FSCALE
Floating-point adjust exponent by vector
This instruction multiplies the floating-point elements of the first
source vector by 2.0 to the power of the signed integer values in the
corresponding elements of the second source vector, and places the
results in the corresponding elements of the destination vector.
It has encodings from 2 classes:
Half-precision
and
Single-precision and double-precision
0
1
0
1
1
1
0
1
1
0
0
0
1
1
1
1
FSCALE <Vd>.<T>, <Vn>.<T>, <Vm>.<T>
if !IsFeatureImplemented(FEAT_FP8) then EndOfDecode(Decode_UNDEF); end;
let esize : integer{} = 16;
let d : integer{} = UInt(Rd);
let n : integer{} = UInt(Rn);
let m : integer{} = UInt(Rm);
let datasize : integer{} = if Q == '1' then 128 else 64;
let elements : integer = datasize DIV esize;
0
1
0
1
1
1
0
1
x
1
1
1
1
1
1
1
FSCALE <Vd>.<T>, <Vn>.<T>, <Vm>.<T>
if !IsFeatureImplemented(FEAT_FP8) then EndOfDecode(Decode_UNDEF); end;
if Q == '0' && size == '11' then EndOfDecode(Decode_UNDEF); end;
let esize : integer{} = 8 << UInt(size);
let d : integer{} = UInt(Rd);
let n : integer{} = UInt(Rn);
let m : integer{} = UInt(Rm);
let datasize : integer{} = if Q == '1' then 128 else 64;
let elements : integer = datasize DIV esize;
<Vd>
Is the name of the SIMD&FP destination register, encoded in the "Rd" field.
<T>
For the "Half-precision" variant: is an arrangement specifier,
<T>
For the "Single-precision and double-precision" variant: is an arrangement specifier,
size[0]
Q
<T>
0
0
2S
0
1
4S
1
0
RESERVED
1
1
2D
<Vn>
Is the name of the first SIMD&FP source register, encoded in the "Rn" field.
<Vm>
Is the name of the second SIMD&FP source register, encoded in the "Rm" field.
AArch64_CheckFPAdvSIMDEnabled();
let operand1 : bits(datasize) = V{}(n);
let operand2 : bits(datasize) = V{}(m);
var result : bits(datasize);
for e = 0 to elements-1 do
let op1 : bits(esize) = operand1[e*:esize];
let op2 : integer = SInt(operand2[e*:esize]);
result[e*:esize] = FPScale{esize}(op1, op2, FPCR());
end;
V{datasize}(d) = result;
2026-03-26 20:27:25
2026-03_rel