[clang] [clang][CFG] Fix assertion failure in checkIncorrectLogicOperator (PR #142897)

[via cfe-commits]

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@@ -1261,6 +1261,28 @@ class CFGBuilder {
         L2Result.Val.getKind() == APValue::Float) {
       llvm::APFloat L1 = L1Result.Val.getFloat();
       llvm::APFloat L2 = L2Result.Val.getFloat();
+      // Note that L1 and L2 do not necessarily have the same type.  For example
+      // `x != 0 || x != 1.0`, if `x` is a float16, the two literals `0` and
+      // `1.0` are float16 and double respectively.  In this case, we should do
+      // a conversion before comparing L1 and L2.  Their types must be
+      // compatible since they are comparing with the same DRE.
+      int8_t Order = Context->getFloatingTypeOrder(NumExpr1->getType(),
+                                                   NumExpr2->getType());
+      bool convertLoseInfo = false;
+
+      if (Order > 0) {
+        // type rank L1 > L2:
+        if (L2.convert(L1.getSemantics(), llvm::APFloat::rmNearestTiesToEven,
+                       &convertLoseInfo))
+          return {};
+      } else if (Order < 0)
+        // type rank L1 < L2:
+        if (L1.convert(L2.getSemantics(), llvm::APFloat::rmNearestTiesToEven,
+                       &convertLoseInfo))
+          return {};
+      if (convertLoseInfo)
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yronglin wrote:

Seems we check APFloat::opStatus is enough. We already ignore loseInfo in constant evaluator https://github.com/llvm/llvm-project/blob/f8714666b1d1442cb1174e69032415fc54a31779/clang/lib/AST/ExprConstant.cpp#L2871

https://github.com/llvm/llvm-project/pull/142897