VSELEQ, VSELGE, VSELGT, VSELVS

Floating-point conditional select allows the destination register to take the value in either one or the other source register according to the condition codes in the APSR.

It has encodings from the following instruction sets: A32 ( A1 ) and T32 ( T1 ) .

A1

if size == '00' || (size == '01' && !HaveFP16Ext()) then UNDEFINED; integer esize; integer d; integer n; integer m; case size of when '01' esize = 16; d = UInt(Vd:D); n = UInt(Vn:N); m = UInt(Vm:M); when '10' esize = 32; d = UInt(Vd:D); n = UInt(Vn:N); m = UInt(Vm:M); when '11' esize = 64; d = UInt(D:Vd); n = UInt(N:Vn); m = UInt(M:Vm); cond = cc:(cc<1> EOR cc<0>):'0';

T1

if InITBlock() then UNPREDICTABLE; if size == '00' || (size == '01' && !HaveFP16Ext()) then UNDEFINED; integer esize; integer d; integer n; integer m; case size of when '01' esize = 16; d = UInt(Vd:D); n = UInt(Vn:N); m = UInt(Vm:M); when '10' esize = 32; d = UInt(Vd:D); n = UInt(Vn:N); m = UInt(Vm:M); when '11' esize = 64; d = UInt(D:Vd); n = UInt(N:Vn); m = UInt(M:Vm); cond = cc:(cc<1> EOR cc<0>):'0';

CONSTRAINED UNPREDICTABLE behavior

If InITBlock(), then one of the following behaviors must occur:

• The instruction is undefined.
• The instruction executes as if it passes the Condition code check.
• The instruction executes as NOP. This means it behaves as if it fails the Condition code check.