[PATCH] D48399: [ConstantRange] Add support of mul in makeGuaranteedNoWrapRegion.

[Sanjoy Das via Phabricator via llvm-commits]

sanjoy requested changes to this revision.
sanjoy added inline comments.
This revision now requires changes to proceed.


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Comment at: llvm/lib/IR/ConstantRange.cpp:270
+                                        BitWidth](APInt V) -> ConstantRange {
+      const auto DivRoundDown = [Unsigned](APInt A, APInt B) -> APInt {
+        if (Unsigned)
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Sorry for being difficult, but these should live on `APInt` and be individually unit-tested.


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Comment at: llvm/lib/IR/ConstantRange.cpp:336
+    };
+    return SubsetIntersect(
+        makeSingleValueRegion(Unsigned ? Other.getUnsignedMin()
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Can you please given an informal description of how this works?  For example, naively I'd think for unsigned overflow just checking `[0,Other.getUnsignedMax())` would be sufficient.


https://reviews.llvm.org/D48399