Page 324 - ARM 64 Bit Assembly Language

Floating point 313

• cond is one of the two character condition codes from Table 3.2.
• #uimm4 is a value that is used to set the NZCV flags if cond is not true.

9.7.6.2 Operations

Name Effect Description
fcmp{e} PSTATE ← flags(Fn − Fm) Compare two registers
fcmp{e} PSTATE ← flags(Fn − 0) Compare to zero
fccmp{e} if cond is True then Conditional compare two registers
PSTATE ← flags(Fn − Fm)
else
PSTATE ← uimm4
end if
fccmp{e} if cond is True then Conditional compare to zero
PSTATE ← flags(Fn − 0)
else
PSTATE ← uimm4
end if

9.7.6.3 Examples

1 fcmp s0, s1 // Subtract s1 from s0 and set NZCV flags

9.7.7 Conditional select

The conditional select instruction selects a value from one of two registers, based on the given
condition, and stores it in the result register. The instruction is:

fcsel Conditional Select.

9.7.7.1 Syntax

fcsel Fd, Fn, Fm, cond

• Fd, Fn,and Fm must specify either three single precision registers or three double preci-
sion registers.
• cond is one of the two character condition codes from Table 3.2.