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int128.h File Reference
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Data Structures

struct  INT128
 

Macros

#define USE_NATIVE_INT128   0
 
#define INT64_AU32(i64)   ((i64) >> 32)
 
#define INT64_AL32(i64)   ((i64) & UINT64CONST(0xFFFFFFFF))
 

Functions

static void int128_add_uint64 (INT128 *i128, uint64 v)
 
static void int128_add_int64 (INT128 *i128, int64 v)
 
static void int128_add_int64_mul_int64 (INT128 *i128, int64 x, int64 y)
 
static int int128_compare (INT128 x, INT128 y)
 
static INT128 int64_to_int128 (int64 v)
 
static int64 int128_to_int64 (INT128 val)
 

Macro Definition Documentation

◆ INT64_AL32

#define INT64_AL32 (   i64)    ((i64) & UINT64CONST(0xFFFFFFFF))

Definition at line 171 of file int128.h.

Referenced by int128_add_int64_mul_int64().

◆ INT64_AU32

#define INT64_AU32 (   i64)    ((i64) >> 32)

Definition at line 170 of file int128.h.

Referenced by int128_add_int64_mul_int64().

◆ USE_NATIVE_INT128

#define USE_NATIVE_INT128   0

Definition at line 28 of file int128.h.

Function Documentation

◆ int128_add_int64()

static void int128_add_int64 ( INT128 i128,
int64  v 
)
inlinestatic

Definition at line 143 of file int128.h.

References INT128::hi, and INT128::lo.

Referenced by main().

144 {
145  /*
146  * This is much like the above except that the carry logic differs for
147  * negative v. Ordinarily we'd need to subtract 1 from the .hi part
148  * (corresponding to adding the sign-extended bits of v to it); but if
149  * there is a carry out of the .lo part, that cancels and we do nothing.
150  */
151  uint64 oldlo = i128->lo;
152 
153  i128->lo += v;
154  if (v >= 0)
155  {
156  if ((int64) oldlo < 0 && (int64) i128->lo >= 0)
157  i128->hi++;
158  }
159  else
160  {
161  if (!((int64) oldlo < 0 || (int64) i128->lo >= 0))
162  i128->hi--;
163  }
164 }
uint64 lo
Definition: int128.h:113
int64 hi
Definition: int128.h:114

◆ int128_add_int64_mul_int64()

static void int128_add_int64_mul_int64 ( INT128 i128,
int64  x,
int64  y 
)
inlinestatic

Definition at line 177 of file int128.h.

References INT128::hi, int128_add_uint64(), INT64_AL32, INT64_AU32, and StaticAssertStmt.

Referenced by interval_cmp_value(), and main().

178 {
179  /* INT64_AU32 must use arithmetic right shift */
180  StaticAssertStmt(((int64) -1 >> 1) == (int64) -1,
181  "arithmetic right shift is needed");
182 
183  /*----------
184  * Form the 128-bit product x * y using 64-bit arithmetic.
185  * Considering each 64-bit input as having 32-bit high and low parts,
186  * we can compute
187  *
188  * x * y = ((x.hi << 32) + x.lo) * (((y.hi << 32) + y.lo)
189  * = (x.hi * y.hi) << 64 +
190  * (x.hi * y.lo) << 32 +
191  * (x.lo * y.hi) << 32 +
192  * x.lo * y.lo
193  *
194  * Each individual product is of 32-bit terms so it won't overflow when
195  * computed in 64-bit arithmetic. Then we just have to shift it to the
196  * correct position while adding into the 128-bit result. We must also
197  * keep in mind that the "lo" parts must be treated as unsigned.
198  *----------
199  */
200 
201  /* No need to work hard if product must be zero */
202  if (x != 0 && y != 0)
203  {
204  int64 x_u32 = INT64_AU32(x);
205  uint64 x_l32 = INT64_AL32(x);
206  int64 y_u32 = INT64_AU32(y);
207  uint64 y_l32 = INT64_AL32(y);
208  int64 tmp;
209 
210  /* the first term */
211  i128->hi += x_u32 * y_u32;
212 
213  /* the second term: sign-extend it only if x is negative */
214  tmp = x_u32 * y_l32;
215  if (x < 0)
216  i128->hi += INT64_AU32(tmp);
217  else
218  i128->hi += ((uint64) tmp) >> 32;
219  int128_add_uint64(i128, ((uint64) INT64_AL32(tmp)) << 32);
220 
221  /* the third term: sign-extend it only if y is negative */
222  tmp = x_l32 * y_u32;
223  if (y < 0)
224  i128->hi += INT64_AU32(tmp);
225  else
226  i128->hi += ((uint64) tmp) >> 32;
227  int128_add_uint64(i128, ((uint64) INT64_AL32(tmp)) << 32);
228 
229  /* the fourth term: always unsigned */
230  int128_add_uint64(i128, x_l32 * y_l32);
231  }
232 }
static void int128_add_uint64(INT128 *i128, uint64 v)
Definition: int128.h:122
#define StaticAssertStmt(condition, errmessage)
Definition: c.h:842
int64 hi
Definition: int128.h:114
#define INT64_AU32(i64)
Definition: int128.h:170
#define INT64_AL32(i64)
Definition: int128.h:171

◆ int128_add_uint64()

static void int128_add_uint64 ( INT128 i128,
uint64  v 
)
inlinestatic

Definition at line 122 of file int128.h.

References INT128::hi, and INT128::lo.

Referenced by int128_add_int64_mul_int64(), and main().

123 {
124  /*
125  * First add the value to the .lo part, then check to see if a carry needs
126  * to be propagated into the .hi part. A carry is needed if both inputs
127  * have high bits set, or if just one input has high bit set while the new
128  * .lo part doesn't. Remember that .lo part is unsigned; we cast to
129  * signed here just as a cheap way to check the high bit.
130  */
131  uint64 oldlo = i128->lo;
132 
133  i128->lo += v;
134  if (((int64) v < 0 && (int64) oldlo < 0) ||
135  (((int64) v < 0 || (int64) oldlo < 0) && (int64) i128->lo >= 0))
136  i128->hi++;
137 }
uint64 lo
Definition: int128.h:113
int64 hi
Definition: int128.h:114

◆ int128_compare()

static int int128_compare ( INT128  x,
INT128  y 
)
inlinestatic

Definition at line 238 of file int128.h.

References INT128::hi, and INT128::lo.

Referenced by in_range_interval_interval(), in_range_timestamp_interval(), in_range_timestamptz_interval(), interval_cmp_internal(), and main().

239 {
240  if (x.hi < y.hi)
241  return -1;
242  if (x.hi > y.hi)
243  return 1;
244  if (x.lo < y.lo)
245  return -1;
246  if (x.lo > y.lo)
247  return 1;
248  return 0;
249 }
uint64 lo
Definition: int128.h:113
int64 hi
Definition: int128.h:114

◆ int128_to_int64()

static int64 int128_to_int64 ( INT128  val)
inlinestatic

Definition at line 269 of file int128.h.

References INT128::lo.

Referenced by interval_hash(), and interval_hash_extended().

270 {
271  return (int64) val.lo;
272 }
uint64 lo
Definition: int128.h:113

◆ int64_to_int128()

static INT128 int64_to_int128 ( int64  v)
inlinestatic

Definition at line 255 of file int128.h.

References INT128::hi, INT128::lo, and val.

Referenced by in_range_interval_interval(), in_range_timestamp_interval(), in_range_timestamptz_interval(), and interval_cmp_value().

256 {
257  INT128 val;
258 
259  val.lo = (uint64) v;
260  val.hi = (v < 0) ? -INT64CONST(1) : INT64CONST(0);
261  return val;
262 }
uint64 lo
Definition: int128.h:113
int64 hi
Definition: int128.h:114
Definition: int128.h:107
long val
Definition: informix.c:684