1 # IBM POWER __gmpn_sub_n -- Subtract two limb vectors of equal, non-zero length.
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6 # This file is part of the GNU MP Library.
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33 .csect __gmpn_sub_n[DS]
35 .long .__gmpn_sub_n, TOC[tc0], 0
39 andil. 10,6,1 # odd or even number of limbs?
40 l 8,0(4) # load least significant s1 limb
41 l 0,0(5) # load least significant s2 limb
42 cal 3,-4(3) # offset res_ptr, it's updated before it's used
43 sri 10,6,1 # count for unrolled loop
44 sf 7,0,8 # subtract least significant limbs, set cy
45 mtctr 10 # copy count into CTR
46 beq 0,Leven # branch if even # of limbs (# of limbs >= 2)
48 # We have an odd # of limbs. Add the first limbs separately.
49 cmpi 1,10,0 # is count for unrolled loop zero?
50 bc 4,6,L1 # bne cr1,L1 (misassembled by gas)
52 sfe 3,0,0 # load !cy into ...
53 sfi 3,3,0 # ... return value register
56 # We added least significant limbs. Now reload the next limbs to enter loop.
57 L1: lu 8,4(4) # load s1 limb and update s1_ptr
58 lu 0,4(5) # load s2 limb and update s2_ptr
60 sfe 7,0,8 # subtract limbs, set cy
61 Leven: lu 9,4(4) # load s1 limb and update s1_ptr
62 lu 10,4(5) # load s2 limb and update s2_ptr
63 bdz Lend # If done, skip loop
65 Loop: lu 8,4(4) # load s1 limb and update s1_ptr
66 lu 0,4(5) # load s2 limb and update s2_ptr
67 sfe 11,10,9 # subtract previous limbs with cy, set cy
69 lu 9,4(4) # load s1 limb and update s1_ptr
70 lu 10,4(5) # load s2 limb and update s2_ptr
71 sfe 7,0,8 # subtract previous limbs with cy, set cy
73 bdn Loop # decrement CTR and loop back
75 Lend: sfe 11,10,9 # subtract limbs with cy, set cy
78 sfe 3,0,0 # load !cy into ...
79 sfi 3,3,0 # ... return value register