r341710 - Make -Watomic-alignment say whether the atomic operation was oversized

[Richard Smith via cfe-commits]

Author: rsmith
Date: Fri Sep  7 14:24:27 2018
New Revision: 341710

URL: http://llvm.org/viewvc/llvm-project?rev=341710&view=rev
Log:
Make -Watomic-alignment say whether the atomic operation was oversized
or misaligned.

Modified:
    cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
    cfe/trunk/lib/CodeGen/CGAtomic.cpp
    cfe/trunk/test/CodeGen/atomics-sema-alignment.c

Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=341710&r1=341709&r2=341710&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Fri Sep  7 14:24:27 2018
@@ -7093,8 +7093,8 @@ def warn_atomic_op_has_invalid_memory_or
 def err_atomic_op_has_invalid_synch_scope : Error<
   "synchronization scope argument to atomic operation is invalid">;
 def warn_atomic_op_misaligned : Warning<
-  "misaligned or large atomic operation may incur significant performance penalty">,
-  InGroup<DiagGroup<"atomic-alignment">>;
+  "%select{large|misaligned}0 atomic operation may incur "
+  "significant performance penalty">, InGroup<DiagGroup<"atomic-alignment">>;
 
 def err_overflow_builtin_must_be_int : Error<
   "operand argument to overflow builtin must be an integer (%0 invalid)">;

Modified: cfe/trunk/lib/CodeGen/CGAtomic.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGAtomic.cpp?rev=341710&r1=341709&r2=341710&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGAtomic.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGAtomic.cpp Fri Sep  7 14:24:27 2018
@@ -765,11 +765,15 @@ RValue CodeGenFunction::EmitAtomicExpr(A
   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 =

Modified: cfe/trunk/test/CodeGen/atomics-sema-alignment.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/atomics-sema-alignment.c?rev=341710&r1=341709&r2=341710&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/atomics-sema-alignment.c (original)
+++ cfe/trunk/test/CodeGen/atomics-sema-alignment.c Fri Sep  7 14:24:27 2018
@@ -12,10 +12,10 @@ typedef int __attribute__((aligned(1)))
 
 void func(IntPair *p) {
   IntPair res;
-  __atomic_load(p, &res, 0); // expected-warning {{misaligned or large atomic operation may incur significant performance penalty}}
-  __atomic_store(p, &res, 0); // expected-warning {{misaligned or large atomic operation may incur significant performance penalty}}
-  __atomic_fetch_add((unaligned_int *)p, 1, 2); // expected-warning {{misaligned or large atomic operation may incur significant performance penalty}}
-  __atomic_fetch_sub((unaligned_int *)p, 1, 3); // expected-warning {{misaligned or large atomic operation may incur significant performance penalty}}
+  __atomic_load(p, &res, 0); // expected-warning {{misaligned atomic operation may incur significant performance penalty}}
+  __atomic_store(p, &res, 0); // expected-warning {{misaligned atomic operation may incur significant performance penalty}}
+  __atomic_fetch_add((unaligned_int *)p, 1, 2); // expected-warning {{misaligned atomic operation may incur significant performance penalty}}
+  __atomic_fetch_sub((unaligned_int *)p, 1, 3); // expected-warning {{misaligned atomic operation may incur significant performance penalty}}
 }
 
 void func1(LongStruct *p) {