[clang] a653749 - [clang][Interp] Implement compound assign operators on bitfields (#67306)

[via cfe-commits]

Author: Timm Baeder
Date: 2023-10-14T09:17:35+02:00
New Revision: a653749acab8d5cb84e7f15cccc97e76ebe8c84b

URL: https://github.com/llvm/llvm-project/commit/a653749acab8d5cb84e7f15cccc97e76ebe8c84b
DIFF: https://github.com/llvm/llvm-project/commit/a653749acab8d5cb84e7f15cccc97e76ebe8c84b.diff

LOG: [clang][Interp] Implement compound assign operators on bitfields (#67306)

Added: 
    

Modified: 
    clang/lib/AST/Interp/ByteCodeExprGen.cpp
    clang/test/AST/Interp/bitfields.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Interp/ByteCodeExprGen.cpp b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
index 2b745d6a1509868..71aac8c6245c5af 100644
--- a/clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -1170,8 +1170,13 @@ bool ByteCodeExprGen<Emitter>::VisitCompoundAssignOperator(
   }
 
   // And store the result in LHS.
-  if (DiscardResult)
+  if (DiscardResult) {
+    if (LHS->refersToBitField())
+      return this->emitStoreBitFieldPop(*ResultT, E);
     return this->emitStorePop(*ResultT, E);
+  }
+  if (LHS->refersToBitField())
+    return this->emitStoreBitField(*ResultT, E);
   return this->emitStore(*ResultT, E);
 }
 

diff  --git a/clang/test/AST/Interp/bitfields.cpp b/clang/test/AST/Interp/bitfields.cpp
index e078704fce51ff0..9a144e2f0d9610e 100644
--- a/clang/test/AST/Interp/bitfields.cpp
+++ b/clang/test/AST/Interp/bitfields.cpp
@@ -31,8 +31,6 @@ namespace Basic {
     return a.a = 10;
   }
   static_assert(storeA2() == 2, "");
-
-  // TODO: +=, -=, etc. operators.
 }
 
 namespace Overflow {
@@ -45,3 +43,39 @@ namespace Overflow {
 
   static_assert(f() == 3, "");
 }
+
+namespace Compound {
+  struct A {
+    unsigned int a : 2;
+    constexpr A() : a(0) {}
+    constexpr A(int a) : a(a) {}
+  };
+
+  constexpr unsigned add() {
+    A a;
+    a.a += 10;
+    return a.a;
+  }
+  static_assert(add() == 2, "");
+
+  constexpr unsigned sub() {
+    A a;
+    a.a -= 10;
+    return a.a;
+  }
+  static_assert(sub() == 2, "");
+
+  constexpr unsigned mul() {
+    A a(1);
+    a.a *= 5;
+    return a.a;
+  }
+  static_assert(mul() == 1, "");
+
+  constexpr unsigned div() {
+    A a(2);
+    a.a /= 2;
+    return a.a;
+  }
+  static_assert(div() == 1, "");
+}