[llvm] [GlobalISel] Add iterative known-bits evaluation to GISelValueTracking (PR #221755)

[via llvm-commits]

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@@ -56,6 +63,23 @@ class LLVM_ABI GISelValueTracking : public GISelChangeObserver {
                            FPClassTest InterestedClasses, KnownFPClass &Known,
                            unsigned Depth);
 
+  void computeKnownBits(Register R, KnownBits &Known, const APInt &DemandedElts,
+                        unsigned Depth = 0);
+
+  bool getKnownBitsResult(const Register &Reg, const APInt &DemandedElts,
+                          unsigned Depth, KnownBits &Known) {
+    auto It = Results.find({Reg, DemandedElts, Depth});
+    if (It == Results.end())
+      return false;
+    Known = It->second;
+    return true;
+  }
+
+  void setKnownBitsResult(const Register &Reg, const APInt &DemandedElts,
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daemonpilot wrote:

Done.

https://github.com/llvm/llvm-project/pull/221755