[flang-commits] [flang] [flang][CodeGen] Add initial SystemZ ABI support (PR #208618)

[Ulrich Weigand via flang-commits]

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@@ -1893,6 +1893,111 @@ struct TargetLoongArch64 : public GenericTarget<TargetLoongArch64> {
 };
 } // namespace
 
+//===----------------------------------------------------------------------===//
+// SystemZ target specifics.
+//===----------------------------------------------------------------------===//
+
+namespace {
+struct TargetSystemZ : public GenericTarget<TargetSystemZ> {
+  using GenericTarget::GenericTarget;
+
+  static constexpr int defaultWidth = 64;
+
+  auto complexType(mlir::Type eleTy, bool isResult) const {
+    assert(fir::isa_real(eleTy));
+    CodeGenSpecifics::Marshalling marshal;
+    unsigned short align{std::max(
+        static_cast<unsigned short>(getDataLayout().getTypeABIAlignment(eleTy)),
+        static_cast<unsigned short>(8))};
+    marshal.emplace_back(
+        fir::ReferenceType::get(mlir::TupleType::get(
+            eleTy.getContext(), mlir::TypeRange{eleTy, eleTy})),
+        AT{/*align=*/align, /*byval=*/!isResult, /*sret=*/isResult});
+    return marshal;
+  }
+
+  CodeGenSpecifics::Marshalling
+  complexArgumentType(mlir::Location /*loc*/, mlir::Type eleTy) const override {
+    return complexType(eleTy, false);
+  }
+
+  CodeGenSpecifics::Marshalling
+  complexReturnType(mlir::Location /*loc*/, mlir::Type eleTy) const override {
+    return complexType(eleTy, true);
+  }
+
+  CodeGenSpecifics::Marshalling
+  integerArgumentType(mlir::Location loc,
+                      mlir::IntegerType argTy) const override {
+    // SystemZ ABI requires all integers < 64 bits to be sign/zero extended.
+    // Handle widths 32 to 63 explicitly; GenericTarget handles widths < 32
+    // including the i1 zero-extension special case.
+    if (argTy.getWidth() >= 32 && argTy.getWidth() < defaultWidth) {
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uweigand wrote:

Probably better to hard-code 64 here as well; it's an external requirement.

https://github.com/llvm/llvm-project/pull/208618