[PATCH] D131677: [clang][RISCV][WIP] Fix incorrect ABI lowering for inherited structs with hard-float ABIs

[Alex Bradbury via Phabricator via cfe-commits]

asb updated this revision to Diff 451915.
asb added reviewers: kito-cheng, craig.topper, reames.
asb added a comment.
Herald added subscribers: frasercrmck, apazos, jocewei, PkmX, the_o, brucehoult, MartinMosbeck, edward-jones, zzheng, MaskRay, jrtc27, niosHD, sabuasal, johnrusso, rbar.

Add test (I've pre-committed the current behaviour).

Now that update_cc_test_checks.py supports both `--function-signature` and `--filter '^define '` I'd hoped I could massively improve the maintainability of the tests by using it. Unfortunately it seems that merging identical output under common CHECK lines isn't working as it does for update_llc_test_checks.py and the generated CHECK lines don't match against the function return type. It would definitely be good to address these issues and move all the RISC-V ABI tests to using update_cc_test_checks.py, but obviously I leave that for future work in favour of landing a fix quickly.

The previous lowering was broken (as opposed to being working but not in compliance with the official ABI). As such, I don't think there's any argument for providing a flag for the old behaviour (as sometimes happens with other targets after fixing ABI issues).


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D131677/new/

https://reviews.llvm.org/D131677

Files:
  clang/lib/CodeGen/TargetInfo.cpp
  clang/test/CodeGen/RISCV/riscv-abi.cpp


Index: clang/test/CodeGen/RISCV/riscv-abi.cpp
===================================================================
--- clang/test/CodeGen/RISCV/riscv-abi.cpp
+++ clang/test/CodeGen/RISCV/riscv-abi.cpp
@@ -39,12 +39,10 @@
   float f1;
 };
 
-// TODO: Fix incorrect lowering for hard-float ABIs.
-
 // ILP32: define{{.*}} [2 x i32] @_Z30int32_float_struct_inheritance14child2_float_s([2 x i32] %a.coerce)
-// ILP32F-ILP32D: define{{.*}} float @_Z30int32_float_struct_inheritance14child2_float_s(float %0)
+// ILP32F-ILP32D: define{{.*}} { i32, float } @_Z30int32_float_struct_inheritance14child2_float_s(i32 %0, float %1)
 // LP64: define{{.*}} i64 @_Z30int32_float_struct_inheritance14child2_float_s(i64 %a.coerce)
-// LP64F-LP64D: define{{.*}} float @_Z30int32_float_struct_inheritance14child2_float_s(float %0)
+// LP64F-LP64D: define{{.*}} { i32, float } @_Z30int32_float_struct_inheritance14child2_float_s(i32 %0, float %1)
 struct child2_float_s int32_float_struct_inheritance(struct child2_float_s a) {
   return a;
 }
@@ -57,10 +55,9 @@
   int64_t i1;
 };
 
-// TODO: Fix incorrect lowering for lp64f/lp64d ABIs.
-
 // ILP32-ILP32F-ILP32D-LABEL: define{{.*}} void @_Z30float_int64_struct_inheritance14child3_int64_s(ptr noalias sret(%struct.child3_int64_s)
-// LP64-LP64F-LP64D-LABEL: define{{.*}} [2 x i64] @_Z30float_int64_struct_inheritance14child3_int64_s([2 x i64] %a.coerce)
+// LP64-LABEL: define{{.*}} [2 x i64] @_Z30float_int64_struct_inheritance14child3_int64_s([2 x i64] %a.coerce)
+// LP64F-LP64D-LABEL: define{{.*}} { float, i64 } @_Z30float_int64_struct_inheritance14child3_int64_s(float %0, i64 %1)
 struct child3_int64_s float_int64_struct_inheritance(struct child3_int64_s a) {
   return a;
 }
@@ -73,12 +70,10 @@
   double d1;
 };
 
-// TODO: Fix incorrect lowering for ilp32d/lp64d ABIs.
-
 // ILP32-ILP32F-LABEL: define{{.*}} void @_Z32double_double_struct_inheritance15child4_double_s(ptr noalias sret(%struct.child4_double_s)
-// ILP32D-LABEL: define{{.*}} double @_Z32double_double_struct_inheritance15child4_double_s(double %0)
+// ILP32D-LABEL: define{{.*}} { double, double } @_Z32double_double_struct_inheritance15child4_double_s(double %0, double %1)
 // LP64-LP64F-LABEL: define{{.*}} [2 x i64] @_Z32double_double_struct_inheritance15child4_double_s([2 x i64] %a.coerce)
-// LP64D-LABEL: define{{.*}} double @_Z32double_double_struct_inheritance15child4_double_s(double %0)
+// LP64D-LABEL: define{{.*}} { double, double } @_Z32double_double_struct_inheritance15child4_double_s(double %0, double %1)
 struct child4_double_s double_double_struct_inheritance(struct child4_double_s a) {
   return a;
 }
Index: clang/lib/CodeGen/TargetInfo.cpp
===================================================================
--- clang/lib/CodeGen/TargetInfo.cpp
+++ clang/lib/CodeGen/TargetInfo.cpp
@@ -10979,6 +10979,15 @@
     // Unions aren't eligible unless they're empty (which is caught above).
     if (RD->isUnion())
       return false;
+    // If this is a C++ record, check the bases first.
+    if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
+      for (const CXXBaseSpecifier &B : CXXRD->bases()) {
+        bool Ret = detectFPCCEligibleStructHelper(
+            B.getType(), CurOff, Field1Ty, Field1Off, Field2Ty, Field2Off);
+        if (!Ret)
+          return false;
+      }
+    }
     int ZeroWidthBitFieldCount = 0;
     for (const FieldDecl *FD : RD->fields()) {
       const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D131677.451915.patch
Type: text/x-patch
Size: 3497 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20220811/26b258b0/attachment.bin>