[clang] [clang][LoongArch] Check target features in CheckLoongArchBuiltinFunctionCall (PR #191811)

[via cfe-commits]

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@@ -22,6 +25,20 @@ SemaLoongArch::SemaLoongArch(Sema &S) : SemaBase(S) {}
 bool SemaLoongArch::CheckLoongArchBuiltinFunctionCall(const TargetInfo &TI,
                                                       unsigned BuiltinID,
                                                       CallExpr *TheCall) {
+  ASTContext &Context = getASTContext();
+  const FunctionDecl *FD = SemaRef.getCurFunctionDecl();
+
+  llvm::StringRef Features = Context.BuiltinInfo.getRequiredFeatures(BuiltinID);
+  // Only check it when the builtin is not used in a function.
+  if (!Features.empty() && !FD) {
+    llvm::SmallVector<StringRef> RequiredFeatures;
+    Features.split(RequiredFeatures, ',');
+    for (auto RF : RequiredFeatures)
+      if (!TI.hasFeature(RF))
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wangleiat wrote:

`TargetInfo::hasFeature()` is backend-dependent and may not reliably cover all builtin feature checks. Consider using `Builtin::evaluateRequiredTargetFeatures()` as the common path to ensure consistent feature evaluation.

```
typedef long long __m128i __attribute__ ((__vector_size__ (16), __may_alias__));
__m128i foo = __builtin_lsx_vfrsqrte_s(foo);
```

https://github.com/llvm/llvm-project/pull/191811