[PATCH] D118118: [SDAG] Preserve unpredictable metadata, teach X86CmovConversion to respect this metadata

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/Target/X86/X86CmovConversion.cpp:309
+
+      // If cmov instruction is marked as unpredicatable, do not convert it to
+      // branch.
----------------
unpredictable*


================
Comment at: llvm/lib/Target/X86/X86CmovConversion.cpp:312
+      if (I.getFlag(MachineInstr::MIFlag::Unpredictable))
+        continue;
+  
----------------
xbolva00 wrote:
> nikic wrote:
> > Is it safe to just skip it entirely, or do we need to treat it as a non-cmov instruction?
> Good point,  I am not sure, probably we should threat it that way.
> 
> @RKSimon / @craig.topper any suggestions?
What instructions can this flag appear on? There's a check later for instructions that define EFLAGS we can't skip that check.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D118118/new/

https://reviews.llvm.org/D118118