction Output. -* PRINT_OPERAND_ADDRESS: Instruction Output. -* PRINT_OPERAND_PUNCT_VALID_P: Instruction Output. -* product: Arithmetic. -* PROFILE_BEFORE_PROLOGUE: Profiling. -* profiling, code generation: Profiling. -* program counter: Regs and Memory. -* prologue: Function Entry. -* PROMOTE_FUNCTION_ARGS: Storage Layout. -* PROMOTE_FUNCTION_RETURN: Storage Layout. -* PROMOTE_MODE: Storage Layout. -* PROMOTE_PROTOTYPES: Stack Arguments. -* promotion of formal parameters: Function Prototypes. -* pseudo registers: Regs and Memory. -* PSImode: Machine Modes. -* PTRDIFF_TYPE: Type Layout. -* push address instruction: Simple Constraints. -* PUSH_ROUNDING: Stack Arguments. -* putenv: Config. -* PUT_CODE: RTL Objects. -* PUT_MODE: Machine Modes. -* PUT_REG_NOTE_KIND: Insns. -* PUT_SDB_...: SDB and DWARF. -* QImode: Machine Modes. -* question mark: Multi-Alternative. -* quotient: Arithmetic. -* r0-relative references (88k): M88K Options. -* ranges in case statements: Case Ranges. -* read-only strings: Incompatibilities. -* READONLY_DATA_SECTION: Sections. -* REAL_ARITHMETIC: Cross-compilation. -* REAL_INFINITY: Cross-compilation. -* REAL_NM_FILE_NAME: Macros for Initialization. -* 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. -* recognizing insns: RTL Template. -* recog_operand: Instruction Output. -* reg: Regs and Memory. -* 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 Transfer Language (RTL): RTL. -* register usage: Registers. -* register use analysis: Passes. -* register variable after longjmp: Global Reg Vars. -* register-to-stack conversion: Passes. -* 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. -* REGISTER_MOVE_COST: Costs. -* REGISTER_NAMES: Instruction Output. -* register_operand: RTL Template. -* REGISTER_PREFIX: Instruction Output. -* REGNO_OK_FOR_BASE_P: Register Classes. -* REGNO_OK_FOR_INDEX_P: Register Classes. -* REGNO_REG_CLASS: Register Classes. -* regs_ever_live: Function Entry. -* 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_names: Instruction Output. -* 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 costs: Costs. -* RELATIVE_PREFIX_NOT_LINKDIR: Driver. -* reload pass: Regs and Memory. -* reloading: Passes. -* reload_completed: Standard Names. -* reload_in_progress: Standard Names. -* 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. -* RETURN_IN_MEMORY: Aggregate Return. -* RETURN_POPS_ARGS: Stack Arguments. -* right rotate: Arithmetic. -* right shift: Arithmetic. -* rotate: Arithmetic. -* rotate: Arithmetic. -* rotatert: Arithmetic. -* ROUND_TYPE_ALIGN: Storage Layout. -* ROUND_TYPE_SIZE: Storage Layout. -* RS/6000 Options: RS/6000 Options. -* RT options: RT Options. -* RT PC: Interoperation. -* 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. -* 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. -* SCCS_DIRECTIVE: Misc. -* scheduling, delayed branch: Passes. -* scheduling, instruction: Passes. -* scheduling, instruction: Passes. -* SCHED_GROUP_P: Flags. -* SCmode: Machine Modes. -* 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. -* 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. -* search path: Directory Options. -* SECONDARY_INPUT_RELOAD_CLASS: Register Classes. -* SECONDARY_MEMORY_NEEDED: 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. -* separate directory, compilation in: Other Dir. -* sequence: Side Effects. -* sequential consistency on 88k: M88K Options. -* set: Side Effects. -* setjmp: Global Reg Vars. -* SETUP_INCOMING_VARARGS: Varargs. -* set_attr: Tagging Insns. -* set_attr_alternative: Tagging Insns. -* SET_DEST: Side Effects. -* SET_SRC: Side Effects. -* SFmode: Machine Modes. -* shared strings: Incompatibilities. -* shared VMS run time system: VMS Misc. -* SHARED_SECTION_ASM_OP: Sections. -* sharing of RTL components: Sharing. -* shift: Arithmetic. -* SHIFT_COUNT_TRUNCATED: Misc. -* SHORT_TYPE_SIZE: Type Layout. -* side effect in ?:: Conditionals. -* side effects, macro argument: Statement Exprs. -* signed division: Arithmetic. -* signed maximum: Arithmetic. -* signed minimum: Arithmetic. -* SIGNED_CHAR_SPEC: Driver. -* sign_extend: Conversions. -* sign_extract: Bit Fields. -* SImode: Machine Modes. -* simple constraints: Simple Constraints. -* simplifications, arithmetic: Passes. -* sizeof: Typeof. -* SIZE_TYPE: Type Layout. -* SLOW_BYTE_ACCESS: Costs. -* SLOW_UNALIGNED_ACCESS: Costs. -* SLOW_ZERO_EXTEND: Costs. -* smaller data references (88k): M88K Options. -* smaller data references (MIPS): MIPS Options. -* SMALL_REGISTER_CLASSES: Register Classes. -* smax: Arithmetic. -* smin: Arithmetic. -* SPARC options: Sparc Options. -* 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_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_pointer_rtx: Frame Registers. -* STACK_REGS: Stack Registers. -* stage1: Installation. -* standard pattern names: Standard Names. -* STANDARD_EXEC_PREFIX: Driver. -* STANDARD_INCLUDE_DIR: Driver. -* STANDARD_STARTFILE_PREFIX: Driver. -* STARTFILE_SPEC: Driver. -* STARTING_FRAME_OFFSET: Frame Layout. -* statements inside expressions: Statement Exprs. -* 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. -* storage layout: Storage Layout. -* STORE_FLAG_VALUE: Misc. -* strcpy: Storage Layout. -* strength-reduction: Passes. -* STRICT_ALIGNMENT: Storage Layout. -* strict_low_part: RTL Declarations. -* string constants: Incompatibilities. -* STRIP_NAME_ENCODING: Sections. -* structure passing (88k): M88K Options. -* structure value address: Aggregate Return. -* structures: Incompatibilities. -* structures, constructor expression: Constructors. -* structures, returning: Interface. -* 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. -* stupid register allocation: Passes. -* submodel options: Submodel Options. -* subreg: Regs and Memory. -* SUBREG_PROMOTED_UNSIGNED_P: Flags. -* SUBREG_PROMOTED_VAR_P: Flags. -* SUBREG_REG: Regs and Memory. -* SUBREG_WORD: Regs and Memory. -* subscripting: Subscripting. -* subscripting and function values: Subscripting. -* SUCCESS_EXIT_CODE: Config. -* Sun installation: Sun Install. -* suppressing warnings: Warning Options. -* SVr4: M88K Options. -* SWITCHES_NEED_SPACES: Driver. -* SWITCH_TAKES_ARG: Driver. -* symbolic label: Sharing. -* symbol_ref: Constants. -* SYMBOL_REF_FLAG: Flags. -* SYMBOL_REF_USED: Flags. -* syntax checking: Warning Options. -* SYSTEM_INCLUDE_DIR: Driver. -* 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. -* TARGET_BELL: Type Layout. -* TARGET_BS: Type Layout. -* TARGET_CR: Type Layout. -* TARGET_EDOM: Library Calls. -* 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. -* termination routines: Initialization. -* text_section: Sections. -* TEXT_SECTION_ASM_OP: Sections. -* TFmode: Machine Modes. -* thunks: Nested Functions. -* TImode: Machine Modes. -* TMPDIR: Environment Variables. -* top level of compiler: Passes. -* traditional C language: Dialect Options. -* TRADITIONAL_RETURN_FLOAT: Scalar Return. -* trampolines for nested functions: Trampolines. -* TRAMPOLINE_ALIGNMENT: Trampolines. -* TRAMPOLINE_SECTION: Trampolines. -* TRAMPOLINE_SIZE: Trampolines. -* TRAMPOLINE_TEMPLATE: Trampolines. -* TRANSFER_FROM_TRAMPOLINE: Trampolines. -* TRULY_NOOP_TRUNCATION: Misc. -* truncate: Conversions. -* type alignment: Alignment. -* typedef names as function parameters: Incompatibilities. -* typeof: Typeof. -* udiv: Arithmetic. -* UDIVDI3_LIBCALL: Library Calls. -* UDIVSI3_LIBCALL: Library Calls. -* Ultrix calling convention: Interoperation. -* umax: Arithmetic. -* umin: Arithmetic. -* umod: Arithmetic. -* UMODDI3_LIBCALL: Library Calls. -* UMODSI3_LIBCALL: Library Calls. -* 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. -* UNITS_PER_WORD: Storage Layout. -* UNKNOWN_FLOAT_FORMAT: Storage Layout. -* Unos installation: Unos Install. -* 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. -* USER_LABEL_PREFIX: Instruction Output. -* USE_C_ALLOCA: Config. -* USE_PROTOTYPES: Config. -* USG: Config. -* 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. -* Vax calling convention: Interoperation. -* 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. -* void pointers, arithmetic: Pointer Arith. -* void, size of pointer to: Pointer Arith. -* VOIDmode: Machine Modes. -* volatil: Flags. -* volatile memory references: Flags. -* voting between constraint alternatives: Class Preferences. -* vprintf: Config. -* warning messages: Warning Options. -* WCHAR_TYPE: Type Layout. -* WCHAR_TYPE_SIZE: Type Layout. -* which_alternative: Output Statement. -* whitespace: Incompatibilities. -* WORDS_BIG_ENDIAN: Storage Layout. -* word_mode: Machine Modes. -* WORD_SWITCH_TAKES_ARG: Driver. -* XCmode: Machine Modes. -* XCOFF_DEBUGGING_INFO: DBX Options. -* XEXP: Accessors. -* XFmode: Machine Modes. -* XINT: Accessors. -* xor: Arithmetic. -* XSTR: Accessors. -* XVEC: Accessors. -* XVECEXP: Accessors. -* XVECLEN: Accessors. -* XWINT: Accessors. -* zero division on 88k: M88K Options. -* zero-length arrays: Zero Length. -* zero_extend: Conversions. -* zero_extract: Bit Fields. -* \: Output Template. -* __bb_init_func: Profiling. -* __builtin_args_info: Varargs. -* __builtin_classify_type: Varargs. -* __builtin_next_arg: Varargs. -* __builtin_saveregs: Varargs. -* __CTOR_LIST__: Initialization. -* __DTOR_LIST__: Initialization. +* Frame Layout:: +* Frame Registers:: +* Elimination:: +* Stack Arguments:: +* Register Arguments:: +* Scalar Return:: +* Aggregate Return:: +* Caller Saves:: +* Function Entry:: +* Profiling:: + + +File: gcc.info, Node: Frame Layout, Next: Frame Registers, Up: Stack and Calling + +Basic Stack Layout +------------------ + + Here is the basic stack layout. + +`STACK_GROWS_DOWNWARD' + Define this macro if pushing a word onto the stack moves the stack + pointer to a smaller address. + + When we say, "define this macro if ...," it means that the + compiler checks this macro only with `#ifdef' so the precise + definition used does not matter. + +`FRAME_GROWS_DOWNWARD' + Define this macro if the addresses of local variable slots are at + negative offsets from the frame pointer. + +`ARGS_GROW_DOWNWARD' + Define this macro if successive arguments to a function occupy + decreasing addresses on the stack. + +`STARTING_FRAME_OFFSET' + Offset from the frame pointer to the first local variable slot to + be allocated. + + If `FRAME_GROWS_DOWNWARD', find the next slot's offset by + subtracting the first slot's length from `STARTING_FRAME_OFFSET'. + Otherwise, it is found by adding the length of the first slot to + the value `STARTING_FRAME_OFFSET'. + +`STACK_POINTER_OFFSET' + Offset from the stack pointer register to the first location at + which outgoing arguments are placed. If not specified, the + default value of zero is used. This is the proper value for most + machines. + + If `ARGS_GROW_DOWNWARD', this is the offset to the location above + the first location at which outgoing arguments are placed. + +`FIRST_PARM_OFFSET (FUNDECL)' + Offset from the argument pointer register to the first argument's + address. On some machines it may depend on the data type of the + function. + + If `ARGS_GROW_DOWNWARD', this is the offset to the location above + the first argument's address. + +`STACK_DYNAMIC_OFFSET (FUNDECL)' + Offset from the stack pointer register to an item dynamically + allocated on the stack, e.g., by `alloca'. + + The default value for this macro is `STACK_POINTER_OFFSET' plus the + length of the outgoing arguments. The default is correct for most + machines. See `function.c' for details. + +`DYNAMIC_CHAIN_ADDRESS (FRAMEADDR)' + A C expression whose value is RTL representing the address in a + stack frame where the pointer to the caller's frame is stored. + Assume that FRAMEADDR is an RTL expression for the address of the + stack frame itself. + + If you don't define this macro, the default is to return the value + of FRAMEADDR--that is, the stack frame address is also the address + of the stack word that points to the previous frame. + +`SERTUP_FRAME_ADDRESSES ()' + If defined, a C expression that produces the machine-specific code + to setup the stack so that arbitrary frames can be accessed. For + example, on the Sparc, we must flush all of the register windows + to the stack before we can access arbitrary stack frames. This + macro will seldom need to be defined. + +`RETURN_ADDR_RTX (COUNT, FRAMEADDR)' + A C expression whose value is RTL representing the value of the + return address for the frame COUNT steps up from the current frame. + fRAMEADDR is the frame pointer of the COUNT frame, or the frame + pointer of the COUNT - 1 frame if `RETURN_ADDR_IN_PREVIOUS_FRAME' + is defined. + +`RETURN_ADDR_IN_PREVIOUS_FRAME' + Define this if the return address of a particular stack frame is + accessed from the frame pointer of the previous stack frame. + + +File: gcc.info, Node: Frame Registers, Next: Elimination, Prev: Frame Layout, Up: Stack and Calling + +Registers That Address the Stack Frame +-------------------------------------- + + This discusses registers that address the stack frame. + +`STACK_POINTER_REGNUM' + The register number of the stack pointer register, which must also + be a fixed register according to `FIXED_REGISTERS'. On most + machines, the hardware determines which register this is. + +`FRAME_POINTER_REGNUM' + The register number of the frame pointer register, which is used to + access automatic variables in the stack frame. On some machines, + the hardware determines which register this is. On other + machines, you can choose any register you wish for this purpose. + +`HARD_FRAME_POINTER_REGNUM' + On some machines the offset between the frame pointer and starting + offset of the automatic variables is not known until after register + allocation has been done (for example, because the saved registers + are between these two locations). On those machines, define + `FRAME_POINTER_REGNUM' the number of a special, fixed register to + be used internally until the offset is known, and define + `HARD_FRAME_POINTER_REGNUM' to be actual the hard register number + used for the frame pointer. + + You should define this macro only in the very rare circumstances + when it is not possible to calculate the offset between the frame + pointer and the automatic variables until after register + allocation has been completed. When this macro is defined, you + must also indicate in your definition of `ELIMINABLE_REGS' how to + eliminate `FRAME_POINTER_REGNUM' into either + `HARD_FRAME_POINTER_REGNUM' or `STACK_POINTER_REGNUM'. + + Do not define this macro if it would be the same as + `FRAME_POINTER_REGNUM'. + +`ARG_POINTER_REGNUM' + The register number of the arg pointer register, which is used to + access the function's argument list. On some machines, this is + the same as the frame pointer register. On some machines, the + hardware determines which register this is. On other machines, + you can choose any register you wish for this purpose. If this is + not the same register as the frame pointer register, then you must + mark it as a fixed register according to `FIXED_REGISTERS', or + arrange to be able to eliminate it (*note Elimination::.). + +`STATIC_CHAIN_REGNUM' +`STATIC_CHAIN_INCOMING_REGNUM' + Register numbers used for passing a function's static chain + pointer. If register windows are used, the register number as + seen by the called function is `STATIC_CHAIN_INCOMING_REGNUM', + while the register number as seen by the calling function is + `STATIC_CHAIN_REGNUM'. If these registers are the same, + `STATIC_CHAIN_INCOMING_REGNUM' need not be defined. + + The static chain register need not be a fixed register. + + If the static chain is passed in memory, these macros should not be + defined; instead, the next two macros should be defined. + +`STATIC_CHAIN' +`STATIC_CHAIN_INCOMING' + If the static chain is passed in memory, these macros provide rtx + giving `mem' expressions that denote where they are stored. + `STATIC_CHAIN' and `STATIC_CHAIN_INCOMING' give the locations as + seen by the calling and called functions, respectively. Often the + former will be at an offset from the stack pointer and the latter + at an offset from the frame pointer. + + The variables `stack_pointer_rtx', `frame_pointer_rtx', and + `arg_pointer_rtx' will have been initialized prior to the use of + these macros and should be used to refer to those items. + + If the static chain is passed in a register, the two previous + macros should be defined instead. + + +File: gcc.info, Node: Elimination, Next: Stack Arguments, Prev: Frame Registers, Up: Stack and Calling + +Eliminating Frame Pointer and Arg Pointer +----------------------------------------- + + This is about eliminating the frame pointer and arg pointer. + +`FRAME_POINTER_REQUIRED' + A C expression which is nonzero if a function must have and use a + frame pointer. This expression is evaluated in the reload pass. + If its value is nonzero the function will have a frame pointer. + + The expression can in principle examine the current function and + decide according to the facts, but on most machines the constant 0 + or the constant 1 suffices. Use 0 when the machine allows code to + be generated with no frame pointer, and doing so saves some time + or space. Use 1 when there is no possible advantage to avoiding a + frame pointer. + + In certain cases, the compiler does not know how to produce valid + code without a frame pointer. The compiler recognizes those cases + and automatically gives the function a frame pointer regardless of + what `FRAME_POINTER_REQUIRED' says. You don't need to worry about + them. + + In a function that does not require a frame pointer, the frame + pointer register can be allocated for ordinary usage, unless you + mark it as a fixed register. See `FIXED_REGISTERS' for more + information. + +`INITIAL_FRAME_POINTER_OFFSET (DEPTH-VAR)' + A C statement to store in the variable DEPTH-VAR the difference + between the frame pointer and the stack pointer values immediately + after the function prologue. The value would be computed from + information such as the result of `get_frame_size ()' and the + tables of registers `regs_ever_live' and `call_used_regs'. + + If `ELIMINABLE_REGS' is defined, this macro will be not be used and + need not be defined. Otherwise, it must be defined even if + `FRAME_POINTER_REQUIRED' is defined to always be true; in that + case, you may set DEPTH-VAR to anything. + +`ELIMINABLE_REGS' + If defined, this macro specifies a table of register pairs used to + eliminate unneeded registers that point into the stack frame. If + it is not defined, the only elimination attempted by the compiler + is to replace references to the frame pointer with references to + the stack pointer. + + The definition of this macro is a list of structure + initializations, each of which specifies an original and + replacement register. + + On some machines, the position of the argument pointer is not + known until the compilation is completed. In such a case, a + separate hard register must be used for the argument pointer. + This register can be eliminated by replacing it with either the + frame pointer or the argument pointer, depending on whether or not + the frame pointer has been eliminated. + + In this case, you might specify: + #define ELIMINABLE_REGS \ + {{ARG_POINTER_REGNUM, STACK_POINTER_REGNUM}, \ + {ARG_POINTER_REGNUM, FRAME_POINTER_REGNUM}, \ + {FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}} + + Note that the elimination of the argument pointer with the stack + pointer is specified first since that is the preferred elimination. + +`CAN_ELIMINATE (FROM-REG, TO-REG)' + A C expression that returns non-zero if the compiler is allowed to + try to replace register number FROM-REG with register number + TO-REG. This macro need only be defined if `ELIMINABLE_REGS' is + defined, and will usually be the constant 1, since most of the + cases preventing register elimination are things that the compiler + already knows about. + +`INITIAL_ELIMINATION_OFFSET (FROM-REG, TO-REG, OFFSET-VAR)' + This macro is similar to `INITIAL_FRAME_POINTER_OFFSET'. It + specifies the initial difference between the specified pair of + registers. This macro must be defined if `ELIMINABLE_REGS' is + defined. + +`LONGJMP_RESTORE_FROM_STACK' + Define this macro if the `longjmp' function restores registers from + the stack frames, rather than from those saved specifically by + `setjmp'. Certain quantities must not be kept in registers across + a call to `setjmp' on such machines. + + +File: gcc.info, Node: Stack Arguments, Next: Register Arguments, Prev: Elimination, Up: Stack and Calling + +Passing Function Arguments on the Stack +--------------------------------------- + + The macros in this section control how arguments are passed on the +stack. See the following section for other macros that control passing +certain arguments in registers. + +`PROMOTE_PROTOTYPES' + Define this macro if an argument declared in a prototype as an + integral type smaller than `int' should actually be passed as an + `int'. In addition to avoiding errors in certain cases of + mismatch, it also makes for better code on certain machines. + +`PUSH_ROUNDING (NPUSHED)' + A C expression that is the number of bytes actually pushed onto the + stack when an instruction attempts to push NPUSHED bytes. + + If the target machine does not have a push instruction, do not + define this macro. That directs GNU CC to use an alternate + strategy: to allocate the entire argument block and then store the + arguments into it. + + On some machines, the definition + + #define PUSH_ROUNDING(BYTES) (BYTES) + + will suffice. But on other machines, instructions that appear to + push one byte actually push two bytes in an attempt to maintain + alignment. Then the definition should be + + #define PUSH_ROUNDING(BYTES) (((BYTES) + 1) & ~1) + +`ACCUMULATE_OUTGOING_ARGS' + If defined, the maximum amount of space required for outgoing + arguments will be computed and placed into the variable + `current_function_outgoing_args_size'. No space will be pushed + onto the stack for each call; instead, the function prologue should + increase the stack frame size by this amount. + + Defining both `PUSH_ROUNDING' and `ACCUMULATE_OUTGOING_ARGS' is + not proper. + +`REG_PARM_STACK_SPACE (FNDECL)' + Define this macro if functions should assume that stack space has + been allocated for arguments even when their values are passed in + registers. + + The value of this macro is the size, in bytes, of the area + reserved for arguments passed in registers for the function + represented by FNDECL. + + This space can be allocated by the caller, or be a part of the + machine-dependent stack frame: `OUTGOING_REG_PARM_STACK_SPACE' says + which. + +`MAYBE_REG_PARM_STACK_SPACE' +`FINAL_REG_PARM_STACK_SPACE (CONST_SIZE, VAR_SIZE)' + Define these macros in addition to the one above if functions might + allocate stack space for arguments even when their values are + passed in registers. These should be used when the stack space + allocated for arguments in registers is not a simple constant + independent of the function declaration. + + The value of the first macro is the size, in bytes, of the area + that we should initially assume would be reserved for arguments + passed in registers. + + The value of the second macro is the actual size, in bytes, of the + area that will be reserved for arguments passed in registers. + This takes two arguments: an integer representing the number of + bytes of fixed sized arguments on the stack, and a tree + representing the number of bytes of variable sized arguments on + the stack. + + When these macros are defined, `REG_PARM_STACK_SPACE' will only be + called for libcall functions, the current function, or for a + function being called when it is known that such stack space must + be allocated. In each case this value can be easily computed. + + When deciding whether a called function needs such stack space, + and how much space to reserve, GNU CC uses these two macros + instead of `REG_PARM_STACK_SPACE'. + +`OUTGOING_REG_PARM_STACK_SPACE' + Define this if it is the responsibility of the caller to allocate + the area reserved for arguments passed in registers. + + If `ACCUMULATE_OUTGOING_ARGS' is defined, this macro controls + whether the space for these arguments counts in the value of + `current_function_outgoing_args_size'. + +`STACK_PARMS_IN_REG_PARM_AREA' + Define this macro if `REG_PARM_STACK_SPACE' is defined, but the + stack parameters don't skip the area specified by it. + + Normally, when a parameter is not passed in registers, it is + placed on the stack beyond the `REG_PARM_STACK_SPACE' area. + Defining this macro suppresses this behavior and causes the + parameter to be passed on the stack in its natural location. + +`RETURN_POPS_ARGS (FUNTYPE, STACK-SIZE)' + A C expression that should indicate the number of bytes of its own + arguments that a function pops on returning, or 0 if the function + pops no arguments and the caller must therefore pop them all after + the function returns. + + FUNTYPE is a C variable whose value is a tree node that describes + the function in question. Normally it is a node of type + `FUNCTION_TYPE' that describes the data type of the function. + From this it is possible to obtain the data types of the value and + arguments (if known). + + When a call to a library function is being considered, FUNTYPE + will contain an identifier node for the library function. Thus, if + you need to distinguish among various library functions, you can + do so by their names. Note that "library function" in this + context means a function used to perform arithmetic, whose name is + known specially in the compiler and was not mentioned in the C + code being compiled. + + STACK-SIZE is the number of bytes of arguments passed on the + stack. If a variable number of bytes is passed, it is zero, and + argument popping will always be the responsibility of the calling + function. + + On the Vax, all functions always pop their arguments, so the + definition of this macro is STACK-SIZE. On the 68000, using the + standard calling convention, no functions pop their arguments, so + the value of the macro is always 0 in this case. But an + alternative calling convention is available in which functions + that take a fixed number of arguments pop them but other functions + (such as `printf') pop nothing (the caller pops all). When this + convention is in use, FUNTYPE is examined to determine whether a + function takes a fixed number of arguments. + + +File: gcc.info, Node: Register Arguments, Next: Scalar Return, Prev: Stack Arguments, Up: Stack and Calling + +Passing Arguments in Registers +------------------------------ + + This section describes the macros which let you control how various +types of arguments are passed in registers or how they are arranged in +the stack. + +`FUNCTION_ARG (CUM, MODE, TYPE, NAMED)' + A C expression that controls whether a function argument is passed + in a register, and which register. + + The arguments are CUM, which summarizes all the previous + arguments; MODE, the machine mode of the argument; TYPE, the data + type of the argument as a tree node or 0 if that is not known + (which happens for C support library functions); and NAMED, which + is 1 for an ordinary argument and 0 for nameless arguments that + correspond to `...' in the called function's prototype. + + The value of the expression should either be a `reg' RTX for the + hard register in which to pass the argument, or zero to pass the + argument on the stack. + + For machines like the Vax and 68000, where normally all arguments + are pushed, zero suffices as a definition. + + The usual way to make the ANSI library `stdarg.h' work on a machine + where some arguments are usually passed in registers, is to cause + nameless arguments to be passed on the stack instead. This is done + by making `FUNCTION_ARG' return 0 whenever NAMED is 0. + + You may use the macro `MUST_PASS_IN_STACK (MODE, TYPE)' in the + definition of this macro to determine if this argument is of a + type that must be passed in the stack. If `REG_PARM_STACK_SPACE' + is not defined and `FUNCTION_ARG' returns non-zero for such an + argument, the compiler will abort. If `REG_PARM_STACK_SPACE' is + defined, the argument will be computed in the stack and then + loaded into a register. + +`FUNCTION_INCOMING_ARG (CUM, MODE, TYPE, NAMED)' + Define this macro if the target machine has "register windows", so + that the register in which a function sees an arguments is not + necessarily the same as the one in which the caller passed the + argument. + + For such machines, `FUNCTION_ARG' computes the register in which + the caller passes the value, and `FUNCTION_INCOMING_ARG' should be + defined in a similar fashion to tell the function being called + where the arguments will arrive. + + If `FUNCTION_INCOMING_ARG' is not defined, `FUNCTION_ARG' serves + both purposes. + +`FUNCTION_ARG_PARTIAL_NREGS (CUM, MODE, TYPE, NAMED)' + A C expression for the number of words, at the beginning of an + argument, must be put in registers. The value must be zero for + arguments that are passed entirely in registers or that are + entirely pushed on the stack. + + On some machines, certain arguments must be passed partially in + registers and partially in memory. On these machines, typically + the first N words of arguments are passed in registers, and the + rest on the stack. If a multi-word argument (a `double' or a + structure) crosses that boundary, its first few words must be + passed in registers and the rest must be pushed. This macro tells + the compiler when this occurs, and how many of the words should go + in registers. + + `FUNCTION_ARG' for these arguments should return the first + register to be used by the caller for this argument; likewise + `FUNCTION_INCOMING_ARG', for the called function. + +`FUNCTION_ARG_PASS_BY_REFERENCE (CUM, MODE, TYPE, NAMED)' + A C expression that indicates when an argument must be passed by + reference. If nonzero for an argument, a copy of that argument is + made in memory and a pointer to the argument is passed instead of + the argument itself. The pointer is passed in whatever way is + appropriate for passing a pointer to that type. + + On machines where `REG_PARM_STACK_SPACE' is not defined, a suitable + definition of this macro might be + #define FUNCTION_ARG_PASS_BY_REFERENCE\ + (CUM, MODE, TYPE, NAMED) \ + MUST_PASS_IN_STACK (MODE, TYPE) + +`FUNCTION_ARG_CALLEE_COPIES (CUM, MODE, TYPE, NAMED)' + If defined, a C expression that indicates when it is the called + function's responsibility to make a copy of arguments passed by + invisible reference. Normally, the caller makes a copy and passes + the address of the copy to the routine being called. When + FUNCTION_ARG_CALLEE_COPIES is defined and is nonzero, the caller + does not make a copy. Instead, it passes a pointer to the "live" + value. The called function must not modify this value. If it can + be determined that the value won't be modified, it need not make a + copy; otherwise a copy must be made. + +`CUMULATIVE_ARGS' + A C type for declaring a variable that is used as the first + argument of `FUNCTION_ARG' and other related values. For some + target machines, the type `int' suffices and can hold the number + of bytes of argument so far. + + There is no need to record in `CUMULATIVE_ARGS' anything about the + arguments that have been passed on the stack. The compiler has + other variables to keep track of that. For target machines on + which all arguments are passed on the stack, there is no need to + store anything in `CUMULATIVE_ARGS'; however, the data structure + must exist and should not be empty, so use `int'. + +`INIT_CUMULATIVE_ARGS (CUM, FNTYPE, LIBNAME)' + A C statement (sans semicolon) for initializing the variable CUM + for the state at the beginning of the argument list. The variable + has type `CUMULATIVE_ARGS'. The value of FNTYPE is the tree node + for the data type of the function which will receive the args, or 0 + if the args are to a compiler support library function. + + When processing a call to a compiler support library function, + LIBNAME identifies which one. It is a `symbol_ref' rtx which + contains the name of the function, as a string. LIBNAME is 0 when + an ordinary C function call is being processed. Thus, each time + this macro is called, either LIBNAME or FNTYPE is nonzero, but + never both of them at once. + +`INIT_CUMULATIVE_INCOMING_ARGS (CUM, FNTYPE, LIBNAME)' + Like `INIT_CUMULATIVE_ARGS' but overrides it for the purposes of + finding the arguments for the function being compiled. If this + macro is undefined, `INIT_CUMULATIVE_ARGS' is used instead. + + The value passed for LIBNAME is always 0, since library routines + with special calling conventions are never compiled with GNU CC. + The argument LIBNAME exists for symmetry with + `INIT_CUMULATIVE_ARGS'. + +`FUNCTION_ARG_ADVANCE (CUM, MODE, TYPE, NAMED)' + A C statement (sans semicolon) to update the summarizer variable + CUM to advance past an argument in the argument list. The values + MODE, TYPE and NAMED describe that argument. Once this is done, + the variable CUM is suitable for analyzing the *following* + argument with `FUNCTION_ARG', etc. + + This macro need not do anything if the argument in question was + passed on the stack. The compiler knows how to track the amount + of stack space used for arguments without any special help. + +`FUNCTION_ARG_PADDING (MODE, TYPE)' + If defined, a C expression which determines whether, and in which + direction, to pad out an argument with extra space. The value + should be of type `enum direction': either `upward' to pad above + the argument, `downward' to pad below, or `none' to inhibit + padding. + + The *amount* of padding is always just enough to reach the next + multiple of `FUNCTION_ARG_BOUNDARY'; this macro does not control + it. + + This macro has a default definition which is right for most + systems. For little-endian machines, the default is to pad + upward. For big-endian machines, the default is to pad downward + for an argument of constant size shorter than an `int', and upward + otherwise. + +`FUNCTION_ARG_BOUNDARY (MODE, TYPE)' + If defined, a C expression that gives the alignment boundary, in + bits, of an argument with the specified mode and type. If it is + not defined, `PARM_BOUNDARY' is used for all arguments. +`FUNCTION_ARG_REGNO_P (REGNO)' + A C expression that is nonzero if REGNO is the number of a hard + register in which function arguments are sometimes passed. This + does *not* include implicit arguments such as the static chain and + the structure-value address. On many machines, no registers can be + used for this purpose since all function arguments are pushed on + the stack.