[llvm] [llvm] Add KnownBits implementations for avgFloor and avgCeil (PR #86445)

[Jay Foad via llvm-commits]

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@@ -559,6 +559,42 @@ TEST(KnownBitsTest, BinaryExhaustive) {
       KnownBits::mulhu,
       [](const APInt &N1, const APInt &N2) { return APIntOps::mulhu(N1, N2); },
       checkCorrectnessOnlyBinary);
+
+  testBinaryOpExhaustive(
+      [](const KnownBits &Known1, const KnownBits &Known2) {
+        return KnownBits::avgFloorS(Known1, Known2);
+      },
+      [](const APInt &N1, const APInt &N2) {
+        return APIntOps::avgFloorS(N1, N2);
+      },
+      checkCorrectnessOnlyBinary);
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jayfoad wrote:

I think you could probably make the KnownBits implementation optimal by using the ext/add/shift/trunc method.

https://github.com/llvm/llvm-project/pull/86445