[flang] Don't convert actual argument if IGNORE_TKR is present for the corresponding dummy.

[DanielCChen]

Summary

Consider the following code:

interface
integer(4) function foo4(arg1, arg2)
integer :: arg1
integer(4) :: arg2
!dir$ ignore_tkr(k) arg1
end
end interface

integer(4) :: res, a
integer(2) :: b
res = foo4(b, a)
end

Flang currently converts arg1 from i16 to i32 when lowering.

%3 = fir.convert %1 : (!fir.ref<i16>) -> !fir.ref<i32>
This PR is to remove the conversion.

[klausler]

flang/lib/Semantics/check-call.cpp

223

I think you want to only be affected here by the first two parts of the typesCompatible conjunction, which depend on IgnoreTKR, but not the last one. So you'll have to split typesCompatible, with a new Boolean indicating whether IgnoreTKR was applied, and then use that new Boolean in your new &= !....

[DanielCChen]

To address review comments. Separating typeCompatible into two Booleans.

[klausler]

Looks great. Thanks for digging into this!

[DanielCChen]

Sorry that the patch file was accidentally added to the review. This revision is to remove it.

flang/lib/Semantics/check-call.cpp

static void CheckExplicitDataArg(const characteristics::DummyDataObject &dummy,
   parser::ContextualMessages &messages{foldingContext.messages()};
   CheckCharacterActual(actual, dummy, actualType, context, messages);
   bool dummyIsAllocatable{
       dummy.attrs.test(characteristics::DummyDataObject::Attr::Allocatable)};
   bool dummyIsPointer{
       dummy.attrs.test(characteristics::DummyDataObject::Attr::Pointer)};
   bool dummyIsAllocatableOrPointer{dummyIsAllocatable || dummyIsPointer};
   allowActualArgumentConversions &= !dummyIsAllocatableOrPointer;
-  if (allowActualArgumentConversions) {
-    ConvertIntegerActual(actual, dummy.type, actualType, messages);
-  }
-  bool typesCompatible{
+  bool typesCompatibleWithIgnoreTKR{
       (dummy.ignoreTKR.test(common::IgnoreTKR::Type) &&
           (dummy.type.type().category() == TypeCategory::Derived ||
               actualType.type().category() == TypeCategory::Derived ||
               dummy.type.type().category() != actualType.type().category())) ||
       (dummy.ignoreTKR.test(common::IgnoreTKR::Kind) &&
-          dummy.type.type().category() == actualType.type().category()) ||
+          dummy.type.type().category() == actualType.type().category())};
+  allowActualArgumentConversions &= !typesCompatibleWithIgnoreTKR;
+  if (allowActualArgumentConversions) {
+    ConvertIntegerActual(actual, dummy.type, actualType, messages);
+  }
+  bool typesCompatible{typesCompatibleWithIgnoreTKR ||
       dummy.type.type().IsTkCompatibleWith(actualType.type())};
   if (!typesCompatible && dummy.type.Rank() == 0 &&
       allowActualArgumentConversions) {
     // Extension: pass Hollerith literal to scalar as if it had been BOZ
     if (auto converted{evaluate::HollerithToBOZ(
             foldingContext, actual, dummy.type.type())}) {
       messages.Say(
           "passing Hollerith or character literal as if it were BOZ"_port_en_US);
       actual = *converted;
       actualType.type() = dummy.type.type();

flang/test/Semantics/ignore_tkr02.f90

subroutine sub2(j, k)
       !dir$ ignore_tkr(kr) k
     end
     subroutine sub4(j, k)
       integer(4) j
       integer k
       !dir$ ignore_tkr(kr) k
     end
   end interface
-!CHECK: CALL sub1(1_1,int(1_1,kind=4))
+!CHECK: CALL sub1(1_1,1_1)
   call generic(1_1,1_1)
-!CHECK: CALL sub1(1_1,int(1_2,kind=4))
+!CHECK: CALL sub1(1_1,1_2)
   call generic(1_1,1_2)
 !CHECK: CALL sub1(1_1,[INTEGER(1)::1_1])
   call generic(1_1,[1_1])
-!CHECK: CALL sub2(1_2,int(1_1,kind=4))
+!CHECK: CALL sub2(1_2,1_1)
   call generic(1_2,1_1)
-!CHECK: CALL sub2(1_2,int(1_2,kind=4))
+!CHECK: CALL sub2(1_2,1_2)
   call generic(1_2,1_2)
 !CHECK: CALL sub2(1_2,[INTEGER(1)::1_1])
   call generic(1_2,[1_1])
-!CHECK: CALL sub4(1_4,int(1_1,kind=4))
+!CHECK: CALL sub4(1_4,1_1)
   call generic(1_4,1_1)
-!CHECK: CALL sub4(1_4,int(1_2,kind=4))
+!CHECK: CALL sub4(1_4,1_2)
   call generic(1_4,1_2)
 !CHECK: CALL sub4(1_4,[INTEGER(1)::1_1])
   call generic(1_4,[1_1])
 end