 ROOT   Reference Guide helpers.h File Reference
#include <cstdint>
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## Functions

static uint64_t add_carry (uint64_t a, uint64_t b, unsigned &carry)
Compute a + b and increment carry if there was an overflow. More...

static uint64_t add_overflow (uint64_t a, uint64_t b, unsigned &overflow)
Compute a + b and set overflow accordingly. More...

static int64_t compute_r (const uint64_t *upper, uint64_t *r)
Update r = r - (t1 + t2) + (t3 + t2) * b ** 10. More...

static uint64_t sub_carry (uint64_t a, uint64_t b, unsigned &carry)
Compute a - b and increment carry if there was an overflow. More...

static uint64_t sub_overflow (uint64_t a, uint64_t b, unsigned &overflow)
Compute a - b and set overflow accordingly. More...

## Function Documentation

 static uint64_t add_carry ( uint64_t a, uint64_t b, unsigned & carry )
inlinestatic

Compute a + b and increment carry if there was an overflow.

Definition at line 26 of file helpers.h.

 static uint64_t add_overflow ( uint64_t a, uint64_t b, unsigned & overflow )
inlinestatic

Compute a + b and set overflow accordingly.

Definition at line 18 of file helpers.h.

## ◆ compute_r()

 static int64_t compute_r ( const uint64_t * upper, uint64_t * r )
inlinestatic

Update r = r - (t1 + t2) + (t3 + t2) * b ** 10.

This function also yields cbar = floor(r / m) as its return value (int64_t because the value can be -1). With an initial value of r = t0, this can be used for computing the remainder after division by m (see the function mod_m in mulmod.h). The function to_ranlux passes r = 0 and uses only the return value to obtain the decimal expansion after divison by m.

Definition at line 62 of file helpers.h.

## ◆ sub_carry()

 static uint64_t sub_carry ( uint64_t a, uint64_t b, unsigned & carry )
inlinestatic

Compute a - b and increment carry if there was an overflow.

Definition at line 45 of file helpers.h.

## ◆ sub_overflow()

 static uint64_t sub_overflow ( uint64_t a, uint64_t b, unsigned & overflow )
inlinestatic

Compute a - b and set overflow accordingly.

Definition at line 37 of file helpers.h.