[PATCH] D116551: [AVR] Mark call-clobbered registers as clobbered in interrupt handlers

[Ayke via Phabricator via llvm-commits]

aykevl created this revision.
aykevl added reviewers: dylanmckay, benshi001, Rahix.
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I have matched the RISCV backend, which only uses the interrupt save
list in getCalleeSavedRegs, _not_ in getCallPreservedMask. I don't know
the details of these two methods, but with it, the correct amount of
registers is saved and restored.

Without this patch, practically all interrupt handlers that call a
function will miscompile.

I have added a test to verify this behavior. I've also added a very
simple test to verify that more normal interrupt operations (in this
case, incrementing a global value) behave as expected.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D116551

Files:
  llvm/lib/Target/AVR/AVRCallingConv.td
  llvm/lib/Target/AVR/AVRRegisterInfo.cpp
  llvm/test/CodeGen/AVR/interrupts.ll

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