[clang] [HLSL] Implement the 'and' HLSL function (PR #127098)

[Chris B via cfe-commits]

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@@ -2245,6 +2245,36 @@ bool SemaHLSL::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
 
     break;
   }
+  case Builtin::BI__builtin_hlsl_and: {
+    if (SemaRef.checkArgCount(TheCall, 2))
+      return true;
+    if (CheckVectorElementCallArgs(&SemaRef, TheCall))
+      return true;
+
+    // CheckVectorElementCallArgs(...) guarantees both args are the same type.
+    assert(TheCall->getArg(0)->getType() == TheCall->getArg(1)->getType() &&
+           "Both args must be of the same type");
+
+    // check that the arguments are bools or, if vectors,
+    // vectors of bools
+    QualType ArgTy = TheCall->getArg(0)->getType();
+    if (const auto *VecTy = ArgTy->getAs<VectorType>()) {
+      ArgTy = VecTy->getElementType();
+    }
+    if (!getASTContext().hasSameUnqualifiedType(ArgTy,
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llvm-beanz wrote:

Why is "doing what `select` does" an ad-hoc fix?

My suggestion to @Icohedron [here](https://github.com/llvm/llvm-project/pull/127098#discussion_r1957372179), is literally to just do what we do to validate the first argument to `__builtin_hlsl_select`, which has the exact same requirement, and produces a meaningful and accurate diagnostic.

https://github.com/llvm/llvm-project/pull/127098