[flang] add ABI argument attributes in indirect calls (#126896)

Last piece that implements the TODO for sret and byval setting on
indirect calls.

This includes a fix to the codegen last patch. I thought types in in
type attributes were automatically converted in dialect conversion
passes, but that is not the case. The sret and byval type needs to be
converted to llvm types in codegen (mlir FuncOp conversion is doing a
similar conversion).

1 files changed, 34 insertions, 9 deletions

diff --git a/flang/lib/Optimizer/CodeGen/TargetRewrite.cpp b/flang/lib/Optimizer/CodeGen/TargetRewrite.cpp
index c099a08..5c9da03 100644
--- a/flang/lib/Optimizer/CodeGen/TargetRewrite.cpp
+++ b/flang/lib/Optimizer/CodeGen/TargetRewrite.cpp
@@ -534,19 +534,44 @@ public:
     } else if constexpr (std::is_same_v<std::decay_t<A>, fir::CallOp>) {
       fir::CallOp newCall;
       if (callOp.getCallee()) {
-        newCall =
-            rewriter->create<A>(loc, *callOp.getCallee(), newResTys, newOpers);
+        newCall = rewriter->create<fir::CallOp>(loc, *callOp.getCallee(),
+                                                newResTys, newOpers);
       } else {
-        // TODO: llvm dialect must be updated to propagate argument on
-        // attributes for indirect calls. See:
-        // https://discourse.llvm.org/t/should-llvm-callop-be-able-to-carry-argument-attributes-for-indirect-calls/75431
-        if (hasByValOrSRetArgs(newInTyAndAttrs))
-          TODO(loc,
-               "passing argument or result on the stack in indirect calls");
         newOpers[0].setType(mlir::FunctionType::get(
             callOp.getContext(),
             mlir::TypeRange{newInTypes}.drop_front(dropFront), newResTys));
-        newCall = rewriter->create<A>(loc, newResTys, newOpers);
+        newCall = rewriter->create<fir::CallOp>(loc, newResTys, newOpers);
+        // Set ABI argument attributes on call operation since they are not
+        // accessible via a FuncOp in indirect calls.
+        if (hasByValOrSRetArgs(newInTyAndAttrs)) {
+          llvm::SmallVector<mlir::Attribute> argAttrsArray;
+          for (const auto &arg :
+               llvm::ArrayRef<fir::CodeGenSpecifics::TypeAndAttr>(
+                   newInTyAndAttrs)
+                   .drop_front(dropFront)) {
+            mlir::NamedAttrList argAttrs;
+            const auto &attr = std::get<fir::CodeGenSpecifics::Attributes>(arg);
+            if (attr.isByVal()) {
+              mlir::Type elemType =
+                  fir::dyn_cast_ptrOrBoxEleTy(std::get<mlir::Type>(arg));
+              argAttrs.set(mlir::LLVM::LLVMDialect::getByValAttrName(),
+                           mlir::TypeAttr::get(elemType));
+            } else if (attr.isSRet()) {
+              mlir::Type elemType =
+                  fir::dyn_cast_ptrOrBoxEleTy(std::get<mlir::Type>(arg));
+              argAttrs.set(mlir::LLVM::LLVMDialect::getStructRetAttrName(),
+                           mlir::TypeAttr::get(elemType));
+              if (auto align = attr.getAlignment()) {
+                argAttrs.set(mlir::LLVM::LLVMDialect::getAlignAttrName(),
+                             rewriter->getIntegerAttr(
+                                 rewriter->getIntegerType(32), align));
+              }
+            }
+            argAttrsArray.emplace_back(
+                argAttrs.getDictionary(rewriter->getContext()));
+          }
+          newCall.setArgAttrsAttr(rewriter->getArrayAttr(argAttrsArray));
+        }
       }
       LLVM_DEBUG(llvm::dbgs() << "replacing call with " << newCall << '\n');
       if (wrap)