[PATCH] D127712: Prevent crash when TurnSwitchRangeIntoICmp recieves default null dest

[Arthur Eubanks via Phabricator via llvm-commits]

aeubanks added a comment.

can you put the bug number (e.g. #12345) in the description?



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Comment at: llvm/lib/Transforms/Utils/SimplifyCFG.cpp:5190
+/// Switches with more than 2 destinations are ignored.
+/// Switches with 1 destation are also ignored.
 bool SimplifyCFGOpt::TurnSwitchRangeIntoICmp(SwitchInst *SI,
----------------
destination


================
Comment at: llvm/lib/Transforms/Utils/SimplifyCFG.cpp:5222
   }
+  // All destinations are the same and the default is undef
+  if (!DestB) {
----------------
this comment makes it sound like at this point your comment is always true


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Comment at: llvm/lib/Transforms/Utils/SimplifyCFG.cpp:5223
+  // All destinations are the same and the default is undef
+  if (!DestB) {
+    return false;
----------------
LLVM style is no braces for a one line if


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Comment at: llvm/test/Transforms/SimplifyCFG/switch-default-undef.ll:1
+; RUN: opt -passes=simplifycfg"<switch-range-to-icmp>" -S %s | FileCheck %s
+
----------------
can you use `llvm/utils/update_test_checks.py`?


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https://reviews.llvm.org/D127712