PR20557: Fix the bug that bogus cpu parameter crashes llc on AArch64 backend.

Initial patch by Oleg Ranevskyy.

llvm-svn: 220945

2 files changed, 13 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index a5889db9104..d0acf0e6913 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -1200,8 +1200,12 @@ void TargetLoweringBase::computeRegisterProperties() {
         TransformToType[i] = MVT::Other;
         if (PreferredAction == TypeScalarizeVector)
           ValueTypeActions.setTypeAction(VT, TypeScalarizeVector);
-        else
+        else if (PreferredAction == TypeSplitVector)
           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
+        else
+          // Set type action according to the number of elements.
+          ValueTypeActions.setTypeAction(VT, NElts == 1 ? TypeScalarizeVector
+                                                        : TypeSplitVector);
       } else {
         TransformToType[i] = NVT;
         ValueTypeActions.setTypeAction(VT, TypeWidenVector);
diff --git a/llvm/test/CodeGen/AArch64/legalize-bug-bogus-cpu.ll b/llvm/test/CodeGen/AArch64/legalize-bug-bogus-cpu.ll
new file mode 100644
index 00000000000..b785a8f045f
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/legalize-bug-bogus-cpu.ll
@@ -0,0 +1,8 @@
+; RUN: llc -march=aarch64 -mcpu=bogus -o - %s
+
+; Fix the bug in PR20557. Set mcpu to a bogus name, llc will crash in type
+; legalization.
+define <4 x float> @fneg4(<4 x float> %x) {
+  %sub = fsub <4 x float> zeroinitializer, %x
+  ret <4 x float> %sub
+}