DAGCombiner: Don't fold xor into not if getNOT would introduce an illegal constant.

This happens e.g. with <2 x i64> -1 on x86_32. It cannot be generated directly
because i64 is illegal. It would be nice if getNOT would handle this
transparently, but I don't see a way to generate a legal constant there right
now. Fixes PR17487.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192795 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 8d6eab7c7b97e2365e29733c2b60df828c429aed..23e33d4ed221e5ff42d4fed9973200486fe4869c 100644 (file)
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3583,7 +3583,7 @@ SDValue DAGCombiner::visitXOR(SDNode *N) {
   }
   // fold (xor (and x, y), y) -> (and (not x), y)
   if (N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
-      N0->getOperand(1) == N1) {
+      N0->getOperand(1) == N1 && isTypeLegal(VT.getScalarType())) {
     SDValue X = N0->getOperand(0);
     SDValue NotX = DAG.getNOT(SDLoc(X), X, VT);
     AddToWorkList(NotX.getNode());

diff --git a/test/CodeGen/X86/xor.ll b/test/CodeGen/X86/xor.ll
index b56ce0f52cc879df5c44a541a9228aee4ac636c0..be2ea525b156f81b47c749a8926d0fd47b23d8cf 100644 (file)
--- a/test/CodeGen/X86/xor.ll
+++ b/test/CodeGen/X86/xor.ll
@@ -165,3 +165,17 @@ define <4 x i32> @test10(<4 x i32> %a) nounwind {
 ; X32-LABEL: test10:
 ; X32:    andnps
 }
+
+define i32 @PR17487(i1 %tobool) {
+  %tmp = insertelement <2 x i1> undef, i1 %tobool, i32 1
+  %tmp1 = zext <2 x i1> %tmp to <2 x i64>
+  %tmp2 = xor <2 x i64> %tmp1, <i64 1, i64 1>
+  %tmp3 = extractelement <2 x i64> %tmp2, i32 1
+  %add = add nsw i64 0, %tmp3
+  %cmp6 = icmp ne i64 %add, 1
+  %conv7 = zext i1 %cmp6 to i32
+  ret i32 %conv7
+
+; X64-LABEL: PR17487:
+; X64: andn
+}