tree 04bc072706d2d59461e9b170f130cff9496c6f54
parent 98791e778153bdf2a940f8370d047aba22a6e34d
author Gabor Mezei <gabor.mezei@arm.com> 1677510353 +0100
committer Gabor Mezei <gabor.mezei@arm.com> 1677511962 +0100
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Add comments to illustrate the second round of carry reduction is unnecessary

The first round of carry reduction can not generate a carry thus the
secound round is not needed. The comments illustrating when the
carry is 1. The reduction is simmetric so the case when the carry is
-1 is similar.
The illustration is trying to calculate the input value starting with
setting the carry to 1 before the second round of the carry reduction.
It calculates backwords and tries to determine the value range of
each word. It ends up with a contradiction that A10 must have the
value of 0 and UINT32_MAX.

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>