[PATCH] D88823: [CodeGen][TailDuplicator] Don't duplicate blocks with INLINEASM_BR

[Bill Wendling via Phabricator via llvm-commits]

void created this revision.
void added reviewers: nickdesaulniers, jyknight, melver.
Herald added subscribers: llvm-commits, hiraditya.
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Blocks with INLINEASM_BR have indirect branches which make duplicating
them more complicated than normal instructions.

See: https://github.com/ClangBuiltLinux/linux/issues/1125


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D88823

Files:
  llvm/lib/CodeGen/TailDuplicator.cpp


Index: llvm/lib/CodeGen/TailDuplicator.cpp
===================================================================
--- llvm/lib/CodeGen/TailDuplicator.cpp
+++ llvm/lib/CodeGen/TailDuplicator.cpp
@@ -627,6 +627,10 @@
     if (PreRegAlloc && MI.isCall())
       return false;
 
+    // FIXME: This may be too restrictive.
+    if (MI.getOpcode() == TargetOpcode::INLINEASM_BR)
+      return false;
+
     if (MI.isBundle())
       InstrCount += MI.getBundleSize();
     else if (!MI.isPHI() && !MI.isMetaInstruction())


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