#method: range reduction to [1/8,1], poly appox, newtons method
# J F Jarvis, August 10,1978
mnegd r4,r4 # |arg| in r0,r1
movl $0x100,r3 # sign bit of result
insv $128,$7,$8,r4 # 0.5<= frac: r4,r5 <1.0
ediv $3,r6,r6,r7 # r6= expnt/3; r7= expnt%3
bisl2 r3,r6 # sign,exponent of result
polyf r4,$3,pcoef # initial estimate is Hart&Cheney CBRT 0642
muld3 r0,r0,r2 # Newtons method, iteration 1, H&C 6.1.10
muld3 r0,r0,r2 # iteration 2
muld2 hc[r7],r0 # set range
insv r6,$7,$9,r0 # set sign,exponent
third: .double 0d0.33333333333333333333e+0
.double 0d1.25992104989487316476e+0
.double 0d1.58740105196819947475e+0
.float 0f-0.5173964673e+0