[Hexagon] Explicitly reserve aliases of reserved registers

llvm-svn: 292836

Author: Krzysztof Parzyszek

llvm/lib/Target/Hexagon/HexagonRegisterInfo.cpp

@@ -139,19 +139,26 @@ BitVector HexagonRegisterInfo::getReservedRegs(const MachineFunction &MF)
   Reserved.set(Hexagon::R29);
   Reserved.set(Hexagon::R30);
   Reserved.set(Hexagon::R31);
-  Reserved.set(Hexagon::PC);
-  Reserved.set(Hexagon::D14);
-  Reserved.set(Hexagon::D15);
-  Reserved.set(Hexagon::LC0);
-  Reserved.set(Hexagon::LC1);
-  Reserved.set(Hexagon::SA0);
-  Reserved.set(Hexagon::SA1);
-  Reserved.set(Hexagon::UGP);
-  Reserved.set(Hexagon::GP);
-  Reserved.set(Hexagon::CS0);
-  Reserved.set(Hexagon::CS1);
-  Reserved.set(Hexagon::CS);
-  Reserved.set(Hexagon::USR);
+  Reserved.set(Hexagon::SA0); // C0
+  Reserved.set(Hexagon::LC0); // C1
+  Reserved.set(Hexagon::SA1); // C2
+  Reserved.set(Hexagon::LC1); // C3
+  Reserved.set(Hexagon::USR); // C8
+  Reserved.set(Hexagon::PC);  // C9
+  Reserved.set(Hexagon::UGP); // C10
+  Reserved.set(Hexagon::GP);  // C11
+  Reserved.set(Hexagon::CS0); // C12
+  Reserved.set(Hexagon::CS1); // C13
+
+  // Out of the control registers, only C8 is explicitly defined in
+  // HexagonRegisterInfo.td. If others are defined, make sure to add
+  // them here as well.
+  Reserved.set(Hexagon::C8);
+  Reserved.set(Hexagon::USR_OVF);
+
+  for (int x = Reserved.find_first(); x >= 0; x = Reserved.find_next(x))
+    markSuperRegs(Reserved, x);
+
   return Reserved;
 }
 

llvm/lib/Target/Hexagon/HexagonRegisterInfo.td

@@ -146,6 +146,8 @@ let Namespace = "Hexagon" in {
   def LC1  : Rc<3,  "lc1",       ["c3"]>,   DwarfRegNum<[70]>;
   def P3_0 : Rc<4,  "p3:0",      ["c4"], [P0, P1, P2, P3]>,
                                             DwarfRegNum<[71]>;
+  // When defining more Cn registers, make sure to explicitly mark them
+  // as reserved in HexagonRegisterInfo.cpp.
   def C5   : Rc<5,  "c5",        ["c5"]>,   DwarfRegNum<[72]>; // future use
   def C6   : Rc<6,  "c6",        [], [M0]>, DwarfRegNum<[73]>;
   def C7   : Rc<7,  "c7",        [], [M1]>, DwarfRegNum<[74]>;