[flang-commits] [flang] [flang] Implement `sinpi` (PR #149525)

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@@ -8060,6 +8061,21 @@ mlir::Value IntrinsicLibrary::genSind(mlir::Type resultType,
   return getRuntimeCallGenerator("sin", ftype)(builder, loc, {arg});
 }
 
+// SINPI
+mlir::Value IntrinsicLibrary::genSinpi(mlir::Type resultType,
+                                       llvm::ArrayRef<mlir::Value> args) {
+  assert(args.size() == 1);
+  mlir::MLIRContext *context = builder.getContext();
+  mlir::FunctionType ftype =
+      mlir::FunctionType::get(context, {resultType}, {args[0].getType()});
+  llvm::APFloat pi = llvm::APFloat(llvm::numbers::pi);
+  mlir::Value dfactor =
+      builder.createRealConstant(loc, mlir::Float64Type::get(context), pi);
+  mlir::Value factor = builder.createConvert(loc, args[0].getType(), dfactor);
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c8ef wrote:

Yes, handling these is somewhat tricky. I'm not exactly sure how to handle this correctly in flang. I am currently working on adding sinpi-related functions to libquadmath in the GCC source tree. The GCC maintainers are not satisfied with the precision of the generic implementation imported from glibc, so this patch has not been merged yet.

C23 has added support for sinpi-related functions, and eventually libc will also have support. This will allow us to achieve better precision. If neither glibc nor libquadmath have it, we can fallback to our current approach. 

However, glibc does not provide sind-related functions. We just need to fix the constant pi type later.

https://github.com/llvm/llvm-project/pull/149525