[PATCH] D29369: [ubsan] Omit superflous overflow checks for promoted arithmetic (PR20193)

[Filipe Cabecinhas via Phabricator via cfe-commits]

filcab added a comment.

Minor nits, now.
LGTM, but having someone more familiar with clang chime in would be great.



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Comment at: lib/CodeGen/CGExprScalar.cpp:1700
   case LangOptions::SOB_Trapping:
+    if (getUnwidenedIntegerType(CGF.getContext(), E->getSubExpr()).hasValue())
+      return Builder.CreateNSWAdd(InVal, Amount, Name);
----------------
Maybe a helper `IsWidenedIntegerOp(...)` (or `IsOpWiderThanBaseType`or something) would make this (and others, like the first return of `getUnwidenedIntegerType`) easier to read?


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Comment at: test/CodeGen/ubsan-promoted-arith.cpp:90
+
+// Note: -INT_MIN / -1 can overflow.
+//
----------------
Extra `-`. `INT_MIN/-1` is what you want. You already have a test above for `-INT_MIN` (which would overflow before the division.


https://reviews.llvm.org/D29369