SQABS
Signed saturating absolute value
This instruction reads each vector element from the source SIMD&FP register,
puts the absolute value of the result into a vector, and writes the
vector to the destination SIMD&FP register.
All the values in this instruction are signed integer values.
If overflow occurs with any of the results, those results are saturated.
If saturation occurs, the cumulative saturation bit
FPSR.QC is set.
Depending on the settings in the CPACR_EL1,
CPTR_EL2, and CPTR_EL3 registers,
and the current Security state and Exception level,
an attempt to execute the instruction might be trapped.
It has encodings from 2 classes:
Scalar
and
Vector
0
1
0
1
1
1
1
0
1
0
0
0
0
0
0
1
1
1
1
0
SQABS <V><d>, <V><n>
constant integer d = UInt(Rd);
constant integer n = UInt(Rn);
constant integer esize = 8 << UInt(size);
constant integer datasize = esize;
constant integer elements = 1;
0
0
0
1
1
1
0
1
0
0
0
0
0
0
1
1
1
1
0
SQABS <Vd>.<T>, <Vn>.<T>
if size:Q == '110' then UNDEFINED;
constant integer d = UInt(Rd);
constant integer n = UInt(Rn);
constant integer esize = 8 << UInt(size);
constant integer datasize = 64 << UInt(Q);
constant integer elements = datasize DIV esize;
<V>
Is a width specifier,
size
<V>
00
B
01
H
10
S
11
D
<d>
Is the number of the SIMD&FP destination register, encoded in the "Rd" field.
<n>
Is the number of the SIMD&FP source register, encoded in the "Rn" field.
<Vd>
Is the name of the SIMD&FP destination register, encoded in the "Rd" field.
<T>
Is an arrangement specifier,
size
Q
<T>
00
0
8B
00
1
16B
01
0
4H
01
1
8H
10
0
2S
10
1
4S
11
0
RESERVED
11
1
2D
<Vn>
Is the name of the SIMD&FP source register, encoded in the "Rn" field.
CheckFPAdvSIMDEnabled64();
constant bits(datasize) operand = V[n, datasize];
bits(datasize) result;
integer element;
boolean sat;
for e = 0 to elements-1
element = SInt(Elem[operand, e, esize]);
element = Abs(element);
(Elem[result, e, esize], sat) = SignedSatQ(element, esize);
if sat then FPSR.QC = '1';
V[d, datasize] = result;