[PATCH] D157462: LoopRotate: Add code to update branch weights

[Wenlei He via Phabricator via llvm-commits]

wenlei added inline comments.


================
Comment at: llvm/lib/Transforms/Utils/LoopRotationUtils.cpp:308
+        // ... but don't overflow.
+        uint32_t const high_bit = uint32_t{1} << (sizeof(uint32_t) * 8 - 1);
+        if (OrigLoopBackedgeCount + OrigLoopExitCount >= high_bit) {
----------------
nit: follow convention for variable naming. 


================
Comment at: llvm/lib/Transforms/Utils/LoopRotationUtils.cpp:309-310
+        uint32_t const high_bit = uint32_t{1} << (sizeof(uint32_t) * 8 - 1);
+        if (OrigLoopBackedgeCount + OrigLoopExitCount >= high_bit) {
+          break;
+        }
----------------
Could `OrigLoopBackedgeCount + OrigLoopExitCount` already overflow and defeat the check? 

Maybe spell it explicitly with `OrigLoopBackedgeCount >= high_bit || OrigLoopExitCount >= high_bit`? 


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D157462/new/

https://reviews.llvm.org/D157462