[llvm] [RegisterCoalescer] The COPY with the implicit-def of super register is not coalescable. (PR #169997)

[Sander de Smalen via llvm-commits]

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@@ -0,0 +1,24 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 6
+# RUN: llc -run-pass register-coalescer -mtriple x86_64-unknown-linux-gnu -o - %s | FileCheck %s
+
+# Checks that we do not merge %1 into %0.
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sdesmalen-arm wrote:

I'm a bit confused why we wouldn't want to coalesce in this case, because both COPY's say they write 64-bits of the %gpr64.

https://github.com/llvm/llvm-project/pull/169997