[PATCH] D78688: [ValueTracking] Handle shufflevector constants in ComputeNumSignBits

[Eli Friedman via Phabricator via llvm-commits]

efriedma marked an inline comment as done.
efriedma added inline comments.


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Comment at: llvm/test/Transforms/InstCombine/nsw.ll:138
+;
+  %xx = zext <vscale x 2 x i8> %z to <vscale x 2 x i64>
+  %shuf = shufflevector <vscale x 2 x i64> insertelement (<vscale x 2 x i64> undef, i64 1, i32 0), <vscale x 2 x i64> zeroinitializer, <vscale x 2 x i32> zeroinitializer
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huihuiz wrote:
> Not needed, just shuffle(insertelement) + mul will get this crash.
> But not very important.
Since I'm here, might as well add a testcase where we could, in theory, mark the mul as nsw/nuw.


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https://reviews.llvm.org/D78688