diff --git a/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp index 77e167dfb08..a9f144c06e9 100644 --- a/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp +++ b/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp @@ -575,6 +575,7 @@ void DAGTypeLegalizer::RemapValue(SDValue &V) { void DAGTypeLegalizer::RemapId(TableId &Id) { auto I = ReplacedValues.find(Id); if (I != ReplacedValues.end()) { + assert(Id != I->second && "Id is mapped to itself."); // Use path compression to speed up future lookups if values get multiply // replaced with other values. RemapId(I->second); @@ -652,7 +653,8 @@ void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) { auto FromId = getTableId(From); auto ToId = getTableId(To); - ReplacedValues[FromId] = ToId; + if (FromId != ToId) + ReplacedValues[FromId] = ToId; DAG.ReplaceAllUsesOfValueWith(From, To); // Process the list of nodes that need to be reanalyzed. @@ -685,7 +687,8 @@ void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) { auto OldValId = getTableId(OldVal); auto NewValId = getTableId(NewVal); DAG.ReplaceAllUsesOfValueWith(OldVal, NewVal); - ReplacedValues[OldValId] = NewValId; + if (OldValId != NewValId) + ReplacedValues[OldValId] = NewValId; } // The original node continues to exist in the DAG, marked NewNode. } diff --git a/lib/CodeGen/SelectionDAG/LegalizeTypes.h b/lib/CodeGen/SelectionDAG/LegalizeTypes.h index 6d577adc6f4..e4d4aac3340 100644 --- a/lib/CodeGen/SelectionDAG/LegalizeTypes.h +++ b/lib/CodeGen/SelectionDAG/LegalizeTypes.h @@ -186,7 +186,8 @@ public: TableId NewId = getTableId(SDValue(New, i)); TableId OldId = getTableId(SDValue(Old, i)); - ReplacedValues[OldId] = NewId; + if (OldId != NewId) + ReplacedValues[OldId] = NewId; // Delete Node from tables. ValueToIdMap.erase(SDValue(Old, i)); diff --git a/test/CodeGen/X86/legalize-types-remapid.ll b/test/CodeGen/X86/legalize-types-remapid.ll new file mode 100644 index 00000000000..d24ec2d3b55 --- /dev/null +++ b/test/CodeGen/X86/legalize-types-remapid.ll @@ -0,0 +1,16 @@ +; RUN: llc -mtriple=i386 -mcpu=generic -O0 -o /dev/null %s + +@c = global i32 0 +@d = global <2 x i64> zeroinitializer + +define void @test() { +bb1: + %t0 = load <2 x i64>, <2 x i64>* @d + %t0.i0 = extractelement <2 x i64> %t0, i32 0 + %t0.i0.cast = bitcast i64 %t0.i0 to <2 x i32> + %t0.i0.cast.i0 = extractelement <2 x i32> %t0.i0.cast, i32 0 + store volatile i32 %t0.i0.cast.i0, i32* @c + %t0.i0.cast.i1 = extractelement <2 x i32> %t0.i0.cast, i32 1 + store volatile i32 %t0.i0.cast.i1, i32* @c + ret void +}