CodeGen: Correctly convert atomic bool from i8 to i1

Bools are a little tricky, they are i8 in memory and must be coerced
back to i1 before further operations can be performed on them.

This fixes PR22577.

llvm-svn: 229204

2 files changed, 11 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 568f949c342..d82fff85dd3 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -1140,7 +1140,7 @@ llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
     LValue lvalue = LValue::MakeAddr(Addr, Ty,
                                      CharUnits::fromQuantity(Alignment),
                                      getContext(), TBAAInfo);
-    return EmitAtomicLoad(lvalue, Loc).getScalarVal();
+    return EmitFromMemory(EmitAtomicLoad(lvalue, Loc).getScalarVal(), Ty);
   }
 
   llvm::LoadInst *Load = Builder.CreateLoad(Addr);
diff --git a/clang/test/CodeGen/atomic_ops.c b/clang/test/CodeGen/atomic_ops.c
index 29009bef894..5f2a1966a2a 100644
--- a/clang/test/CodeGen/atomic_ops.c
+++ b/clang/test/CodeGen/atomic_ops.c
@@ -16,3 +16,13 @@ void foo(int x)
   // CHECK: {{(cmpxchg i16*|i1 @__atomic_compare_exchange\(i32 2, )}}
 
 }
+
+extern _Atomic _Bool b;
+
+_Bool bar() {
+// CHECK-LABEL: @bar
+// CHECK: %[[load:.*]] = load atomic i8* @b seq_cst, align 1
+// CHECK: %[[tobool:.*]] = trunc i8 %[[load]] to i1
+// CHECK: ret i1 %[[tobool]]
+  return b;
+}