CTERMEQ, CTERMNE
Compare and terminate loop
Detect termination conditions in serialized vector loops. Tests whether the comparison between the scalar source operands holds true and if not 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.
Green
False
True
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 UNDEFINED;
constant integer esize = 32 << UInt(sz);
constant integer n = UInt(Rn);
constant integer m = UInt(Rm);
constant SVECmp cmp_op = 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 UNDEFINED;
constant integer esize = 32 << UInt(sz);
constant integer n = UInt(Rn);
constant integer m = UInt(Rm);
constant SVECmp cmp_op = 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();
constant bits(esize) operand1 = X[n, esize];
constant bits(esize) operand2 = X[m, esize];
constant integer element1 = UInt(operand1);
constant integer element2 = UInt(operand2);
boolean term;
case cmp_op of
when Cmp_EQ term = element1 == element2;
when Cmp_NE term = element1 != element2;
if term then
PSTATE.N = '1';
PSTATE.V = '0';
else
PSTATE.N = '0';
PSTATE.V = (NOT PSTATE.C);