[PATCH] D77207: [AVR] Fix I/O instructions on XMEGA

[Dylan McKay via Phabricator via llvm-commits]

dylanmckay added a comment.

Nice work, I didn't know of this particular XMEGA quirk.

I left a couple comments, then it looks good to merge.

Could you also add a CodeGen test to `test/CodeGen/AVR/features` for an XMEGA chip, along with a `CHECK` line that verifies that the correct assembly output is generated for XMEGA?



================
Comment at: llvm/lib/Target/AVR/AVRDevices.td:127
+                                  "true", "The device has CPU registers "
+                                  "mapped in data addres space">;
+
----------------
add an extra `s` to `addres`


================
Comment at: llvm/lib/Target/AVR/AVRInstrInfo.td:110
 [{
-  return CurDAG->getTargetConstant(uint8_t(N->getZExtValue()) - 0x20, SDLoc(N), MVT::i8);
+  uint8_t offset = Subtarget->hasMemMappedGPR() ? 0x20 : 0x0;
+  return CurDAG->getTargetConstant(uint8_t(N->getZExtValue()) - offset,
----------------
Rather than hardcoding these magic constants in this file, recommend adding a new method to `AVRSubtarget`, like `uint8_t getIoRegisterOffset()` and moving the ternary logic there.

Reuse this method in the below `PatLeaf`s


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D77207/new/

https://reviews.llvm.org/D77207