[PATCH] D153773: ValueTracking: Handle ptrmask in computeKnownBits

[Nikita Popov via Phabricator via llvm-commits]

nikic accepted this revision.
nikic added a comment.
This revision is now accepted and ready to land.

LGTM



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Comment at: llvm/lib/Analysis/ValueTracking.cpp:1719
+        const Value *Mask = I->getOperand(1);
+        Known2 = KnownBits(Mask->getType()->getIntegerBitWidth());
+        computeKnownBits(Mask, Known2, Depth + 1, Q);
----------------
arsenm wrote:
> nikic wrote:
> > This will assert if ptrmask is working on vectors.
> It seems to not work on vectors:
> 
> ```
> 
> declare <2 x ptr> @llvm.ptrmask.v2p0.v2i64(<2 x ptr>, <2 x i64>)
> define <2 x ptr> @ptrmask_align4_ptr_align1_vector(<2 x ptr> %ptr) {
>    %ptrmask = call <2 x ptr> @llvm.ptrmask.v2p0.v2i64(<2 x ptr> %ptr, <2 x i64> <i64 -4, i64 -4>)
>    ret <2 x ptr> %ptrmask
> }
> 
> Intrinsic has incorrect return type!
> ptr @llvm.ptrmask.v2p0.v2i64
> 
> ```
Interesting, that seems like an oversight.

I'd still suggest to use getScalarSizeInBits() here for robustness.


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  https://reviews.llvm.org/D153773/new/

https://reviews.llvm.org/D153773