[PATCH] D51849: [RegisterCoalescer] Avoid "Use not jointly dominated by defs" in removePartialRedundancy

[Quentin Colombet via Phabricator via llvm-commits]

qcolombet added a comment.

> I finally tracked down why I couldn't get a mir test before: Compiling a ll file as usual, arriving at RegisterCoalescer, the numbering of the MBBs was not quite in order. Using -stop-before names the MBBs in the mir according to those out-of-order numbers, but reading the mir in again with -run-pass fails to preserve it. Instead it renumbers the MBBs in order. RegisterCoalescing processes MBBs with the same loop depth and critical edgeness and connectedness in numbering order, so the pass behaved differently.

Could you file a public report for this issue?



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Comment at: test/CodeGen/AMDGPU/regcoal-removepartial-redundancy-not-jointly-dominated.mir:8
+#
+# GCN: body:
+
----------------
Please check that the code after coalescing is correct.
Eg., the pass could silently crash and produce an empty function, the test would still pass!


Repository:
  rL LLVM

https://reviews.llvm.org/D51849