Module rustc_apfloat::ieee::sig
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Implementation details of IeeeFloat significands, such as big integer arithmetic. As a rule of thumb, no functions in this module should dynamically allocate.
Functions
add 🔒
a += b + c
where c
is zero or one. Returns the carry flag.a += b
or a -= b
. Does not preserve b
.Clear the given bit.
cmp 🔒
Comparison (unsigned) of two significands.
Decrement in-place, return the borrow flag.
div 🔒
quotient = dividend / divisor
. Returns the lost fraction.
Does not preserve dividend
or divisor
.For every consecutive chunk of
bits
bits from limbs
,
going from most significant to the least significant bits,
call f
to transform those bits and store the result back.extract 🔒
Copies the bit vector of width
src_bits
from src
, starting at bit SRC_LSB,
to dst
, such that the bit SRC_LSB becomes the least significant bit of dst
.
All high bits above src_bits
in dst
are zero-filled.We want the most significant PRECISION bits of
src
. There may not
be that many; extract what we can.get_bit 🔒
Extracts the given bit.
Increment in-place, return the carry flag.
mul 🔒
dst = a * b
(for normal a
and b
). Returns the lost fraction.olsb 🔒
One, not zero, based LSB. That is, returns 0 for a zeroed significand.
omsb 🔒
One, not zero, based MSB. That is, returns 0 for a zeroed significand.
set_bit 🔒
Sets the given bit.
Shifts
dst
left bits
bits, subtract bits
from its exponent.Shifts
dst
right bits
bits noting lost fraction.sub 🔒
a -= b + c
where c
is zero or one. Returns the borrow flag.[low, high] = a * b
.