FCCMPE
Floating-point conditional signaling compare (scalar)
This instruction compares the two SIMD&FP source register values
and writes the result to the
PSTATE.{N, Z, C, V} flags.
If the condition does not pass, then the PSTATE.{N, Z, C, V} flags
are set to the flag bit specifier.
This instruction raises an Invalid Operation floating-point exception if either or both of the operands
is any type of NaN.
A floating-point exception can be generated by this instruction.
Depending on the settings in FPCR,
the exception results in either a flag being set in FPSR,
or a synchronous exception being generated.
For more information, see
Floating-point exception traps.
Depending on the settings in the CPACR_EL1,
CPTR_EL2, and CPTR_EL3 registers,
and the current Security state and Exception level,
an attempt to execute the instruction might be trapped.
The IEEE 754 standard specifies that the result of a comparison is precisely
one of <, ==, > or unordered. If either or both of the operands is a NaN, they
are unordered, and all three of (Operand1 < Operand2), (Operand1 == Operand2)
and (Operand1 > Operand2) are false. An unordered comparison sets the PSTATE
condition flags to N=0, Z=0, C=1, and V=1.
0
0
0
1
1
1
1
0
1
0
1
1
1
1
FCCMPE <Hn>, <Hm>, #<nzcv>, <cond>
0
0
FCCMPE <Sn>, <Sm>, #<nzcv>, <cond>
0
1
FCCMPE <Dn>, <Dm>, #<nzcv>, <cond>
if ftype == '10' || (ftype == '11' && !IsFeatureImplemented(FEAT_FP16)) then UNDEFINED;
constant integer n = UInt(Rn);
constant integer m = UInt(Rm);
constant integer datasize = 8 << UInt(ftype EOR '10');
constant bits(4) condition = cond;
bits(4) flags = nzcv;
<Hn>
Is the 16-bit name of the first SIMD&FP source register, encoded in the "Rn" field.
<Hm>
Is the 16-bit name of the second SIMD&FP source register, encoded in the "Rm" field.
<nzcv>
Is the flag bit specifier, an immediate in the range 0 to 15, giving the alternative state for the 4-bit NZCV condition flags, encoded in the "nzcv" field.
<cond>
Is one of the standard conditions, encoded in the standard way, and
cond
<cond>
0000
EQ
0001
NE
0010
CS
0011
CC
0100
MI
0101
PL
0110
VS
0111
VC
1000
HI
1001
LS
1010
GE
1011
LT
1100
GT
1101
LE
1110
AL
1111
NV
<Sn>
Is the 32-bit name of the first SIMD&FP source register, encoded in the "Rn" field.
<Sm>
Is the 32-bit name of the second SIMD&FP source register, encoded in the "Rm" field.
<Dn>
Is the 64-bit name of the first SIMD&FP source register, encoded in the "Rn" field.
<Dm>
Is the 64-bit name of the second SIMD&FP source register, encoded in the "Rm" field.
CheckFPEnabled64();
constant bits(datasize) operand1 = V[n, datasize];
constant bits(datasize) operand2 = V[m, datasize];
if ConditionHolds(condition) then
constant boolean signal_all_nans = TRUE;
flags = FPCompare(operand1, operand2, signal_all_nans, FPCR);
PSTATE.<N,Z,C,V> = flags;