CTERMEQ, CTERMNE
Compare and terminate loop
This instruction detects termination conditions in serialized vector
loops by testing whether the comparison
between the scalar source operands holds true. If the comparison is
not successful, the instruction tests the state of the !Last condition flag
(C), which indicates whether the previous flag-setting
predicate instruction selected the last element of the
vector partition.
The Z and C condition flags are preserved by this
instruction. The N and V condition flags are set as a
pair to generate one of the following conditions for a
subsequent conditional instruction:
Condition
N
V
Meaning
GE
0
0
Continue loop (compare failed and last element not selected)
LT
0
1
Terminate loop (last element selected)
LT
1
0
Terminate loop (compare succeeded)
GE
1
1
Never generated
The scalar source operands are 32-bit or 64-bit general-purpose
registers of the same size.
False
True
This instruction is a data-independent-time instruction as described in About PSTATE.DIT.
It has encodings from 2 classes:
Equal
and
Not equal
0
0
1
0
0
1
0
1
1
1
0
0
1
0
0
0
0
0
0
0
0
CTERMEQ <R><n>, <R><m>
if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then
EndOfDecode(Decode_UNDEF);
end;
let esize : integer{} = 32 << UInt(sz);
let n : integer = UInt(Rn);
let m : integer = UInt(Rm);
let cmp_op : CmpOp = Cmp_EQ;
0
0
1
0
0
1
0
1
1
1
0
0
1
0
0
0
1
0
0
0
0
CTERMNE <R><n>, <R><m>
if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then
EndOfDecode(Decode_UNDEF);
end;
let esize : integer{} = 32 << UInt(sz);
let n : integer = UInt(Rn);
let m : integer = UInt(Rm);
let cmp_op : CmpOp = Cmp_NE;
<R>
Is a width specifier,
<n>
Is the number [0-30] of the source general-purpose register or the name ZR (31), encoded in the "Rn" field.
<m>
Is the number [0-30] of the source general-purpose register or the name ZR (31), encoded in the "Rm" field.
CheckSVEEnabled();
let operand1 : bits(esize) = X{}(n);
let operand2 : bits(esize) = X{}(m);
let element1 : integer = UInt(operand1);
let element2 : integer = UInt(operand2);
var term : boolean;
case cmp_op of
when Cmp_EQ => term = element1 == element2;
when Cmp_NE => term = element1 != element2;
end;
if term then
PSTATE.N = '1';
PSTATE.V = '0';
else
PSTATE.N = '0';
PSTATE.V = (NOT PSTATE.C);
end;
2026-03-26 20:27:25
2026-03_rel