Fix the case where an instruction is not properly marked as using all registers that alias its inputs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57286 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp
index 82691ba..4792452 100644
--- a/lib/CodeGen/RegAllocLocal.cpp
+++ b/lib/CodeGen/RegAllocLocal.cpp
@@ -575,8 +575,26 @@
// them for later. Also, we have to process these
// _before_ processing the defs, since an instr
// uses regs before it defs them.
- if (MO.isReg() && MO.getReg() && MO.isUse())
+ if (MO.isReg() && MO.getReg() && MO.isUse()) {
LastUseDef[MO.getReg()] = std::make_pair(I, i);
+
+
+ if (TargetRegisterInfo::isVirtualRegister(MO.getReg())) continue;
+
+ const unsigned* subregs = TRI->getAliasSet(MO.getReg());
+ if (subregs) {
+ while (*subregs) {
+ DenseMap<unsigned, std::pair<MachineInstr*, unsigned> >::iterator
+ alias = LastUseDef.find(*subregs);
+
+ if (alias != LastUseDef.end() &&
+ alias->second.first != I)
+ LastUseDef[*subregs] = std::make_pair(I, i);
+
+ ++subregs;
+ }
+ }
+ }
}
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {