Handle ConstantExpr correctly in SelectionDAGBuilder

This change fixes a bug in SelectionDAGBuilder::visitInsertValue and SelectionDAGBuilder::visitExtractValue where constant expressions (InsertValueConstantExpr and ExtractValueConstantExpr) would be treated as non-constant instructions (InsertValueInst and ExtractValueInst). This bug resulted in an incorrect memory access, which manifested as an assertion failure in SDValue::SDValue.

Fixes PR#33094.

Submitted on behalf of @Praetonus (Benoit Vey)

Differential Revision: https://reviews.llvm.org/D34538

llvm-svn: 307502

1 files changed, 18 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/Generic/pr33094.ll b/llvm/test/CodeGen/Generic/pr33094.ll
new file mode 100644
index 00000000000..afa464f63f6
--- /dev/null
+++ b/llvm/test/CodeGen/Generic/pr33094.ll
@@ -0,0 +1,18 @@
+; RUN: llc < %s
+
+; PR33094
+; Make sure that a constant extractvalue doesn't cause a crash in
+; SelectionDAGBuilder::visitExtractValue.
+
+%A = type {}
+%B = type {}
+%Tuple = type { i64 }
+
+@A_Inst = global %A zeroinitializer
+@B_Inst = global %B zeroinitializer
+
+define i64 @foo() {
+  ret i64 extractvalue (%Tuple select (i1 icmp eq
+                        (%B* bitcast (%A* @A_Inst to %B*), %B* @B_Inst),
+                        %Tuple { i64 33 }, %Tuple { i64 42 }), 0)
+}