[PATCH] D63677: [ARM] Don't reserve R12 on Thumb1 as an emergency spill slot.

[Eli Friedman via Phabricator via llvm-commits]

efriedma marked an inline comment as done.
efriedma added a comment.

In D63677#1555727 <https://reviews.llvm.org/D63677#1555727>, @ostannard wrote:

> This looks a lot like a bug I hit a while ago while writing a fuzzer for ABI
>  compatibility between clang and gcc. I've currently got Thumb1-only targets
>  disabled because of this.


My team ran into this when we added some new configurations of SPEC; it's good to hear we aren't the only ones doing any Thumb1 testing. :)



================
Comment at: test/CodeGen/Thumb/emergency-spill-slot.ll:334
+; so we don't generate code that requires an emergency spill slot we never
+; allocated.  If the store gets eliminated, this testcase probably needs
+; to be rewritten.)
----------------
ostannard wrote:
> Could we just not have any CHECK lines for this test, if we don't care about the output, and are just making sure we don't crash?
I prefer not to do that, generally; yes, we primarily care that it doesn't crash, but a change to the generated code could indicate the test is no longer testing what it's supposed to test.


Repository:
  rL LLVM

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https://reviews.llvm.org/D63677