LiveRegUnits: Break register loop when a clobber is encountered

diff --git a/llvm/lib/CodeGen/LiveRegUnits.cpp b/llvm/lib/CodeGen/LiveRegUnits.cpp
index 0b20e91..34de09d 100644 (file)
--- a/llvm/lib/CodeGen/LiveRegUnits.cpp
+++ b/llvm/lib/CodeGen/LiveRegUnits.cpp
@@ -22,8 +22,10 @@ using namespace llvm;
 void LiveRegUnits::removeRegsNotPreserved(const uint32_t *RegMask) {
   for (unsigned U = 0, E = TRI->getNumRegUnits(); U != E; ++U) {
     for (MCRegUnitRootIterator RootReg(U, TRI); RootReg.isValid(); ++RootReg) {
-      if (MachineOperand::clobbersPhysReg(RegMask, *RootReg))
+      if (MachineOperand::clobbersPhysReg(RegMask, *RootReg)) {
         Units.reset(U);
+        break;
+      }
     }
   }
 }
@@ -31,8 +33,10 @@ void LiveRegUnits::removeRegsNotPreserved(const uint32_t *RegMask) {
 void LiveRegUnits::addRegsInMask(const uint32_t *RegMask) {
   for (unsigned U = 0, E = TRI->getNumRegUnits(); U != E; ++U) {
     for (MCRegUnitRootIterator RootReg(U, TRI); RootReg.isValid(); ++RootReg) {
-      if (MachineOperand::clobbersPhysReg(RegMask, *RootReg))
+      if (MachineOperand::clobbersPhysReg(RegMask, *RootReg)) {
         Units.set(U);
+        break;
+      }
     }
   }
 }