[PATCH] D69960: [ConstantRange] Add `ushl_sat()`/`sshl_sat()` methods.

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.
lebedev.ri added inline comments.


================
Comment at: llvm/lib/IR/ConstantRange.cpp:1359
+    NewU = getSignedMax().sshl_sat(Other.getUnsignedMax()) + 1;
+  }
+  return getNonEmpty(std::move(NewL), std::move(NewU));
----------------
nikic wrote:
> Wondering if a formulation along the lines of
> 
> ```
> APInt Min = getSignedMin(), Max = getSignedMax();
> APInt ShiftMin = getUnsignedMin(), ShiftMax = getUnsignedMax();
> APInt NewL = Min.sshl_sat(Min.isNonNegative() ? ShiftMin : ShiftMax);
> APInt NewU = Max.sshl_sat(Max.isNonNegative() ? ShiftMax : ShiftMin) + 1;
> ```
> 
> might be cleaner?
A bit, yes.


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https://reviews.llvm.org/D69960