commit edb9fbb78a18d796e497e83ff912b19d064cf5a1
author Richard Smith <richard-llvm@metafoo.co.uk> Fri Sep 07 21:24:27 2018 +0000
committer Richard Smith <richard-llvm@metafoo.co.uk> Fri Sep 07 21:24:27 2018 +0000
tree 9cd20a4bb5a38c68523bee758bfa7603e0a90e15
parent f98c2c5e6d65fb2a0194fd3ea9f52d793035f63c

Make -Watomic-alignment say whether the atomic operation was oversized
or misaligned.

llvm-svn: 341710

clang/lib/CodeGen/CGAtomic.cpp

diff --git a/clang/lib/CodeGen/CGAtomic.cpp b/clang/lib/CodeGen/CGAtomic.cpp
index eaf29df..5b63b3f 100644
--- a/clang/lib/CodeGen/CGAtomic.cpp
+++ b/clang/lib/CodeGen/CGAtomic.cpp
@@ -765,11 +765,15 @@
   std::tie(sizeChars, alignChars) = getContext().getTypeInfoInChars(AtomicTy);
   uint64_t Size = sizeChars.getQuantity();
   unsigned MaxInlineWidthInBits = getTarget().getMaxAtomicInlineWidth();
-  bool UseLibcall = ((Ptr.getAlignment() % sizeChars) != 0 ||
-                     getContext().toBits(sizeChars) > MaxInlineWidthInBits);
 
-  if (UseLibcall)
-    CGM.getDiags().Report(E->getBeginLoc(), diag::warn_atomic_op_misaligned);
+  bool Oversized = getContext().toBits(sizeChars) > MaxInlineWidthInBits;
+  bool Misaligned = (Ptr.getAlignment() % sizeChars) != 0;
+  bool UseLibcall = Misaligned | Oversized;
+
+  if (UseLibcall) {
+    CGM.getDiags().Report(E->getBeginLoc(), diag::warn_atomic_op_misaligned)
+        << !Oversized;
+  }
 
   llvm::Value *Order = EmitScalarExpr(E->getOrder());
   llvm::Value *Scope =