SSAT16
Signed Saturate 16
Signed Saturate 16 saturates two signed 16-bit values to a
selected signed range.
This instruction sets PSTATE.Q to 1 if the
operation saturates.
For more information about the CONSTRAINED UNPREDICTABLE behavior of this instruction, see Architectural Constraints on UNPREDICTABLE behaviors.
It has encodings from the following instruction sets:
A32 (
A1
)
and
T32 (
T1
)
.
!= 1111
0
1
1
0
1
0
1
0
(1)
(1)
(1)
(1)
0
0
1
1
SSAT16{<c>}{<q>} <Rd>, #<imm>, <Rn>
let d : integer = UInt(Rd);
let n : integer = UInt(Rn);
let saturate_to : integer{} = UInt(sat_imm)+1;
if d == 15 || n == 15 then UnpredictableProcedure(); end;
1
1
1
1
0
(0)
1
1
0
0
1
0
0
0
0
0
0
0
(0)
(0)
SSAT16{<c>}{<q>} <Rd>, #<imm>, <Rn>
let d : integer = UInt(Rd);
let n : integer = UInt(Rn);
let saturate_to : integer{} = UInt(sat_imm)+1;
// Armv8-A removes UNPREDICTABLE for R13
if d == 15 || n == 15 then UnpredictableProcedure(); end;
<c>
See Standard assembler syntax fields.
<q>
See Standard assembler syntax fields.
<Rd>
Is the general-purpose destination register, encoded in the "Rd" field.
<imm>
Is the bit position for saturation, in the range 1 to 16, encoded in the "sat_imm" field as <imm>-1.
<Rn>
Is the general-purpose source register, encoded in the "Rn" field.
if ConditionPassed() then
EncodingSpecificOperations();
let (result1, sat1) : (bits(saturate_to), boolean) = SignedSatQ{saturate_to}(SInt(R(n)[15:0]));
let (result2, sat2) : (bits(saturate_to), boolean) = SignedSatQ{saturate_to}(SInt(R(n)[31:16]));
R(d)[15:0] = SignExtend{16}(result1);
R(d)[31:16] = SignExtend{16}(result2);
if sat1 || sat2 then
PSTATE.Q = '1';
end;
end;
2026-03-26 20:27:25
2026-03_rel