3 Commits

Author SHA1 Message Date
Sanjoy Das
7f0da20b97 Fix PR22179.
We were incorrectly inferring nsw for certain SCEVs. We can be more
aggressive here (see Richard Smith's comment on
http://llvm.org/bugs/show_bug.cgi?id=22179) but this change just
focuses on correctness.

Differential Revision: http://reviews.llvm.org/D6914



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225591 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-10 23:41:24 +00:00
Quentin Colombet
50d4008b47 [LSR] Canonicalize reg1 + ... + regN into reg1 + ... + 1*regN.
This commit introduces a canonical representation for the formulae.
Basically, as soon as a formula has more that one base register, the scaled
register field is used for one of them. The register put into the scaled
register is preferably a loop variant.
The commit refactors how the formulae are built in order to produce such
representation.
This yields a more accurate, but still perfectible, cost model.

<rdar://problem/16731508>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209230 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-20 19:25:04 +00:00
Quentin Colombet
9e93e47b7f [X86] Implement TargetLowering::getScalingFactorCost hook.
Scaling factors are not free on X86 because every "complex" addressing mode
breaks the related instruction into 2 allocations instead of 1.

<rdar://problem/16730541>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207301 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-26 01:11:26 +00:00