From 6f87b44fe378184316b9e7bfdd2316d3ce80eac7 Mon Sep 17 00:00:00 2001
From: Eli Friedman <eli.friedman@gmail.com>
Date: Thu, 15 Mar 2012 23:12:51 +0000
Subject: [PATCH] When a variable has a specified asm name, but isn't using the
 register storage class, the asm name doesn't specify a register. PR12244.

llvm-svn: 152873
---
 clang/lib/CodeGen/CGStmt.cpp      | 2 ++
 clang/test/CodeGen/asm-variable.c | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index b2da32bb529e..e65c5f468f58 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -1295,6 +1295,8 @@ AddVariableConstraints(const std::string &Constraint, const Expr &AsmExpr,
   const VarDecl *Variable = dyn_cast<VarDecl>(&Value);
   if (!Variable)
     return Constraint;
+  if (Variable->getStorageClass() != SC_Register)
+    return Constraint;
   AsmLabelAttr *Attr = Variable->getAttr<AsmLabelAttr>();
   if (!Attr)
     return Constraint;
diff --git a/clang/test/CodeGen/asm-variable.c b/clang/test/CodeGen/asm-variable.c
index a37132d16c23..dc087bd9e211 100644
--- a/clang/test/CodeGen/asm-variable.c
+++ b/clang/test/CodeGen/asm-variable.c
@@ -57,3 +57,9 @@ unsigned long long foo2(unsigned long long addr, double a0,
 }
 
 // CHECK: call i64 asm "call *$1", "={rax},r,{xmm0},{xmm1},{xmm2},{xmm3},{xmm4},{xmm5},{xmm6},{xmm7},~{dirflag},~{fpsr},~{flags}
+
+int randomvar asm("randomvar");
+void foo3() {
+  asm("vartest %0" : : "r"(randomvar));
+}
+// CHECK: call void asm sideeffect "vartest $0", "r,~{dirflag},~{fpsr},~{flags}"