[Fix] Non i1 typed select condition for weird pw aff functions.

  In case the pieceweise affine function used to create an isl_ast_expr
  had empty cases (e.g., with contradicting constraints on the
  parameters), it was possible that the condition of the isl_ast_expr
  select was not a comparison but a constant (thus of type i64).

  This patch does two thing:
   1) Handle the case the condition of a select is not a i1 type like C.
   2) Try to simplify the pieceweise affine functions for the min/max
      access when we generate runtime alias checks. That step can often
      remove empty or redundant cases as well as redundant constrains.

  This fixes bug: http://llvm.org/PR21167

Differential Revision: http://reviews.llvm.org/D5627

llvm-svn: 219208

1 files changed, 2 insertions, 0 deletions

diff --git a/polly/lib/CodeGen/IslExprBuilder.cpp b/polly/lib/CodeGen/IslExprBuilder.cpp
index 158288dca46..39a9bb6a0fe 100644
--- a/polly/lib/CodeGen/IslExprBuilder.cpp
+++ b/polly/lib/CodeGen/IslExprBuilder.cpp
@@ -249,6 +249,8 @@ Value *IslExprBuilder::createOpSelect(__isl_take isl_ast_expr *Expr) {
   Type *MaxType = getType(Expr);
 
   Cond = create(isl_ast_expr_get_op_arg(Expr, 0));
+  if (!Cond->getType()->isIntegerTy(1))
+    Cond = Builder.CreateIsNotNull(Cond);
 
   LHS = create(isl_ast_expr_get_op_arg(Expr, 1));
   RHS = create(isl_ast_expr_get_op_arg(Expr, 2));