llvm-project/llvm/lib/Transforms
Igor Laevsky df9db45c94 [RewriteStatepointsForGC] All constant should have null base pointer
Currently we consider that each constant has itself as a base value. I.e "base(const) = const". 
This introduces couple of problems when we are trying to avoid reporting constants in statepoint live sets:

1. When querying "base( phi(const1, const2) )" we will get "phi(const1, const2)" as a base pointer. Since 
   it's not a constant we will record it in a stack map. However on practice we don't want this to happen
   (constant are never relocated).
2. base( phi(const, gc ptr) ) = phi( const, base(gc ptr) ). This particular case imposes challenge on our 
   runtime - we don't expect to see constant base pointers other than null. This problems can be avoided 
   by treating all constant as if they were derived from null pointer base. I.e in a first case we will 
   not include constant pointer in a stack map at all. In a second case we will get "phi(null, base(gc ptr))" 
   as a base pointer which is a lot more convenient.

Differential Revision: http://reviews.llvm.org/D20584

llvm-svn: 270993
2016-05-27 13:13:59 +00:00
..
Hello Add auto-exporting of symbols from tools so that plugins work on Windows 2016-05-26 11:16:43 +00:00
IPO Avoid some copies by using const references. 2016-05-27 12:30:51 +00:00
InstCombine Revert: r270973 - [X86][SSE] Replace (V)PMOVSX and (V)PMOVZX integer extension intrinsics with generic IR (llvm) 2016-05-27 09:02:25 +00:00
Instrumentation Attach profile summary in IR based instrumentation pass. 2016-05-26 22:57:11 +00:00
ObjCARC Form objc_storeStrong in the presence of bitcasts. 2016-05-27 02:13:53 +00:00
Scalar [RewriteStatepointsForGC] All constant should have null base pointer 2016-05-27 13:13:59 +00:00
Utils Avoid some copies by using const references. 2016-05-27 12:30:51 +00:00
Vectorize [BBVectorize] Don't vectorize selects with a scalar condition and vector operands. 2016-05-26 18:43:57 +00:00
CMakeLists.txt
LLVMBuild.txt