[flang-commits] [flang] [flang] Use correct int extension flags for C-ABI calls on aarch64 (PR #137105)

[Kiran Chandramohan via flang-commits]

================
@@ -810,6 +810,33 @@ struct TargetAArch64 : public GenericTarget<TargetAArch64> {
     return marshal;
   }
 
+  CodeGenSpecifics::Marshalling
+  integerArgumentType(mlir::Location loc,
+                      mlir::IntegerType argTy) const override {
+    if (argTy.getWidth() < getCIntTypeWidth() && argTy.isSignless()) {
+      AT::IntegerExtension intExt;
+      if (argTy.getWidth() == 1) {
+        // Zero extend for 'i1'.
+        intExt = AT::IntegerExtension::Zero;
+      } else {
+        if (triple.isOSDarwin())
+          // On Darwin, sign extend. The apple developer guide specifies this as
+          // a divergence from the AArch64PCS:
+          // https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms#Pass-arguments-to-functions-correctly
+          intExt = AT::IntegerExtension::Sign;
+        else
+          // On linux, pass directly and do not extend.
+          intExt = AT::IntegerExtension::None;
----------------
kiranchandramohan wrote:

Nit: braces (even if it is multi-line only due to comments)
https://llvm.org/docs/CodingStandards.html#don-t-use-braces-on-simple-single-statement-bodies-of-if-else-loop-statements

https://github.com/llvm/llvm-project/pull/137105