Chandler Carruth 1c8db50a9a Port the SSAUpdater-based promotion logic from the old SROA pass to the ... new one, and add support for running the new pass in that mode and in that slot of the pass manager. With this the new pass can completely replace the old one within the pipeline. The strategy for enabling or disabling the SSAUpdater logic is to do it by making the requirement of the domtree analysis optional. By default, it is required and we get the standard mem2reg approach. This is usually the desired strategy when run in stand-alone situations. Within the CGSCC pass manager, we disable requiring of the domtree analysis and consequentially trigger fallback to the SSAUpdater promotion. In theory this would allow the pass to re-use a domtree if one happened to be available even when run in a mode that doesn't require it. In practice, it lets us have a single pass rather than two which was simpler for me to wrap my head around. There is a hidden flag to force the use of the SSAUpdater code path for the purpose of testing. The primary testing strategy is just to run the existing tests through that path. One notable difference is that it has custom code to handle lifetime markers, and one of the tests has been enhanced to exercise that code. This has survived a bootstrap and the test suite without serious correctness issues, however my run of the test suite produced *very* alarming performance numbers. I don't entirely understand or trust them though, so more investigation is on-going. To aid my understanding of the performance impact of the new SROA now that it runs throughout the optimization pipeline, I'm enabling it by default in this commit, and will disable it again once the LNT bots have picked up one iteration with it. I want to get those bots (which are much more stable) to evaluate the impact of the change before I jump to any conclusions. NOTE: Several Clang tests will fail because they run -O3 and check the result's order of output. They'll go back to passing once I disable it again. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163965 91177308-0d34-0410-b5e6-96231b3b80d8		2012-09-15 11:43:14 +00:00
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IPO	Add an option to turn off the expensive GVN load PRE part of GVN.	2012-04-02 22:16:50 +00:00
Utils	Stylistic and 80-col fixes	2012-09-14 21:25:34 +00:00
Instrumentation.h	move the bounds checking pass to the instrumentation folder, where it belongs. I dunno why in the world I dropped it in the Scalar folder in the first place.	2012-07-20 22:39:33 +00:00
IPO.h	Add a pass that renames everything with metasyntatic names. This works well after using bugpoint to reduce the confusion presented by the original names, which no longer mean what they used to.	2012-09-11 02:46:18 +00:00
Scalar.h	Port the SSAUpdater-based promotion logic from the old SROA pass to the	2012-09-15 11:43:14 +00:00
Vectorize.h	Allow BBVectorize to form non-2^n-length vectors.	2012-06-28 05:42:42 +00:00