Fix __builtin_assume_aligned with too large values.

Code to handle __builtin_assume_aligned was allowing larger values, but
would convert this to unsigned along the way. This patch removes the
EmitAssumeAligned overloads that take unsigned to do away with this
problem.

Additionally, it adds a warning that values greater than 1 <<29 are
ignored by LLVM.

Differential Revision: https://reviews.llvm.org/D68824

llvm-svn: 374450
diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index e50cdb1..fa4304d 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -1519,14 +1519,14 @@
   if (!CGF.HaveInsertPoint())
     return;
   for (const auto *Clause : D.getClausesOfKind<OMPAlignedClause>()) {
-    unsigned ClauseAlignment = 0;
+    size_t ClauseAlignment = 0;
     if (const Expr *AlignmentExpr = Clause->getAlignment()) {
       auto *AlignmentCI =
           cast<llvm::ConstantInt>(CGF.EmitScalarExpr(AlignmentExpr));
-      ClauseAlignment = static_cast<unsigned>(AlignmentCI->getZExtValue());
+      ClauseAlignment = AlignmentCI->getZExtValue();
     }
     for (const Expr *E : Clause->varlists()) {
-      unsigned Alignment = ClauseAlignment;
+      size_t Alignment = ClauseAlignment;
       if (Alignment == 0) {
         // OpenMP [2.8.1, Description]
         // If no optional parameter is specified, implementation-defined default
@@ -1542,7 +1542,8 @@
       if (Alignment != 0) {
         llvm::Value *PtrValue = CGF.EmitScalarExpr(E);
         CGF.EmitAlignmentAssumption(
-            PtrValue, E, /*No second loc needed*/ SourceLocation(), Alignment);
+            PtrValue, E, /*No second loc needed*/ SourceLocation(),
+            llvm::ConstantInt::get(CGF.SizeTy, Alignment));
       }
     }
   }