llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-07 14:33:15 +00:00

History

Louis Gerbarg a5423f2598 Add support for combining GEPs across PHI nodes

Currently LLVM will generally merge GEPs. This allows backends to use more
complex addressing modes. In some cases this is not happening because there
is PHI inbetween the two GEPs:

  GEP1--\
        |-->PHI1-->GEP3
  GEP2--/

This patch checks to see if GEP1 and GEP2 are similiar enough that they can be
cloned (GEP12) in GEP3's BB, allowing GEP->GEP merging (GEP123):

  GEP1--\                     --\                           --\
        |-->PHI1-->GEP3  ==>    |-->PHI2->GEP12->GEP3 == >    |-->PHI2->GEP123
  GEP2--/                     --/                           --/

This also breaks certain use chains that are preventing GEP->GEP merges that the
the existing instcombine would merge otherwise.

Tests included.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209755 91177308-0d34-0410-b5e6-96231b3b80d8

2014-05-28 17:38:31 +00:00

Analysis

remove constant terms

2014-05-27 22:41:45 +00:00

Assembler

No need for those tests to go thru llvm-as and/or llvm-dis.

2014-05-27 22:03:28 +00:00

Bindings

…

Bitcode

Add 'nonnull', a new parameter and return attribute which indicates that the pointer is not null. Instcombine will elide comparisons between these and null. Patch by Luqman Aden!

2014-05-20 01:23:40 +00:00