[libc-commits] [PATCH] D138541: [libc][math] Implement full multiplication and quick_mul_hi for UInt class.

[Siva Chandra via Phabricator via libc-commits]

sivachandra accepted this revision.
sivachandra added inline comments.
This revision is now accepted and ready to land.


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Comment at: libc/src/__support/UInt.h:219
+  // Fast hi part of the full product.  Differ with the truncation from full
+  // multiplication by at most 1 last bit.
+  constexpr UInt<Bits> quick_mul_hi(const UInt<Bits> &other) const {
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sivachandra wrote:
> Can you add more commentary here explaining how this is different from `operator*`? IIUC, `operator*` returns the LS `Bits` of the result, while this is will return the MS `Bits` of the result with an additional condition that the LS-Bit of the result need not be the same as that in the MS `Bits` of the result produced by `ful_mul`.
Add an example of where this kind of multiplication will be useful.


Repository:
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  https://reviews.llvm.org/D138541/new/

https://reviews.llvm.org/D138541