[PATCH-AVR] avr-rust/rust-legacy-fork#37: DREGS_WITHOUT_Z

Author: TimNN

lib/Target/AVR/AVRInstrInfo.td

@@ -832,7 +832,7 @@ let isCall = 1 in
 //===----------------------------------------------------------------------===//
 let isTerminator = 1,
 isReturn = 1,
-isBarrier = 1 in 
+isBarrier = 1 in
 {
   def RET : F16<0b1001010100001000,
                 (outs),
@@ -1222,7 +1222,7 @@ isReMaterializable = 1 in
   // ldd Rd,   P+q
   // ldd Rd+1, P+q+1
   let Constraints = "@earlyclobber $dst" in
-  def LDDWRdPtrQ : Pseudo<(outs DREGS:$dst),
+  def LDDWRdPtrQ : Pseudo<(outs DREGS_WITHOUT_Z:$dst),
                           (ins memri:$memri),
                           "lddw\t$dst, $memri",
                           [(set i16:$dst, (load addr:$memri))]>,

lib/Target/AVR/AVRRegisterInfo.td

@@ -157,6 +157,18 @@ def DREGS : RegisterClass<"AVR", [i16], 8,
     R9R8, R7R6, R5R4, R3R2, R1R0
   )>;
 
+// Main 16-bit pair register class.
+def DREGS_WITHOUT_Z : RegisterClass<"AVR", [i16], 8,
+  (
+    // Return value and arguments.
+    add R25R24, R19R18, R21R20, R23R22,
+    // Scratch registers.
+    R27R26,
+    // Callee saved registers.
+    R29R28, R17R16, R15R14, R13R12, R11R10,
+    R9R8, R7R6, R5R4, R3R2, R1R0
+  )>;
+
 // 16-bit register class for immediate instructions.
 def DLDREGS : RegisterClass<"AVR", [i16], 8,
   (