[mlir] Annotate functions used only in debug mode with LLVM_ATTRIBUTE_UNUSED

[ezhulenev]

Summary

Functions used only in assert cause warnings in release mode

[dcaballe]

Thanks for addressing this issue! Would this work if we compiled in release mode and with asserts enabled?

[mehdi_amini]

Would this work if we compiled in release mode and with asserts enabled?

Yes: the way asserts are enabled is by defining -DNDEBUG.

[mehdi_amini]

We also have an attribute which may be nicer than the macro: https://github.com/llvm/llvm-project/blob/main/mlir/lib/Transforms/Utils/LoopUtils.cpp#L1509

[ezhulenev]

Use LLVM_ATTRIBUTE_UNUSED

[dcaballe]

Thanks!

mlir/lib/Dialect/Math/Transforms/PolynomialApproximation.cpp

 #include "mlir/Transforms/GreedyPatternRewriteDriver.h"
 #include <limits.h>
 
 using namespace mlir;
 using namespace mlir::vector;
 
 using TypePredicate = llvm::function_ref<bool(Type)>;
 
-static bool isF32(Type type) { return type.isF32(); }
-
-static bool isI32(Type type) { return type.isInteger(32); }
-
 // Returns vector width if the element type is matching the predicate (scalars
 // that do match the predicate have width equal to `1`).
 static Optional<int> vectorWidth(Type type, TypePredicate pred) {
   // If the type matches the predicate then its width is `1`.
   if (pred(type))
     return 1;
 
   // Otherwise check if the type is a vector type.
   auto vectorType = type.dyn_cast<VectorType>();
   if (vectorType && pred(vectorType.getElementType())) {
     assert(vectorType.getRank() == 1 && "only 1d vectors are supported");
     return vectorType.getDimSize(0);
   }
 
   return llvm::None;
 }
 
 // Returns vector width of the type. If the type is a scalar returns `1`.
 static int vectorWidth(Type type) {
   auto vectorType = type.dyn_cast<VectorType>();
   return vectorType ? vectorType.getDimSize(0) : 1;
 }
 
 // Returns vector element type. If the type is a scalar returns the argument.
-static Type elementType(Type type) {
+LLVM_ATTRIBUTE_UNUSED static Type elementType(Type type) {
   auto vectorType = type.dyn_cast<VectorType>();
   return vectorType ? vectorType.getElementType() : type;
 }
 
+LLVM_ATTRIBUTE_UNUSED static bool isF32(Type type) { return type.isF32(); }
+
+LLVM_ATTRIBUTE_UNUSED static bool isI32(Type type) {
+  return type.isInteger(32);
+}
+
 //----------------------------------------------------------------------------//
 // Broadcast scalar types and values into vector types and values.
 //----------------------------------------------------------------------------//
 
 // Broadcasts scalar type into vector type (iff width is greater then 1).
 static Type broadcast(Type type, int width) {
   assert(!type.isa<VectorType>() && "must be scalar type");
   return width > 1 ? VectorType::get({width}, type) : type;