Give up on register class recalculation when the register is used with subreg
operands. We don't currently have a hook to provide "the largest super class of
A where all registers' getSubReg(subidx) is valid and in B".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110730 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CalcSpillWeights.cpp b/lib/CodeGen/CalcSpillWeights.cpp
index a39503b..8ecce4a 100644
--- a/lib/CodeGen/CalcSpillWeights.cpp
+++ b/lib/CodeGen/CalcSpillWeights.cpp
@@ -181,10 +181,19 @@
SmallPtrSet<const TargetRegisterClass*,8> rcs;
for (MachineRegisterInfo::reg_nodbg_iterator I = mri.reg_nodbg_begin(reg),
- E = mri.reg_nodbg_end(); I != E; ++I)
+ E = mri.reg_nodbg_end(); I != E; ++I) {
+ // The targets don't have accurate enough regclass descriptions that we can
+ // handle subregs. We need something similar to
+ // TRI::getMatchingSuperRegClass, but returning a super class instead of a
+ // sub class.
+ if (I.getOperand().getSubReg()) {
+ DEBUG(dbgs() << "Cannot handle subregs: " << I.getOperand() << '\n');
+ return;
+ }
if (const TargetRegisterClass *rc =
I->getDesc().getRegClass(I.getOperandNo(), tri))
rcs.insert(rc);
+ }
// If we found no regclass constraints, just leave reg as is.
// In theory, we could inflate to the largest superclass of reg's existing