CMP<cc> (immediate)

Compare vector to immediate

Compare active integer elements in the source vector with an immediate, and place the boolean results of the specified comparison in the corresponding elements of the destination predicate. Inactive elements in the destination predicate register are set to zero. Sets the First (N), None (Z), !Last (C) condition flags based on the predicate result, and the V flag to zero.

<cc> Comparison
EQ equal
GE signed greater than or equal
GT signed greater than
HI unsigned higher than
HS unsigned higher than or same
LE signed less than or equal
LO unsigned lower than
LS unsigned lower than or same
LT signed less than
NE not equal

It has encodings from 10 classes: Equal , Greater than , Greater than or equal , Higher , Higher or same , Less than , Less than or equal , Lower , Lower or same and Not equal

Equal

313029282726252423222120191817161514131211109876543210
00100101size0imm5100PgZn0Pd
ne

CMPEQ <Pd>.<T>, <Pg>/Z, <Zn>.<T>, #<imm>

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer g = UInt(Pg); constant integer n = UInt(Zn); constant integer d = UInt(Pd); constant SVECmp op = Cmp_EQ; constant integer imm = SInt(imm5); constant boolean unsigned = FALSE;

Greater than

313029282726252423222120191817161514131211109876543210
00100101size0imm5000PgZn1Pd
ltne

CMPGT <Pd>.<T>, <Pg>/Z, <Zn>.<T>, #<imm>

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer g = UInt(Pg); constant integer n = UInt(Zn); constant integer d = UInt(Pd); constant SVECmp op = Cmp_GT; constant integer imm = SInt(imm5); constant boolean unsigned = FALSE;

Greater than or equal

313029282726252423222120191817161514131211109876543210
00100101size0imm5000PgZn0Pd
ltne

CMPGE <Pd>.<T>, <Pg>/Z, <Zn>.<T>, #<imm>

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer g = UInt(Pg); constant integer n = UInt(Zn); constant integer d = UInt(Pd); constant SVECmp op = Cmp_GE; constant integer imm = SInt(imm5); constant boolean unsigned = FALSE;

Higher

313029282726252423222120191817161514131211109876543210
00100100size1imm70PgZn1Pd
ltne

CMPHI <Pd>.<T>, <Pg>/Z, <Zn>.<T>, #<imm>

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer g = UInt(Pg); constant integer n = UInt(Zn); constant integer d = UInt(Pd); constant SVECmp op = Cmp_GT; constant integer imm = UInt(imm7); constant boolean unsigned = TRUE;

Higher or same

313029282726252423222120191817161514131211109876543210
00100100size1imm70PgZn0Pd
ltne

CMPHS <Pd>.<T>, <Pg>/Z, <Zn>.<T>, #<imm>

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer g = UInt(Pg); constant integer n = UInt(Zn); constant integer d = UInt(Pd); constant SVECmp op = Cmp_GE; constant integer imm = UInt(imm7); constant boolean unsigned = TRUE;

Less than

313029282726252423222120191817161514131211109876543210
00100101size0imm5001PgZn0Pd
ltne

CMPLT <Pd>.<T>, <Pg>/Z, <Zn>.<T>, #<imm>

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer g = UInt(Pg); constant integer n = UInt(Zn); constant integer d = UInt(Pd); constant SVECmp op = Cmp_LT; constant integer imm = SInt(imm5); constant boolean unsigned = FALSE;

Less than or equal

313029282726252423222120191817161514131211109876543210
00100101size0imm5001PgZn1Pd
ltne

CMPLE <Pd>.<T>, <Pg>/Z, <Zn>.<T>, #<imm>

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer g = UInt(Pg); constant integer n = UInt(Zn); constant integer d = UInt(Pd); constant SVECmp op = Cmp_LE; constant integer imm = SInt(imm5); constant boolean unsigned = FALSE;

Lower

313029282726252423222120191817161514131211109876543210
00100100size1imm71PgZn0Pd
ltne

CMPLO <Pd>.<T>, <Pg>/Z, <Zn>.<T>, #<imm>

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer g = UInt(Pg); constant integer n = UInt(Zn); constant integer d = UInt(Pd); constant SVECmp op = Cmp_LT; constant integer imm = UInt(imm7); constant boolean unsigned = TRUE;

Lower or same

313029282726252423222120191817161514131211109876543210
00100100size1imm71PgZn1Pd
ltne

CMPLS <Pd>.<T>, <Pg>/Z, <Zn>.<T>, #<imm>

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer g = UInt(Pg); constant integer n = UInt(Zn); constant integer d = UInt(Pd); constant SVECmp op = Cmp_LE; constant integer imm = UInt(imm7); constant boolean unsigned = TRUE;

Not equal

313029282726252423222120191817161514131211109876543210
00100101size0imm5100PgZn1Pd
ne

CMPNE <Pd>.<T>, <Pg>/Z, <Zn>.<T>, #<imm>

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer g = UInt(Pg); constant integer n = UInt(Zn); constant integer d = UInt(Pd); constant SVECmp op = Cmp_NE; constant integer imm = SInt(imm5); constant boolean unsigned = FALSE;

Assembler Symbols

<Pd>

Is the name of the destination scalable predicate register, encoded in the "Pd" field.

<T>

Is the size specifier, encoded in size:

size <T>
00 B
01 H
10 S
11 D
<Pg>

Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field.

<Zn>

Is the name of the source scalable vector register, encoded in the "Zn" field.

<imm>

For the equal, greater than, greater than or equal, less than, less than or equal and not equal variant: is the signed immediate operand, in the range -16 to 15, encoded in the "imm5" field.

For the higher, higher or same, lower and lower or same variant: is the unsigned immediate operand, in the range 0 to 127, encoded in the "imm7" field.

Operation

CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV esize; constant bits(PL) mask = P[g, PL]; constant bits(VL) operand1 = if AnyActiveElement(mask, esize) then Z[n, VL] else Zeros(VL); bits(PL) result; constant integer psize = esize DIV 8; for e = 0 to elements-1 constant integer element1 = Int(Elem[operand1, e, esize], unsigned); if ActivePredicateElement(mask, e, esize) then boolean cond; case op of when Cmp_EQ cond = element1 == imm; when Cmp_NE cond = element1 != imm; when Cmp_GE cond = element1 >= imm; when Cmp_LT cond = element1 < imm; when Cmp_GT cond = element1 > imm; when Cmp_LE cond = element1 <= imm; constant bit pbit = if cond then '1' else '0'; Elem[result, e, psize] = ZeroExtend(pbit, psize); else Elem[result, e, psize] = ZeroExtend('0', psize); PSTATE.<N,Z,C,V> = PredTest(mask, result, esize); P[d, PL] = result;

Operational information

If FEAT_SVE2 is implemented or FEAT_SME is implemented, then if PSTATE.DIT is 1:

If FEAT_SME is implemented and the PE is in Streaming SVE mode, then any subsequent instruction which is dependent on the predicate register or NZCV condition flags written by this instruction might be significantly delayed.


Internal version only: aarchmrs v2024-03_relA, pseudocode v2024-03_rel, sve v2024-03_rel ; Build timestamp: 2024-03-26T09:45

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