[PATCH] D109103: [ISEL][BitTestBlock] omit additional bit test when default destination is unreachable

[Nick Desaulniers via Phabricator via llvm-commits]

nickdesaulniers added inline comments.


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Comment at: llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp:3022
       MachineBasicBlock *NextMBB;
-      if (BTB.ContiguousRange && j + 2 == ej) {
+      if ((BTB.ContiguousRange || BTB.OmitRangeCheck) && j + 2 == ej) {
         // Second-to-last bit-test with contiguous range: fall through to the
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nickdesaulniers wrote:
> hans wrote:
> > I think UnreachableDefault (or UnreachableFallthrough) would be a better name now, since it doesn't just omit the range check, it also omits the last bit test.
> > 
> > Also some day we should unify all the switch lowering implementations in LLVM, I think there are four or so now :-)
> Should this be renamed for BitTestBlock //AND JumpTableHeader//?
Created https://reviews.llvm.org/D109455 as a child revision. I'm going to land this as is to unblock https://reviews.llvm.org/D106056 ASAP (and get our failing boot tests back online).


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D109103/new/

https://reviews.llvm.org/D109103