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.

Show/hideSyntax

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.

Show/hideResults for out-of-range inputs

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<= 0x3FFFFFFF0xFFFFFFFF
Floating-pointNaNNaN, Negative Normal, Negative InfinityDefault NaN
Negative 0, Negative DenormalNegative 0, Negative DenormalNegative Infinity [a]
Positive 0, Positive DenormalPositive 0, Positive DenormalPositive Infinity [a]
Positive infinityPositive infinityPositive 0
Negative infinity Negative 0

[a] The Division by Zero exception bit in the FPSCR (FPSCR[1]) is set


Show/hideSee also

Reference:
Copyright © 2010-2011 ARM. All rights reserved.ARM DUI 0489C
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