X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Ftv%2Ftv.h;h=32f28af45688e674fafd4f3d2c72b4056c6bdf9e;hb=f7898331f5ad54e43402413c1d369cefe5e95335;hp=39decd5e534b3426a86005256c4aaf4ef4495c8a;hpb=ec8e854b4d72b62ab2caa636d90dc7af65f38fa9;p=libfirm diff --git a/ir/tv/tv.h b/ir/tv/tv.h index 39decd5e5..32f28af45 100644 --- a/ir/tv/tv.h +++ b/ir/tv/tv.h @@ -1,214 +1,604 @@ -/* Declarations for Target Values. - Copyright (C) 1995, 1996 Christian von Roques -*/ +/* + * Project: libFIRM + * File name: ir/tv/tv.h + * Purpose: Representation of and static computations on target machine + * values. + * Author: Mathias Heil + * Modified by: + * Created: + * CVS-ID: $Id$ + * Copyright: (c) 2003 Universität Karlsruhe + * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE. + */ /** * @file tv.h * * Declarations for Target Values. */ - -/* $Id$ */ - -/* -Discussion of new interface, proposals by Prof. Waite: -(email of 13.6.2001) -> 1. You say that you plan to replace the tv module. That replacement is -> absolutely essential for an ANSI C translator: Section 6.1.3.2 of the -> standard says that the representation of an integer_constant depends -> upon its value as well as any suffixes that are attached to it. The -> possible Firm modes for such a constant are i, I, l, and L. The -> current tv module provides only one integer conversion routine, and -> that requires conversion by the client. Since the type of the value -> argument is long, this may preclude the representation of an unsigned -> long constant. -> -> There is a similar problem with floating constants. Floating -> constants can be suffixed in C, and the mode depends upon the suffix. -> It can indicate that the constant is of type long double, which your -> current tv module is incapable of representing. -> -> Your tv module interface accepts two kinds of information: modes and -> values. Values obtained from the program text might be uninterpreted -> strings, strings interpreted as integers, and strings interpreted as -> reals. Values provided by the compiler are usually integers. Modes are -> always Firm modes. It seems to me that the tv module should provide -> tarval* constructors for three of the four kinds of values. Each of these -> constructors should have an ir_mode parameter and one or more parameters -> appropriate for the kind of value. As is currently the case, one -> constructor should be provided for both compiler-generated integers and -> source strings interpreted as integers. (This avoids problems of -> different conversion radices -- the client does the conversion.) For -> symmetry, the constructor for source strings interpreted as reals should -> accept a long double parameter and require the client to do the -> conversion. - -*/ - #ifndef _TV_H_ #define _TV_H_ -# include "irmode.h" -# include "entity.h" -# include +#include "irmode.h" +#include "irnode.h" + +/****h* libfirm/tv + * + * NAME + * tv -- TargetValue, short tarval. + * Internal representation for machine values. + * + * AUTHORS + * Matthias Heil + * + * DESCRIPTION + * Tarvals represent target machine values. They are typed by modes. + * Tarvals only represent values of mode_sort: + * int_number, + * float_number, + * boolean, + * reference, + * character + * + * In case of references the module accepts an entity to represent the + * value. + * Furthermore, computations and conversions of these values can + * be performed. + * + * USES + * This module is closely related to the irmode module, as the modes + * defined there are thoroughly used throughout the whole module. + * Also, the comparison functions rely on the definition of comparison + * values in the irnode module. + * + * HISTORY + * The original tv module originated in the fiasco compiler written ... + * This is the new version, described in the tech report 1999-14 by ... + * + * SEE ALSO + * Techreport 1999-14 + * irmode.h for the modes definitions + * irnode.h for the pn_Cmp table + * + * tarval_init1 and tarval_init2 for initialization of the + * module + * + ******/ #ifndef _TARVAL_TYPEDEF_ #define _TARVAL_TYPEDEF_ -typedef struct tarval tarval; + typedef struct tarval tarval; #endif -/*@{*/ -/** how to represent target types on host */ -typedef float tarval_F; -typedef double tarval_D; -typedef long double tarval_E; -typedef long tarval_sInt; -typedef unsigned long tarval_uInt; -typedef char tarval_C; -typedef unsigned short tarval_U; /* 16 bit ?! wchar could be defined as char... */ -/*@}*/ - -/** tarval_P */ -typedef struct { - /** if ent then xname is missing or mangled from ent, - else if xname then xname is a linker symbol that is not mangled - from an entity, - else this is tarval_p_void. - if this tarval describes a symbolic address of another tarval, tv points - to this val */ - const char *xname; - entity *ent; - tarval *tv; -} tarval_P; - -/** a trval */ -struct tarval { - union { - tarval_F F; /**< float */ - tarval_D D; /**< double */ - tarval_E E; /**< extended */ - tarval_sInt sInt; /**< signed integral */ - tarval_uInt uInt; /**< unsigned integral */ - tarval_C C; /**< character */ - tarval_U U; /**< unicode character */ - tarval_P P; /**< pointer */ - bool b; /**< boolean */ - } u; - ir_mode *mode; -}; - - -extern tarval *tarval_bad; tarval *get_tarval_bad(void); -/* We should have a tarval_undefined */ -extern tarval *tarval_b_false; tarval *get_tarval_b_false (void); -extern tarval *tarval_b_true; tarval *get_tarval_b_true (void); -extern tarval *tarval_D_NaN; tarval *get_tarval_D_NaN (void); -extern tarval *tarval_D_Inf; tarval *get_tarval_D_Inf (void); -extern tarval *tarval_P_void; tarval *get_tarval_P_void (void); -extern tarval *tarval_mode_null[]; tarval *get_tarval_mode_null(ir_mode *mode); - -/*@{*/ -/** @bug These are not initialized!! Don't use. */ -extern tarval *tarval_mode_min[]; tarval *get_tarval_mode_min (ir_mode *mode); -extern tarval *tarval_mode_max[]; tarval *get_tarval_mode_max (ir_mode *mode); -/*@}*/ - -void tarval_init_1 (void); -void tarval_init_2 (void); - -/*@{*/ -/** Constructors for tarvals */ -tarval *tarval_F_from_str (const char *s, size_t len); -tarval *tarval_D_from_str (const char *s, size_t len); -tarval *tarval_int_from_str (const char *s, size_t len, int base, ir_mode *m); -tarval *tarval_from_long (ir_mode *m, long val); -/*@}*/ - -tarval *tarval_P_from_str (const char *xname); -/* The tarval represents the address of the entity. As the address must - be constant the entity must have as owner the global type. */ -tarval *tarval_P_from_entity (entity *ent); - -tarval *tarval_convert_to (tarval *src, ir_mode *m); - -/* Building an irm_C, irm_s, irm_S or irm_B target value step by step. */ -void tarval_start (void); -void tarval_append (const char *p, size_t n); -void tarval_append1 (char ch); -tarval *tarval_finish_as (ir_mode *m); -tarval *tarval_cancel (void); /* returns tarval_bad */ - -/** The flags for projecting a comparison result */ +/* ************************ Constructors for tarvals ************************ */ + +/** + * Constructor function for new tarvals. + * + * @param str The string representing the target value + * @param len The length of the string + * @param mode The mode requested for the result tarval + * + * This function creates a new tarval representing the value represented + * by a CString, aka char array. If a tarval representing this value already + * exists, this tarval is returned instead of a new one. So tarvals are + * directly comparable since their representation is unique. + * + * This function accepts the following strings: + * + * if mode is int_number: + * - 0(x|X)[0-9a-fA-F]+ (hexadecimal representation) + * - 0[0-7]* (octal representation) + * - (+|-)?[1-9][0-9]* (decimal representation) + * + * if mode if float_number: + * - (+|-)?(decimal int) (. (decimal int))? ((e|E)(+|-)?(decimal int))? + * + * if mode is boolean: true, True, TRUE ... False... 0, 1, + * + * if mode is reference: hexadecimal of decimal number as int + * + * if mode is character: hex or dec + * + * Leading and/or trailing spaces are ignored + * + * @return + * A tarval of proper type representing the requested value is returned. + * Tarvals are unique, so for any value/mode pair at most one tarval will + * exist, which will be returned upon further requests with an identical + * value/mode pair. + * + * @note + * If the string is not representable in the given mode an assertion is + * thrown in assert build. + * + * @sa + * irmode.h for predefined modes + * new_tarval_from_long() + * new_tarval_from_double() + */ +tarval *new_tarval_from_str(const char *str, size_t len, ir_mode *mode); + +/** + * Constructor function for new tarvals + * + * @param l The long representing the value + * @param mode The mode requested for the result tarval + * + * This function creates a new tarval representing the value represented + * by a long integer. If a tarval representing this value already exists, + * this tarval is returned instead of a new one. So tarvals are directly + * comparable since their representation is unique. + * + * @return + * A tarval of proper type representing the requested value is returned. + * Tarvals are unique, so for any value/mode pair at most one tarval will + * exist, which will be returned upon further requests with an identical + * value/mode pair. + * + * @note + * If the long is not representable in the given mode an assertion is + * thrown in assert build. + * + * @sa + * irmode.h for predefined modes + * new_tarval_from_str() + * new_tarval_from_double() + * + */ +tarval *new_tarval_from_long(long l, ir_mode *mode); + +/** Return value as long if possible. + * + * This returns a long int with the value represented value, or + * gibberish, depending on the size of long int and the size of the + * stored value. It works for e.g. 1 as mode_Ls, but might not work for + * get_mode_max(mode_Ls). + * This will overflow silently, so use only if you know what + * you are doing! (better check with tarval_is_long()...) + * Works only for int modes, even not for character modes! + */ +long get_tarval_long(tarval *tv); + +/** + * This validates if get_tarval_long() will return a satisfying + * result. I.e. if tv is an int_number and between min, max + * of long int (signed!) + */ +int tarval_is_long(tarval *tv); + +/** + * Constructor function for new tarvals. + * + * @param d The (long) double representing the value + * @param mode The mode requested for the result tarval + * + * This function creates a new tarval representing the value represented + * by a (long) double. If a tarval representing this value already exists, + * this tarval is returned instead of a new one. So tarvals are directly + * comparable since their representation is unique. + * Only modes of sort float_number can be constructed this way. + * + * @return + * A tarval of proper type representing the requested value is returned. + * Tarvals are unique, so for any value/mode pair at most one tarval will + * exist, which will be returned upon further requests with an identical + * value/mode pair. + * + * @note + * If the (long) double is not representable in the given mode an assertion + * is thrown. This will happen for any mode not of sort float_number. + * + * @sa + * irmode.h for predefined values + * new_tarval_from_str() + * new_tarval_from_long() + */ +tarval *new_tarval_from_double(long double d, ir_mode *mode); + +/** + * This returns a double with the value represented value, or + * gibberish, depending on the size of double and the size of the + * stored value. + * This will overflow silently, so use only if you know what + * you are doing! (better check with tarval_is_long...) + */ +long double get_tarval_double(tarval *tv); + +/** + * This validates if tarval_to_double() will return a satisfying + * result. I.e. if tv is an float_number and between min, max + * of double + */ +int tarval_is_double(tarval *tv); + + +/** ********** Access routines for tarval fields ********** **/ + +/* + * NAME + * get_tarval_mode + * get_tarval_ ... + * + * SYNOPSIS + * ir_mode *get_tarval_mode(tarval *tv) + * ... + * + * DESCRIPTION + * These are access function for tarval struct members. It is encouraged + * to use them instead of direct access to the struct fields. + * + * PARAMETERS + * tv - The tarval to access fields of + * + * RESULT + * get_tv_mode: The mode of the tarval + * + * SEE ALSO + * the struct tarval + */ + +/** Returns the mode of the tarval. */ +ir_mode *get_tarval_mode (const tarval *tv); + +/** Returns the contents of the 'link' field of the tarval */ +/* void *get_tarval_link (tarval*); */ + +/* Testing properties of the represented values */ + +/** + * Returns 1 if tv is negative + * + * @param a the tarval + */ +int tarval_is_negative(tarval *a); + +/** + * Returns 1 if tv is null + * + * @param a the tarval + */ +int tarval_is_null(tarval *a); + +/** + * Returns 1 if tv is the "one" + * + * @param a the tarval + */ +int tarval_is_one(tarval *a); + +/** The 'bad' tarval. */ +extern tarval *tarval_bad; +/** Returns the 'bad tarval. */ +tarval *get_tarval_bad(void); + +/** The 'undefined' tarval. */ +extern tarval *tarval_undefined; +/** Returns the 'undefined' tarval. */ +tarval *get_tarval_undefined(void); + +/** The mode_b tarval 'false'. */ +extern tarval *tarval_b_false; + +/** Returns the mode_b tarval 'false'. */ +tarval *get_tarval_b_false(void); + +/** The mode_b tarval 'true'. */ +extern tarval *tarval_b_true; +/** Returns the mode_b tarval 'true'. */ +tarval *get_tarval_b_true(void); + +/** The 'void' pointer tarval. */ +extern tarval *tarval_P_void; +/** Returns the 'void' pointer tarval. */ +tarval *get_tarval_P_void(void); + +/* These functions calculate and return a tarval representing the requested + * value. + * The functions get_mode_{Max,Min,...} return tarvals retrieved from these + * functions, but these are stored on initialization of the irmode module and + * therefore the irmode functions should be prefered to the functions below. */ + +/** Returns the maximum value of a given mode. */ +tarval *get_tarval_max(ir_mode *mode); + +/** Returns the minimum value of a given mode. */ +tarval *get_tarval_min(ir_mode *mode); + +/** Returns the 0 value (additive neutral) of a given mode. */ +tarval *get_tarval_null(ir_mode *mode); + +/** Returns the 1 value (multiplicative neutral) of a given mode. */ +tarval *get_tarval_one(ir_mode *mode); + +/** Returns the -1 value (multiplicative neutral) of a given mode. + * Returns tarval bad for unsigned modes */ +tarval *get_tarval_minus_one(ir_mode *mode); + +/** Return quite nan for float_number modes. */ +tarval *get_tarval_nan(ir_mode *mode); + +/** Return +inf for float_number modes. */ +tarval *get_tarval_plus_inf(ir_mode *mode); + +/** Return -inf for float_number modes. */ +tarval *get_tarval_minus_inf(ir_mode *mode); + +/* ******************** Arithmetic operations on tarvals ******************** */ + +typedef enum _tarval_int_overflow_mode_t { + TV_OVERFLOW_BAD, /**< tarval module will return tarval_bad if a overflow occurs */ + TV_OVERFLOW_WRAP, /**< tarval module will overflow will be ignored, wrap around occurs */ + TV_OVERFLOW_SATURATE /**< tarval module will saturate the overflow */ +} tarval_int_overflow_mode_t; + +/** + * Sets the overflow mode for integer operations. + */ +void tarval_set_integer_overflow_mode(tarval_int_overflow_mode_t ov_mode); + +/** + * Get the overflow mode for integer operations. + */ +tarval_int_overflow_mode_t tarval_get_integer_overflow_mode(void); + +/** + * Compares two tarvals + * + * Compare a with b and return a pn_Cmp describing the relation + * between a and b. This is either pn_Cmp_Uo, pn_Cmp_Lt, pn_Cmp_Eq, pn_Cmp_Gt, + * or pn_Cmp_False if a or b are symbolic pointers which can not be compared at all. + * + * @param a A tarval to be compared + * @param b A tarval to be compared + * + * @return + * The pn_Cmp best describing the relation between a and b is returned. + * This means the mode with the least bits set is returned, e.g. if the + * tarvals are equal the pn_Cmp 'pn_Cmp_Eq' is returned, not 'pn_Cmp_Ge' which + * indicates 'greater or equal' + * + * @sa + * irnode.h for the definition of pn_Cmp + */ +pn_Cmp tarval_cmp(tarval *a, tarval *b); + +/** + * Converts a tarval to another mode. + * + * Convert tarval 'src' to mode 'mode', this will succeed if and only if mode + * 'mode' is wider than the mode of src, as defined in the firm documentation + * and as returned by the function mode_is_smaller defined in irmode.h. + * + * @param src The tarval to convert + * @param mode Tho mode to convert to + * + * @return + * If a tarval of mode 'mode' with the result of the conversion of the 'src' + * tarvals value already exists, it will be returned, else a new tarval is + * constructed and returned + * + * @note + * Illegal conversations will trigger an assertion + * + * @sa + * FIRM documentation for conversion rules + * mode_is_smaller defined in irmode.h + */ +tarval *tarval_convert_to(tarval *src, ir_mode *mode); + +/* + * These function implement basic computations representable as opcodes + * in FIRM nodes. + * + * PARAMETERS + * tarval_neg: + * traval_abs: + * a - the tarval to operate on + * + * all others: + * a - the first operand tarval + * b - the second operand tarval + * + * RESULT + * If necessary a new tarval is constructed for the resulting value, + * or the one already carrying the computation result is retrieved and + * returned as result. + * + * NOTES + * The order the arguments are given in is important, imagine postfix + * notation. + * Illegal operations will trigger an assertion. + * The sort member of the struct mode defines which operations are valid + */ + +/** bitwise Negation of a tarval. */ +tarval *tarval_not(tarval *a); + +/** arithmetic Negation of a tarval. */ +tarval *tarval_neg(tarval *a); + +/** Addition of two tarvals. */ +tarval *tarval_add(tarval *a, tarval *b); + +/** Subtraction from a tarval. */ +tarval *tarval_sub(tarval *a, tarval *b); + +/** Multiplication of tarvals. */ +tarval *tarval_mul(tarval *a, tarval *b); + +/** 'Exact' division. */ +tarval *tarval_quo(tarval *a, tarval *b); + +/** Integer division. */ +tarval *tarval_div(tarval *a, tarval *b); + +/** Remainder of integer division. */ +tarval *tarval_mod(tarval *a, tarval *b); + +/** Absolute value. */ +tarval *tarval_abs(tarval *a); + +/** Bitwise and. */ +tarval *tarval_and(tarval *a, tarval *b); + +/** Bitwise or. */ +tarval *tarval_or(tarval *a, tarval *b); + +/** Bitwise exclusive or. */ +tarval *tarval_eor(tarval *a, tarval *b); + +/** Left shift. */ +tarval *tarval_shl(tarval *a, tarval *b); + +/** Unsigned (logical) right shift. */ +tarval *tarval_shr(tarval *a, tarval *b); + +/** Signed (arithmetic) right shift. */ +tarval *tarval_shrs(tarval *a, tarval *b); + +/** Rotation. */ +tarval *tarval_rot(tarval *a, tarval *b); + +/** Carry flag of the last operation */ +int tarval_carry(void); + +/* *********** Output of tarvals *********** */ + +/** + * The output mode for tarval values. + * + * Some modes allow more that one representation, for instance integers + * can be represented hex or decimal. Of course it would be enough to have + * one and let every backend convert it into the 'right' one. + * However, we can do this in the tarval much simpler... + */ typedef enum { - irpn_False=0, /**< 0000 false */ - irpn_Eq, /**< 0001 equal */ - irpn_Lt, /**< 0010 less */ - irpn_Le, /**< 0011 less or equal */ - irpn_Gt, /**< 0100 greater */ - irpn_Ge, /**< 0101 greater of equal */ - irpn_Lg, /**< 0110 less or greater */ - irpn_Leg, /**< 0111 less, equal or greater = ordered */ - irpn_Uo, /**< 1000 unordered */ - irpn_Ue, /**< 1001 unordered or equal */ - irpn_Ul, /**< 1010 unordered or less */ - irpn_Ule, /**< 1011 unordered, less or equal */ - irpn_Ug, /**< 1100 unordered or greater */ - irpn_Uge, /**< 1101 unordered, greater or equal */ - irpn_Ne, /**< 1110 unordered, less or greater = not equal */ - irpn_True /**< 1111 true */ - /*irpn_notmask = irpn_Leg @@@ removed for JNI builder */ -} ir_pncmp; -#define irpn_notmask irpn_Leg - -/*@{*/ -/** Arithmethic operations on tarvals */ -tarval *tarval_neg (tarval *a); -tarval *tarval_add (tarval *a, tarval *b); -tarval *tarval_sub (tarval *a, tarval *b); -tarval *tarval_mul (tarval *a, tarval *b); -tarval *tarval_quo (tarval *a, tarval *b); -tarval *tarval_div (tarval *a, tarval *b); -tarval *tarval_mod (tarval *a, tarval *b); -tarval *tarval_abs (tarval *a); -tarval *tarval_and (tarval *a, tarval *b); -tarval *tarval_or (tarval *a, tarval *b); -tarval *tarval_eor (tarval *a, tarval *b); -tarval *tarval_shl (tarval *a, tarval *b); -tarval *tarval_shr (tarval *a, tarval *b); -/*@}*/ - -/** Compare a with b and return an ir_pncmp describing the relation - between a and b. This is either Uo, Lt, Eq, Gt, or False if a or b - are symbolic pointers which can not be compared at all. */ -ir_pncmp tarval_comp (tarval *a, tarval *b); - - -/* Identifying some tarvals */ -long tarval_classify (tarval *tv); -long tarval_ord (tarval *tv, int *fail); - -/*@{*/ -/** return a mode-specific value */ -tarval_F tv_val_F (tarval *tv); -tarval_D tv_val_D (tarval *tv); -tarval_sInt tv_val_sInt (tarval *tv); -tarval_uInt tv_val_uInt (tarval *tv); -/* @@@ temporarily removed. - jni builder can not deal with the return value. - All definitions of types are interpreted as pointer values until - type analysis exists for crecoder. - tarval_p tv_val_p (tarval *tv); -*/ -bool tv_val_b (tarval *tv); -/*@}*/ - -ir_mode *get_tv_mode (tarval *tv); -/** Returns the entity if the tv is a pointer to an entity, else - returns NULL; */ -entity *get_tv_entity(tarval *tv); -/* Removes tarvals that are pointers to ent. */ -void free_tv_entity(entity *ent); - -/** Returns 0 if tv is positive, else > 0. @todo not tested! */ -int tv_is_negative(tarval *a); + TVO_NATIVE, /**< the default output mode, depends on the mode */ + TVO_HEX, /**< use hex representation, always possible */ + TVO_DECIMAL, /**< use decimal representation */ + TVO_OCTAL, /**< use octal representation */ + TVO_BINARY, /**< use binary representation */ + TVO_FLOAT, /**< use floating point representation (i.e 1.342e-2)*/ + TVO_HEXFLOAT /**< use hexadecimal floating point representation (i.e 0x1.ea32p-12)*/ +} tv_output_mode; + +/** + * This structure contains helper information to format the output + * of a tarval of a mode. + */ +typedef struct tarval_mode_info { + tv_output_mode mode_output; /**< if != TVO_NATIVE select a special mode */ + const char *mode_prefix; /**< if set, this prefix will be printed + before a value of this mode */ + const char *mode_suffix; /**< if set, this suffix will be printed + after a value of this mode */ +} tarval_mode_info; + +/** + * Specify the output options of one mode. + * + * This functions stores the mode info, so DO NOT DESTROY it. + * + * @param mode a ir_mode that should be associated + * @param modeinfo the output format info + * + * @return zero on success. + */ +int set_tarval_mode_output_option(ir_mode *mode, const tarval_mode_info *modeinfo); + +/** + * Returns the output options of one mode. + * + * This functions returns the mode info of a given mode. + * + * @param mode a ir_mode that should be associated + * + * @return the output option + */ +const tarval_mode_info *get_tarval_mode_output_option(ir_mode *mode); + +/** + * Returns Bit representation of a tarval value, as string of '0' and '1' + * + * @param tv The tarval + * + * This function returns a printable bit representation of any value + * stored as tarval. This representation is a null terminated C string. + * + * @return + * As usual in C a pointer to a char is returned. The length of the + * returned string if fixed, just read as many chars as the mode defines + * as size. + * + * @note + * The string is allocated using malloc() and is free()ed on the next call + * of this function. + * The string consists of the ASCII characters '0' and '1' and is + * null terminated + * + * @sa + * irmode.h for the definition of the ir_mode struct + * the size member of aforementioned struct + */ +char *get_tarval_bitpattern(tarval *tv); + +/** + * Returns the bitpattern of the bytes_ofs byte. + * + * This function succeeds even if the mode of the tarval uses lesser bits + * than requested, in that case the bitpattern is filled with zero bits. + * + * To query a 32bit value the following code can be used: + * + * val0 = tarval_sub_bits(tv, 0); + * val1 = tarval_sub_bits(tv, 1); + * val2 = tarval_sub_bits(tv, 2); + * val3 = tarval_sub_bits(tv, 3); + * + * Because this is the bit representation of the target machine, only the following + * operations are legal on the result: + * + * - concatenation (endian dependence MUST be handled by the CALLER) + * - bitwise logical operations to select/mask bits + * + * @param tv the tarval + * @param byte_ofs the byte offset + * + * @note + * The result of this function is undefined if the mode is neither integer nor float. + */ +unsigned char get_tarval_sub_bits(tarval *tv, unsigned byte_ofs); + +/** + * Return values of tarval classify + */ +typedef enum _tarval_classification_t { + TV_CLASSIFY_NULL = 0, /**< the tarval represents the additive neutral element */ + TV_CLASSIFY_ONE = +1, /**< the tarval represents the multiplicative neutral element */ + TV_CLASSIFY_ALL_ONE = -1, /**< the tarval represents the bitwise-and neutral element */ + TV_CLASSIFY_OTHER = 2 /**< all other tarvals */ +} tarval_classification_t; + +/** + * Identifying tarvals values for algebraic simplifications. + * @param tv + * @return + * - TV_CLASSIFY_NULL for additive neutral, + * - TV_CLASSIFY_ONE for multiplicative neutral, + * - TV_CLASSIFY_ALL_ONE for bitwise-and neutral + * - TV_CLASSIFY_OTHER else + */ +tarval_classification_t classify_tarval(tarval *tv); + +/** + * Output of tarvals to a buffer. + */ +int tarval_snprintf(char *buf, size_t buflen, tarval *tv); + +/** + * Output of tarvals to stdio. + */ +int tarval_printf(tarval *tv); + #endif /* _TV_H_ */