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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
commit | e6918187568dbd01842d8d1d2c808ce16a894239 (patch) | |
tree | 64f88b554b444a49f656b6c656111a145cbbaa28 /src/fmt/support/compute-powers.py | |
parent | Initial commit. (diff) | |
download | ceph-upstream/18.2.2.tar.xz ceph-upstream/18.2.2.zip |
Adding upstream version 18.2.2.upstream/18.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rwxr-xr-x | src/fmt/support/compute-powers.py | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src/fmt/support/compute-powers.py b/src/fmt/support/compute-powers.py new file mode 100755 index 000000000..601063d42 --- /dev/null +++ b/src/fmt/support/compute-powers.py @@ -0,0 +1,53 @@ +#!/usr/bin/env python +# Compute 10 ** exp with exp in the range [min_exponent, max_exponent] and print +# normalized (with most-significant bit equal to 1) significands in hexadecimal. + +from __future__ import print_function + +min_exponent = -348 +max_exponent = 340 +step = 8 +significand_size = 64 +exp_offset = 2000 + +class fp: + pass + +powers = [] +for i, exp in enumerate(range(min_exponent, max_exponent + 1, step)): + result = fp() + n = 10 ** exp if exp >= 0 else 2 ** exp_offset / 10 ** -exp + k = significand_size + 1 + # Convert to binary and round. + binary = '{:b}'.format(n) + result.f = (int('{:0<{}}'.format(binary[:k], k), 2) + 1) / 2 + result.e = len(binary) - (exp_offset if exp < 0 else 0) - significand_size + powers.append(result) + # Sanity check. + exp_offset10 = 400 + actual = result.f * 10 ** exp_offset10 + if result.e > 0: + actual *= 2 ** result.e + else: + for j in range(-result.e): + actual /= 2 + expected = 10 ** (exp_offset10 + exp) + precision = len('{}'.format(expected)) - len('{}'.format(actual - expected)) + if precision < 19: + print('low precision:', precision) + exit(1) + +print('Significands:', end='') +for i, fp in enumerate(powers): + if i % 3 == 0: + print(end='\n ') + print(' {:0<#16x}'.format(fp.f, ), end=',') + +print('\n\nExponents:', end='') +for i, fp in enumerate(powers): + if i % 11 == 0: + print(end='\n ') + print(' {:5}'.format(fp.e), end=',') + +print('\n\nMax exponent difference:', + max([x.e - powers[i - 1].e for i, x in enumerate(powers)][1:])) |