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add the hackers delight version of div10

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better test too
remove remnants of 64bit multiplication
This commit is contained in:
Torsten Ruger
2015-11-21 14:19:07 +02:00
parent 91a0365c2e
commit ffc69fd2a5
3 changed files with 31 additions and 127 deletions
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93
lib/soml/parfait/integer.soml
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@ -8,85 +8,24 @@ class Integer < Value
end
end
int high_times( int by_high , int by_low)
int num_high = self >> 16
int num_low = self & 65535
int res_high = by_high * num_high
num_low = by_high * num_low
num_high = num_high * by_low
num_high = num_low + num_high
num_high = num_high >> 16
res_high = res_high + num_high
return res_high
end
int low_times( int by_high , int by_low)
int num_high = self >> 16
int num_low = self & 65535
int res_low = by_low * num_low
num_low = by_high * num_low
num_high = num_high * by_low
num_low = num_low + num_high
num_low = num_low << 16
res_low = res_low + num_low
return res_low
end
int div10()
int minus_10 = self - 10
int me = self
int tmp = me >> 2
me = me - tmp
tmp = me >> 4
me = me + tmp
tmp = me >> 8
me = me + tmp
tmp = me >> 16
me = me + tmp
me = me >> 3
int tmp2 = me << 2
tmp2 = me + tmp2
tmp2 = tmp2 << 1
if_minus(tmp2 - minus_10)
me = me + 1
end
return me
end
int div10_almost()
int me = self
if_zero( me >> 26 )
me = me + 1
end
int res_high = me.high_times( 26214 , 26215 )
int res_low = self >> 31
res_high = res_high >> 2
return res_high + res_low
int div10_soml()
int tmp = self >> 1
int q = self >> 2
q = q + tmp
tmp = q >> 4
q = q + tmp
tmp = q >> 8
q = q + tmp
tmp = q >> 16
q = q + tmp
q = q >> 3
int r = q * 10
r = self - r
r = r + 6
r = r >> 4
return q + r
end
Word as_string(Word str)