PR10998: It is not legal to sink an instruction past the terminator of a block; make sure we don't do that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140428 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index dfd258d..d879378 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -177,6 +177,10 @@
bool TwoAddressInstructionPass::Sink3AddrInstruction(MachineBasicBlock *MBB,
MachineInstr *MI, unsigned SavedReg,
MachineBasicBlock::iterator OldPos) {
+ // FIXME: Shouldn't we be trying to do this before we three-addressify the
+ // instruction? After this transformation is done, we no longer need
+ // the instruction to be in three-address form.
+
// Check if it's safe to move this instruction.
bool SeenStore = true; // Be conservative.
if (!MI->isSafeToMove(TII, AA, SeenStore))
@@ -217,7 +221,11 @@
break;
}
- if (!KillMI || KillMI->getParent() != MBB || KillMI == MI)
+ // If we find the instruction that kills SavedReg, and it is in an
+ // appropriate location, we can try to sink the current instruction
+ // past it.
+ if (!KillMI || KillMI->getParent() != MBB || KillMI == MI ||
+ KillMI->getDesc().isTerminator())
return false;
// If any of the definitions are used by another instruction between the