2 Commits

Author	SHA1	Message	Date
Roman Lebedev	23646952e2	[InstCombine] Fold (A - B) u>=/u< A --> B u>/u<= A iff B != 0 ... https://rise4fun.com/Alive/KtL This also shows that the fold added in D67412 / r372257 was too specific, and the new fold allows those test cases to be handled more generically, therefore i delete now-dead code. This is yet again motivated by D67122 "[UBSan][clang][compiler-rt] Applying non-zero offset to nullptr is undefined behaviour" llvm-svn: 372912	2019-09-25 19:06:40 +00:00
Roman Lebedev	dfda7d2d90	[NFC][InstCombine] Add tests for (X - Y) < X --> Y <= X iff Y != 0 ... https://rise4fun.com/Alive/KtL This should go to InstCombiner::foldICmpBinO(), next to "Convert sub-with-unsigned-overflow comparisons into a comparison of args." llvm-svn: 372911	2019-09-25 19:06:26 +00:00