[LFI] Reserve LFI registers

Author: zyedidia

llvm/lib/Target/AArch64/AArch64RegisterInfo.cpp

@@ -461,6 +461,17 @@ AArch64RegisterInfo::getStrictlyReservedRegs(const MachineFunction &MF) const {
       markSuperRegs(Reserved, i);
   }
 
+  if (MF.getSubtarget<AArch64Subtarget>().isLFI()) {
+    markSuperRegs(Reserved, AArch64::W28);
+    markSuperRegs(Reserved, AArch64::W27);
+    markSuperRegs(Reserved, AArch64::W26);
+    markSuperRegs(Reserved, AArch64::W25);
+    if (!MF.getProperties().hasNoVRegs()) {
+      markSuperRegs(Reserved, AArch64::LR);
+      markSuperRegs(Reserved, AArch64::W30);
+    }
+  }
+
   for (size_t i = 0; i < AArch64::GPR32commonRegClass.getNumRegs(); ++i) {
     if (MF.getSubtarget<AArch64Subtarget>().isXRegisterReserved(i))
       markSuperRegs(Reserved, AArch64::GPR32commonRegClass.getRegister(i));

llvm/lib/Target/AArch64/AArch64Subtarget.h

@@ -293,6 +293,7 @@ class AArch64Subtarget final : public AArch64GenSubtargetInfo {
   bool isTargetAndroid() const { return TargetTriple.isAndroid(); }
   bool isTargetFuchsia() const { return TargetTriple.isOSFuchsia(); }
   bool isWindowsArm64EC() const { return TargetTriple.isWindowsArm64EC(); }
+  bool isLFI() const { return TargetTriple.isLFI(); }
 
   bool isTargetCOFF() const { return TargetTriple.isOSBinFormatCOFF(); }
   bool isTargetELF() const { return TargetTriple.isOSBinFormatELF(); }