Chandler Carruth 0c25726596 [PM] Remove the preverifier and directly compute the DominatorTree for ... the verifier after ensuring the CFG is at least usefully formed. This fixes a number of problems: 1) The PreVerifier was missing the controls the Verifier provides over *how* an invalid module is handled -- it just aborted the program! Now it uses the same logic as the Verifier which is significantly more library-friendly. 2) The DominatorTree used previously could have been cached and not updated due to bugs in prior passes and we would silently use the stale tree. This could cause dominance errors to not be as quickly diagnosed. 3) We can now (in the next patch) pull the functionality of the verifier apart from the pass infrastructure so that you can verify IR without having any form of pass manager. This in turn frees the code to share logic between old and new pass manager variants. Along the way I fixed at least one annoying bug -- the state for 'Broken' wasn't being cleared from run to run causing all functions visited after the first broken function to be marked as broken regardless of whether *they* were a problem. Fortunately, I don't really know much of a way to observe this peculiarity. In case folks are worried about the runtime cost, its negligible. I looked at running the entire regression test suite (which should be a relatively good use of the verifier) before and after but was unable to even measure the time spent on the verifier and there was no regresion from before to after. I checked both with debug builds and optimized builds. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199487 91177308-0d34-0410-b5e6-96231b3b80d8		2014-01-17 10:56:02 +00:00
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llvm	[PM] Remove the preverifier and directly compute the DominatorTree for	2014-01-17 10:56:02 +00:00
llvm-c	LTO: document LTO_API_VERSION for each API	2014-01-16 21:37:17 +00:00