[flang][NFC] static assert intrinsic table is sorted

[jeanPerier]

This invariant is used below when searching for intrinsic implementation. Currently, if the map is not sorted, the compiler will just silently assume there is no such implementation.

[llvmbot]

@llvm/pr-subscribers-flang-fir-hlfir

Author: None (jeanPerier)

Changes

This invariant is used below when searching for intrinsic implementation. Currently, if the map is not sorted, the compiler will just silently assume there is no such implementation.

---

Full diff: https://github.com/llvm/llvm-project/pull/120399.diff

1 Files Affected:

• (modified) flang/lib/Optimizer/Builder/IntrinsicCall.cpp (+14)

diff --git a/flang/lib/Optimizer/Builder/IntrinsicCall.cpp b/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
index 547cebefd2df47..7fe233f1090703 100644
--- a/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
+++ b/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
@@ -678,6 +678,20 @@ static constexpr IntrinsicHandler handlers[]{
      /*isElemental=*/true},
 };
 
+template <std::size_t N>
+static constexpr bool isSorted(const IntrinsicHandler (&array)[N]) {
+  // Replace by std::sorted when C++20 is default (will be constexpr).
+  const IntrinsicHandler *lastSeen{nullptr};
+  bool isSorted{true};
+  for (const auto &x : array) {
+    if (lastSeen)
+      isSorted &= std::string_view{lastSeen->name} < std::string_view{x.name};
+    lastSeen = &x;
+  }
+  return isSorted;
+}
+static_assert(isSorted(handlers) && "map must be sorted");
+
 static const IntrinsicHandler *findIntrinsicHandler(llvm::StringRef name) {
   auto compare = [](const IntrinsicHandler &handler, llvm::StringRef name) {
     return name.compare(handler.name) > 0;

[clementval]

Thanks Jean! LGTM