[llvm] 740f920 - LiveRegUnits: Break register loop when a clobber is encountered

[Matt Arsenault via llvm-commits]

Author: Matt Arsenault
Date: 2022-09-13T10:15:08-04:00
New Revision: 740f920a1f82f86a7fdb0cf0bd8282696529b0fd

URL: https://github.com/llvm/llvm-project/commit/740f920a1f82f86a7fdb0cf0bd8282696529b0fd
DIFF: https://github.com/llvm/llvm-project/commit/740f920a1f82f86a7fdb0cf0bd8282696529b0fd.diff

LOG: LiveRegUnits: Break register loop when a clobber is encountered

Added: 
    

Modified: 
    llvm/lib/CodeGen/LiveRegUnits.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/LiveRegUnits.cpp b/llvm/lib/CodeGen/LiveRegUnits.cpp
index 0b20e917e036..34de09dd2944 100644
--- 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;
+      }
     }
   }
 }