llvm/include
Chandler Carruth da49414c4b [TTI] Make the cost APIs in TargetTransformInfo consistently use 'int'
rather than 'unsigned' for their costs.

For something like costs in particular there is a natural "negative"
value, that of savings or saved cost. As a consequence, there is a lot
of code that subtracts or creates negative values based on cost, all of
which is prone to awkwardness or bugs when dealing with an unsigned
type. Similarly, we *never* want these values to wrap, as that would
cause Very Bad code generation (likely percieved as an infinite loop as
we try to emit over 2^32 instructions or some such insanity).

All around 'int' seems a much better fit for these basic metrics. I've
added asserts to ensure that at least the TTI interface never returns
negative numbers here. If we ever have a use case for negative numbers,
we can remove this, but this way a bug where someone used '-1' to
produce a 'very large' cost will be caught by the assert.

This passes all tests, and is also UBSan clean.

No functional change intended.

Differential Revision: http://reviews.llvm.org/D11741

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244080 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-05 18:08:10 +00:00
..
llvm [TTI] Make the cost APIs in TargetTransformInfo consistently use 'int' 2015-08-05 18:08:10 +00:00
llvm-c Add support to set/get ordering for load/store from the C API 2015-08-02 12:16:57 +00:00