SLI
Shift left and insert (immediate)
This instruction reads each vector element in the
source SIMD&FP register,
left shifts each vector element by an immediate value, and
inserts the result into the corresponding vector element
in the destination SIMD&FP register such that the new zero bits created
by the shift are not inserted but retain their existing value.
Bits shifted out of the left of each vector element in the
source register are lost.
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.
If PSTATE.DIT is 1:
The execution time of this instruction is independent of:
The values of the data supplied in any of its registers.
The values of the NZCV flags.
The response of this instruction to asynchronous exceptions does not vary based on:
The values of the data supplied in any of its registers.
The values of the NZCV flags.
It has encodings from 2 classes:
Scalar
and
Vector
0
1
1
1
1
1
1
1
0
1
x
x
x
0
1
0
1
0
1
SLI D<d>, D<n>, #<shift>
if immh<3> != '1' then UNDEFINED;
constant integer d = UInt(Rd);
constant integer n = UInt(Rn);
constant integer esize = 8 << 3;
constant integer datasize = esize;
constant integer elements = 1;
constant integer shift = UInt(immh:immb) - esize;
0
1
0
1
1
1
1
0
!= 0000
0
1
0
1
0
1
SLI <Vd>.<T>, <Vn>.<T>, #<shift>
if immh == '0000' then SEE(asimdimm);
if immh<3>:Q == '10' then UNDEFINED;
constant integer d = UInt(Rd);
constant integer n = UInt(Rn);
constant integer esize = 8 << HighestSetBitNZ(immh);
constant integer datasize = 64 << UInt(Q);
constant integer elements = datasize DIV esize;
constant integer shift = UInt(immh:immb) - esize;
<d>
Is the number of the SIMD&FP destination register, in the "Rd" field.
<n>
Is the number of the first SIMD&FP source register, encoded in the "Rn" field.
<shift>
For the scalar variant: is the left shift amount, in the range 0 to 63, encoded as UInt("immh:immb") - 64.
<shift>
For the vector variant: is the left shift amount, in the range 0 to the element width in bits minus 1,
immh
<shift>
0001
UInt(immh:immb) - 8
001x
UInt(immh:immb) - 16
01xx
UInt(immh:immb) - 32
1xxx
UInt(immh:immb) - 64
<Vd>
Is the name of the SIMD&FP destination register, encoded in the "Rd" field.
<T>
Is an arrangement specifier,
immh
Q
<T>
0001
0
8B
0001
1
16B
001x
0
4H
001x
1
8H
01xx
0
2S
01xx
1
4S
1xxx
0
RESERVED
1xxx
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];
constant bits(datasize) operand2 = V[d, datasize];
constant bits(esize) mask = LSL(Ones(esize), shift);
bits(datasize) result;
bits(esize) shifted;
for e = 0 to elements-1
shifted = LSL(Elem[operand, e, esize], shift);
Elem[result, e, esize] = (Elem[operand2, e, esize] AND NOT(mask)) OR shifted;
V[d, datasize] = result;