[Windows] Fix mangling of number literal '0'

Do this by making the mangleNumber(APSInt) overload look like
the int64_t version. (The latter should probably just delegate
to the former).

Test from Evgeny Eltsin!

llvm-svn: 167599

2 files changed, 5 insertions, 2 deletions

diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 3765f3087e5..b7bfc70123e 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -351,10 +351,10 @@ void MicrosoftCXXNameMangler::mangleNumber(const llvm::APSInt &Value) {
     char *CurPtr = EndPtr;
     llvm::APSInt NibbleMask(Value.getBitWidth(), Value.isUnsigned());
     NibbleMask = 0xf;
-    for (int i = 0, e = (Value.getActiveBits() + 3) / 4; i != e; ++i) {
+    do {
       *--CurPtr = 'A' + Temp.And(NibbleMask).getLimitedValue(0xf);
       Temp = Temp.lshr(4);
-    }
+    } while (Temp != 0);
     Out.write(CurPtr, EndPtr-CurPtr);
     Out << '@';
   }
diff --git a/clang/test/CodeGenCXX/mangle-ms-templates.cpp b/clang/test/CodeGenCXX/mangle-ms-templates.cpp
index efe9565d332..e16fe936bc2 100644
--- a/clang/test/CodeGenCXX/mangle-ms-templates.cpp
+++ b/clang/test/CodeGenCXX/mangle-ms-templates.cpp
@@ -48,6 +48,9 @@ void template_mangling() {
 // CHECK: call {{.*}} @"\01??0?$BoolTemplate@$00@@QAE@XZ"
 // CHECK: call {{.*}} @"\01??$Foo@H@?$BoolTemplate@$00@@QAEXH@Z"
 
+  IntTemplate<0> zero;
+// CHECK: call {{.*}} @"\01??0?$IntTemplate@$0A@@@QAE@XZ"
+
   IntTemplate<5> five;
 // CHECK: call {{.*}} @"\01??0?$IntTemplate@$04@@QAE@XZ"