[PATCH] D62463: [ValueTracking][ConstantRange] Distinguish low/high always overflow

Nikita Popov via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Sun May 26 12:54:48 PDT 2019


nikic marked an inline comment as done.
nikic added inline comments.


================
Comment at: llvm/include/llvm/Analysis/ValueTracking.h:416
+  enum class OverflowResult {
+    AlwaysOverflowsLow, AlwaysOverflowsHigh, MayOverflow, NeverOverflows
+  };
----------------
lebedev.ri wrote:
> These now need a comment for each.
> While with the enum on the LHS of the diff it is obvious,
> here i'm not sure what low/high means.
> The direction of the overflow?
Yeah, this is the direction of overflow. For AlwaysOverflowLow the real result would be lower than signed/unsigned min, for AlwaysOverflowHigh it would be higher than signed/unsigned max.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D62463/new/

https://reviews.llvm.org/D62463





More information about the llvm-commits mailing list