commit 6f4f8083931a92f9959168d4430da7ddf9183100
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 407d3975378c3ece851f4a166b8ad4c0f0840968
parent a1c50a1f55086cda654a903abd4ce1908e580faa

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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@187694 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/SemaChecking.cpp

diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 4e0e76b..78995e3 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/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)