[llvm] [RegisterCoalescer] Fix issue in the RegisterCoalescer. (PR #96839)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,26 @@
+# RUN: llc -mtriple powerpc64le-unknown-linux-gnu -mcpu=pwr8 -x mir < %s \
+# RUN:   -verify-machineinstrs --run-pass=register-coalescer -o - | FileCheck %s
+
+---
+name: check_subregs
+alignment:       16
+tracksRegLiveness: true
+body:             |
+  bb.0.entry:
+    liveins: $x3
+
+    %0:g8rc_and_g8rc_nox0 = COPY $x3
+    %3:f8rc, %4:g8rc_and_g8rc_nox0 = LFSUX %0, %0
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arsenm wrote:

Can you run run-pass=none to compact the virtual register numbers 

https://github.com/llvm/llvm-project/pull/96839