[flang-commits] [clang] [flang] [RFC][flang][runtime] Add FortranFloat128Math wrapper library. (PR #81971)

[Slava Zakharin via flang-commits]

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@@ -657,10 +657,61 @@ static llvm::cl::opt<bool>
                                     "instead of libm complex operations"),
                      llvm::cl::init(false));
 
+/// Return a string containing the given Fortran intrinsic name
+/// with the type of its arguments specified in funcType
+/// surrounded by the given prefix/suffix.
+static std::string
+prettyPrintIntrinsicName(fir::FirOpBuilder &builder, mlir::Location loc,
+                         llvm::StringRef prefix, llvm::StringRef name,
+                         llvm::StringRef suffix, mlir::FunctionType funcType) {
+  std::string output = prefix.str();
+  llvm::raw_string_ostream sstream(output);
+  if (name == "pow") {
+    assert(funcType.getNumInputs() == 2 && "power operator has two arguments");
+    std::string displayName{" ** "};
+    sstream << numericMlirTypeToFortran(builder, funcType.getInput(0), loc,
+                                        displayName)
+            << displayName
+            << numericMlirTypeToFortran(builder, funcType.getInput(1), loc,
+                                        displayName);
+  } else {
+    sstream << name.upper() << "(";
+    if (funcType.getNumInputs() > 0)
+      sstream << numericMlirTypeToFortran(builder, funcType.getInput(0), loc,
+                                          name);
+    for (mlir::Type argType : funcType.getInputs().drop_front()) {
+      sstream << ", " << numericMlirTypeToFortran(builder, argType, loc, name);
+    }
+    sstream << ")";
+  }
+  sstream << suffix;
+  return output;
+}
+
+// Generate a call to the Fortran runtime library providing
+// support for 128-bit float math via a third-party library.
+// If the compiler is built without FLANG_RUNTIME_F128_MATH_LIB,
+// this function will report an error.
+static mlir::Value genLibF128Call(fir::FirOpBuilder &builder,
+                                  mlir::Location loc,
+                                  const MathOperation &mathOp,
+                                  mlir::FunctionType libFuncType,
+                                  llvm::ArrayRef<mlir::Value> args) {
+#ifndef FLANG_RUNTIME_F128_MATH_LIB
+  std::string message = prettyPrintIntrinsicName(
+      builder, loc, "compiler is built without support for '", mathOp.key, "'",
----------------
vzakhari wrote:

I expect that we hit this code only when there is support for an intrinsic, but the compiler was built without `FLANG_RUNTIME_F128_MATH_LIB` set up.  So `not yet implemented` would be confusing a bit.  I can change this code to use the regular TODO macro, because it is probably irrelevant to the user whether it is intrinsic implementation gap or the configuration issue of the compiler build.

https://github.com/llvm/llvm-project/pull/81971