commit 50ad5b7354187308b3cb7319ff387b3409c06af3
author Craig Topper <craig.topper@gmail.com> Sat Aug 03 17:40:38 2013 +0000
committer Craig Topper <craig.topper@gmail.com> Sat Aug 03 17:40:38 2013 +0000
tree 98aafd332542f4936896f4214518aa471a475f60
parent b176acb6b72e12f301e0ea9c9e8664f5ba6de610

Add support for passing -1 to __builtin_shufflevector to signify an undefined element value to match IR capabilities.

llvm-svn: 187694

clang/lib/Sema/SemaChecking.cpp

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 4e0e76b..78995e3 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -1786,6 +1786,10 @@
                             diag::err_shufflevector_nonconstant_argument)
                        << TheCall->getArg(i)->getSourceRange());
 
+    // Allow -1 which will be translated to undef in the IR.
+    if (Result.isSigned() && Result.isAllOnesValue())
+      continue;
+
     if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2)
       return ExprError(Diag(TheCall->getLocStart(),
                             diag::err_shufflevector_argument_too_large)