[clang] [CIR] Upstream support for logical not operations (PR #133966)

[Andy Kaylor via cfe-commits]

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@@ -1358,6 +1360,33 @@ mlir::Value CIRGenFunction::emitScalarConversion(mlir::Value src,
       .emitScalarConversion(src, srcTy, dstTy, loc);
 }
 
+mlir::Value ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *e) {
+  // Perform vector logical not on comparison with zero vector.
+  if (e->getType()->isVectorType() &&
+      e->getType()->castAs<VectorType>()->getVectorKind() ==
+          VectorKind::Generic) {
+    assert(!cir::MissingFeatures::vectorType());
+    cgf.cgm.errorNYI(e->getSourceRange(), "vector logical not");
+    return {};
+  }
+
+  // Compare operand to zero.
+  mlir::Value boolVal = cgf.evaluateExprAsBool(e->getSubExpr());
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andykaylor wrote:

When I went to test the change, it became obvious why this is here, and I remembered that we had this same discussion a couple of weeks ago with the for-loop upstreaming. We have a boolean expression, but we need to emit a value. The AST will have an implicit cast to bool here, but `EvaluateExprAsBool()` does a couple of other things, like setting the current PGO statement, and doing RAII on FP operations.

I tried replacing this with emitScalarExpr in the classic codegen, and it does cause problems when the `!` operator is used with floating point values. I'm not clear why it doesn't handle the implicit cast in such cases, but it doesn't.

https://github.com/llvm/llvm-project/pull/133966