[llvm] [MCP] Avoid Folding Spill Chains Over Across Source Clobbers (PR #207169)

[Jack Styles via llvm-commits]

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@@ -0,0 +1,33 @@
+# RUN: llc -mtriple=aarch64 -run-pass=machine-cp -enable-spill-copy-elim -verify-machineinstrs -o - %s | FileCheck %s
+# When running MachineCopyPropagation, we need to make sure COPY's do not get removed
+# when calls outside of the chain clobber a source included in the chain.
+# See: https://github.com/llvm/llvm-project/issues/206839
+---
+name: spill_chain_copy_clobbers_source
+tracksRegLiveness: true
+body: |
+  bb.0:
+    liveins: $w10, $w13, $w23, $w25, $x7
+
+    ; CHECK: renamable $w10 = COPY killed renamable $w13
+    ; CHECK: renamable $w13 = COPY killed renamable $w10
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Stylie777 wrote:

I've generated the output using `update_mir_test_checks.py` so we capture the full output. 

https://github.com/llvm/llvm-project/pull/207169