Fix PromoteIntRes_BUILD_VECTOR crash with i1 vectors

This fixes a bug (found by llvm-stress) in
DAGTypeLegalizer::PromoteIntRes_BUILD_VECTOR where it assumed that the result
type would always be larger than the original operands. This is not always
true, however, with boolean vectors. For example, promoting a node of type v8i1
(where the operands will be of type i32, the type to which i1 is promoted) will
yield a node with a result vector element type of i16 (and operands of type
i32). As a result, we cannot blindly assume that we can ANY_EXTEND the operands
to the result type.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185794 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index b3ec9bc02296bc4db46691bbb4cc8f76e5b41f94..df388981aed8bf82468c93a14970198d70112158 100644 (file)
--- a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -2930,7 +2930,13 @@ SDValue DAGTypeLegalizer::PromoteIntRes_BUILD_VECTOR(SDNode *N) {
   SmallVector<SDValue, 8> Ops;
   Ops.reserve(NumElems);
   for (unsigned i = 0; i != NumElems; ++i) {
-    SDValue Op = DAG.getNode(ISD::ANY_EXTEND, dl, NOutVTElem, N->getOperand(i));
+    SDValue Op;
+    // It is possible for the operands to be larger than the result, for example,
+    // when the operands are promoted booleans and the result was an i1 vector.
+    if (N->getOperand(i).getValueType().bitsLT(NOutVTElem))
+      Op = DAG.getNode(ISD::ANY_EXTEND, dl, NOutVTElem, N->getOperand(i));
+    else
+      Op = N->getOperand(i);
     Ops.push_back(Op);
   }
 

diff --git a/test/CodeGen/PowerPC/bv-pres-v8i1.ll b/test/CodeGen/PowerPC/bv-pres-v8i1.ll
new file mode 100644 (file)
index 0000000..5bf84ed
--- /dev/null
+++ b/test/CodeGen/PowerPC/bv-pres-v8i1.ll
@@ -0,0 +1,39 @@
+; RUN: llc -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 < %s
+target triple = "powerpc64-unknown-linux-gnu"
+
+define void @autogen_SD70() {
+BB:
+  br label %CF78
+
+CF78:                                             ; preds = %CF87, %CF78, %BB
+  br i1 undef, label %CF78, label %CF87
+
+CF87:                                             ; preds = %CF78
+  %Cmp19 = icmp sge <8 x i1> zeroinitializer, zeroinitializer
+  %Cmp26 = icmp slt i32 -1, undef
+  br i1 %Cmp26, label %CF78, label %CF79
+
+CF79:                                             ; preds = %CF79, %CF87
+  br i1 undef, label %CF79, label %CF82
+
+CF82:                                             ; preds = %CF82, %CF79
+  br i1 undef, label %CF82, label %CF84
+
+CF84:                                             ; preds = %CF82
+  br label %CF
+
+CF:                                               ; preds = %CF88, %CF, %CF84
+  br i1 undef, label %CF, label %CF85
+
+CF85:                                             ; preds = %CF85, %CF
+  %I52 = insertelement <8 x i1> %Cmp19, i1 %Cmp26, i32 6
+  %Cmp61 = icmp ult i32 477567, undef
+  br i1 %Cmp61, label %CF85, label %CF88
+
+CF88:                                             ; preds = %CF85
+  %E63 = extractelement <8 x i1> %I52, i32 5
+  br i1 %E63, label %CF, label %CF80
+
+CF80:                                             ; preds = %CF80, %CF88
+  br label %CF80
+}