[ValueTracking] add test for non-canonical shuffle; NFC
llvm-svn: 346025
diff --git a/llvm/unittests/Analysis/ValueTrackingTest.cpp b/llvm/unittests/Analysis/ValueTrackingTest.cpp
index f7d715c..e66d8f7 100644
--- a/llvm/unittests/Analysis/ValueTrackingTest.cpp
+++ b/llvm/unittests/Analysis/ValueTrackingTest.cpp
@@ -514,6 +514,29 @@
EXPECT_EQ(ComputeNumSignBits(RVal, M->getDataLayout()), 1u);
}
+// FIXME:
+// No guarantees for canonical IR in this analysis, so a shuffle element that
+// references an undef value means this can't return any extra information.
+TEST(ValueTracking, ComputeNumSignBits_Shuffle2) {
+ StringRef Assembly = "define <2 x i32> @f(<2 x i1> %x) { "
+ " %sext = sext <2 x i1> %x to <2 x i32> "
+ " %val = shufflevector <2 x i32> %sext, <2 x i32> undef, <2 x i32> <i32 0, i32 2> "
+ " ret <2 x i32> %val "
+ "} ";
+
+ LLVMContext Context;
+ SMDiagnostic Error;
+ auto M = parseAssemblyString(Assembly, Error, Context);
+ assert(M && "Bad assembly?");
+
+ auto *F = M->getFunction("f");
+ assert(F && "Bad assembly?");
+
+ auto *RVal =
+ cast<ReturnInst>(F->getEntryBlock().getTerminator())->getOperand(0);
+ EXPECT_EQ(ComputeNumSignBits(RVal, M->getDataLayout()), 32u);
+}
+
TEST(ValueTracking, ComputeKnownBits) {
StringRef Assembly = "define i32 @f(i32 %a, i32 %b) { "
" %ash = mul i32 %a, 8 "