Add comments detailing a known bug, so that people writing other
backends don't use it as an example.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80105 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PIC16/PIC16ISelLowering.cpp b/lib/Target/PIC16/PIC16ISelLowering.cpp
index d4cbc0a..7a5b5ff 100644
--- a/lib/Target/PIC16/PIC16ISelLowering.cpp
+++ b/lib/Target/PIC16/PIC16ISelLowering.cpp
@@ -533,6 +533,10 @@
SDValue SrcLo, SrcHi;
GetExpandedParts(Src, DAG, SrcLo, SrcHi);
SDValue ChainLo = Chain, ChainHi = Chain;
+ // FIXME: This makes unsafe assumptions. The Chain may be a TokenFactor
+ // created for an unrelated purpose, in which case it may not have
+ // exactly two operands. Also, even if it does have two operands, they
+ // may not be the low and high parts of an aligned load that was split.
if (Chain.getOpcode() == ISD::TokenFactor) {
ChainLo = Chain.getOperand(0);
ChainHi = Chain.getOperand(1);
@@ -560,16 +564,19 @@
GetExpandedParts(SrcHi, DAG, SrcHi1, SrcHi2);
SDValue ChainLo = Chain, ChainHi = Chain;
+ // FIXME: This makes unsafe assumptions; see the FIXME above.
if (Chain.getOpcode() == ISD::TokenFactor) {
ChainLo = Chain.getOperand(0);
ChainHi = Chain.getOperand(1);
}
SDValue ChainLo1 = ChainLo, ChainLo2 = ChainLo, ChainHi1 = ChainHi,
ChainHi2 = ChainHi;
+ // FIXME: This makes unsafe assumptions; see the FIXME above.
if (ChainLo.getOpcode() == ISD::TokenFactor) {
ChainLo1 = ChainLo.getOperand(0);
ChainLo2 = ChainLo.getOperand(1);
}
+ // FIXME: This makes unsafe assumptions; see the FIXME above.
if (ChainHi.getOpcode() == ISD::TokenFactor) {
ChainHi1 = ChainHi.getOperand(0);
ChainHi2 = ChainHi.getOperand(1);
@@ -601,6 +608,7 @@
SDValue SrcLo, SrcHi;
GetExpandedParts(Src, DAG, SrcLo, SrcHi);
SDValue ChainLo = Chain, ChainHi = Chain;
+ // FIXME: This makes unsafe assumptions; see the FIXME above.
if (Chain.getOpcode() == ISD::TokenFactor) {
ChainLo = Chain.getOperand(0);
ChainHi = Chain.getOperand(1);