1 files changed, 12 insertions, 2 deletions
diff --git a/backend/lib/CodeGen/RegAllocFast.cpp b/backend/lib/CodeGen/RegAllocFast.cpp
index 9b087cc..897f217 100644
--- a/backend/lib/CodeGen/RegAllocFast.cpp
+++ b/backend/lib/CodeGen/RegAllocFast.cpp
@@ -266,7 +266,7 @@ private:
         return std::unexpected(Evicted.error());
     }
 
-    auto Candidates = regalloc_detail::allocationOrder(Function, Target, Reg);
+    auto Candidates = regalloc_detail::allocationOrder(Function, Target, TargetInfo, Reg);
     if (!Candidates)
       return std::unexpected(Candidates.error());
     for (const PhysicalRegister Candidate : *Candidates) {
@@ -319,7 +319,7 @@ private:
       const Register Reg = *LiveIn.InitialVirtualRegister;
       if (!Function.registerInfo().isKnownVirtualRegister(Reg))
         continue;
-      auto Candidates = regalloc_detail::allocationOrder(Function, Target, Reg);
+      auto Candidates = regalloc_detail::allocationOrder(Function, Target, TargetInfo, Reg);
       if (!Candidates)
         return std::unexpected(Candidates.error());
       if (std::ranges::find(*Candidates, LiveIn.PhysReg) == Candidates->end()) {
@@ -577,6 +577,12 @@ Expected<MachinePassResult> FastAllocatorPass::run(MachineFunction &Function,
   auto Trial = regalloc_detail::cloneForAllocation(Function, Target);
   if (!Trial)
     return std::unexpected(Trial.error());
+  const std::vector<PhysicalRegister> FunctionReserved =
+      regalloc_detail::functionReservedRegisters(Function, Target, *Info);
+  auto TrialReserved =
+      regalloc_detail::reserveFunctionRegisters(*Trial->ClonedFunction, FunctionReserved);
+  if (!TrialReserved)
+    return std::unexpected(TrialReserved.error());
   MachineAnalysisManager TrialAnalyses;
   auto Registered = registerStage11MachineAnalyses(TrialAnalyses);
   if (!Registered)
@@ -602,6 +608,10 @@ Expected<MachinePassResult> FastAllocatorPass::run(MachineFunction &Function,
     return std::unexpected(regalloc_detail::withPrefix(
         Allocated.error(), "FastAllocator diverged after a successful transaction preflight: "));
   }
+  auto Reserved = regalloc_detail::reserveFunctionRegisters(Function, FunctionReserved);
+  if (!Reserved)
+    return std::unexpected(Reserved.error());
+  Allocated->Changed |= *Reserved;
   return regalloc_detail::passResult(*Allocated);
 }