Fix PR14565. Don't if-convert loops that have switch statements in them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169813 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 43 insertions, 0 deletions

diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp
index feeececedb..a69124032b 100644
--- a/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -1263,6 +1263,10 @@ bool LoopVectorizationLegality::canVectorizeWithIfConvert() {
   for (unsigned i = 0, e = LoopBlocks.size(); i < e; ++i) {
     BasicBlock *BB = LoopBlocks[i];
 
+    // We don't support switch statements inside loops.
+    if (!isa<BranchInst>(BB->getTerminator()))
+      return false;
+
     // We must have at most two predecessors because we need to convert
     // all PHIs to selects.
     unsigned Preds = std::distance(pred_begin(BB), pred_end(BB));
diff --git a/test/Transforms/LoopVectorize/if-conv-crash.ll b/test/Transforms/LoopVectorize/if-conv-crash.ll
new file mode 100644
index 0000000000..c82df5a9be
--- /dev/null
+++ b/test/Transforms/LoopVectorize/if-conv-crash.ll
@@ -0,0 +1,39 @@
+; RUN: opt < %s  -loop-vectorize -force-vector-width=4 -enable-if-conversion
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.8.0"
+
+define fastcc void @DD_dump() nounwind uwtable ssp {
+entry:
+  br i1 undef, label %lor.lhs.false, label %if.end25
+
+lor.lhs.false:                                    ; preds = %entry
+  br i1 undef, label %if.end21, label %if.else
+
+if.else:                                          ; preds = %lor.lhs.false
+  br i1 undef, label %num_q.exit, label %while.body.i.preheader
+
+while.body.i.preheader:                           ; preds = %if.else
+  br label %while.body.i
+
+while.body.i:                                     ; preds = %if.end.i, %while.body.i.preheader
+  switch i8 undef, label %if.end.i [
+    i8 39, label %if.then.i
+    i8 92, label %if.then.i
+  ]
+
+if.then.i:                                        ; preds = %while.body.i, %while.body.i
+  br label %if.end.i
+
+if.end.i:                                         ; preds = %if.then.i, %while.body.i
+  br i1 undef, label %num_q.exit, label %while.body.i
+
+num_q.exit:                                       ; preds = %if.end.i, %if.else
+  unreachable
+
+if.end21:                                         ; preds = %lor.lhs.false
+  unreachable
+
+if.end25:                                         ; preds = %entry
+  ret void
+}