[PATCH] D104472: [ValueTracking] look through bitcast of vector in computeKnownBits

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: llvm/lib/Analysis/ValueTracking.cpp:1217
+        Known.One |= KnownSrc.One.zext(BitWidth).shl(ShiftAmt);
+        Known.Zero |= KnownSrc.Zero.zext(BitWidth).shl(ShiftAmt);
+      }
----------------
spatel wrote:
> RKSimon wrote:
> > Can you use APInt::insertBits here ?
> Yes - at least that's how I drafted it originally. But I made it match the existing DAG code, so we'd get more testing for both versions once this is in (there seems to be much more fuzz/bot coverage for IR than codegen).
> 
> How about a TODO that we could update both versions simultaneously?
Updated in rG7353beda4aa1 - there's several additional cases where we could use insertBits/extractBits that I'll deal with at another time.


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  https://reviews.llvm.org/D104472/new/

https://reviews.llvm.org/D104472