organicmaps/fast_double_parser
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Update table_generation.py

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Daniel Lemire 2021-01-13 09:17:53 -05:00 • committed by GitHub
parent 6a47c2a5a1
commit d52e3059bd
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1 changed files with 10 additions and 8 deletions
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script/table_generation.py
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@ -1,10 +1,4 @@
def format(number):
# move the most significant bit in position
while(number < (1<<127)):
number *= 2
# then *truncate*
while(number >= (1<<128)):
number //= 2
upper = number // (1<<64)
lower = number % (1<<64)
print(""+hex(upper)+","+hex(lower)+",")
@ -14,16 +8,24 @@ for q in range(-342,0):
z = 0
while( (1<<z) < power5) :
z += 1
if( q >= -17 ):
if(q >= -27):
b = z + 127
c = 2 ** b // power5 + 1
assert c < (1<<128)
format(c)
else:
b = 2 * z + 2 * 64
c = 2 ** b // power5 + 1
# truncate
while(c >= (1<<128)):
c //= 2
format(c)
for q in range(0,308+1):
power5 = 5 ** q
# move the most significant bit in position
while(power5 < (1<<127)):
power5 *= 2
# *truncate*
while(power5 >= (1<<128)):
power5 //= 2
format(power5)