From: Fariborz Jahanian <fjahanian@apple.com>
Date: Tue, 9 Aug 2011 00:26:11 +0000 (+0000)
Subject: Don't emit memcpy for copying fields of arrays of volatile elements.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6b167f4fc40477847687c004b73166f53eeda8da;p=clang

Don't emit memcpy for copying fields of arrays of volatile elements.
Use the the path that generates a loop. This fixes
bogus error that clang puts out. // rdar://9894548



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@137080 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 5d81205137..4671a87423 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -6933,8 +6933,8 @@ void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
     // explicit assignments, do so. This optimization only applies for arrays 
     // of scalars and arrays of class type with trivial copy-assignment 
     // operators.
-    if (FieldType->isArrayType() && 
-        BaseType.hasTrivialCopyAssignment(Context)) {
+    if (FieldType->isArrayType() && !FieldType.isVolatileQualified()
+        && BaseType.hasTrivialCopyAssignment(Context)) {
       // Compute the size of the memory buffer to be copied.
       QualType SizeType = Context.getSizeType();
       llvm::APInt Size(Context.getTypeSize(SizeType), 
diff --git a/test/CodeGenCXX/copy-assign-volatile-synthesis.cpp b/test/CodeGenCXX/copy-assign-volatile-synthesis.cpp
new file mode 100644
index 0000000000..eb13503fdc
--- /dev/null
+++ b/test/CodeGenCXX/copy-assign-volatile-synthesis.cpp
@@ -0,0 +1,43 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - | FileCheck %s
+// rdar://9894548
+
+typedef unsigned long word_t;
+typedef unsigned long u64_t;
+typedef unsigned int u32_t;
+
+class ioapic_redir_t {
+public:
+ union {
+  struct {
+   word_t vector : 8;
+
+   word_t delivery_mode : 3;
+   word_t dest_mode : 1;
+
+   word_t delivery_status : 1;
+   word_t polarity : 1;
+   word_t irr : 1;
+   word_t trigger_mode : 1;
+
+   word_t mask : 1;
+   word_t _pad0 : 15;
+
+   word_t dest : 8;
+  };
+  volatile u32_t raw[2];
+  volatile u64_t raw64;
+ };
+};
+
+struct ioapic_shadow_struct
+{
+ ioapic_redir_t redirs[24];
+} ioapic_shadow[16];
+
+void init_ioapic(unsigned long ioapic_id)
+{
+     ioapic_redir_t entry;
+     ioapic_shadow[ioapic_id].redirs[3] = entry;
+}
+
+// CHECK: call void @llvm.memcpy