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Home > NEON and VFP Programming > NEON general arithmetic instructions > VRECPE and VRSQRTE |
VRECPE
(Vector Reciprocal Estimate) finds an
approximate reciprocal of each element in a vector, and places the
results in a second vector.
VRSQRTE
(Vector Reciprocal Square Root Estimate)
finds an approximate reciprocal square root of each element in a
vector, and places the results in a second vector.
Vop
{cond
}.datatype
Qd
,Qm
Vop
{cond
}.datatype
Dd
,Dm
where:
op
must be either RECPE
or RSQRTE
.
cond
is an optional condition code.
datatype
must be either U32
or F32
.
Qd
, Qm
are the destination vector and the operand vector, for a quadword operation.
Dd
, Dm
are the destination vector and the operand vector, for a doubleword operation.
Table 24 shows the results where input values are out of range.
Table 24. Results for out-of-range inputs
Operand element (VRECPE ) | Operand element (VRSQRTE ) | Result element | |
---|---|---|---|
Integer | <= 0x7FFFFFFF | <= 0x3FFFFFFF | 0xFFFFFFFF |
Floating-point | NaN | NaN, Negative Normal, Negative Infinity | Default NaN |
Negative 0, Negative Denormal | Negative 0, Negative Denormal | Negative Infinity ^{[a]} | |
Positive 0, Positive Denormal | Positive 0, Positive Denormal | Positive Infinity ^{[a]} | |
Positive infinity | Positive infinity | Positive 0 | |
Negative infinity | Negative 0 | ||
^{[a] }The Division by Zero exception bit in the FPSCR (FPSCR[1]) is set |