Nikita Popov 389d1ed239 [ConstantRange] Add overflow check helpers ... Add functions to ConstantRange that determine whether the unsigned/signed addition/subtraction of two ConstantRanges may/always/never overflows. This will allow checking overflow conditions based on known constant ranges in addition to known bits. I'm implementing these methods on ConstantRange to allow them to be unit tested independently of any ValueTracking machinery. The tests include exhaustive testing on 4-bit ranges, to make sure the result is both conservatively correct and maximally precise. The OverflowResult enum is redeclared on ConstantRange, because I wanted to avoid a dependency in either direction between ValueTracking.h and ConstantRange.h. Differential Revision: https://reviews.llvm.org/D59193 llvm-svn: 356276		2019-03-15 17:29:05 +00:00
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llvm	[ConstantRange] Add overflow check helpers	2019-03-15 17:29:05 +00:00
llvm-c	[LLVM-C] Expose the "Add Discriminators" Pass To LLVM-C	2019-03-15 16:57:23 +00:00