ARM mode Thumb mode switching

subs t0, a0, b0
nop

rsblt t0, t0, #0
subs t1, b0, c0

rsblt t1, t1, #0
cmp t0, #25

bge .exit
cmp t1, #30

bge .exit
subs t2, c0, a0

rsblt t2, t2, #0
nop

cmp    t2, # 45
bge .bloc2


    // modify the values of a0,b0,c0
b .exit


.bloc2
//modify the values of a0 and b0

.exit

  SUB  r3,r0,r1
  SUB  r4,r1,r2
  ADDS    r3,r3,#(25-1)
  ADDS    r4,r4,#(30-1) 
  CMP  r3,#(2*(25-1))
  SUB  r3,r2,r0
  CMPLS   r4,#(2*(30-1))
  ADD  r3,r3,#(45-1)
  BHI  Take_None   // modify none
  CMP  r3,#(2*(45-1))
  BHI  Take_Second // modify a0,b0
  B    Take_First  // modify a0,b0,c0

How can optimize the above condition ladder using thumb instructions.
i replace the abs() library function by substraction.

• What what the likelyhood of each branch being taken is
• What values "// modify the val[u]es of a0,b0,c0[color="#000000"]" actually uses are, and[/color]
• [color="#000000"]What the target CPU is[/color]