Assertion failed: (NumUsePointsToFind > 0 && "There must be at least one
releasing instruction for an alloc"), function canPromoteAlloc
Revert "Fix comment for StackPromotion pass in SIL Passes"
Revert "Reapply the StackPromotion commit
0dd045ca04dcc10a33abf57f7e1b08260c4e3de1."
This reverts commit 3f4b1496bd and commit
199cfca13b.
It promotes allocations of native swift objects and array buffers to the stack if it is possible.
The SIL StackPromotion pass is the main part of the optimization. For details see comments there.
Unfortunately we need an additional LLVM pass to handle array buffers, which is not very nice.
I hope that we can get rid of it in future (again: for details see the comments in StackPromotion.cpp)
The optimization gives performance improvements in some benchmarks, mostly related to array literals:
ArrayLiteral: +12%
Combos: +16%
DictionaryLiteral: + 37%
RIPEMD: +10%
StringBuilder: +27%
StringInterpolation: +11%
And last but not least the new benchmark which is dedicated to test stack promotion:
ObjectAllocation: +52%
This pass does things similar to LLVMARCContract so it makes sense to use the
same naming schema.
Also I am going to be implementing some contracting optimziations here later
today.
Swift SVN r30203
OptimizeARC does not only contain an optimize arc pass: the library also
includes aa. What this really is a repository of the extra passes and
infrastructure that we inject into LLVM. Thus LLVMPasses is a more descriptive
name. It also matches SILPasses.
I also taught lit how to use the new llvm-opt driver for running swift llvm
passes through opt without having to remember how to setup the dynamic swift
llvm pass dylib. You can use this in lit tests by using the substitution
%llvm-opt.
Swift SVN r21654
