Nikita Popov c9540fe59b [InstCombine] Fix multi-use handling in cttz transform ...

The select-of-cttz transform can currently duplicate cttz intrinsics
and zext/trunc ops. The cause is that it unnecessarily duplicates
the intrinsic and the zext/trunc when setting the "undef_on_zero"
flag to false. However, it's always legal to set the flag from true
to false, so we can make this replacement even if there are extra users.

Differential Revision: https://reviews.llvm.org/D74685

2020-02-18 17:55:00 +01:00

109 KiB

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