long.h

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#ifndef RBIMPL_ARITHMETIC_LONG_H                     /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_ARITHMETIC_LONG_H
#include "ruby/internal/config.h"
#include "ruby/internal/arithmetic/fixnum.h"   /* FIXABLE */
#include "ruby/internal/arithmetic/intptr_t.h" /* rb_int2big etc.*/
#include "ruby/internal/assume.h"
#include "ruby/internal/attr/artificial.h"
#include "ruby/internal/attr/cold.h"
#include "ruby/internal/attr/const.h"
#include "ruby/internal/attr/constexpr.h"
#include "ruby/internal/attr/noreturn.h"
#include "ruby/internal/cast.h"
#include "ruby/internal/dllexport.h"
#include "ruby/internal/special_consts.h"      /* FIXNUM_FLAG */
#include "ruby/internal/value.h"
#include "ruby/assert.h"
 
#define FIX2LONG     RB_FIX2LONG          
#define FIX2ULONG    RB_FIX2ULONG         
#define INT2FIX      RB_INT2FIX           
#define LONG2FIX     RB_INT2FIX           
#define LONG2NUM     RB_LONG2NUM          
#define NUM2LONG     RB_NUM2LONG          
#define NUM2ULONG    RB_NUM2ULONG         
#define RB_FIX2LONG  rb_fix2long          
#define RB_FIX2ULONG rb_fix2ulong         
#define RB_LONG2FIX  RB_INT2FIX           
#define RB_LONG2NUM  rb_long2num_inline   
#define RB_NUM2LONG  rb_num2long_inline   
#define RB_NUM2ULONG rb_num2ulong_inline  
#define RB_ULONG2NUM rb_ulong2num_inline  
#define ULONG2NUM    RB_ULONG2NUM         
#define rb_fix_new   RB_INT2FIX           
#define rb_long2int  rb_long2int_inline   
#define RB_INT2FIX RB_INT2FIX
RBIMPL_SYMBOL_EXPORT_BEGIN()
 
RBIMPL_ATTR_NORETURN()
RBIMPL_ATTR_COLD()
void rb_out_of_int(SIGNED_VALUE num);
 
RBIMPL_ATTR_NORETURN()
RBIMPL_ATTR_COLD()
void rb_out_of_long(SIGNED_VALUE num);
 
long rb_num2long(VALUE num);
 
unsigned long rb_num2ulong(VALUE num);
RBIMPL_SYMBOL_EXPORT_END()
 
RBIMPL_ATTR_CONST_UNLESS_DEBUG()
RBIMPL_ATTR_CONSTEXPR_UNLESS_DEBUG(CXX14)
RBIMPL_ATTR_ARTIFICIAL()
static inline VALUE
RB_INT2FIX(long i)
{
    RBIMPL_ASSERT_OR_ASSUME(RB_FIXABLE(i));
 
    /* :NOTE: VALUE can be wider than long.  As j being unsigned, 2j+1 is fully
     * defined. Also it can be compiled into a single LEA instruction. */
    const unsigned long j = RBIMPL_CAST((unsigned long)i);
    const unsigned long k = (j << 1) + RUBY_FIXNUM_FLAG;
    const long          l = RBIMPL_CAST((long)k);
    const SIGNED_VALUE  m = l; /* Sign extend */
    const VALUE         n = RBIMPL_CAST((VALUE)m);
 
    RBIMPL_ASSERT_OR_ASSUME(RB_FIXNUM_P(n));
    return n;
}
 
static inline int
rb_long2int_inline(long n)
{
    int i = RBIMPL_CAST((int)n);
 
    if /* constexpr */ (sizeof(long) <= sizeof(int)) {
        RBIMPL_ASSUME(i == n);
    }
 
    if (i != n)
        rb_out_of_int(n);
 
    return i;
}
 
RBIMPL_ATTR_CONST_UNLESS_DEBUG()
RBIMPL_ATTR_CONSTEXPR_UNLESS_DEBUG(CXX14)
static inline long
rbimpl_fix2long_by_idiv(VALUE x)
{
    RBIMPL_ASSERT_OR_ASSUME(RB_FIXNUM_P(x));
 
    /* :NOTE: VALUE  can be wider  than long.  (x-1)/2 never  overflows because
     * RB_FIXNUM_P(x)  holds.   Also it  has  no  portability issue  like  y>>1
     * below. */
    const SIGNED_VALUE y = RBIMPL_CAST((SIGNED_VALUE)(x - RUBY_FIXNUM_FLAG));
    const SIGNED_VALUE z = y / 2;
    const long         w = RBIMPL_CAST((long)z);
 
    RBIMPL_ASSERT_OR_ASSUME(RB_FIXABLE(w));
    return w;
}
 
RBIMPL_ATTR_CONST_UNLESS_DEBUG()
RBIMPL_ATTR_CONSTEXPR_UNLESS_DEBUG(CXX14)
static inline long
rbimpl_fix2long_by_shift(VALUE x)
{
    RBIMPL_ASSERT_OR_ASSUME(RB_FIXNUM_P(x));
 
    /* :NOTE: VALUE can be wider than long.  If right shift is arithmetic, this
     * is noticeably faster than above. */
    const SIGNED_VALUE y = RBIMPL_CAST((SIGNED_VALUE)x);
    const SIGNED_VALUE z = y >> 1;
    const long         w = RBIMPL_CAST((long)z);
 
    RBIMPL_ASSERT_OR_ASSUME(RB_FIXABLE(w));
    return w;
}
 
RBIMPL_ATTR_CONST()
RBIMPL_ATTR_CONSTEXPR(CXX11)
static inline bool
rbimpl_right_shift_is_arithmetic_p(void)
{
    return (-1 >> 1) == -1;
}
 
RBIMPL_ATTR_CONST_UNLESS_DEBUG()
RBIMPL_ATTR_CONSTEXPR_UNLESS_DEBUG(CXX14)
static inline long
rb_fix2long(VALUE x)
{
    if /* constexpr */ (rbimpl_right_shift_is_arithmetic_p()) {
        return rbimpl_fix2long_by_shift(x);
    }
    else {
        return rbimpl_fix2long_by_idiv(x);
    }
}
 
RBIMPL_ATTR_CONST_UNLESS_DEBUG()
RBIMPL_ATTR_CONSTEXPR_UNLESS_DEBUG(CXX14)
static inline unsigned long
rb_fix2ulong(VALUE x)
{
    RBIMPL_ASSERT_OR_ASSUME(RB_FIXNUM_P(x));
    return RBIMPL_CAST((unsigned long)rb_fix2long(x));
}
 
static inline long
rb_num2long_inline(VALUE x)
{
    if (RB_FIXNUM_P(x))
        return RB_FIX2LONG(x);
    else
        return rb_num2long(x);
}
 
static inline unsigned long
rb_num2ulong_inline(VALUE x)
{
    if (RB_FIXNUM_P(x))
        return RB_FIX2ULONG(x);
    else
        return rb_num2ulong(x);
}
 
static inline VALUE
rb_long2num_inline(long v)
{
    if (RB_FIXABLE(v))
        return RB_LONG2FIX(v);
    else
        return rb_int2big(v);
}
 
static inline VALUE
rb_ulong2num_inline(unsigned long v)
{
    if (RB_POSFIXABLE(v))
        return RB_LONG2FIX(RBIMPL_CAST((long)v));
    else
        return rb_uint2big(v);
}
 
#if RBIMPL_HAS_ATTR_CONSTEXPR_CXX14
# /* C++ can write constexpr as enum values. */
 
#elif ! defined(HAVE_BUILTIN___BUILTIN_CHOOSE_EXPR_CONSTANT_P)
# undef INT2FIX
# define INT2FIX(i) (RBIMPL_CAST((VALUE)(i)) << 1 | RUBY_FIXNUM_FLAG)
 
#else
# undef INT2FIX
# define INT2FIX(i)                                     \
    __builtin_choose_expr(                              \
        __builtin_constant_p(i),                        \
        RBIMPL_CAST((VALUE)(i)) << 1 | RUBY_FIXNUM_FLAG, \
        RB_INT2FIX(i))
#endif
#endif /* RBIMPL_ARITHMETIC_LONG_H */